building a fairly budget flat tappet 302, small turbo (gt35), gt40 heads, holley sniper efi, gt40 heads. ill be limiting the rpms, to around 5000, engine will be hooked up to a zf5 transmission with dual transfer cases. vehicle will be used in the woods and driven to the trails. im not shooting for super high horsepower numbers here, but with the dual cases and granny gear low i also dont need a ton of off the line torque.

asked comp cams, and lunati, expected there recommendations to be more similiar but there not as close as i had assumed.

comp cams recomendedan xe250h-14

Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,000-5,200
Intake Duration at 050 inch Lift: 206
Exhaust Duration at 050 inch Lift: 212
Duration at 050 inch Lift: 206 int./212 exh.
Advertised Intake Duration: 250
Advertised Exhaust Duration: 260
Advertised Duration: 250 int./260 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.462 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.474 in.
Valve Lift with Factory Rocker Arm Ratio: 0.462 int./0.474 exh.
Lobe Separation (degrees): 114
Computer-Controlled Compatible: Yes
Grind Number: FS XE250H-14

lunati recommended a more radical


Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,500-5,000
Intake Duration at 050 inch Lift: 218
Exhaust Duration at 050 inch Lift: 218
Duration at 050 inch Lift: 218 int./218 exh.
Advertised Intake Duration: 284
Advertised Exhaust Duration: 284
Advertised Duration: 284 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.488 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.488 in.
Valve Lift with Factory Rocker Arm Ratio: 0.488 int./0.488 exh.
Lobe Separation (degrees): 110

 

If those are the choices, I say the comp. I think it suits the turbo and rpm range better.

 

+1 the comp one would be more than enough.

 

+3 on the Comp.

 

thats the cam that i was more so shooting for. not sure why voodoo would recommend that cam. i had read quite a few threads about lsa with boost, and how more lsa makes an engine lazy but its better for boost, because it helps alleviate some of that back pressure created in oddball setups. but the threads were a bit dated. im not sure if that is still the knowledge. the tech for all automotive things has definitely changed in the past 5 years.

as well when i compared a stock flat tappet 302 cam to even the one that comp cams recommended, its still a sizeable upgrade.

 

Roller cam, spider, lifters out of an explorer 5.0. You would get a wider power band this way and it's an easy retrofit to the older engine.

 

i had actually looked into pulling an explorer 5.0 from the pull n save, because our pull in save has like 15 of them currently, and i was gonna pull the heads off of one anyways. but the block i have has 250k still has cross hatching, and ive had bad luck with used engines, so i was wanting to do a ground up resto on a block. i actually still have my oem 91 truck cam, and considered using it. but i think id like a little more aggressive tone at idle.

engine masters did that episode on flat tappet vs roller, and the 20 hp they gained up top isnt much worth it to me.

 

Don't pull those heads with plans to use them on a boosted 351W.

 

ill only be using those heads for a short while on the 302, likely next year if not before the winter im going to buy some aftermarket aluminum heads. most likely find some used trick flows.