ok fellas i have a buddy(different from another post i made(jic)) that is building a frankenmotor. i want to help him out a little by getting the opinions of people who have this engine and know all about it. i am all over ls1tech.com for my own things, but the tpi is new to me and i am unsure what kinds of things that it can take as far as cam size, the better heads out there, ability to tune, etc.

So here goes. this is what he currently has now. he doesnt have a ton of money so it is a budget build(not my style).

a 1974 350 block out of a vette(if that matters) it has 4 bolt mains and a 2 piece rear main seal. the block is refreshed with a .030 over bore.

The crank is a standard 350 crank .010 under on the rods and mains that came with that block( i believe)

rods are nothing special i am assuming just some budget 350 parts, but the pistons are forged TRW flatops, with valve reliefs 030 over,part number L2256.

from this point for bearings i am telling him that i personally suggest something along the lines of federal mogul or possibility clevite.

for a cam selection he has a brand new comp cams 262H i believe that it is a 218/224 with lift in the mid to upper .4's. he purchased the cam kit for it as well.

The heads are cast number 462 milled .010 and have a 62cc combustion chamber prior to the milling. he says they are out of a 1977 3/4 ton truck.

he currently has shorty headers and a catted ypipe for exhaust.

for an intake he has factory TPI items from an 86 305.

I am looking to help him make good reliable inexpensive horsepower. my inlfuence starts here for him i hope you guys can help me help him.

End result i would really like the car to put down about 300 rwhp at the least. i dont know how capable this setup is.

Thanks
Louie

 

anyone have any opinions on any of this at all? or even what i can possibly do with it in order to attain about 300 rwhp...?

thanks
louie

 

Sounds similar to my engine -- if he hasn't already bought it, discourage him from buying the standard XE-262H

They are awesome camshafts for carburated vehicles, but not so much for a TPI vehicle.

The powerband is too high for a stock TPI intake, and the lobe seperation angle of 110 degrees is going to cause you to have lots of idle issues (run very, very rich due to valve overlap letting fresh air past the 02 sensor)

Comp Cams, along with various other cam manufacturers make cams designed for TPI and other fuel injected vehicles -- With the engine you've described, I'd go with a Comp Cams EFI XE256H Part number 12-256-4. Make sure you get the EFI version, and not the regular one with the 110 LSA.

Its one step smaller than the XE262, and has an LSA of 112 degrees. Pretty much perfect for a stock 350 TPI with no ECM or plenum changes. Also has a powerband of 1200 - 5200, which is more than you'll get out of a stock TPI intake.

Remember, stock TPI intake is for torque, not high revving horsepower

 

also, he's not gonna see 300rwhp w/ a stock TPI intake. He'll see high rwftlbs, but not a lot of hp. - Combo sounds decent, but I'd go a little larger on the cam. Not anymore duration, but maybe a little more lift. Port the heads, bowls atleast, gasket matching the ports would be nice. look into the HSR or FIRST intake. - If the stock intake is staying, even if only for a while, port the plenum and base.