what is the bore and stroke of an 86 305?

 

nvm. Its 3.736" x 3.48".

 

In 1969 the Z/28 had a 302 with a bore of 4.000" and a stroke of 3.00" and it was putting out around 290 hp and torque. Is the 305 and 302 the same engine because I want to bore my 305 out to 4" and change the stroke to 3". Can I do that and is it worth it?

 

Search, search, and search my friend. There is more tech info on this site than you could imagine, use the search button in the future. I only say this because you have some FAQs here.

The bore and stroke of every 305 is the same.

You cannot make a 305 a 302, or vice versa. I hope you realize there is much more difference between your 305 and the SBC 302 than just bore and stroke.

There are many practical ways to give your 305 more power. If you are experienced with real mechanic work and are just ignorant about SBCs, then it's just a matter of getting some flat top pistons for your motor and throwing a nice cam in there and complimenting it with a nice intake. Whether it will net you 290 gross HP like the 302 depends on a lot of things, and it's powerband will certainly have different characteristics (which is good, because the cammed 305 will have a more streetable/practical one), but if you know what you're doing it can be done.

If all of that I just typed was way over your head, you need to dig in and do some good research about this kinda stuff before you think too much about 290 hp, because it may not take too much money to get there, but it will take a lot of know-how and knowledge. Fortunately, there's a ton of it on this site and you don't need to be an ASE certified mechanic or anything to do this stuff (though that would definitely give you a good head start on it, lol).

 

isnt a 302 a destroked 327?
coz that is what i thought, Same bore just shorter stroke.

 

Thats how GM built it. They put in a 283 crank into a 327. So they could compete in racing where the max engine was 5 liters I believe.

 

I have been trying to make my mind up over my 327ci SB, Weather to build it up as it is or turn it into a 302 screamer.
That was one awsome 5.0L!

 

I'm not to expierenced with engines but i love learning. So far I understand that a 305 and a 350 are the same block, except for the bore. They have the same stroke and use the same rods. The heads im sure are different but what else would need to be change if I would want to bore it out to 4.00".

 

to my knowledge thats way to far, a 350, 327, 302, and 383 all share the simlilar bore however, if you want to build a 302 get a 3" stroke crank and a good 350 block

 

Get your head examined before you do that, though.

 

Man, I was hoping someone would come in here and set people straight.

A 305 is not the "same" block as a 350. They're similar. Yes, same stroke (crank is SIMILAR, not identical), same rod length etc. The cylinder bores are basically metal sleeves. The 305 has them at 3.736", you can bore that out to a max of about .060" 3.796 or so, before the sleeve is too thin. You cannot bore it roughly .250" to make it a 350, you'll have punched through the bores into the water jackets and have nothing left.
You could theoretically bore it out, and slip in sleeves and have a 4" bore, but again, read Apeirons post for thoughts about that type of thing.
A 350 block in America is as common as sand in india, just go grab one of those, then start thinking about what you want to put into it.

 

Not even, there wouldn't be any metal left to support a sleeve.

 

yeah got it. Thanks. I thought 305 and 350 were the same block. Is dropping a 350 into the car difficult at all. Will It use the stock Rochester Q-Jet and will it bolt up to my trani. I have a manual.

 

YES!
Swapping in a 350 is easily the single most common modification to these cars - bar none.
It's pretty easy, there are different levels eh? Grabbing a smog dog 350 out of an old suburban and shoehorning it in, or building up a full on race 350 and dropping it in. Everything (EVERYTHING) bolts up as is, so it's like you're pulling out your 305, closing your eyes and counting to 10, then putting it back in.
**except** your dipstick will be on the drivers side, if you're using a pre-80 or so block. Not a big deal.
You'll want to put in a pilot bearing in the back of the crank if you pull a 350 from a vehicle that had an auto tranny, and put your flywheel onto it. If the new 350 doesn't have that necessary starter hole, you have to drill and tap for one. Use your 305 parts like the starter. That's pretty crucial.
But yea, aside from all that, it's easy as pie eh? (there will be snags, but no big ones)

 

ok kool. I'll think about that. Will my carb fit on it? And what will i need to do if I wanted to make it a 383 stroker.

 

if i could go back and do it all again, i would get a 355 or a 383 short block and put my old heads and intake on that, jegs has "blueprint" shortblocks for cheap

 

nice. My friend offered me 2 hundred bucks for a carbed '89 350 with 174,000 miles on it. Should I take it or will it just crap out in a few months.

 

will all of the accessories and components such as power steering and air conditioning work with the 350? Would I be able to put my Q-Jet on it. Will the engine work with all the emissions control crap that are on the 305 now?

 

I wasn't joking, not even a little bit.
So to answer you;
yes, yes, yes, and yes. If you want to put the "emissions control crap" back on that is... Not sure what New Joisey is like as far as emissions control :shurg:
I prefer my no cat boat like exhaust smell.

 

By the way, the 302 was "RATED" at 290 hp. My buddies got a '69 Z with 302 and that thing is M E A N as hell~! Severley underrated.

 

Ok kool. I'll probably buy it and re build it. And as for the 69 Z/28, that is awsome and your friend is freaking lucky.

 

What is the valve size of stock 305 heads?

 

1.84 / 1.50

 

Im getting heads that have an intake of like a little less than 2.02. Will they fit?

 

i think you should do more research to just see what opinions are available to you. And also set performance goals for what you want out of your car and engine. Do you want a 302 that revs to 8k or do you want a 383 powerhouse or is a modded 305 enough to satisfy your thrills? However in the end a well thought out plan will save you time and MONEY in the end.

Here is a article that i think will be beneficial to you, it maybe a long read however it answers the basics quite well. http://www.goingfaster.com/spo/modthel03.html

Hope this helps

Pat

 

thanks, ill check it out. And I do already plan on buying an old 350 and making it a 383. But I'm most likely not going to put it in my camaro. Or at least not this camaro.

 

It is severly under-rated, but does make about 290 hp at the rpm it was rated. Rev the snoot out of it and it makes more like 330-340 HP.

 

You could probably shop around and find something cheaper? I bought a complete 350 (2 bolt) for 24 bucks. It had bad rings (and probably could have used some machine work).

 

JOSH WITH ALL DO RESPECT.........LEARN FROM OTHER THAT HAVE ****ED UP BEFORE YOU...........DONT TEAR INTO THAT 305, DONT DUMP ANY MONEY INTO IT OTHER THAN TO KEEP IT RUNNING, AND BUY YOURSELF A 350 THAT YOU CAN THROW MONEY AT AS IT COMES.MOST LIKELY YOU WILL FIND YOURSELF WITH A TORN APART CAR THAT IS HALF DONE, AND EVENTUALLY YOUR POST ON HERE WILL BE........CAMARO PROJECT CAR FOR SALE.