#32pontiac

Hello all. My father and his engine buliding buddy, are going to build a 305 TPI into a stroker. Has anybody done this before, and what are the results of doing this. My dads friend claims 360 hp, but I do not know?

Fast92RS

iTrader: (2)

I seen a kit in one magazine to make a 305 into a 335 or something like that. I didnt see any results.

MARO-MAN

Do some searching on the board, there are a few guys with stroked 305's. You would be further ahead if you just built a 350. -Nick.

92RS(real slow)

yep its been done but for all that machine work, and everything you could just out a 350 in there, and believe me you will be much happier with the 350

sofakingdom

iTrader: (1)

You have a 305 TPI. It makes, what, 205 HP?

You're proposing to "stroke" it. That adds about 30 cubic inches. Do you honestly think that doing that one thing, all by itself, is going to nearly DOUBLE the power output of this motor?

It isn't.

Your dad's "buddy" is reading the ad copy off of a particular parts supplier on the Internet. They sell this "stroker" kit for like $600 or something. If you read the fine print, what they say is, you take your 305 and put this "kit" in it; you buy $1200 worth of heads; you put a GIANT roller cam in it; you put a carb on it; you put engine-stand headers on it; and ON AN ENGINE STAND, it makes 360 HP.

Which is a WHOLE DIFFERENT BALLGAME from building a TPI motor and putting it in a car. The 2 things are NOT EVEN REMOTELY comparable. If you take YOUR motor, and put that "kit" in it without doing ANYTHING else, you'll get about 225 HP at the end of it all. It's just numbers; you bump up the cubes by 29/305, or just about 10%, you get about 10% more power. ALL that other power they claimed for their "kit" motor, came from somewhere else.

As one of P.T Barnum's competitors claimed P.T had said, "there's a sucker born every minute; and two to take him".

Don't fall for it. Don't be that "sucker".

There's one guy on this board that fell for it, 335TPI I think he calls himself, and he got about 280-290 HP out of his; with all manner of other work done to it (headers, head porting, a better cam, misc tuning, etc. etc. etc.). That's about the end of the line for a 305 block using TPI. NOWHERE CLOSE to the 360 HP ad copy. And he spent WAY too much money doing it, as he himself will be the first to tell you; he writes that he wouldn't do it over, knowing what he knows now.

If you want to "rebuild" your 305 to make more power, the best thing to buy is a "bore kit", to increase the block's bore to 4". Meanwhile, there's all sorts of other things that you need to do to the CAR, that will make what you have NOW run better, and without which no motor in the world will reach its full potential. Headers, full exhaust, and GEARS AND CONVERTER are at the top of the list. Note that ALL of those things will transfer right over to any other motor, and will make any motor produce better results.

zz4monte

The 305 stroker is just a .30 bore with a 400 crank(3.750). It really is not worth it. Alot of guys have done this just to be different though. Your going to need to do things like run a way bigger cam,high flow intake and runners , headers and exhaust and a better set of heads to get 360hp.Yes the motor will have more cubes but it mostly comes from the stroke.The bore will still be small.If you take a 350 block and put the 3.750 crank in it you get a 383 stroker which would probably cost you the same amount of money and make alot more power.Plus like some guys say the tpi will seriously hold you back in the top end if you don't modify it. You will get more from basic bolt ons then just stroking the motor.I think 290-330hp would be alot more resonable goal.Get all the parts like headers,exhaust,aftermarket intake and some better heads and a cam like mine or similar (zz4 cam) and you should make 300hp if you can make the stock TPI breath better.But think of it this way for the same amount of money or close to it you could gain 50 more cubes or 78 totally more cubes if you went from a 305 to a 383.Your goals would get that much easier to reach with the bigger motor.

Shagwell

I agree, but I don't (that really makes sense, huh?)

The 335 is a good engine, but not a good performance engine. Stroke doesn't do near as much for air/fuel intake as bore. The more air/fuel you make it burn, the more power you make. That's why pro stock motors are humoginous bore. Larger bore takes more advantage of better heads. - That stated, the small bore, larger stroke can be more efficient. The smaller bore doesn't use as much air/fuel, therefore is more fuel efficient.
I'm putting a eaton blown 305 TPI into my 4x4 burban. Not a performance app, but efficient torque motor. I may stroke it to 335. The machine work required is not really any different than the machine work required to build a 383. +030 bore and clearance for the cranks & rods. The clearancing is slightly more, because the smaller bore has more material near the crank & rods.

One way or the other, a decent cam will make A LOT more of a difference than the stroke. - Just remember this; "You build the bottom end to stay together, the top end makes your horsepower."

#32pontiac

I know he is going to the roller lifters/cam, and bigger injectors. But as for the exact specs of the motor, I do not know. I tried to convince him of having my 350 TPI out of my 88 GTA. But he is all for this idea. Thanks for your replys