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Messages - 67xr7cat

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1
FE Technical Forum / Re: Cutting valve spring pockets for dual valve springs
« on: July 26, 2026, 11:40:23 AM »
Quote
Any chance you have a part # for that particular cutter? I have an assortment of the cutters for cutting down the guides for seals, but not the one for cutting the seats. Thanks!

I bought it from competition products, but you can find them elsewhere.
PVT4719   Spring Seat Cutting Tool, 1.550"/.630"
PVT4734   Valve Guide Arbor, 3/8" for seat cutting tools

Now this cutter will leave a slight step to the guide so make sure your locator has the right ID to match. 

2
FE Technical Forum / Re: Cutting valve spring pockets for dual valve springs
« on: July 26, 2026, 11:34:00 AM »
Quote from: blykins on July 26, 2026, 11:14:22 AM
Quote from: 67xr7cat on July 26, 2026, 10:24:07 AM
I'm sure Barry was just trying to be helpful, but go back and read what he wrote. To someone not well versed in all this stuff it could have been taken as a spring recommendation. This is why I asked him the question I did. He hasn't come back to clarify his post and I'm not going to read into his post as to intent.

Btw some builders like when a customer supplies the parts as then they do not have to warrantee them.  Personally I never cared if they do, but if I don't like the parts I won't use them.

Who do you build for?

Brent what is your problem?  I work for myself. Sorry if I offend you. Nothing has changed on here. Is a shame.

3
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 26, 2026, 11:25:41 AM »
Quote from: blykins on July 26, 2026, 11:12:00 AM
Widening the LSA would kill the overlap. 

In addition, overlap at seat timing really doesn’t carry as much weight as .050” overlap.
I thought I said that widening the LSA kills the overlap. Sorry I said tightening it, but that is what I meant. Yes .050" has more effect and .200" even more, but I haven't seen a cam with a lot of seat timing work as well as one with less, but your the cam guy so I'll just go back to doing my work and stop wasting time here.

4
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 26, 2026, 11:13:44 AM »
Doesn't "high performance" dictate a lumpy idle?

If we go back aways Isky ground everything on a 108 LSA and kept the intake and exhaust duration the same.  Said it gave the best performance.  Factory stuff like the 427 SFT cams had a bunch of duration and a 114 or 119 LSA.  Now take the CJ.  cam.  That lobe was used on the 351C CJ, 390GT,428CJ,429CJ and a few others.  Amazing how an OEM decided those lobes would work in all those different engines.

As I said you really have to look at value event and really really best is if you can look at the lift profile.  You can have two cams with the same LSA and duration, but be a lot different.
[/quote]

I would say that high performance doesn't always dictate a nasty idle sound.  You can have an absolute mild cam with a really good cylinder head and still make a lot of power. 

It's not just the OEM that makes universal cams, all the cam companies have been doing that for decades.   The same cam that's available for an FE is also available for a SBM or a Buick.  I'm just thankful that we've made leaps and bounds in technology since the 60's.  Unfortunately, a lot of guys still think a single pattern on a 108 is the ticket.  Actually, most people focus way too much on the LSA period.  It's like it's some magical number or something.

I had a guy email for a custom cam and said, "I don't care how you grind it, as long as it's on a 104 LSA". 

Show me that you don't know anything without telling me that you don't know anything.
[/quote]

LOL I was asking that "High performance cam" question tongue and cheek.  Next we will start using terms like "3/4 race cam". The whole LSA and duration numbers thing is just a way to dumb it down and make joe sixpack feel he knows how to pick a cam. A little knowledge certainly can be dangerous. Yes the whole industry been build around a few lobes that work decent. Comp cams Magnum or high energy are examples. I'd say really it comes down to what your goals are and how picky you are. Of course I know guys who are just happy if their old car runs down the road and don't break down. 

5
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 26, 2026, 11:04:26 AM »
Quote from: DuckRyder on July 26, 2026, 10:42:40 AM
Not withstanding Brents friends (Daniel?) findings, i agree with Ross and think that basically every one of them larger than the 8916 would probably be better on like a 113-115 and the jury is out on 8916.

The 8916 might be a nice street cruiser car/truck cam but you'd have to roll it back basically the entire advance for anything with compression and stock heads.

One of them is very very close (like within a degree) of the cam in my truck and i would not describe it as medium chop but at least i know how it would act (assuming i trust the numbers), still it would be better with more split and a wider lsa to keep the overlap in check....

Anyway. The guy i was talking to said he had e-mailed Nutter twice and not gotten a reply, so i guess answering any questions isn't in the marketing plan. In their other "pro" lines they have a wider selection so I guess there maybe "cough" "turbo" cams coming...

Custom is the answer if we want what we want...

At least they didn't off shore them, and choice is good...

Don't take this the wrong way, but you cannot say with any certainty just by looking at the information on the website and a few of them don't have all that much overlap based on the seat timing. Those are some weird cams. Some of those lobes have a lot of lift for the duration.  What Ross is doing is the same thing the OEM's been doing since the 60's which is take a long duration and then tighten up the LSA to kill the overlap ad get some manors. 

6
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 26, 2026, 10:48:16 AM »
Quote
I change LSA based on overlap after lobe choices and what I need for customer and engine intent, not quite that simple, but easiest way to quickly explain it.  It can range from 108 to 115 on most builds.  However, on this one I wanted to see Summit's big cam spread to 114 or 115.  Can't really say "can you revise your entire cam for me" but I did expect maybe an option to spread centers on a special order.

As far as being money guys, some of the best parts are coming from this company, glad to see them make a little.  Trick Flow heads are owned by Summit Racing and their quality is fantastic and availability is good, although I sure wish they'd come back with their single 4 intake. As I said, I suspect either my question didn't get to where it needed to be or it's a stocking core problem, as you spread centers, the company has to stock semi-finiahed cores to meet that need, so maybe they don't see a need for the flexibility.

I am not against a can or electric pump if a customer wants it, but also have many on the street that are on resto cars that do not want any modern externals, and we can easily make 550 HP at well under 6000 and give them good vacuum by controlling overlap.  When you do that, it makes for a very happy street car, and if the head supports it, can make some big power.

Yes I understand it is not LSA per se that you are looking, but rather it is the byproduct of the timing events.  Reason you can do what you want is that you have good heads that don't need all that overlap to make power.  Maybe if they made a cam intended as part of a package with the TFS heads be different. Regardless of what Summit provides it sure does not look like they are being run by car guys. Seems they are very focused on the money and that is not a bad thing if they make parts we can use, but you are a long way from talking to someone who has the interest you are looking for.  Years ago when Joe Lunati ran Lunati cams you could get him on the phone and he would make it happen or tell you why you were wrong.  Now Lunati doesn't even make cams. Honestly I would not be surprised if the guy who designed the cams was contracted and whoever wrote the CNC program was too and they are long gone. Probably have some guy that puts the blank in the machine and only knows how to load a program and hit the go button. Call me cynical, but its all about money. 

7
FE Technical Forum / Re: Cutting valve spring pockets for dual valve springs
« on: July 26, 2026, 10:24:07 AM »
I'm sure Barry was just trying to be helpful, but go back and read what he wrote. To someone not well versed in all this stuff it could have been taken as a spring recommendation. This is why I asked him the question I did. He hasn't come back to clarify his post and I'm not going to read into his post as to intent.

Btw some builders like when a customer supplies the parts as then they do not have to warrantee them.  Personally I never cared if they do, but if I don't like the parts I won't use them.

8
FE Technical Forum / Re: Cutting valve spring pockets for dual valve springs
« on: July 26, 2026, 01:07:45 AM »
Quote from: My427stang on July 25, 2026, 10:05:21 PM
Quote from: 67xr7cat on July 25, 2026, 03:09:36 AM
Quote from: Barry_R on July 23, 2026, 07:15:16 AM
A PAC 1220 beehive will fit nicely on that OEM step, and with a .030 shim and the appropriate retainer and keeper combination should get you around 140ish on the seat.  Not race car stuff but given the light weight of the retainer it should be perfectly fine for a street hydraulic roller deal.  I am not normally a big fan of single springs (like the beehive), but this is a case where they are the best solution for the problem and I have done many using this combination without any issues at all.
Just wondering how you can recommend a spring when the OP never mentioned the valve open lift?

I don't love 140 seat, I'd like to see 10lbs more on a hyd roller and a 45 degree seat FE intake, and maybe 10 more than that on a 30, but open pressure means much less on these hydraulic rollers especially with a lightweight retainer.  Anywhere from 390-425 will run hard. and likely could go less depending on the lobe intensity.

Not that you shouldn't know open pressure, but the PAC is a good start to fit the head, let the builder determine the next step.

"Not that you shouldn't know open pressure, but the PAC is a good start to fit the head, "
I don't agree with this.
"let the builder determine the next step."
Yeah like when he tells the customer you wasted $250 on the wrong spring...

This is what how I see it... seat pressure you just need enough so the valve does not bounce when closed. A big part of that is dictated by the cam geometry along with the mass of the valve assembly and RPM.  Over the nose has to be enough or you will have valve float or loft the valve.  Again cam geometry and valve assembly mass determine this. Also a higher valve lift means a greater valve velocity and the associated acceleration/Deceleration to deal with and usually needs more spring.  Hydraulic roller cams can have .530" lift or .660" lift.  I know better than to believe an extra .130" of lift does not matter both in needed open pressure as well as what is going to be the right spring rate.

I don't know how you figure out the right spring, but how I do it is determine what the pressures are needed for seat and full lift.  Then find a spring that has the seat pressure needed at a installed height that will work. Then multiply the spring rate by the lift and add that to the seat pressure. When that number is right I have my spring. I see builders who will over spring stuff because it is easier and if the valvetrain don't float or bounce nobody notices much, but all you are doing is wearing out parts more than is needed and you may be loosing lift from more deflection and lifter collapse too.

Now lets look at the PAC-1220 and yes it is a quality spring. It is spec'd for 155 lbs at an installed height of 1.88".  Now if the OP's cam has a lift of .530 he will have 351 lbs at full lift.  Even at it's rated .600 lift it is at 377 lbs. For under .600" lift something with a higher spring rate would be better if we use the numbers you like to see.


9
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 26, 2026, 12:29:03 AM »
Quote from: My427stang on July 25, 2026, 09:58:03 PM
Quote from: 67xr7cat on July 25, 2026, 02:18:33 PM
Whether you can run a vacuum boost depends on not just LSA. You need to look at the actual valve events and other things effect it too like how open the throttle blades are. Usually I just add in using a vacuum reserve tank or vacuum pump and be done with the issue.


Nothing wrong in anything you said, but some changes in LSA would make many of those much more universal than they are now and not requiring a band aid of vacuum pump or can, and that is looking at all the events, not just LSA.  Nothing magic there in any of the specs, but my guess is their target market doesn't know or care, just wants 100 bucks cheaper.

I would have to guess my question never got to Nutter, though, may try again for fun.  I find it pretty hard to believe that unless Summit isn't stocking cores with enough spread, that it wouldn't be just a programming change, but such is life.  I spec all my custom cams through Comp and Bullet, figured I'd do a test on a TFS 505 if they could accommodate the change, but no loss here

I don't this those running summit are car guys, more likely money guys.

Btw what LSA were you looking for? Most of those cams are on a 111 and one is on a 111.5 Really looking at them some are not that bad as far as overlap is concerned. A lot of I/E split on some too. Be interesting to see how they actually run, but as I said I'm not that interested.

As for vacuum pump being a band aid look at many modern cars and they use one, usually run off the cam. This is because they don't make enough vacuum. Keep in mind most vacuum boosters are designed to have at least 18" of vacuum. Yes you can get by with less, but I've found cars with 12"-14" vacuum can result in variation of boost. At least is something I've observed, but of course I tend to be sensitive to these types of things. Now a days I won't even do a vacuum booster when I can grab an electric booster from a Tesla and mod it to fit.  Add an electric assist steering column from a Kia soul and no more power steering pump, hoses, and hydraulics to deal with, but I'm getting off topic here.

10
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 25, 2026, 07:30:26 PM »
Quote from: DuckRyder on July 25, 2026, 06:39:30 PM
I was speaking generally about shelf cams seeming to tend toward "idle sound" seems to be less of a market for one that sounds close to stock. We got "rattler" and "thumper" i propose a new line "sleeper" ...  8)

Doesn't "high performance" dictate a lumpy idle?

If we go back aways Isky ground everything on a 108 LSA and kept the intake and exhaust duration the same.  Said it gave the best performance.  Factory stuff like the 427 SFT cams had a bunch of duration and a 114 or 119 LSA.  Now take the CJ.  cam.  That lobe was used on the 351C CJ, 390GT,428CJ,429CJ and a few others.  Amazing how an OEM decided those lobes would work in all those different engines.

As I said you really have to look at value event and really really best is if you can look at the lift profile.  You can have two cams with the same LSA and duration, but be a lot different.   

11
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 25, 2026, 07:15:18 PM »
Quote from: blykins on July 25, 2026, 06:24:36 PM
Quote from: 67xr7cat on July 25, 2026, 02:18:33 PM
Another interesting quote:
"Lobe intensity is aggressive without being hard on the valvetrain, which is specifically designed for stability at high-RPM with modern Beehive and lightweight small-diameter dual-springs"

Good buddy of mine with a Cam Doctor put one of the Summit cams on it.  He said the intake side of the ramp is soft while it slams the valve down hard on the other side. 

Some guy is gonna put one of these in a factory headed/valved FE and tear some stuff up.

Not surprising.  Guess they figure can get away with it using light weight valve springs and a high seat pressure.  Seem to recall was a famous cam designer who used to slam the valve down too.  Don't see it as a good way with that foot long valve stem on the FE.  All I can say is it has cheap and available going for it. One thing I know for certain is I'm not going to be the guinea pig lol

12
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 25, 2026, 02:18:33 PM »
Well went and looked on the Summit page.  Why the .582 lift across the board. It says so right in the ad and is about what I suspected which is spring selection

"Lift is set for compatibility with most aftermarket heads or modified factory heads."
"Most have additional lift so modern beehive or small diameter dual springs"
"specifically designed for stability at high-RPM with modern Beehive and lightweight small-diameter dual-springs"

As for LSA they are not all on 110. Depending on the cam it varies from 108.5 to 111.5 and some between 4-5 degrees advance cut in.  Whether you can run a vacuum boost depends on not just LSA. You need to look at the actual valve events and other things effect it too like how open the throttle blades are. Usually I just add in using a vacuum reserve tank or vacuum pump and be done with the issue.

Another interesting quote:
"Lobe intensity is aggressive without being hard on the valvetrain, which is specifically designed for stability at high-RPM with modern Beehive and lightweight small-diameter dual-springs"

I think the best one is this:
"It's highly recommended the car be run down the strip before making any changes to the cam advance"

I will say at the price they are selling them it is cheap and you would have to try it and then you will know. Just keep in mind an off the shelf cam rarely is gong to be a perfect match for an application as it has to cover varied configurations. That said for many who have a budget they work "well enough".  Just like Joe Sherman used to say the intake manifold is there to hold up the carb, can say the cam is there to move the valves.  I've seem enough engines over the years with off the shelf and custom cams and it's a crap shoot. A custom cam is about the only way to go if your are racing to win, but street or street/strip depends on what is important to you.  In my experience having a combination where all the pieces work together is more important. No custom cam can fix a screwed up combination (maybe can try to crutch it up, but won't fix it). 




13
Non-FE Discussion Forum / Re: Electric A/C
« on: July 25, 2026, 03:57:32 AM »
This guy explains the problem with the 12 volt electric A/C compressors being sold. He starts out a bit slow, but does get around to explaining why they just are not a good choice at around the 2:20 mark.  Keep in mind the one's on electric cars usually run at upwards of 400 volts. As the volts go up the current goes down for the same power and is much easier to get to the power level needed without too high of an amp draw.  Stick with the belt driven system.

https://www.youtube.com/watch?v=z2uNY5n9_Yo

14
Non-FE Discussion Forum / Re: Metal head gasket coating. Which do you use?
« on: July 25, 2026, 03:46:54 AM »
If it is an MLS head gasket it should have a rubber coating that takes care of sealing the oil and coolant. That said MLS gaskets need a fairly smooth surface finish that a lot of old stuff doesn't have from the factory. In those instances (although every MLS manufactures tell you not to coat them) copper coat does work. Back in the old days with a steel shim head gasket guys would just put a coat of silver spray paint on them and go. Copper coat really has not changes other than they updated the look of the can. You can usually find it at your local parts store.

15
FE Technical Forum / Re: Those "new" summit fe HYD roller cams.
« on: July 25, 2026, 03:31:45 AM »
Quote from: pbf777 on May 01, 2026, 11:26:19 AM
   
Quote from: DuckRyder on April 30, 2026, 02:37:04 PM
. . . . . . asking for an explanation of the anomalies including My Gassers cam card not matching the one for the same cam on SummitRacing.com.
 

    I'm not looking at the specific instance at hand, but having a camshaft "as measured" not matching the sales literature wouldn't be anything new!  Now, hopefully somewhat close would be nice, but some deviation often is exhibited because that lobe was originally profiled for a different engine make, most often of a different lifter face (flat-tappet) or roller-wheel presentation which has an effect.   ;)

    If measuring at the valve, then there are many other possible aspects that may be unique to different engine valvetrain iterations which may influence the outcome also.   :-\

    Scott.

Well anything new cam wise or for that matter available and in stock for the FE these days is noteworthy even if its not so good (and in this specific case I don't know if it is good or bad). I've noticed the options on cams and related parts has been consolidated down quite a bit especially on the street, street/strip stuff.  This seems to be a big trend especially with Comp cams (as well as keep raising their prices). They have either discontinued or made "Currently not available" a lot of springs, in particular stuff that is designed for FT cams.

I'd say the market is moving away from FT cams in favor of roller cams and in general trying to reduce the number of different parts like springs and associated hardware. I can see in the case of those Summit cams if they all have the same lift provided you don't end up with a hard to control lift profile because it really needs more lift then you can probably figure out a way to have one valve spring package that works for all. 


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