3.4 stroker questions

[86JeepXJ]

Okay, I know a 3.4 is nothing more than a stroked, and bored 2.8. I have a '93 2.8 from an S-10 that I had. Who markets all of the crap I need to turn it into a 3.4, or even bigger? What is the max displacement I can go?

TIA
Scott

[StudlyCamaro]

RE: 3.4 stroker questions

in order to use the 3.4L crank you done need anything besides the crank, and make sure that you have clearance between the block and the rod

as for boring the block.. im not sure that taking that much material off the cylinder walls is a safe idea

[donk_316]

RE: 3.4 stroker questions

Yeah it can be done and has been done alot. Mine is done that way. I think an engine outfit named Ace, Ari or something does them too.

[TurboZ24]

RE: 3.4 stroker questions

the 2.8 uses a 2.99" stroke, while the 3.1 and 3.4 use a 3.31" stroke. As for the bore, ARI overbores the 2.8 3 times the maximum recomended overbore of .040", so I really wouldn't do it. And definately wouldn't do it for any nitrous or forced induction setup. .120" is almost 1/8th" overbore. I usually only overbore enough too clean up the cylinder, usually .020".

If you really want a 3.4, go pickup a 3.4 Camaro engine (the stock 3.4 is cast different, so it's intended for that bore).

[Guest]

Re: RE: 3.4 stroker questions

the 2.8 uses a 2.99" stroke, while the 3.1 and 3.4 use a 3.31" stroke. As for the bore, ARI overbores the 2.8 3 times the maximum recomended overbore of .040", so I really wouldn't do it. And definately wouldn't do it for any nitrous or forced induction setup. .120" is almost 1/8th" overbore. I usually only overbore enough too clean up the cylinder, usually .020".

If you really want a 3.4, go pickup a 3.4 Camaro engine (the stock 3.4 is cast different, so it's intended for that bore).

Quoted for truth.

[geoffinbc]

Im not suggesting the following in any way...

But I know at least 3 builds where a person has take a 2.8L/3.1L block and bored it to a 3.4L and made it last. I do know however that they inspected the block and had it checked for any core shift before they started. The walls were a little thin for comfort but the old 660 pulled through.

But in the end it would cost far less to dig up a Camaro block and it may only need a cylinder hone and you could be good to go for 300,000kms.

[94Camaro]

Re: RE: 3.4 stroker questions

the 2.8 uses a 2.99" stroke, while the 3.1 and 3.4 use a 3.31" stroke. As for the bore, ARI overbores the 2.8 3 times the maximum recomended overbore of .040", so I really wouldn't do it. And definately wouldn't do it for any nitrous or forced induction setup. .120" is almost 1/8th" overbore. I usually only overbore enough too clean up the cylinder, usually .020".

If you really want a 3.4, go pickup a 3.4 Camaro engine (the stock 3.4 is cast different, so it's intended for that bore).

i talked to those engine builders over the phone. what they do -- is bore the block to .040 over, then they carefully go to .060..and sonic-test the block for weaknesses. if everything is good they go to .080 slowly using the sonic testing process. (least thats what they told me) to get a 2.8->3.4 you have to bore the block a full 0.114" over! thats just slightly dangerous. if you dont have the testing equipment they have, you can seriously weaken the block to where you would toss a rod through the wall of the cylinder! Even the 3.4 isnt reccomended past .060" (gm says .040" max)

the 3.4L (RWD or FWD..depending on your application), like TurboZ24 said is actually cast with a larger bore (the engine is SLIGHTLY bigger than the 2.8/3.1)

2.8/3.1 = 3.509" bore | 3.4 = 3.623" bore

you'd be better off listening to TurboZ24 - he knows his stuff.

[Scott205]

i have heard of people who bored them .60, and people with 3.5L, but it is a one time deal.. you probably won't be able to ever bore it again. So when you wear it out, toss it. Of course this assumes you don't have an issue. There are several people around that will sell you a 3.4L, do it for you, or send your engine and they will bore it to a 3.4. beyond that, people are giving 3.4L away right now, you could adapt a FWD one for pretty cheap