305 becoming a Stroker?

I have a 86 305 engine that i got for free and i am wonding if i would be able to turn it into a stroker engine. if anyone has any ideas on this please let me know.

Anything can be stroked. A 383 or 400 crank (3.75" stroke) in a 305 block will build a 335 IIRC, and you can always go bigger with offset-ground cranks and the more exotic aftermarket crankshafts. You'll have to have it balanced and you'll have to clearance the block in a few places but it can be done.


If you don't have experience with building/modifying engines I wouldn't recommend this. You'll have a lot of learning to do and it's easy to kill a motor with just one or two simple mistakes. You'll also need to upgrade everything else to support the extra airflow, i.e. exhaust, heads, cam, etc. will all probably need to be changed to get any real power out of it. It takes a few bucks to build a good stroker motor. :cool:

The thing is I dont know much about Engines yet but im just trying to get ideas of what can be done with it because i was told that a 305 could only be turned into a 347 stroker but yet no one has a 347 stroker kit for a gm. and the only stroker gm engines i know of are 383's which are upgraded from stock 350's.

Powerhouse makes a 335 stroker kit for the 305. i first saw it in on cardomain.com in a kids IROC, and from what he says his numbers are, for the price of the kit its worth it if you want to build up the 305. yea alot of people are going to tell you to say screw it and build the 350 but hey, building a 305 is something different i guess. wont handle as much power, but it'll also be cheaper. heres the link to that stroker kit Powerhouse 335 Stroker kit (http://www.enginekits.com/ek/RetailCatalog.pdf)

good luck and keep us posted as to how it goes.

the link didnt load to a website. can u give me the address.

stroking a 305 is a VERY poor decision that should ONLY be carried out by someone who knows what thier doing. By stroking a 305, the the valves will eventually hit the piston which equals :no: I'm sure someone will chime in here and give you the technical aspects of it, but unless you go thru MAJOR head work and block work, along with money, it is NOT worth it. But boring it out, on the other hand..

Boring it out to what? Wont work either, look kido i know its hard to get rid of something that ya have (god knows i did the 305 build as well) but dont put any money into the bottom end of your 305. 350s are so common now adays power per dollar you would be better off tossing the 305 and getting a 350. Hey if it runs go ahead and use the 305 and throw a new top end on her (vortec heads are my recommendation cuz of the valve size) and have fun with her till she breaks. Thing about stroking a 305 is the bore is already way to small for the stroke and increasing the stroke even further will just choke it for even more air. If your rich and have some extra cash sitting around and just wanna build a 335 just to be different hey go 4 it. But if your on a budget i say use it till she breaks and get a 350.

I'm gonna have to agree with these guys about the 305 and not building it. Its proven that unless you put a supercharger or a turbo... or 2, on a 305 that you'll make more power with a 350, you are increasing your avaliable volume by 13%. You would need a littel over 9 cylinders on your 305 to equal the volume of a 350. Your cylinder volume is 38 cubic inches while a 350 is 43.75. Multiply those numbers by 8 and you'll come up with the respective 305 and 350 numbers. What I am saying is that by moving to a 350 you have gained the entire volume of 1 of your cylinders... PLUS.... so its just that much more cost effective and rewarding to go to a 350.

yeah hoss,they right,unless you just want a quick cheap orginal engine,dont mess with a 305 if your looking for more power,which apparently you are since u wanna stroke it..loook at it this way..you got it fre...so what...the only thing you going to keep on that short block if you stroke it is the block...so what...a 350 block can be had for almost free...and i mean free..so if you going to be replacing everything else in the 305,why not just run the 350 version....seriuosly,,your getting all new crank rods and pistons for any stroker kit,,new cam regardless....and even if you keep your heads im sure theyll need work cause you wouldnt put old head son a new engine....if you want to just drive,just rebuld 305,if you want power,start with 350 platform...and actually it might be cheaper to buy a 350 block cause aeven though i havent priced the stroker kits,im willing to bet a 350 stroker kit cost less than the 305 kit ,which would offset the cost of the 350 block youll need,,,just a thought

Bad idea. Don't do it.

305s are junk because of their small bore. Adding a longer stroke to too small of a bore is just making it worse, you will gain power because of the added displacement, but it is not very effective.

To the guy that said boring a 305 as opposed to stroking it for performance reasons. You're wrong to. The small amount of added displacement you are going to get from even an .060" overbore are insignificant and you still have a small bore, ****ty engine.

Martin

Bad idea. Don't do it.

305s are junk because of their small bore. Adding a longer stroke to too small of a bore is just making it worse, you will gain power because of the added displacement, but it is not very effective.

To the guy that said boring a 305 as opposed to stroking it for performance reasons. You're wrong to. The small amount of added displacement you are going to get from even an .060" overbore are insignificant and you still have a small bore, ****ty engine.

Martin

What i said, i think he ment bore it out to the same diameter of a 350 tho and that is not possible.

What i said, i think he ment bore it out to the same diameter of a 350 tho and that is not possible.

No, I didn't mean bore it out to the size of a 350. I was simply saying that boring, used on *any* engine tends to increase performance.

No, I didn't mean bore it out to the size of a 350. I was simply saying that boring, used on *any* engine tends to increase performance.

Oh ok well anywayz not worth it.

Don't try to stroke the 305 get either a 327 or a 350 I recommend the 350

^Good luck trying to find a 327. And if you *do* find one, they will cost a fortune. Very good engines; they are basically bullet-proof.

Devilsadvocate- Even boring it out wouldn't be cost-effective?

327 and a 350 are the same blocks. Just different stroke crank and piston pin placement. The blocks use the same bore and crank journal size unless you are using a pre 68 327 block. As for the 305, only thing I would personally use a 305 for is a paper weight. Not worth even rebuilding them as you will never get the performance you want out of it. Take the money and invest it in a 350. They are plentiful and can be found very cheap.

327 and a 350 are the same blocks. Just different stroke crank and piston pin placement. The blocks use the same bore and crank journal size unless you are using a pre 68 327 block. As for the 305, only thing I would personally use a 305 for is a paper weight. Not worth even rebuilding them as you will never get the performance you want out of it. Take the money and invest it in a 350. They are plentiful and can be found very cheap.


That's what I have always though (regarding the 327/350 being the same) until my one "know it all" friend said they are different :rolleyes: What crank does the 327 use.. the 286?

^Good luck trying to find a 327. And if you *do* find one, they will cost a fortune. Very good engines; they are basically bullet-proof.

Devilsadvocate- Even boring it out wouldn't be cost-effective?

How many cubes do you possibly gain? Boreing out in terms of adding cubic inchs just isnt worth the cost and longivety of the block imo. Especially on a 305. Boring to add cubes isnt worth it until you really start hitting above 400cubic inchs and even then i think its not worth it just because of the thinning of the cylinder walls.

That's what I have always though (regarding the 327/350 being the same) until my one "know it all" friend said they are different :rolleyes: What crank does the 327 use.. the 286?
casting number for a large journal 327 is 3930809 cast and 3914681 for forged. You can also use a 307 chevy crank as it is the same stroke as a 327 and has the large journals #3941172

How many cubes do you possibly gain? Boreing out in terms of adding cubic inchs just isnt worth the cost and longivety of the block imo. Especially on a 305. Boring to add cubes isnt worth it until you really start hitting above 400cubic inchs and even then i think its not worth it just because of the thinning of the cylinder walls.

Why would it not matter if you bore your engine out to above 400cid? I also agree with you on the thinner cylinder wall thing. That is one reason why I didn't bore my 305 out is because I can imagine it wouldn't take much for the cyl. walls to blow out.

EvilZ28- What crank are those casting numbers for? And wasn't the 307 crank basically a 305 crank, as I have been told they are basically the same engine?

EvilZ28- What crank are those casting numbers for? And wasn't the 307 crank basically a 305 crank, as I have been told they are basically the same engine?[/QUOTE]
The 307 and the 305 are totally different. The bore size of the 305 is 3.740 as the bore size of a 307 is 3.875 The 305 uses a 3.48 stroke just like the 350 and the 307 uses a 3.25 stroke just like the 327. I wouldn't build either one (305 or 307) as the bore's are to small. But they both are different internally. The numbers I supplied are the crank casting numbers for a 2.45 main diameter, 2.10 rod diameter and a 3.25 stroke.

On another note, you can also build a chevy 302 out of a 350 block. They also utilize a 4.00 bore and a 2.45 diameter main. The crank is the 2.45 diameter main with a 3.00 inch stroke. The only problem is finding a 302 crank. They are very rare. But where extremely high reving motors.

The 350 has alot of potential. It is a very common block and can be found for pretty much free if you search around. They have a wide variety of different configurations you can build utilizing this block.

Why would it not matter if you bore your engine out to above 400cid? I also agree with you on the thinner cylinder wall thing. That is one reason why I didn't bore my 305 out is because I can imagine it wouldn't take much for the cyl. walls to blow out.

EvilZ28- What crank are those casting numbers for? And wasn't the 307 crank basically a 305 crank, as I have been told they are basically the same engine?

No im saying if you have a 400 block with a virgin bore of 4.125". If ya bore it out .030 that brings you to 4.155". Now that would put your total displacement out to 406cis instead of 400. Not too big a difference. Now bore it out another .030, or .060 initially, and you have a grand total of 412cis. Still not too big a difference but the cubes are starting to add up. I dont think they add up enough performance wise to just bore out a perfectly fine virgin bore when you still have tons of life left on the block.

Now lets take a 305, 3.74" bore. Do it 30 over and ya get 3.77" equaling 310cis. Another .30 for a total of .060 over. Gets you a total of 315cis. Not really a big difference with how much added displacement you get from a 400 block (2cis less) and not a big difference in displacement from stock bore size (10cis). So hey if ya have the cash and 10cis or 12cis is worth cutting the expected life span of your block into 1/3rd of what it normally would be, then go 4 it. Just not worth it in my book. And thats what im trying to get at.

EvilZ28- What crank are those casting numbers for? And wasn't the 307 crank basically a 305 crank, as I have been told they are basically the same engine?
The 307 and the 305 are totally different. The bore size of the 305 is 3.740 as the bore size of a 307 is 3.875 The 305 uses a 3.48 stroke just like the 350 and the 307 uses a 3.25 stroke just like the 327. I wouldn't build either one (305 or 307) as the bore's are to small. But they both are different internally. The numbers I supplied are the crank casting numbers for a 2.45 main diameter, 2.10 rod diameter and a 3.25 stroke.

On another note, you can also build a chevy 302 out of a 350 block. They also utilize a 4.00 bore and a 2.45 diameter main. The crank is the 2.45 diameter main with a 3.00 inch stroke. The only problem is finding a 302 crank. They are very rare. But where extremely high reving motors.

The 350 has alot of potential. It is a very common block and can be found for pretty much free if you search around. They have a wide variety of different configurations you can build utilizing this block.

There is a such thing as a 302-crank? It's not a crank from another engine?

DevilsAdvocate- Now I see what your saying :D
Now.. lets say we are talking about a 6.5 horse lawn-mower engine. Wouldn't the effects of boring it out be far greater, as it is a smaller engine and everything works on a smaller scale?

[QUOTE=85_305]There is a such thing as a 302-crank? It's not a crank from another engine?
Yes, It was offered in the 1967 through 1969 Camaro Z28
67-68 are small journal and 69 was a large journal.

Thank you for the information :)

hEY IF THE GUY WANTS TO PUT TONS OF MONEY INTO A ENGINE THATS NOT REALLY GOING TO PUT OUT THAT MUCH POWER LET HIM. iT'S YOUR WORLD! As far as stroker kits for a 305 you have to see if you have new style or old one. The new style block stroker kits are really costly. Lunati makes at kit for like 1500 buck or so. For the kinda ching you can get a nice forged 383 or 396 kit. As far as 327's in SEPA you can go to like 6 junkyards and get them by the truck full. I think they only cost like 100-200 dollars. Good luck in what ever you do.

What heads are you gonna use for any of these 305 combos. Stock? World S/R 305's?