How far can one bore a 305 chevy.

I have a 305 and an old 283 sittin out in the garage. The 283 has some pretty tall pistons. My question is will a 305 accommodate a bore of 3.857 without runnin your cylinder walls too thin? Iv done the math. The displacement would come out to 328ci. Basically a stroked 283..

 

you would have to bore it a bit over 1/8".....forget it and build the 283

i assume you mean 3.875 and not 3.857

 

can't take it ..which is why 305s are throwaway

 

305 is a POS engine 283 327 350 will do you well

 

283 is the way to go!

 

I'm with the other guys saying not worth the rebuild when a 283/327 core is still $200

 

305's have 3.48 stroke and 283's have a 3.00 stroke so the pistons of a 283 will be 0.240 too tall.

If you could bore it ?? a 307 piston would be closer because of the 3.25 stroke but you would still need to lose 0.120 in compression height.

You could fly-cut the heads but this would cost more than a 350 block which would take the 305 crank / rods with 350 pistons

Re-block it

 

We run 305 Chevy powered sprint cars around this area with stock blocks and they can be bored .060" over, and turn 8300 RPM's. Hardly a POS engine.

 

I saw one a while back,, 3 3/4 stroke on a 305 around 335 CID. A local machine shop/Race shop built the unit for a circle track engine. It runs strong.

 

If I had my choice I would build the 283. Good motors and they make my fav SBC which is a 301 (60's race engine) what do you mean by the 283 has tall pistons? Are they aftermarket? the 305's got a bad rap because they were underpowered and bad about the cams going flat all the time in mid 80's cars. This however is easily fixed when building a new motor. but We ran alot of them in simple streetrod builds all through the late 80's and 90's (mostly because they were cheap and relieable)

 

A 305 Chevy has a stock bore of 3.736 so even at .060 over your only at 3.796 so NO.

 

I beleive he was referring to pin placement effctively placing piston higher if put on a 305 rod/crank combination.....
A 305 is a good long lasting little motor actually and due to a small bore ,should end up a [thicker sleeve]- for better cooling and stability.....
the #450 cast 305 4bbl heads are a great add on for 350's for more compression....

A friend who was a machinist used to do 305 engines, bored to use 350 pistons and they were then throwaways if a rebuild was necessary after that......
I was under the impression the sleeves were both the same =outer dimension= on a 350 and 305???

 

Hey Chevyman, I dream the same stuff! But, if they don't make a piston, that will work with your dream, regaurding pin height, then you can't do it.
My latest is a 305 block with a 3.25 stroke = 289ci chevy. (334ci 5.7 rod pistons will work with 6.0in rods and machine .020 off of the piston top.

 

JE Pistons can custom make anything you want if you're willing to add the extra expence.

 

Thats so true...ditch em both and build a basic 355.....parts are cheaper

 

I like 283"s

 

If you bore it 0.75" oversize you won't have to worry about it.

 

what cha gonna put the motor in? you can pretty much come up with any combo you want if you have enough $$$$$ and a smart enough machenist. and don't let any body tell ya 305s are a pos. got one in my 59 elky,i drive it hard ,and it has a W H O L E LOT of miles on it. but the 305/350/327/283 thing has been beat to death on here before. you choise, grasshopper.

 

So no what? I was merely pointing out that 305's are used in high performance applications and that they are not a POS engine. As far as how much they can be bored, I do not know.

 

Fwiw, imho, the old "trip over it for free", 307 engine is way better than the 305...

It has a 3.875" bore and a 3.25" stroke so is the best of the 283 and 327 ...

As for me, I'd take a round-bottomed 283, (or a good 307), and bore it .125" and make a 301, then you got something that can be hopped enough to go big engine hunting..

Somewhere there is a thread with a vid. in it that has an old style hopped up Z-28 type engine on a dyno that was producing something like 470 hp up top with only an old style solid lifter flat tappet cam..

I have everything but a set of cheap pistons to make another junk301 that this time will be shifted above 8,000 rpm to the tune of at least 400 hp.

I want the "ricers" to know what SBC high rpm power is all about is all.

pdq67

 

I was merely answering the original poster question in saying that the 305 has a stock bore of 3.736 so "NO" at .060 over (even .070 over) it cannot be bored out to 3.875.

 

Yea, and i was bringing up the point of.......you can dream up SBC strokes and bores, but if pistons aren't readilly available, then it's not feasable. I haven't ever had special pistons made, but I have been told, by A manufacture, that they will not build unless buy 500 pieces. Either way that is called feasability!
I'd like to have a dollar for every 305 thats been thrown away by closed minded, what somebody will think, what my brother in law says, had a bad one, read something bad about them, bla bla people.

 

I am running a 305 in my '28' and love the little motor...I bought it at swap for $50 and it came with an edel intake and carb....I bought a rebuild kit..gaskets and bearing ect ect...and found a set of stock diameter flat top pistons on ebay for $85 with rings...I drive the car on the street around people and there children...no need for 1100 HP, but the 290HP/310FT TQ it puts out is just fine with the 4 speed it has and it runs out real nice on the highway...and ya its reliable as hell.

 

^^^^^^^^^^^^^^^^amen

 

I freshened up a 305 (freebe low mile) with flat tops and 350 cam for my '29 coupe 23 years ago. It ran great and I loved it.

 

If one is shadetreeing it, if one got it free, then build anything one wants. Having BTDT for many years, no way a 283"/301"/305"/307" holds its own out on the street. Inches are basically free horsepower and torque rules.

Engine shops hate to see the small-small blocks and unrealistic expectations coming. All the labor costs are going to be the same as to build a 350"/383"/400", smaller-bore pistons actually cost more than for a 350" and they're always going to be down 50-100 horsepower.

jack vines

 

And since all SBC's all look the same (except the for 400 ) people won't know it's not a 350.

 

Ross will make any pistons you want from forged blanks i have them in my 307 with a 400 crank,so dream up anything you want just don't mess up the pin height cause they are sorta pricey, having a motor you did yourself and no one else has is worth more than gold to me!

 

thx skidro69 i have a 305 and that 289 sounds interesting going to build it this winter and been wondering about builds trying to think of something differant

 

confuse everyone run a 383 crank 400 rods and stock 5.0 vortec pistons