Guess the horsepower on a little pepped-up 390....

[63galnc]

570hp @ 6750rpm

[WConley]

I'm guessing the valvetrain will start rolling over past 6,500 rpm.  582 at 6,500 is my guess!

[blykins]

I'm guessing the valvetrain will start rolling over past 6,500 rpm.  582 at 6,500 is my guess!

Bill, I’d like to have your input on this.

From my perspective, we see SBF, LS, and late model Mopars turning 7000-7500 rpm all the time with literally factory parts.  Granted, they have lightweight valves, some even have titanium valves from the factory, etc.  I've had SBF's approaching 7000 rpm peaks with hydraulic rollers, with fairly common parts.

The purpose of this mule was to get the FE to those rpm levels with a hydraulic roller setup.  Not only would it get the FE further into this century, but it would give me yet another option to provide to my customers.  Lots of guys like rpms.  Lots of guys don't want to bother with solid flat tappet or solid roller camshafts.

In my mind, I have lighter valves than most small blocks (85 grams on both intake and exhaust), short travel lifters to help eliminate any pump-up or volumetric deficiencies, enough spring pressure, and lightened rocker arms.  Honestly, if the engine doesn’t let me yank it to over 7000 rpm without giving me trouble, because of the valvetrain, then I’m gonna be sitting here scratching my head for quite awhile.

If it won’t get there because I made a mistake on camshaft specs, head volume, etc., then that’s on me but I just don’t wanna hear the lifters give up.

In the past, I have pulled many hydraulic roller FE's to 6500.  The last 390 that I built with the Trick Flow heads just had standard travel lifters and standard weight stainless steel valves.  It peaked at 6200 and we pulled it to 6500, even though the camshaft was done.

I have high hopes for this one....

Your thoughts are welcomed, as always.

[Machspeed]

532 @ 6750 RPM

I think it will pull to 7000 RPM and possibly a little more.

[gt350hr]

   562@ 6725

[WConley]

I'm guessing the valvetrain will start rolling over past 6,500 rpm.  582 at 6,500 is my guess!

Bill, I’d like to have your input on this.

From my perspective, we see SBF, LS, and late model Mopars turning 7000-7500 rpm all the time with literally factory parts.  Granted, they have lightweight valves, some even have titanium valves from the factory, etc.  I've had SBF's approaching 7000 rpm peaks with hydraulic rollers, with fairly common parts.

The purpose of this mule was to get the FE to those rpm levels with a hydraulic roller setup.  Not only would it get the FE further into this century, but it would give me yet another option to provide to my customers.  Lots of guys like rpms.  Lots of guys don't want to bother with solid flat tappet or solid roller camshafts.

In my mind, I have lighter valves than most small blocks (85 grams on both intake and exhaust), short travel lifters to help eliminate any pump-up or volumetric deficiencies, enough spring pressure, and lightened rocker arms.  Honestly, if the engine doesn’t let me yank it to over 7000 rpm without giving me trouble, because of the valvetrain, then I’m gonna be sitting here scratching my head for quite awhile.

If it won’t get there because I made a mistake on camshaft specs, head volume, etc., then that’s on me but I just don’t wanna hear the lifters give up.

In the past, I have pulled many hydraulic roller FE's to 6500.  The last 390 that I built with the Trick Flow heads just had standard travel lifters and standard weight stainless steel valves.  It peaked at 6200 and we pulled it to 6500, even though the camshaft was done.

I have high hopes for this one....

Your thoughts are welcomed, as always.

Brent - 

My peak power rpm guess is colored by those heavy hydraulic roller lifters.  It's just a lot of mass on that side of the rocker.  Are the Trend pushrods double tapered?  That should help. 

Now to the aluminum rockers.  They are light and can handle the spring pressure but I'm wondering if they are stiff enough to keep the hydraulic roller freight train damped at those rpm.  The valves, springs, and retainers are light, which is great.  Are the springs shimmed close to bind at full lift?

Very cool experiment!  I think you can see that this is as much a stiffness problem as a mass problem.  It's just a matter of moving the resonant frequency rpm up as much as possible.  Sometimes you need to trade a bit more mass for a lot more stiffness.  Hopefully the aluminum arm will get you there.  Otherwise I think a steel rocker will pay dividends.

I'll be watching with interest!  I'm a big fan 

[blykins]

I'm guessing the valvetrain will start rolling over past 6,500 rpm.  582 at 6,500 is my guess!

Bill, I’d like to have your input on this.

From my perspective, we see SBF, LS, and late model Mopars turning 7000-7500 rpm all the time with literally factory parts.  Granted, they have lightweight valves, some even have titanium valves from the factory, etc.  I've had SBF's approaching 7000 rpm peaks with hydraulic rollers, with fairly common parts.

The purpose of this mule was to get the FE to those rpm levels with a hydraulic roller setup.  Not only would it get the FE further into this century, but it would give me yet another option to provide to my customers.  Lots of guys like rpms.  Lots of guys don't want to bother with solid flat tappet or solid roller camshafts.

In my mind, I have lighter valves than most small blocks (85 grams on both intake and exhaust), short travel lifters to help eliminate any pump-up or volumetric deficiencies, enough spring pressure, and lightened rocker arms.  Honestly, if the engine doesn’t let me yank it to over 7000 rpm without giving me trouble, because of the valvetrain, then I’m gonna be sitting here scratching my head for quite awhile.

If it won’t get there because I made a mistake on camshaft specs, head volume, etc., then that’s on me but I just don’t wanna hear the lifters give up.

In the past, I have pulled many hydraulic roller FE's to 6500.  The last 390 that I built with the Trick Flow heads just had standard travel lifters and standard weight stainless steel valves.  It peaked at 6200 and we pulled it to 6500, even though the camshaft was done.

I have high hopes for this one....

Your thoughts are welcomed, as always.

Brent - 

My peak power rpm guess is colored by those heavy hydraulic roller lifters.  It's just a lot of mass on that side of the rocker.  Are the Trend pushrods double tapered?  That should help. 

Now to the aluminum rockers.  They are light and can handle the spring pressure but I'm wondering if they are stiff enough to keep the hydraulic roller freight train damped at those rpm.  The valves, springs, and retainers are light, which is great.  Are the springs shimmed close to bind at full lift?

Very cool experiment!  I think you can see that this is as much a stiffness problem as a mass problem.  It's just a matter of moving the resonant frequency rpm up as much as possible.  Sometimes you need to trade a bit more mass for a lot more stiffness.  Hopefully the aluminum arm will get you there.  Otherwise I think a steel rocker will pay dividends.

I'll be watching with interest!  I'm a big fan 

Thanks Bill.  We'll see how it goes.

The lifters are the same lifter bodies that are used in the SBF engines and I've never had issues with pulling the rpms with them.  Only difference is the link bars. 

Trend was not able to do double tapered pushrods, even though I requested it.  Said the wall thickness was going to be too thin at the end and they weren't comfortable with it. 

Springs are setup .060" from bind.

I was looking at the dyno sheet from the TFS headed 390.  It made 540 hp @ 6250 and was still there at 6500.  That was with a factory rocker arm, same lifters, 2.190"/1.650" stainless valves, etc.  The lifter was not giving up at 6500 and my gut tells me that if I would have had enough camshaft, it would have kept on going. 

Time will tell. 

Thanks for your comments, I respect your thoughts.

[Adam Dice]

556 hp at 7050 rpm

Let it scream.

[BigBlueIron]

580 @ 6750

[Posi67]

Lot of good guesses here so mine is more of a comment than anything else and is based on zero intelligence. Nice assortment of parts although the intake may be a bit big and I'd rather have aftermarket heads with little better numbers. I'm going to say this thing will go over 7000 but power will top out around 6500. HP somewhere between 550 and 600.

[falcongeorge]

Surprised by the 114 in @107. Why such a wide lsa, are you trying to keep the vacuum in powerbrake territory?

[blykins]

Surprised by the 114 in @107. Why such a wide lsa, are you trying to keep the vacuum in powerbrake territory?

It's to control overlap. 

When you have too much valve overlap, you can basically pull the intake charge in and it doesn't get translated into power, it just goes right out the exhaust. 

There are as many flavors of hydraulic roller lobes as anything else.  Aggressive lobes can make more power if everything else is correct, but it gets tougher to control the valves/lifters at higher rpms, and in a street car, they can be noisy.  Lazy lobes are nice and quiet and easy on parts, but generally speaking, they have a lot of overlap and it gets tougher to make good vacuum. 

Just like everything else, you have to balance it and find that point of moderation that works for what you're doing. 

The camshaft lobes that I'm using are Comp's HLO lobes, which are a good balance between aggressiveness to make power and laziness to make sure that I don't lose the lifters at higher rpm. 

With a camshaft this large (259/267 @ .050" is a *very* large hydraulic roller, especially for a 390), the advertised duration is going to be high anyway.  Even if you had an aggressive lobe, advertised durations would be over 300°.  When I started looking at overlap, I had a ton.  To decrease overlap, you either tighten the intake/exhaust duration spread, or you widen the LSA.  I widened the LSA.  I still have a lot, but in my mind, it's keeping that balance. 

I had a member of my 351C forum contact me and asked for help back in the spring.  He has a '69 Mustang, running 6.30's and he said that no matter what he tried, he felt like he had hit a wall with getting any more horsepower out of his combination.  He sent me all his specs, along with a cam card from Crower, where they had ground him a solid roller.  It had a tremendous amount of overlap for his displacement, lots of duration, with a 106 or 107 LSA from what I remember.  I basically had a camshaft ground for him, with the same .050" durations, same lift, and decreased the amount of overlap by widening the LSA.  It picked up a full mph in the 1/8th mile. 

So long story longer, overlap can make or break a camshaft, and I felt I needed to tighten this one up a bit.  I would have went wider, but on a typical FE billet core, you can only go so far. 

[CaptCobrajet]

I am with Mr. Conley on the rockers.  You might be surprised at how well the mass moment inertia is on the old Ford ductile rocker.  I have just about stopped using aluminum rockers, and needle bearings, for that matter. "Bushed and Steel" is my norm these days for higher rpm control and durability.  Aluminum rockers won't break for a while, they just snap back like a superband waistband in a pair of Fruit of the Looms. 

I think it will peak power just one side or the other of 7000 rpm.  Where torque occurs will depend somewhat on the header.  I'm a little puzzled with the 114 lobe separation with a big manifold and a relatively shitty exhaust port.  (No reflection on you Brent.....N heads just have a generally shitty exhaust port without brass and serious porting)  Back several years ago,  I tested three cams in the same engine, with heads and a manifold that were borderline on too big.  A 108 was 20 hp better than a 110, and 40 hp better than a 112 .  That engine had a relatively shitty exhaust port.  Every once in a while, I can use a 112 with success with really high compression, and/or a good exhaust port and/or a really good header/collector setup.  I have never seen 113 or more work in an FE, unless it was IR, in which case I like 115-116. 

I think your combo might be soft to come along, but will have a broad powerband.  I could be surprised on the cam.......have been before.  My guess is peak torque at 4800, value of which I have no idea.  Power 540 at 7000.

Those short travel Morels will go 7500 rpm.  I set them up .008 off the bottom, cold.  That ends up about .015 preload when hot.

[blykins]

I am with Mr. Conley on the rockers.  You might be surprised at how well the mass moment inertia is on the old Ford ductile rocker.  I have just about stopped using aluminum rockers, and needle bearings, for that matter. "Bushed and Steel" is my norm these days for higher rpm control and durability.  Aluminum rockers won't break for a while, they just snap back like a superband waistband in a pair of Fruit of the Looms. 

I think it will peak power just one side or the other of 7000 rpm.  Where torque occurs will depend somewhat on the header.  I'm a little puzzled with the 114 lobe separation with a big manifold and a relatively shitty exhaust port.  (No reflection on you Brent.....N heads just have a generally shitty exhaust port without brass and serious porting)  Back several years ago,  I tested three cams in the same engine, with heads and a manifold that were borderline on too big.  A 108 was 20 hp better than a 110, and 40 hp better than a 112 .  That engine had a relatively shitty exhaust port.  Every once in a while, I can use a 112 with success with really high compression, and/or a good exhaust port and/or a really good header/collector setup.  I have never seen 113 or more work in an FE, unless it was IR, in which case I like 115-116. 

I think your combo might be soft to come along, but will have a broad powerband.  I could be surprised on the cam.......have been before.  My guess is peak torque at 4800, value of which I have no idea.  Power 540 at 7000.

Those short travel Morels will go 7500 rpm.  I set them up .008 off the bottom, cold.  That ends up about .015 preload when hot.

BP,

I had planned to use a BT MR 2x4 intake, but kept getting pushed back and back and back on delivery date.  Sooner or later I had to pull the trigger, so it got the Tunnel Wedge. 

As I mentioned on the first page, I know it's too big, but it is what it is at this point.  The port openings line up perfectly with the CJ heads, but I know it's got a ton of plenum.  We'll just have to make due.

As for the LSA stuff, I was going off of my gut based on the camshaft's overlap.  I kinda march to the beat of my own drummer with cams.  I'll just have to see how off-beat I am. 

Dec 7 will be dyno day.  If everything goes well, I'll establish a baseline and then work out a plan for what variables I wanna change for next time. 

Thanks for the input....except for the Fruit of the Loom mental image.

[CaptCobrajet]

We'll don't get a mental image of me in those Fruities.  I gave up underwear a long time ago....... bareback now, just like Tonto.

I just ran a 390 that did have one of those BT manifolds and a pair of Trick Flows that I worked on a little.  It had kind of a long duration cam, 264/270.  Against my better judgement, I put a 112 in it to try to smooth it out below 3000 rpm for street manners.  I am changing the cam now to less duration and tighter centers......this thing would be a pig until it woke up at about 4000 rpm.  I'm going back to 248/252 on a 110.  Just not enough inches to make that work, and I think the TFS heads will want 109 or 110 at the max.