I would think 450 torque is a given with those flamed valve covers....
dashboard said
Apr 16, 2014
Nice numbers Chris. What's it going to go into?
"Final 350 I am working on." But not the last one?
Enganeer said
Apr 16, 2014
Going to guess at 425hp, 460 ft-lbs torque with a good carb.
67ss said
Apr 16, 2014
dashboard wrote:
Nice numbers Chris. What's it going to go into?
"Final 350 I am working on." But not the last one?
It is going into a 1965 Chevrolet pickup truck.
just last one for this year anyway but not the last one ever.
67ss said
Apr 16, 2014
Tried to build this motor like the zz430 motor gm built. This has slightly bigger cam, better intake, and comparable carb. So will see what happens.
67ss said
Apr 20, 2014
Disappointing day at the dyno. Only made 380 horse and 400 torque. I am totally baffled to say the least. To much cam or to much head I don't know. Almost wish I had not gone to the dyno and just believed.
bowtie said
Apr 21, 2014
I think it's the "port velocity" we were talking about yesterday. Over the RPM range, did it pick up or fall off more at higher RPMs? I think "too large" of a port would show itself on the lower RPMs and come into it's own at higher where the air speed through them picks up. Too large of a port doesn't help channel all that air out which affects how much air is drawn in which means the carb is under delivering based on the signal from the engine.
Short of a head swap to the other ones you were talking about (and more dyno time), maybe install it and butt dyno, then swap to 1.5 rockers and see if it butt dyno's better?
the other thing you mentioned: correction factors are different with different dynos could also come into play, though I'm sure that if Ron trusts it, it's good.
Enganeer said
Apr 21, 2014
What is the casting number of the heads?
Flattop pistons?
Piston to deck distance?, Quench height? Intake manifold misaligned or needs to be port matched?
After reading the article below, the numbers are pretty close. What rpm did you stop pulling at? The runners are big, so it going be lazy for awhile unless you really plan on winding it up.
Piston to deck distance?, Quench height? Intake manifold misaligned or needs to be port matched?
After reading the article below, the numbers are pretty close. What rpm did you stop pulling at? The runners are big, so it going be lazy for awhile unless you really plan on winding it up.
I don't remember the casting number of the heads but is it the ones in the article you linked to. Yes I know the big port will affect the low end torque though it really did not in that article but it still should make the same power at the top end. The motor is 0 decked with flat top two valve relief pistons and gasket thickness is 0.39 so it has quench. We pulled it to 6000 rpm and it was making peak power about 5700-5800 and peak torque around 4100-4200. All ports line up correctly I used a vortec style intake to match the taller port of those heads.
My latest engine project. Going to dyno it on Sunday so will have some numbers to post. Hoping to be in the 430-450 horse range and 400+ torque.
Specs:
Later model 350 4 bolt main roller block still standard bore
Gm fastburn aluminum heads with valve sping upgrade otherwise box stock
Speedpro Hyper pistons with two valve relief compression comes in about 10.2-1, balanced rotating assembly
Howards roller camshaft 225/225 525/525 on 110 LSA. Using 1.6 rockers so is actually 560 lift
Weiend air gap dual plane intake
Quick fuel 750 slayer carb
After what you did with mine, I'd say the torque will be 450+ since mine did 411 ft. lbs..
If it made 450 horse and 450 torque that would make me pretty happy.
I would think 450 torque is a given with those flamed valve covers....
Nice numbers Chris. What's it going to go into?
"Final 350 I am working on." But not the last one?
It is going into a 1965 Chevrolet pickup truck.
just last one for this year anyway but not the last one ever.
Tried to build this motor like the zz430 motor gm built. This has slightly bigger cam, better intake, and comparable carb. So will see what happens.
Disappointing day at the dyno. Only made 380 horse and 400 torque. I am totally baffled to say the least. To much cam or to much head I don't know. Almost wish I had not gone to the dyno and just believed.
I think it's the "port velocity" we were talking about yesterday. Over the RPM range, did it pick up or fall off more at higher RPMs? I think "too large" of a port would show itself on the lower RPMs and come into it's own at higher where the air speed through them picks up. Too large of a port doesn't help channel all that air out which affects how much air is drawn in which means the carb is under delivering based on the signal from the engine.
Short of a head swap to the other ones you were talking about (and more dyno time), maybe install it and butt dyno, then swap to 1.5 rockers and see if it butt dyno's better?
the other thing you mentioned: correction factors are different with different dynos could also come into play, though I'm sure that if Ron trusts it, it's good.
What is the casting number of the heads?
Flattop pistons?
Piston to deck distance?, Quench height? Intake manifold misaligned or needs to be port matched?
After reading the article below, the numbers are pretty close. What rpm did you stop pulling at? The runners are big, so it going be lazy for awhile unless you really plan on winding it up.
http://www.hotrod.com/techarticles/engine/hrdp_9902_gm_small_block_cylinder_heads/
I don't remember the casting number of the heads but is it the ones in the article you linked to. Yes I know the big port will affect the low end torque though it really did not in that article but it still should make the same power at the top end. The motor is 0 decked with flat top two valve relief pistons and gasket thickness is 0.39 so it has quench. We pulled it to 6000 rpm and it was making peak power about 5700-5800 and peak torque around 4100-4200. All ports line up correctly I used a vortec style intake to match the taller port of those heads.
It should match this very closely http://paceperformance.com/i-5146502-gmp-12496430-1-gm-zz430-chevy-350cid-430hp-crate-engine.html and the motor made its peak numbers close to what there chart shows. I think I am going to take it to a diffferent dyno and check it again. But I am going to check compression on all cylinders and degree the cam one more time to make sure of things.