Ford Muscle Cars Tech Forum banner

ford 331 stroker

8K views 18 replies 3 participants last post by  GT350HR 
#1 ·
Hi Guys, first time poster on this forum. I live in the UK. I have just ordered a ATK ford 331 stroker short block which uses SCAT stroker kit with Nodular iron crank and Icon forged flat top pistons. I already have Victor jr. heads 60cc combustion chamber and matched victor jr single plane intake. Sitting on top will be a Holley 750 Vac. secondaries carb. I am looking for a suitable hydraulic roller camshaft, the engine is going in a Ford GT40 replica (CAV) which will be used on the street and track. I am aiming for 440 HP at the FLYWHEEL. The engine specs are as below:

Standard ford 302 roller block bored to 4.04"
Scat nodular Iron crankshaft
stroke 3.25"
Icon forged flat top piston with 4 valve relief 11cc
Victor jr heads unported. 60cc chamber.
COMP CAM short travel high revving hydraulic lifters
Victor jr intake manifold
Holley 750 vacuum secondaries
weight of car 2600lb.

For the camshaft I was thinking of COMP CAM 282hr. What do you guys think?.
 
See less See more
#2 ·
#3 ·
Either will work. If it is to see more track time than street time I would go with the 288 and if it's more street than race , use the 282 both should meke the power you are looking for with that induction system. My 331 has a tick more compression and a solid roller and makes 525 flywheel witrh the same head.
Randy
 
#4 ·
Thank guys for the input. I worked out the static compression ratio to be around 9.1 to 9.5:1 depending on the actual measured combustion chamber head volume, it is meant to be 60 cc. With this compression can I use the more aggressive 288 camshaft. With this camshaft will I need to rev beyond 6500 rpm to develop maximum power, any higher then integrity of the standard block may be in question. By the way have any of you guys used ATK engines?.
 
#7 ·
Sorry I haddn'd noticed that, I looked at the 5.0 cams and they're all for fuel injection motors, 114 CL and big lift short duration. For a carb I'd use 240 -245 @ .050 lift duration with .560 to 575 lift 110 CL. I don't know how much spring the heads come with but that can influence your decision. I personally would call Comp and get their input, you might not need as much cam as I think.:grin2:
 
#11 ·
Thanks guys. Any downside to running a retro fit small base circle cam in a roller 302 block eg height of lifetrs in the bores. I probably will have to try to raise the compression from 9.5:1 to 10.5:1. As the ATK 331 shortblock doesn't offer piston choice to raise compression, I will probably have to mill the cylinder heads to reduce chamber volume.
 
#12 ·
Or you can run the cam with the compression that you have.

I have a BB 452" mopar, 9.5 cr, iron heads , stock block (thats 850 gram TRWs) and mec flat tappet 252 @ .050 / .557 lift cam , Comp said cam was too big (duration and wanted 10 degrees less) but I had the cam. 520 hp @ 5600 543 tq @ 4500 not bad for motor you could change the cam and springs and drop in a motorhome.
 
#13 ·
I have decided to go with the retro small base circle cam. However I am a little concerned by the negative comments about the use of small base circle cams on various internet forums. The downside seems to be flex and bad harmonics at higher rpm. I do intend to rev up to 6500rpm. Has anyone used a retro cam in their track car.
 
#14 · (Edited)
Why run a retro /smal base circle in a roller cam block? In my daily driver 408W , I used the '94 roller cam 351 block specifically so i could use SUPER DURABLE factory rollers. I use the Ford Racing X cam in it and with a 150 seat pressure spring , it revs to 7,000 with ease . Again this is on the factory roller lifters. The 150lb seat pressure spring is what allows it to happen. Roller cams are too aggressive for low spring pressures but the lifters don't like more than 150 on the seat. I used a titanium retainer for a little extra safety. 25,000+ street miles , trouble free.
Randy
 
#18 ·
GT350HR, I don't have to run the retro cam, its just that I have one from my previous Ford 302 with the corresponding COMP CAM springs etc. I also have the COMP CAM short travel high revving hydraulic roller lifters and hardened pushrods. My previous ford 302 engine block cracked and the crankshaft broke. The top half of the engine and the retro camshaft is fine. I am just going to use a new roller Ford 331 short block and wondered if i could re use my retro small base circle cam.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top