irocznformula
01-19-2003, 12:28 PM
i might have to rebuild the tpi engine in my 89 formula and if so i need some suggestions of what to do to the engine while its apart. i know its only a 305 and thats what im gonna stick with becuase i dont feel like switching to a 350 and its a gonna have a t5 behind it so i dont need all the power of the 350. but i figured if im gonna rebuild the engine i might as well do it right the first time. im sure i want to put a better cam in it and i was considering some changes to boost compression. but how would you do it with a very limited budget, meaning no new heads and intake or anything like that. i want the engine to look stock and all but perform a little better than stock. im guessing all free mods should be done but what about the heads, pistons, and cam? what do you guys suggest?
Chuck!
01-19-2003, 01:41 PM
Well if you wanna work with your stock heads, you could get a nice bowl cleanup and a good valve job. If you dont want new pistons to increase compression, have the heads shaved .020 or .030 and that'll give you a little more. Run a FPP-1094 head gasket shim and its only .017 compressed thickness, so you'd aucutally add a little compression there too. Pistons would be the best way to go for better compression though, imo. KB hypernutechnic (sp?) or trw forged wont really break the bank and you could just get a 10.0-10.5:1 ratio piston.
Other than that you'll need the regular cam, main and rod bearings, new rings, and if you have the money have the block hot tanked and honed, the crank rebalanced.
Of couse the next person who posts will say dont spend money on a 305, lol.
I EAT T/A
01-19-2003, 01:49 PM
There is nothing wrong with a 305, just stick a lumpier cam in though, don't stick with the stock one. That just isn't fun.... :D
And like the last guy said, you can rework your stock heads. aftermarket heads are just saving you weight. You can make stock heads flow just as well.
baddest305
01-19-2003, 04:50 PM
305's can rock!!
good luck irocznformula.
11.60-1/4
1.58- 60ft.
116-mph
150shot:D
Kevin91Z
01-19-2003, 05:46 PM
If you're rebuilding the 305 that usually involves cleaning up the cylinders with a .030" overbore. That requires new pistons, so you can choose the right ones to get the compression ratio you want. Since 305 heads are all 58cc's, and you're using the stock iron ones, dont go higher than 9.5:1 compression. For a cam to work with the stock computer, the roller Compucam 2030 or 2031 are good choices.
You're still looking at a $2000-2500 price tag for a shop to do this work for you. Good luck.
AutoRoc
01-19-2003, 10:50 PM
I'd splurge for some forged pistons to get more compression (Not over 10.0:1, that would be my limit), run a normal spec/better headgasket. Call comp cams for a reccomendation on the cam. Something mild for sure to work with the TPI intake and it's "tuned" abilities. he he
Get it tuned in nicely with 92+ octane pump gas and then i'd spray the hell out of it with a beautiflully executed Nitrous Express wet kit:bow: Goodluck! Headers would be good also!
Sitting Bull
01-20-2003, 09:02 PM
The parts in my sig will work well but replace my cam with an LT1 GM cam. Should get you mighty close to 13s ;)