Patriot 195cc intake
64cc combustion chamber
2.02 - 1.60 valve
aluminum heads



Summit Performance Vortec heads
170cc intake
67cc combustion chamber
1.94/1.5 intake and exhaust valve


Just how big of a power difference would these two sets of heads make against each other? Wouldn't the vortecs make more low end grunt? I'm sure the patriots would better HP up top but just how much?

Also what compression ratio would a 30 over 350 with flat top pistons have with a 67cc combustion chamber? Thanks

 

The patriots would kill the vortecs hands down, they are made for power, not just an emissions model head converted with valves and springs. The vortec is good if you are not looking past 6000 RPM, but the Patriots will keep going and make all round power with a cam much bigger than the vortecs can even use.

 

i believe carcraft did an article with these two sets of heads and the patriot wasn't that far ahead. they didn't optimize the cam for the new heads tho either

 

GET AFR"s OR DART PLATNUM's! YOU WANT TO KEEP YOUR (MAX VOLUME VELOCITY) AS HI AS POSSIBLE! SO DONT GO HUGE. ITS ONLY A 350!

 

I thought these patriot heads are small with only a 195cc intake runner? Most others run a 200cc or larger? Keep in mind I will be running a Comp ***** Thumper cam which is
.500 lift with flat top pistons, headers and a good flowing intake. Don't 350's respond to more air like an LS1? I'd like for this motor to pull hard all the way to 6500 RPM's like my SS does stock.

 

unless your going stroker in the future, then stay around a 190-195 runner on a 350. you will bog and run like crap from a dig but be ok after you get it turned up.

 

Thanks, I didn't know that. I'm going to stick with the patriot heads as they are hard to beat for the money. By far the cheapest but best quality heads I've found so far.

 

id have to agree about staying in the 180-195 cc range any more than that and port velocities drop severly in the low end and cause the motor to become a pooch until high rpm`s are reached unless u want to rev it to 7500 i would NOT go over 195 on a 355

 

you can manipulate the air flow w/ the intake as well. Don't throw a vic jr on it and expect good street manners. Look into an Air gap or similar dual plane.
I ran ZZ4 heads on a flat top 350 w/ a mild clean up on them(bowl work and gasket matching) and it was around 11:1 (58cc chamber) and smallish ports(160-170_ and it was a beast of a street motor from a dig and spun all the way up to 7k, enough to move a 3700# truck and send me looking for a lot more traction that I could come up w. I moved from the zz3 intake to a vic junior and it lost a lot of low end but picked up like crazy above 5k.

in considering going w/ some 200cc or even a 210 on the next build but its a light weight truck w/ a high rpm roller cam that I hope will have big power from 4500 up on a 355 w/ a big stall and gears.

would like some input on the patriots from someone thats bought them because they are dirt cheap.