Let's talk LSA

[frnkeore]

I'm put this in the Non FE section but, I'm also very interested in how people are tuning the FE with it.

I know a little about it but, not near as much as I would like. I would love to have feed back, if available, of dyno tests, changing only the LSA of the cam, in both high and lower rpm cams.

Some things that I know about are:
1. Lower performance cams have wider angles, usually 114 - 110. Higher performance cams 112 - 102.
2. I understand that wider spacing, Get you more vacuum and torque at the lower end, giving better behavior on the street but, with increased duration, where does it detract from the top end and what does it do in the middle?
3. Closer spacing gives more overlap but, generally more HP at the top of the torque, HP curve and I believe maximizes the average torque, between the max torque and max HP rpm but, really kills any hope of low end response.

What are your thoughts and experiences about LSA and how to use this tuning feature? Does it effect the the FE in different ways? I note that a lot of cam makers, use a little wider LSA on their FE cams.

[blykins]

It’s all application specific and isn’t as generalized as what you think.

One of my pulling truck engines uses a 119 LSA, makes 1200 hp at 8500 and 810 lbft of torque.

I use wider LSAs on my FE hydraulic rollers because aggressive lobes cost hp with heavier valvetrain.  Less aggressive lobes have more overlap and we have to control it.

[frnkeore]

Is the 1200 HP engine, naturally aspired?

Can you explain to us, what effect the LSA has on a aggressive. Lobe shape? It spread the spring load over wider range by a few deg, is that it?

I realize that you need to build, as much as possible to your end result and not fight against the cam but, build to it. The cam is the heart of the engine.

If the 1200 HP engine, is naturally aspired, I'd very entered in the difference in the torque curve if, a 104 LSA where exchanged for the 119.

[chilly460]

I think LSA is considered a more major influencer in cam design because people are accustomed to looking at shelf cams.  Shelf cams are fairly uniform so, in that case, the changes to LSA can have a fairly distinct change in the character of the cam.  You end up with generic trends such as LSA being tighter on “racier” designs as a universal rule

That said, when you get a custom cam, the LSA is more a byproduct of plotting the lobes, not a driver of where the timing events are placed if that makes sense

For an FE which has the heavy valvetrain, you have a less aggressive lobe with longer seat events to have gentler action, it’s going to have more overlap.  If you need power brakes or better idle or don’t want to overscavenge the intake if it has a good port, you’d put a relatively wide lsa on the cam. 

Just guessing, but seeing the rpm peaks on that pulling motor, guessing it’s got a ton of duration, to a point that overlap was getting so large it was beneficial to widen the lsa to decrease overlap. 

LSA really comes into play when you need more or less scavenging effect IMO, otherwise it’s more a result of other calculations not a driver of those calculations

[blykins]

Is the 1200 HP engine, naturally aspired?

Can you explain to us, what effect the LSA has on a aggressive. Lobe shape? It spread the spring load over wider range by a few deg, is that it?

I realize that you need to build, as much as possible to your end result and not fight against the cam but, build to it. The cam is the heart of the engine.

If the 1200 HP engine, is naturally aspired, I'd very entered in the difference in the torque curve if, a 104 LSA where exchanged for the 119.

The 1200 hp engine is naturally aspirated.   It's a max-effort 556ci engine. 

Chris hit on a lot of it, I use LSA to simply control overlap.   

A customer with a 380 cube Cleveland came to me asking for a camshaft as he thought he had maxed out his combination and was looking for improvements.   He was running a custom Crower solid roller, that was spec'd by Crower.   I kept his durations the same, lift the same, but actually decreased the overlap and the car picked up almost a tenth in the 1/8th.   Overlap can make/break vacuum but it can also make/break hp.  If you're holding both valves open together for too long, all your power is going out the exhaust.

I like when guys think outside the box when it comes to camshafts.   My biggest pet peeve is when guys look through cam catalogs, read the notes below, and think that those notes apply to every single engine, every single head/intake combination, etc.  My second biggest pet peeve is all the "universal" cams out there.  If you look through some of the catalogs, the same exact camshaft (advertised duration, .050" duration, LSA/ICL) is available for every engine family, from SBC to BBF.  Universal works, but it's by no means optimal. 

If you look at a lot of high rpm, large cubic inch competition engines, you will see LSA's from 118-124, and that's for the reason we've been discussing. 

[My427stang]

I am with Brent completely.  LSA is only a design/machining term to determine overlap based on a lobe pair.

It's all about valve timing and the effect you want, bills you need to pay.  I have been spreading centers lately on these 461s on purpose.  I do this to keep overlap in check to keep vacuum up and part throttle behavior for the restomod power brake builds.  A quiet hydraulic roller also has a bunch of advertised duration compared to a flat tappet, so you can see the two CJs I did were at 114, however, a smaller cam in my EFI 461, I narrowed to 112, because the lobe let me, and it actually has less overlap, not only for the vacuum, but in that case to leave the exhaust clean for the EFI O2 sensor.

I have a 462 tunnel wedge build coming in, no power brakes, good gear, that one will likely have a bit more overlap as I don't have to be bound by idle vacuum as much.  I expect the curves to be steeper and higher, more peaky if you will, because at some range, the exhaust will be pulling harder on the intake than it would with less overlap

Chilly is spot on with the need for overlap.  I think a rule of thumb though can be, the better the head, intake and exhaust combo, the less overlap you need. The problem is, defining "better", it's not bigger, and not even peak flow alone, it's efficiency and matching the rest of the build

[cjshaker]

My biggest pet peeve is when guys look through cam catalogs, read the notes below, and think that those notes apply to every single engine, every single head/intake combination, etc.  My second biggest pet peeve is all the "universal" cams out there.  If you look through some of the catalogs, the same exact camshaft (advertised duration, .050" duration, LSA/ICL) is available for every engine family, from SBC to BBF.  Universal works, but it's by no means optimal. 

A byproduct from the days when custom cams weren't an easy option like they are today. Remember, there used to be 3 choices in the days of flatheads, hence the term 3/4 or "full race" cam. Things sure have changed.

[BattlestarGalactic]

Remember the old 1980's Summit catalogs where the options for cam were "if you want the baddest sounding hot rod"?  No where did it say "most power".

[frnkeore]

I hadn't intended this be only about FE's, that's why I put it in this section but, I'm happy to have FE info.

Brent, could you give the rpm of the 810 ft lb of torque and explain this a little more?

"I use wider LSAs on my FE hydraulic rollers because aggressive lobes cost hp with heavier valvetrain."

The only difference that I can see, between the FE and say a Yates or SB2 engine, is the length of the push rods but, there valve stems are longer than most FE's. Now a days there is really no reason for the valve train, to be any heavier than a NASCAR engine.

For street engines, because of the length of the valves and expense to replace them, I can see people keeping the 3/8 valve stems but, for anything else, 5/16 or 7mm valve stems would be more desirable.

I was also hoping to get input on SBF, both W&C. I'm not a canted valve guy but, with that type valve angle, the flow is not as direct from the intake to the exhaust. That being one of the big advantages of the hemi and 4 valve, pent roof designs.

The race engines that I ran, where of the latter design and we ran 102 lsa on those, at 8500 - 10,000 rpm.

The last I new, the canted valve, NASCAR engines were running 106 lsa at 9,000+ rpm but, 106 lsa has been standard for more than 40 years in both, Ford and Chev wedge & canted engines. One cam maker, John DeLong, promoted 108 lsa for short track engines, over the 106 lsa, that was univeral. Presumably for a little more torque, exiting corners. I sponsored a  a car that used his cams. He was one of the great, early cam grinder and made a gear drive, that I liked, too. 

Increased vacuum is not what I submitted this thread about. What I'm interested in, is how to pick up torque, using lsa, between the max torque and max HP in the top 2000-2500 rpm range, whether that be 6,000 or 10,000 rpm, as that is where it counts, in race engines.

[blykins]

Cup engines probably used some 106 lobe centers, but they used everything in between depending on the track they were on, and how the engines were set up.  That’s kinda what I’m getting at, is there are no real generalizations that you can make, because each component changes the need for something else.

FE valves are heavy.  Factory valves are 3/8” diameter and are long in comparison to SBF, SBC, even some Cleveland and BBC applications.  In addition, on adjustable rocker arms, you have a lot of weight hanging off the back of the rocker arm, where most rockers on other applications are stud mounted and the adjuster is on the fulcrum.

On hydraulic rollers, the more aggressive the lobe, the quicker you lose control of the valvetrain.  The quicker lobes are also noisier.  Without running unrealistic amounts of spring pressure, it’s more efficient and beneficial to use a less aggressive lobe.  Running a lazier lobe increases the advertised duration which increases overlap, which necessitates a LSA change.

Clevelands are a whole different animal and are similar to Tunnel Port FEs where you have a humongous intake port and need more overlap to scavenge it.  Cleveland cams are a little more trickier to spec.

Without asking a specific question about a specific combination, you’re likely just gonna get generalized answers. 

[70tp]

In regard to the tunnel port and Cleveland needing more overlap to help scavenge , what is usable in this situation assuming maybe a 6500 power peak?  (106-108cl?).  A lot of “it depends” is in this, I’m sure.  Crane used to always recommend a 114 center on any that I inquired on.   And how narrow can the lobe centers get to where an engine tends to get like a two stroke dirt bike with a abrupt point to where the power hit comes on?  Do breathing limited engines , such as a factory headed small block benefit from narrow lobe centers also?   

[blykins]

In regard to the tunnel port and Cleveland needing more overlap to help scavenge , what is usable in this situation assuming maybe a 6500 power peak?  (106-108cl?).  A lot of “it depends” is in this, I’m sure.  Crane used to always recommend a 114 center on any that I inquired on.   And how narrow can the lobe centers get to where an engine tends to get like a two stroke dirt bike with a abrupt point to where the power hit comes on?  Do breathing limited engines , such as a factory headed small block benefit from narrow lobe centers also?

Yep, it depends on a lot of things.  On the Cleveland and TP, the main variables are the displacement and if the factory intake volumes have been reduced.  Again, vacuum requirements also play a huge role.  If you have power brakes, then the overall picture has to be eyeballed and some concessions may need to be made.  On stock displacement engines with no vacuum worries I have used 104-108 LSA cams quite a bit.

I really can’t stress enough that I’m being extremely vague in my answers because there are so many variables.

Stock style heads, again, can use all sorts of cams.  The cam for my 352 is on a 104.

[CaptCobrajet]

I've been reading this thread along.  Apparently I must be a little slow on camshaft design.  I have never seen a 6000-ish rpm engine (hydraulic roller) that benefits from wide separation and lazy cam lobes.  Individual runners excluded, lazy lobes and wide centers will get you a lazy engine from what I have seen. Beehive and conical springs pretty much eliminate valvetrain weight issues in engines up to 6000 rpm.  The reduction in spring and retainer weight is almost like having a valve that weighs nothing with conventional springs.  Moving mass weight is reduced by more than the weight of the valve.  I go 112 on occasion for power brakes, but big heavy cars and trucks with big tires ain't gonna like anything wider than a 110 in a streetable FE.  I'd say you lose 20 average hp for every 2° past a 108 if .050 duration is 250s or less.  Sometimes I put a 112 on a big street engine to kill some bottom end on purpose, to help with wheel spin.  A by-product is that they will hang on a little longer past peak power also.  Going 108 for the John Force cruise-in rumpity rump deal will beat the ground, and sometimes will be faster, but I discourage that idea because most get tired of the rough idle and the bumping up against a straight shift in the lower gears.

I think spreading the lobes to decrease overlap is the wrong way to go on mild to mid-level street or towing apps.  I think you can make more steam in a usable range by staying tighter and taking duration away, with a head that moves a lot of air at low lifts.  The better head being the key, in my opinion, and also it is VERY important to decide on an operating range, and then choose duration to work there with all things considered.  High revving, big duration, with high flow can benefit from wider separation......much wider than what will work on the street, but every time I have seen that work, there is "excess" flow and big inches involved.  It is hard to go wrong  with a 110 separation in most cases where duration is 220 to 240 @ .050, when brake vacuum is not a consideration.  Everybody has opinions.......and I could fill a phone book with opinions......the ones expressed here about this particular topic are pretty general.  There are always factors that change the requirements.  My comments on this are with a pump gas, fairly well mannered street car or towing/4x4 piece in mind.

[frnkeore]

In regard to the tunnel port and Cleveland needing more overlap to help scavenge , what is usable in this situation assuming maybe a 6500 power peak?  (106-108cl?).  A lot of “it depends” is in this, I’m sure.  Crane used to always recommend a 114 center on any that I inquired on.   And how narrow can the lobe centers get to where an engine tends to get like a two stroke dirt bike with a abrupt point to where the power hit comes on?  Do breathing limited engines , such as a factory headed small block benefit from narrow lobe centers also?

In your case, I'd try a 108 lsa, with 234 deg @ .050. Installed 106 intake but, try 108 or split over lap (straight up) too. I'd also try 104 or, 4 deg advanced, if you have the time and resources. That said, if your still close to 350 CI. If your in the 400 CI range, you might be better served with 236 @ .050 and you can tune with more exhaust duration on the C.

Porting and intake/headers, can be used to tune engine size and streetability also.

[blykins]

Blair, a 112 LSA is wide in comparison to some shelf cams, and a 56 degree hydraulic intensity IS lazy.    An aggressive lobe is similar to some of the Xtreme Energy lobes or Voodoo lobes, with 50-52-53 degrees hydraulic intensity.  Those cams are flat out noisy and require much different valve spring pressures.

Again, LSA is relative and overlap is application specific.  I’ve done lots of towing cams on 106-108-109 because that’s what they need.

[blykins]

In regard to the tunnel port and Cleveland needing more overlap to help scavenge , what is usable in this situation assuming maybe a 6500 power peak?  (106-108cl?).  A lot of “it depends” is in this, I’m sure.  Crane used to always recommend a 114 center on any that I inquired on.   And how narrow can the lobe centers get to where an engine tends to get like a two stroke dirt bike with a abrupt point to where the power hit comes on?  Do breathing limited engines , such as a factory headed small block benefit from narrow lobe centers also?

In your case, I'd try a 108 lsa, with 234 deg @ .050. Installed 106 intake but, try 108 or split over lap (straight up) too. I'd also try 104 or, 4 deg advanced, if you have the time and resources. That said, if your still close to 350 CI. If your in the 400 CI range, you might be better served with 236 @ .050

You can’t make LSA suggestions without looking at advertised durations.

[70tp]

My tunnelport is 9:1. 458”  roughly 4000 stall converter.  4:10 gear.   Single four barrel.     Has a f244 crane in it now.  I think it’s 244@.050.  Solid flat tappet.   Going by memory here.   I think about .580 lift.      I thought it was on a 114 spread.     I tried to get closer lobe center but the crane rep didn’t think it was wise.     I always thought some power was left in the table.     Motor ran ok but always seemed like it needed something

[70tp]

Crane f 248.   248@.050. .587 lift. 112 center

[blykins]

You’re leaving a ton on the table just  by using a single pattern cam alone. 

[70tp]

A “ton” of power as in 20 or like 50?      I have been seriously thinking of doing a big 460 ish engine (385 series) swap, but it starting to seem like this combo may need more attention before a full on engine swap. 

[blykins]

30-40 at least. 

Without knowing the rest of your specs, my gut says the wide lobe center with the single pattern was a big shot in the foot.

[frnkeore]

"Again, LSA is relative and overlap is application specific."

Yes, that is my point. Duration dictates most of the rpm band. What I'm looking for are trends and limits, to lsa, in the last 2,000 rpm of the HP/torque area. Dyno testing, using the same duration and varying the lsa would show what happens in that regard. Of course, it would be engine specific and depend to some extent to intake and exhaust but could show a direction to focus on.

In other words, less separation of the of the max torque and the max HP torque. Torque is what moves the car and it falls off as the max HP is reached.

HP is how fast you can generate torque.

[frnkeore]

And again, I put this in Non-FE, because I wanted more than FE specific input (or output, if you like ).

Cup engines use valves that are longer than FE valves. They even use valve seems that are as small as 6mm (.236). A scary size to me!!

To me, unless your budget is very limited AND your staying 6000 rpm, or less. There is no reason to use 3/8 valve stems. I do note that some builders on this forum, use 11/16 11/32 valve stems.

[blykins]

I use 7mm and 11/32” in most of my stuff, but even an 11/32” FE valve can be heavier than a BBC valve.  3/8” stem valves are horribly heavy and there are still a lot of guys running them.

I agree with Blair that the modern spring/retainer packages overcome a lot of issues, but IMO, a light valve with the correct cam lobe is a necessity on a lot of applications, mainly hydraulic rollers.

[70tp]

I had a Cleveland once that had power that came on like a two stroke.   That was a fun motor.  I always thought that it was the combination that made the exhaust pull on the intake system and made it run. “Came up on the pipe”. Change one thing in the combo and it was a dud.  If this tunnel port would run like that Cleveland , it would be What I hoped it would be.   Maybe time for a cam swap in the near future to see?     Thanks guys for the cam lesson today

[My427stang]

Saying any certain number is too big or too small for anything generally is dangerous in my book. Cam design did change quite a bit (an understatement) and what we did in the 70s isn't what we all do now.   Heck 10 years ago a 230 @ .050 cam wasn't making 500 hp with a pocket port in a small bore street wedge, but they can now, with non-adjustable rockers and zero maintenance.

This will sound cocky, but even on the street it isn't just idle vacuum, it isn't always just HP, it's the whole personality and performance of an engine when you aren't just banging the rev limiter for 1320.  I have built, and will build, plenty of engines with tighter LSA, but when right is right, its right.

I can't even say I think 114 is wide, the nicest little street 390 I know is at 112, but the cam is an absolutely baby compared to a healthy cam at at 114, and as you move into electronics and un-natural aspiration, we'll keep adjusting all the cam design specs to make the engine do what we want.

Heck I'd go 116 LSA on a street vehicle in an absolute heartbeat if that's what it took to get the valve events correct for the combo,  especially as we go deeper in all throttle condition EFI use and better performing heads, but again, the LSA is just a machining reference, it's all the valve events, not just the standard few we talk about that drives the overall cam design.

I'd also add that most hyd rollers are lazy in my book, that is unless you don't care if they are noisy or try to bounce valves against the seats.  Always getting better, and why lobe design matters so much, but they are where they are. 

[CaptCobrajet]

Yes, that Tunnel Port needs tight centers and 10-12 more duration on the exhaust.  The single pattern and 114 is killing you, but the 9:1 compression is REALLY killing the TP!  The same ideas that pick up the Cleveland are relative to the Tunnel Port.  Big intake tract with lots of flow, somewhat shitty exhaust.......needs a fast rocker or extremely aggressive intake lobe, opening early, then tight separation and a long exhaust......fast to open, slow to close on the exhaust to yank on the big intake port.

So put the cam that works there over in a very efficient, properly sized aluminum head with a good flowing exhaust and blow all the potential power right out the tailpipe........cam has to be right for the combo!

[My427stang]

My tunnelport is 9:1. 458”  roughly 4000 stall converter.  4:10 gear.   Single four barrel.     Has a f244 crane in it now.  I think it’s 244@.050.  Solid flat tappet.   Going by memory here.   I think about .580 lift.      I thought it was on a 114 spread.     I tried to get closer lobe center but the crane rep didn’t think it was wise.     I always thought some power was left in the table.     Motor ran ok but always seemed like it needed something

Although the cam is old school, 310/310 244/244 112 on 107, as Blair said, your main issue is compression, absolutely and positively.

I am wondering if your 9:1 is a typo, it takes a good dish to get that low, even with a big TP chamber.  That's in the ballpark of 6:1 DCR for those who use it.  I would expect that the cheapest way out for you to be a little happier would be to run a shim head gasket (if you think it could seal up) and crank that cam forward to 103/104, then run as much initial and as quick of a curve as it will bear. 

It sure wouldn't be as efficient as getting above 10:1 and getting the right lobes in there, but another option would be the same cam at 11:1, get that old school cam popping like they did in the old days   With that much duration, it'll still run on pump gas.  At 86 degrees overlap, it's not as good as the asymmetric lobes would be, but with some compression it would feel like you gained 2 cylinders

As cool as that ride sounds, either pistons and cam, or even just pistons would make all the difference in the world.

[70tp]

The motor has been together forever.   The low compression was to make it happy on a decent shot of nitrous but never hooked that up.  The pistons are flat top venolia.  Heads have been cut a mile, 72cc, I think.   Going by memory, I dont remember the pistons being down the hole.  Most of it was done by the machine shop.   I kinda think I may have the piston box with all the info on it somewhere. I’ll look for it after the Christmas holidays.  Pump gas was pretty bad around here in the late 80’s when this was done.  I drove it a lot on the street and wasn’t too concerned about nice drivability.     It’s in a 70 Mach 1.     Previous motor was a 11.7:1 medium riser and keeping that from rattling on anything but race gas got old. 

[blykins]

So it's a 4.280 x 3.980 combo? 

With a 72cc head, you'd need a 33cc dish to be at 9:1.  Running a 72cc chamber with a normal 6-8cc flat top puts you in the 11.6-11.8 range.  An 82cc chamber with an 8cc piston is 10.4. 

I love that 4.2x-4.3x bore with a 3.980" stroke combination.  I have made 600 hp with that combo and unported Tunnel Port heads.  Worked heads put me at 700 hp.

[plovett]

It is certainly application specific and Brent it going to kick my ass, BUT for MOST street/strip FE's in the 390-482 inch range a tighter lobe separation angle is going to get you more average power and better ET's.  And again it depends on the cam duration, but in general a 106-108 LSA is good for 90% of pump gas street/strip FE combinations if you are not looking for a smooth idle and good mpg.

JMO,

paulie

[blykins]

Why would I kick your butt?

I don’t necessarily disagree with you, but I think 90% is stretching it.

Remember, LSA just changes overlap.  There are other ways of changing overlap.

[plovett]

Why would I kick your butt?

I don’t necessarily disagree with you, but I think 90% is stretching it.

Remember, LSA just changes overlap.  There are other ways of changing overlap.

Because I am over generalizing.  I did say, "in general" though. 

[plovett]

Why would I kick your butt?

I don’t necessarily disagree with you, but I think 90% is stretching it.

Remember, LSA just changes overlap.  There are other ways of changing overlap.

I understand.  You are an engine builder and have seen many more varied combinations than I have.  Mine have just been my own.  Mine have varied from maybe 450 hp to 550 hp  in street combinations.   All around 428 inches.  So a narrow range.  I understand a 560 cid engine making 1000 hp might need a different LSA.  And that LSA is more a result than cause.

Anyhoo, just acknowledging that my statement is not applicable to everything.  Maybe not even 90%.  But in general, most street/strip FE's like a little tigher LSA than most catalog cams have.  IMO. 

[frnkeore]

Hmm, not exactly was I was looking for but, maybe it confirms that FE and or large V8's need a wider LSA than <400 CI? Any thoughts on that?

While I did mention vacuum, it was in passing and not really a consideration, regarding max average HP, in the upper HP range. For street engines, you can increase HP and keep vac, by adding CI. I'm not interested in "streetable" engines, just high output ones, 6000 rpm and up.

There has been no comment at all, regarding the SB engine, either in C or W form. I would have thought that there would have been many builds on that platform and why I put this in the Non-FE section.

Although I'm a "old school" guy, even at 75 yrs old, I've never lost the desire to learn and share info and my personal reason for this thread is that I'm putting together a 307 CI engine on a C80E block, with a internally balanced, forged crank. It will have a ~270-6 @ .050, roller cam, with ~6 deg more on the exhaust. Flat top 10.2 c/r pistons. Probably a Howard cam, with std rate lift. Howard have been very accommodating to me, in the past. I will try 2 sets of heads. Old school, 53.5cc HP 289's with 1.94 x 1.6 valves, then a set of alum 2.05 x 1.6 (as I remember 195 cc intake) heads that I bought 12 yrs ago. I bought those 63cc heads, to build a 351W so, I'll bring them down to maybe 53cc for this. I don't like pop up pistons.

I know I can get good HP numbers with 106 lsa but, I'm wanting to try 104. In any case, I'll install 2 cams with the same timing but different LSA. I'm hoping to get it on a local dyno this Spring.

I don't want to get to side tracked but, has anyone tried sinking the intake, to redirect some of the incoming a/f mixture, away from the exhaust?

Joe, if your reading this, do you have any thoughts on LC or intake valve sinking?

[frnkeore]

Why would I kick your butt?

I don’t necessarily disagree with you, but I think 90% is stretching it.

Remember, LSA just changes overlap.  There are other ways of changing overlap.

This and Brent's response is starting to confuse me. I suggest tighter LC and get push back and then some else suggests, it will do what I think it will do and there's agreement??? 

[My427stang]

Why would I kick your butt?

I don’t necessarily disagree with you, but I think 90% is stretching it.

Remember, LSA just changes overlap.  There are other ways of changing overlap.

This and Brent's response is starting to confuse me. I suggest tighter LC and get push back and then some else suggests, it will do what I think it will do and there's agreement??? 

LSA is just an angular measurement from the center of one lobe to another....it means nothing without the specific lobes, and even then, the information you are looking for is degrees of overlap, not LSA as a value

The better the head and supporting airflow pieces in and out, the less overlap you need.  With your planned iron heads, pick the ballpark RPM range and lean toward tighter.  104 might be much depending on use, a degree or two won't blow you away in the difference, but your combo should like tighter 

[Joe-JDC]

Yes, I have been watching the replies, and since you are building a 307 cubic inch engine instead of a FE, I will add my thoughts.  On my 303 Y engine, my camshaft was 233/240* @ .050", 106 LSA, installed at 99.75*.  The engine is 10.4:1 compression, and the lobe lift is .375" for 1.6 rocker ratio, with .009" hot lash.  My engine makes 390.8 tq @ 5400, 453.7 hp @ 6800, pulling to 7200 rpm.  I firmly believe that your camshaft selection of 270* is much too high if at .050" lift figure for 307 cubic inches.  My advertised duration is 284/292*.  Last year's EMC 375 Y block was higher compression at 13.0:1, and the camshaft was designed to peak at 6200 rpm since the crankshaft was a 4.000" stroke.  The camshaft was 254/260* @ .050, 104 LSA, installed at 101*, and made 561 tq @ 3800, 595 hp @ 6200, pulling to 6800 rpm.  Both engines could make more ultimate horsepower with a slightly different camshaft profile, but the average torque and average horsepower was highest with the camshafts installed advanced.  On the 289 SBF that placed second this year at EMC, the camshaft was a hydraulic roller with solid roller lifters with 242* duration on the intake, and it peaked at 6800 rpm, pulling to 7200 rpm for the dyno test.  Smaller engines do not need wide LSAs to make power, but they do to idle well, and produce vacuum for power brakes, etc.  We have dyno tested the same camshafts with LSA of 110, 111, 112, 113, 114*, and the horsepower climbed each time until the 114*, which lost 20 hp.  That engine made 560 hp, pulls the front wheels on the car, and the owner is extremely happy that it is not so hard to drive on the street with the 114* LSA.    Each engine family has its own sensitivity to LSA, ICL, ECL, and it takes dyno testing, or track testing to determine what actually works, not a catalog number.  My dynamic compression ratio with the 303 Y is 8.21, which will run on pump gas 93 octane quite well.  Joe-JDC

[blykins]

Hmm, not exactly was I was looking for but, maybe it confirms that FE and or large V8's need a wider LSA than <400 CI? Any thoughts on that?

While I did mention vacuum, it was in passing and not really a consideration, regarding max average HP, in the upper HP range. For street engines, you can increase HP and keep vac, by adding CI. I'm not interested in "streetable" engines, just high output ones, 6000 rpm and up.

There has been no comment at all, regarding the SB engine, either in C or W form. I would have thought that there would have been many builds on that platform and why I put this in the Non-FE section.

Although I'm a "old school" guy, even at 75 yrs old, I've never lost the desire to learn and share info and my personal reason for this thread is that I'm putting together a 307 CI engine on a C80E block, with a internally balanced, forged crank. It will have a ~270-6 @ .050, roller cam, with ~6 deg more on the exhaust. Flat top 10.2 c/r pistons. Probably a Howard cam, with std rate lift. Howard have been very accommodating to me, in the past. I will try 2 sets of heads. Old school, 53.5cc HP 289's with 1.94 x 1.6 valves, then a set of alum 2.05 x 1.6 (as I remember 195 cc intake) heads that I bought 12 yrs ago. I bought those 63cc heads, to build a 351W so, I'll bring them down to maybe 53cc for this. I don't like pop up pistons.

I know I can get good HP numbers with 106 lsa but, I'm wanting to try 104. In any case, I'll install 2 cams with the same timing but different LSA. I'm hoping to get it on a local dyno this Spring.

I don't want to get to side tracked but, has anyone tried sinking the intake, to redirect some of the incoming a/f mixture, away from the exhaust?

Joe, if your reading this, do you have any thoughts on LC or intake valve sinking?

I have spoken several times in this thread alone about Cleveland heads.  If you need more specific info, email me, or you can join my Cleveland forum for a discussion.

270 at .050” for a factory head?   Why?  There’s a specific trend with cams and head flow.  You keep adding hp and rpm until you reach a specific point where all you are doing is holding the valve open and nothing else is coming in.  My guess is that you’d make more power with a much smaller cam.  The duration split depends on the amount of overlap and how well the exhaust functions relative to the intake.  A 6 deg split is what you commonly see with shelf cams.

[blykins]

Why would I kick your butt?

I don’t necessarily disagree with you, but I think 90% is stretching it.

Remember, LSA just changes overlap.  There are other ways of changing overlap.

This and Brent's response is starting to confuse me. I suggest tighter LC and get push back and then some else suggests, it will do what I think it will do and there's agreement??? 

I’ll tell you the same thing I’ve said multiple times during this thread:  it depends on a ton of other stuff.  Have I seen torque pick up on certain combinations with a tighter LSA?  Absolutely.  Does it happen every time with every engine?  Nope.

[Joe-JDC]

Never sink the intake valve lower than the exhaust!  Detonation central, cracked exhaust valves, if anything, sink the exhaust lower than the intake seats.  Flows better.  Joe-JDC

[frnkeore]

Thank you, very much Joe, for sharing that.

To be a little more specific, my goal is peak HP at a minimum of 7600 rpm, with 1200 cfm of carb (I may also try a Victor Jr & 850 carb) in a ~1350 lb car. I have a old Formula Car that I will cut off back of the roll bar and add the engine, C4 (if it will take it) and 9" gears, as a unit. It will be a drag racer. That, after the dyno work is done.

Brent, you'll note that I will not use the 289 heads, in the end result but, I will heavily modify the exhaust ports. I have them and will try them, to see how they compare with the 2.05 x 1.6 heads. I don't expect them to get very close to the aluminum heads BUT, they did run at that rpm level, in the 60's and 70's in Trans am, Shelby Cobra's and Can Am. Off the subject but, Gurney ran his 3V Westlake heads at Indy and placed 2nd, one year. I loved what Gurney did with the SBF.

[blykins]

Thank you, very much Joe, for sharing that.

To be a little more specific, my goal is peak HP at a minimum of 7600 rpm, with 1200 cfm of carb (I may also try a Victor Jr & 850 carb) in a ~1350 lb car. I have a old Formula Car that I will cut off back of the roll bar and add the engine, C4 (if it will take it) and 9" gears, as a unit. It will be a drag racer. That, after the dyno work is done.

Brent, you'll note that I will not use the 289 heads, in the end result but, I will heavily modify the exhaust ports. I have them and will try them, to see how they compare with the 2.05 x 1.6 heads. I don't expect them to get very close to the aluminum heads BUT, they did run at that rpm level, in the 60's and 70's in Trans am, Shelby Cobra's and Can Am. Off the subject but, Gurney ran his 3V Westlake heads at Indy and placed 2nd, one year. I loved what Gurney did with the SBF.

A 7500 rpm peak is easy.  Will take a lot less cam than what you’re thinking.

[frnkeore]

Brent, I said a min of 7600 not 7500. So tell me how much duration I need to peak @ 8000 and still pull to at least 8300?

That's where I'm try to go.

Also, the modern day cam catalogs list 10 - 12 more degrees, ex duration. I'd rather close the ex earlier and start building compression then work on ex flow.

[blykins]

Well, then you need a minimum peak of 8000, not 7600.

Tell me what the heads flow.

[frnkeore]

314 in / 223 ex @ .600

[blykins]

Based on some of my SBF stuff that I’ve done, I’d be in the low 250’s at .050”.  I’d also split the durations by 10 deg.  That’s just a rough ballpark, I’d have to look at advertised durations and some other numbers.

[frnkeore]

 The camshaft was 254/260* @ .050, 104 LSA, installed at 101*, and made 561 tq @ 3800, 595 hp @ 6200

The above is Joe's results, with a 375 CI engine, for what you suggest.

[blykins]

The camshaft was 254/260* @ .050, 104 LSA, installed at 101*, and made 561 tq @ 3800, 595 hp @ 6200

The above is Joe's results, with a 375 CI engine, for what you suggest.

So you think the same cam would make the exact same peak in an engine that’s 70 cubic inches smaller? 

[frnkeore]

No but, I don't think there will be 1800 rpm difference, either.

Let's look at it this way, my 8000 rpm air requirement is 712 cfm. The 375 @ 6200 is only 673 cfm.

Point taken though and I'll down grade to 260/266.

[blykins]

No but, I don't think there will be 1800 rpm difference, either.

Let's look at it this way, my 8000 rpm air requirement is 712 cfm. The 375 @ 6200 is only 673 cfm.

Point taken though and I'll down grade to 260/266.

There will be 1800 rpm and then some. 

You can do whatever you want, but it's a humongous difference in cam specs between 70 cubic inches.   Displacement and head flow are the two biggest components of what cam specs are needed.   The cam's job is to open the valves to fill the cylinders.  If the cylinder volume is much smaller, then the valves don't need to be open as long.   Same with the cylinder heads, if they flow well, they can pack it in, in a smaller amount of time. 

FWIW, I did a 351C, stock stroke, that peaked at 8000 with a camshaft with around 258° @ .050".  The factory 4V heads with no port work and just the correct valve job flowed 312 cfm at lift. 

You have about 50 less cubes.

I have a ton of dyno results for small block road/drag race engines, from 292 cubic inches to 460, from ported factory 289 heads to 400 cfm CHI 3V heads.   They all needed extremely different camshafts.  One size doesn't fit all and you can't just arbitrarily pick durations and splits without taking into account the advertised durations, which LSA's you're going with, etc.  I will tell you though, that with the head flow numbers you gave me, a 6° split will not be optimal by any means. 

I would also kick your cfm calculations to the curb and let the engine dictate which carb you need.  It won't be a 1200 cfm Dominator.

[Joe-JDC]

Don't use my Y Block for anything more than an example of what I had to do to make the engine work in the rpm band EMC chose.  That same 375 Y block now has a 268/274* @ .050" on a 110 LCA with a .403" lobe for 1.7 rocker arms, shooting for 625 hp NA.  I dyno'ed it with a 1250 Dominator, and with a tunnel ram with several combinations, ultimately two 850 cfm Pro System carbs.  What I would be asking myself, if I were looking at your parts, is:  How much horsepower do I want to make, and what camshaft do I need to get me there?  Whenever you set a rpm as a goal, you create a whole lot of expectations of what is needed, but in reality can only be achieved with a whole lot of money.  RPM needs lightweight parts, and the best of everything, and the best machine work.  That costs in today's economy. My engine blocks are 58 years old, and the heads are 61 years old on the 303Y.  I do this because I like to take the underdog and try to make it a winner.   Joe-JDC

[frnkeore]

A overview of the intake tract. It will include a 850 on a Victor Jr, Tunnel ram that includes pairs of 550, 600 and 650 Holley's. I'll also try to find a Hilborn type (lawn sprinkler type) FI. I do have experience with that type FI, as I used it on my Formula Atlantic, for a short time and when dynoed, it produced the exact same HP/Torque as my Weber's but, at the expensive of a lot more plumbing, so, I removed it. Because of it's performance, in that test, I think that it will have excellent tunability in this range, especially with the trumpets.

Based on every ones help,I've settled on the Howard cam spec at 257/263 .640 lift, 104 LSA, ICL 101 or 102. That will be my base, reference point.

If the max HP, exceeds 8600, I'll cut back on timing. Then change only LSA and see what the result is.

Again, I'm not looking for highest peak HP, I'm looking for highest average torque, in the last 2000 rpm, of the usable power band and how LSA will effect it. I should have, at least 3 examples, in the next 12 months.

Can I assume, from the response, that no one has tested, changing only the LSA, in tuning a engine?

[My427stang]

A overview of the intake tract. It will include a 850 on a Victor Jr, Tunnel ram that includes pairs of 550, 600 and 650 Holley's. I'll also try to find a Hilborn type (lawn sprinkler type) FI. I do have experience with that type FI, as I used it on my Formula Atlantic, for a short time and when dynoed, it produced the exact same HP/Torque as my Weber's but, at the expensive of a lot more plumbing, so, I removed it. Because of it's performance, in that test, I think that it will have excellent tunability in this range, especially with the trumpets.

Based on every ones help,I've settled on the Howard cam spec at 257/263 .640 lift, 104 LSA, ICL 101 or 102. That will be my base, reference point.

If the max HP, exceeds 8600, I'll cut back on timing. Then change only LSA and see what the result is.

Again, I'm not looking for highest peak HP, I'm looking for highest average torque, in the last 2000 rpm, of the usable power band and how LSA will effect it. I should have, at least 3 examples, in the next 12 months.

Can I assume, from the response, that no one has tested, changing only the LSA, in tuning a engine?

I would not assume that Frank, plenty of testing referenced here, it just seems to be not scratching your itch.

I personally have lost track of the entire configuration you are asking about, specific heads, exact compression, all cam specs, etc. I assume you are building for the aluminum heads and just going to play with the iron?   I think header and collector design will have to be taken into account if you want the benefit of the high overlap (however, I think you should be posting planned advertised duration too, to allow us to help) .050 duration isn't great for assessing overlap

Finally, I am not sure the early ICL is a benefit for you unless somehow you are limited on compression, would be interested in those numbers too. 

[blykins]

Can I assume, from the response, that no one has tested, changing only the LSA, in tuning a engine?

Sure have.  On multiple engine families. 

If I were you, I'd be focusing real hard on advertised durations. 

[frnkeore]

First, I didn't start this thread for my particular build but, to research how to maximize average torque at the upper end of usable rpm, discounting any effect of what it might do to the low end. I put it in the Non-FE section, hoping for broad input.

The reason for my build, is that last summer I came up with a virgin C80E block and 3 weeks ago, I got a good deal on a new, internally balanced 4340, forged crank. I already had both sets of heads and the rod/piston combo. I'm building the 289 heads, myself and will match the springs to the cam. The alum heads are complete so, I have to make sure the springs will work with the cam. I chose the lower lift range on the cam, to mitigate spring problems. If everything works out and I have enough spring and valve clearance, I'll go to 1.7 shaft rockers.

This is the cam spec, I will use:

Howard Standard Ramp Mech Roller
Cam #      .006   .020   .050   .200   Max Lift    Lash   Total lift 1.6               1.7

BR257400   298    289    257    174    0.400      0.022    .640 - lash .618    .658 net
-------------------------------------------------------------------------------------------------------
BR263400   304    295    263    179    0.400      0.022    .640

"Sure have.  On multiple engine families."

Brent, it's your proprietary property and to do as you please with it but, that was my original question. What does only changing the LSA, do to the torque/hp curve and dyno results would show that.  That is what I was asking for. Nothing else.

Regarding the headers, they will be boat or F5000 style headers, for my application. Primary length and collector style, to be determined. At this time, I think I want them tuned for 7000 rpm, the range that I want to pick up the most torque.

Since we are talking about my build, I do have a question. What size should the primary be and assuming I need a step, how should the step be configured?

 

[blykins]

First, I didn't start this thread for my particular build but, to research how to maximize average torque at the upper end of usable rpm, discounting any effect of what it might do to the low end. I put it in the Non-FE section, hoping for broad input.

The reason for my build, is that last summer I came up with a virgin C80E block and 3 weeks ago, I got a good deal on a new, internally balanced 4340, forged crank. I already had both sets of heads and the rod/piston combo. I'm building the 289 heads, myself and will match the springs to the cam. The alum heads are complete so, I have to make sure the springs will work with the cam. I chose the lower lift range on the cam, to mitigate spring problems. If everything works out and I have enough spring and valve clearance, I'll go to 1.7 shaft rockers.

This is the cam spec, I will use:

Howard Standard Ramp Mech Roller
Cam #      .006   .020   .050   .200   Max Lift    Lash   Total lift 1.6               1.7

BR257400   298    289    257    174    0.400      0.022    .640 - lash .618    .658 net
-------------------------------------------------------------------------------------------------------
BR263400   304    295    263    179    0.400      0.022    .640

"Sure have.  On multiple engine families."

Brent, it's your proprietary property and to do as you please with it but, that was my original question. What does only changing the LSA, do to the torque/hp curve and dyno results would show that.  That is what I was asking for. Nothing else.

Regarding the headers, they will be boat or F5000 style headers, for my application. Primary length and collector style, to be determined. At this time, I think I want them tuned for 7000 rpm, the range that I want to pick up the most torque.

Since we are talking about my build, I do have a question. What size should the primary be and assuming I need a step, how should the step be configured?

First of all, Merry Christmas.

Second, I can’t answer your question, nor can really anyone here.  I can’t count how many times I’ve said in this thread alone that it varies from application to application and you can’t make a general statement about what varying the LSA will do.......because it’s varying the amount of overlap!  It just depends.   I’ve seen tighter LSAs make more torque and I’ve seen them make less in comparison. 

With a 32 deg major intensity on those lobes, you’re gonna need a lot of spring pressure for 8000+ rpm.  Shaft rockers will be a blessing along with the newest valve spring sizes and technology, unless you’re running titanium valves.  At 8000 rpm, things start getting real serious.

Lastly, you’re setting at 84 degrees overlap at 104 LSA.  I personally wouldn’t run it at a 104 with that small of an engine.  As several of us have pointed out, there’s a point where you push more power out the exhaust valve than you translate into crankshaft rotation. 

I think I’ve reached the point of where I can be of any help, so I’ll bow out.

[Rory428]

Although I can`t really offer much input on the LCA question, I do have to ask what do you plan to do with this engine ? I have a 331 SB Ford in my drag car, it only dynoed at 482 HP, and I run nowhere near the RPM you are planning (pump gas flat top piston with a much smaller solid flat tappet cam than you are looking at), but it has gone a best of 10.15ET@129.9 MPH in my 2800 pound 4 speed car. I normally shift at 6600 RPM, and on a good pass with hit a little over 7000 across the finish line. That said, despite my much lower RPM use, I have had one factory 302 block split thru the main webbing. You seem to be expecting an awful lot of a factory Ford 302 block. I am currently running another stock 302 block, but now with a main bearing girdle, and so far so good. But if I ever decided I wanted to make any more power than it currently has, an aftermarket block would be the first thing on my list.

[frnkeore]

Thank you, very much Joe, for sharing that.

To be a little more specific, my goal is peak HP at a minimum of 7600 rpm, with 1200 cfm of carb (I may also try a Victor Jr & 850 carb) in a ~1350 lb car. I have a old Formula Car that I will cut off back of the roll bar and add the engine, C4 (if it will take it) and 9" gears, as a unit. It will be a drag racer. That, after the dyno work is done.

Brent, you'll note that I will not use the 289 heads, in the end result but, I will heavily modify the exhaust ports. I have them and will try them, to see how they compare with the 2.05 x 1.6 heads. I don't expect them to get very close to the aluminum heads BUT, they did run at that rpm level, in the 60's and 70's in Trans am, Shelby Cobra's and Can Am. Off the subject but, Gurney ran his 3V Westlake heads at Indy and placed 2nd, one year. I loved what Gurney did with the SBF.

Rory,
This will be the car configuration.

This 302 block was a real find. Based on a allen wrench measurement, the cylinder walls are 1/32 thicker than a 80's block that I have and I will use a girdle on it.

If your at all familiar with the F5000 engines, of the 70's, they ran 302's at 8k and 480+ hp. If not, take a look at this video.

https://www.youtube.com/watch?v=AR-1qO2i3Nw

The Aussy's still run them. The car in my avatar is a Formula Atlantic. SCCA grouped the F5000 and my class, together, in club races. I started my road racing, at the same time Danny Ongias did, at Willow Springs and Riverside, CA. My type cars where 1000 lb and 200 hp vs 1350+lb and 480+ hp. Top speeds where 150 vs 180 mph (Riverside) but, the Atlantic's corner better than F5000. Traco and Al Barts where the prominent engine builders for the F5000's, in those days. Barts even did a few 180 crank engines.

This engine will have very limited running, in comparison to the above described, just a few seconds at the drags and dyno time but, I know it will be highly stressed, in those short runs. I had been looking for a 3.25 forged crank, when this one fell into my hands. It could still happen.

Yours sounds like a very healthy 331. Is it in a Falcon or Mustang, or what?

[gt350hr]

   Frank,
      You've been schooled by some pretty smart guys. Though I am 8 years younger than you I would like to help you a bit from my 53 years experience with building and racing 8.2 deck Ford engines.
    First IF you had two ( or 5) 289 cams ground the same except for "ground in LSA" being two degrees different on each , you would see the "power band" would be lower across the board with the tighter LSA and it "might" have a small effect on maximum RPM. Again "20* valve angle , wedge" head. No Tunnel port , Boss , Gurney , TFS twisted , etc. No FE , Lima , 351C etc. NO generalities , SBC BBC MOPAR, JUST  289-302 SPECIFIC. EVERY engine has it's own peculularities.
   Second dump the idea of the 289 HiPo heads because they will not flow enough air , I don't care WHO ported them or how much. You're looking at 240 on a good day. GO with the aluminum heads as air flow has always been the limiting factor in the small block Ford.
   Third, You NEED compression. Yes I remember the late great Doug Nash(rip) telling me I needed to run flat top pistons for flame travel , and that is true for factory iron heads. BUT "modern heads" have altered spark plug placement and THRIVE on additional compression.
    Fourth , Buy an 8" 5,500 stall torque convertor because you will need ALL you can get to make your car move. You will also need a 4.86 (or so) gear ratio and a 28"tall slick to go 130ish mph . Use a 36" long 1-3/4" primary tube length "boat header" with an 18" long collector. Use the Vic Jr intake and an 850 DP of your choice.
     The stuff that was done back then doesn't work in today's world .I prove this to myself every time I go to the track with my old school dual quad intake and carbs instead of the Vic Jr I know will go two tenths quicker but doesn't look as cool.
   Randy

[Joe-JDC]

There are couple of newer intakes that would be my choice for an all out 289-310 SBF with inline valves.  Super Victor, Parker Funnel Web(Aussie version), or new TFS.  The Victor Jr is a good manifold, and I have probably ported 40 or more of them over the years for drag racers with flow anywhere from 310 cfm to 420 cfm depending on the cubic inch of the engine.  The only issue with the Victor Jr is the floor angle is too flat for 7500 rpm efficiently.  I like the manifold, and I have three of them myself.   Joe-JDC

Real Parker Funnel Web is the one on the left.

[Rory428]

Thank you, very much Joe, for sharing that.

To be a little more specific, my goal is peak HP at a minimum of 7600 rpm, with 1200 cfm of carb (I may also try a Victor Jr & 850 carb) in a ~1350 lb car. I have a old Formula Car that I will cut off back of the roll bar and add the engine, C4 (if it will take it) and 9" gears, as a unit. It will be a drag racer. That, after the dyno work is done.

Brent, you'll note that I will not use the 289 heads, in the end result but, I will heavily modify the exhaust ports. I have them and will try them, to see how they compare with the 2.05 x 1.6 heads. I don't expect them to get very close to the aluminum heads BUT, they did run at that rpm level, in the 60's and 70's in Trans am, Shelby Cobra's and Can Am. Off the subject but, Gurney ran his 3V Westlake heads at Indy and placed 2nd, one year. I loved what Gurney did with the SBF.

Rory,
This will be the car configuration.

This 302 block was a real find. Based on a allen wrench measurement, the cylinder walls are 1/32 thicker than a 80's block that I have and I will use a girdle on it.

If your at all familiar with the F5000 engines, of the 70's, they ran 302's at 8k and 480+ hp. If not, take a look at this video.

https://www.youtube.com/watch?v=AR-1qO2i3Nw

The Aussy's still run them. The car in my avatar is a Formula Atlantic. SCCA grouped the F5000 and my class, together, in club races. I started my road racing, at the same time Danny Ongias did, at Willow Springs and Riverside, CA. My type cars where 1000 lb and 200 hp vs 1350+lb and 480+ hp. Top speeds where 150 vs 180 mph (Riverside) but, the Atlantic's corner better than F5000. Traco and Al Barts where the prominent engine builders for the F5000's, in those days. Barts even did a few 180 crank engines.

This engine will have very limited running, in comparison to the above described, just a few seconds at the drags and dyno time but, I know it will be highly stressed, in those short runs. I had been looking for a 3.25 forged crank, when this one fell into my hands. It could still happen.






































Yours sounds like a very healthy 331. Is it in a Falcon or Mustang, or what?

No, I have the 331 in my 78 Fairmont, which I have raced for over 30 years, mostly with 427 & 428 FE engines. I put the small block in a couple of years ago, after getting warned by track tech not to run anymore 9 second ETs unless I do all the chassis and safety upgrades to be compliant to be legal to run 9s. Since I am still unsure that I want to deal with the extra expense to do all that (full roll cage, certified chassis inspection, plus full face helmet, window net, neck collar, gloves, heavier fire jacket and pants, NHRA Competition license etc), I decided to slow it down with the small block until I figure out if I will bother with all the changes. This photo is with the FE engine, but basically the car has looked pretty much identical for 30 years.

[Rory428]

There are couple of newer intakes that would be my choice for an all out 289-310 SBF with inline valves.  Super Victor, Parker Funnel Web(Aussie version), or new TFS.  The Victor Jr is a good manifold, and I have probably ported 40 or more of them over the years for drag racers with flow anywhere from 310 cfm to 420 cfm depending on the cubic inch of the engine.  The only issue with the Victor Jr is the floor angle is too flat for 7500 rpm efficiently.  I like the manifold, and I have three of them myself.   Joe-JDC
Joe, on my 331, I am currently using out of the box AFR 185 heads, an out of the box Victor Jr. intake (although it does have Ford Motorsport cast into it), and a 4777 Holley 650. I recently picked up a Super Victor for cheap (the seller had it on a stock 302 in a PU truck, said it wasn`t all that good , imagine that!). Since I shift at 6600, and hit just over 7000 at the finish line, do you think it will be worth anything on my combo? I will likely try it someday anyhow, just curious on your thoughts. I may also try a 750 Holley down the road too, who knows, maybe I can get the 302 near the 9s as well.

Real Parker Funnel Web is the one on the left.

[Joe-JDC]

If you do anything to the Super Victor, just clean up the plenum area, and keep the exits to the heads as small as possible.  It is quite a bit better than the Victor JR. as cast.  The Jr. averages ~307-310 cfm, whereas the Super Victor is ~340 cfm as cast.  Believe it or not, the 289 that took second place at EMC this year used a Performer RPM with the divider cut down, and dimples in the floor of the plenum.  He had iron heads that were CNC ported and hand massaged.  The AFR 185 heads are much better.  Joe-JDC

[frnkeore]

Rory, Randy and Joe. Thank you again. I am lessening closely.

Joe, where might I find one of the Parker Funnel Webs? I'll see if I can find the TF and check it out, too.

Randy, I still want to stick with flat tops (I already have them) but, I'll reduce the combustion chamber to 50cc, giving 10.7/1 static & 8.09 Dyna, I'm at 1400 ft elev and want to run pump gas.

Regarding the chamber reduction, I can angle mill the chambers 1 deg, while doing that. Is there any reason not to?

My planed deck clearance is .005 (8.200 Deck) I could go to .000, if it would give a noticeable boost.

Rory, I'm very encouraged with what your doing with the 331 and would be grateful, to be kept informed.

[frnkeore]

Joe, is this the TF manifold your talking about?

https://www.ebay.com/itm/Trick-Flow-R-Series-Carbureted-Intake-Manifolds-for-Small-Block-Ford-52400111/193227588922?epid=1239591948&hash=item2cfd43053a:g:N3sAAOSw10Fd3E9U:sc:ShippingMethodExpress!97502!US!-1

[Joe-JDC]

Yes, but it will need some plenum clean-up work to make it the best it can be.  The Parker Funnel Web was cast in Australia and is hard to find.  The knock-off Chinese copies are $180.00, but the originals were around $650.00.  Some of the Chinese copies are terrible, but the earlier ones from around 2005 were actually decent.  I bought my fake one back in 2006 for $150.00, and it is nearly as good as the original.  Joe-JDC

[70tp]

I ran across a funnelweb a while back.  I’m sure it’s one of the fake ones.  What Do you look for to tell if it’s one of the “good” ones? 

[gt350hr]

  Frank,
     You need to resign yourself to making less than 480 hp if you are going to run pump gas compression ratios. Milling the heads will also have you cutting deeper valve pockets and losing about half of what you gain. Angle milling brings along intake manifold face machining and moves the spark plug closer to the deck , something you are trying NOT to do . I am not trying to rain on your parade , just forewarn you of disappointments and obstacles your WILL be experiencing. Think about dropping the duration @ .050 by 10*s as a roller in the 250's is now too much for what you are doing. It's your deal and you don't have to listen to this " youngster" . BTW a 480 hp "Bartz" Ford F5000 engine was a Weber carbed , Boss 302 with 12.5cr My friend Ray Wolfe (rip) used to own one "in the day".
   Randy

[Joe-JDC]

I ran across a funnelweb a while back.  I’m sure it’s one of the fake ones.  What Do you look for to tell if it’s one of the “good” ones?

Look at the third picture above.  The real Funnel Web will have the Australian logo cast into the bottom of the intake.  Joe-JDC

[frnkeore]

Is there any info on the 2x4, short runner, Holley Sniper?

[frnkeore]

Randy, I met Al in 1976. I was trying to sell a dry sump pump, I had just finished. I was a prototype,  of a H&M type pump that I have. He wasn't interested in trying it but, we had a great conversation.

In the F5000 days, everyone ran 48mm IDA Webers, Lucas injection or side draft, 58mm DCOE.

I've not set a HP goal but, this is to see if the average torque can be maximized in the last 2000 rpm of the power band at the 8000 rpm level, using LSA.

Randy, where you ever involved in the Trans Am racing?

[gt350hr]

   Frank ,
      "In the day ", no. I was too busy drag racing. For the last 50 some years I have had a fascination for Ford experimental parts like were used in the Trans Am Mustangs. Some people call me an authority but I am just obsessed with the stuff. I have helped many of the "vintage T/A" guys that own the original cars with parts and advice.
    Randy

[frnkeore]

I will start with a 4v but, these are my 8v options.

The Holley 300-275, with my own top plate.

[gt350hr]

  The sniper is the way to go . Don't waste your time on the Offy or Weiand tunnel ram unless you do some cutting and welding. The Sniper has all the mods done already.