matt_82transam

I have a big dilema. I have an 82 trans am with a 305 cfi. It has a lot of kms. so I was just going to clean everything and bore it down 0.30 over. However, when I talked to one specialist, he said id have to go on and replace other things to go along with the boring like replace the bearings, new pistons and that type of stuff. I was wondering what the total costs for this job were sitting around. Is it worth transforming this engine to a 0.30 bored out one with new pistons and bearings and either way what are the possible gains. *when estimating costs keep in mind that the only labour ide be paying for is the actual boring out..everything else(not including parts) I have covered.*
this engine has 165hp stock.
Please reply soon, thanks.

91Bird305

I would say just Mild and thats just for learning experince.

Don't waste ur time and money on that engine. Buy the time u add up all the parts and **** u would have to replace to run 13's (and that is not including all the money into the suspension, rear end and tranny). Then u could have bought a crate engine and have a sh*t load more potential from that 350 (or higher). Besides, that CFI is horrible. Ditch it in the long run. Not worth the troubles getting it to work well.

iroc22

If you're really interested in keeping the 305 then do it, but if not then I'd recommend outright buying a 327-350-383 something along those lines and building it up right. Rebuilding a bottom end V8 shortblock around here costs $1k

matt_82transam

your from vancouver and I'm from winnipeg, so when you say that rebuilding a 305 would cost around 1k..then it should cost about same at my part of town..and I am willing to pay around $1k. However I was wondering how much horsies i might get the rebuild..because it is being bored 0.30.
I just want a newer or rebuilt engine that will last me for about 100 000 more kms yet. And trust me i have beans in my pocket so I cant afford buying a $1599+ crate engine..but i can afford rebuilding it for $1k..but the question again is...HOW MUCH REALISTIC HORSEPOWER AM I LOOKING AT???

91Bird305

from what I have seen on here. Boring a 305 .030 over creates headaches.

How fast do u want to go anyways? And u can spend 1K on a rebuild but u can't spend an extra 566 for a brand new engine? And who said a crate engine is gonna cost only 1,566? And ur gonna have to spend more then 1K on ur car to make it move good.

matt_82transam

well im not retarded..im not looking for 13 seconds..im looking at mid or high 15's..or around 250 hp..is that realistic boring it 0.30 over.???

Berlinetta

no, you'll have to do more than bore it out. Headers and some intake work would be the first place to start if you're looking for 15's

matt_82transam

i already have headers..3inch exhaust all the way out, smogs out too. Does this help any???

JokerRS

I was playing with desk top dyno one day and just for fun I checked out how much HP a .030 bore job would add to a particular combo. Adding .030" only added a max of 3 HP to a much modified motor. Hope this answers your question.

Nitroburn

I have a 305 that I rebuilt last year. I had it bored .030. Not because I wanted to, because I had to. As far as the gain, you're not gonna notice much, if any, gain. You will, however, notice an over-all gain simply due to the fact that you rebuilt the motor.

The only extra that I did during the rebuild was replaced the stock cam with something bigger.

IMO, if you want to rebuild the 305 you have now because it has high mileage on it and you want some experience, then do it. But I would not spend the extra money to have it bored and replace the pistons just because you're looking for more power. Take the $300 you'll save in boring and pistons, and put it elsewhere into the motor for aftermaket stuff (intake and carb, cam, heads, etc...).

If you want a lot more power, then dump the 305 and buy a 350 crate engine. You'll enjoy the extra power you'll get out of having more cubes.

Good luck,
-Mike

D Stroy H8

Unfortunately they're right bro. Rebuilding the 305 properly will wind up costing you about as much as a crate. Think, you have to have it hot tanked, bored over, then get the pistons, rods, crank, etc. Don;t bother if you'd just do the boring and the pistons - that's half ***. What about a non-performance crate 350? Like a goodwrench or somethin? You can mod those to make em a more serious engine, and not break your pocket on the initial purchase.

matt_82transam

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matt_82transam

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matt_82transam

thanks for all the replys. That kinda sucks that it won't turn out like I was expecting. I thought that because the engine has high mileage, that I would rebuild it and spend about $1200 and it would be bored a little more so it would have a bit more power than stock. But isnt it better to bore it out and replace the bearings and pistons to restore compression and have the peace of mind that the motor will have a lot more miles left rather than putting all this money towards a good intake and a nice exhaust system.
***All of you know way more than me on this,,but what your saying is that leave the major things(pistons, bearings,etc) alone and spend the $1200+ that would normally go towards the rebuild on things like a good intake(manifold,polish heads) and exhaust system(3'' from collector to muffler and out). SO I guess the rebuild would restore compression and make a difference but not a dramatic one that I would immediately pick up and I should just use like additives to solve most of this internal problems???
If thats the best solution adise from getting a crate engine(not enough$) than Im all for it.
*POwer wise..the engine is an 82cfi and its 21 years old so stock hp would be 165,,but now its probably 150 due to its age..new intake manifold and polished and ported heads would im guessing give it 20hp...ultimate tbi mods..maybe 2hp..and headers(3'' exhaust throughout) maybe 35hp..and hopefully unless i missed something I should roughly get 200+ hp..right???***

Deemax

iTrader: (1)

The guys telling you an overbore with no other mods won't give you much are exactly right. You'll pick up some power 'cause everythings fresh..but realistically, what are ya adding? 3 cubes? Not gonna add much to the output. Then again...if you spend the money on other things and bolt all that extra power on a tired high mileage block, you run the risk of just blowing that up in short order...of course, you can always then swap the goodies on to the new engine you'd end up building... I built my 350 last year. Paid 200 for the core...I think about 6 or 800 more for the machine work, pistons, rings, bearings, cam...if you did the labor yourself, you're still inline with your 1K budget, and you'd have a new engine with a lot more power than a stock (but overbored) 305. If you don't have to worry about FI or computer (82 is carb, no comp, right?) you'd be in pretty good shape....could easily have 200-225HP, and a nice platform to add all the goodies on to in the future.