Can i bore and stroke my 2.8 into a 3.4.
2.8 = 3.5 bore and 2.99 stroke
3.1 = 3.5 bore and 3.31 stroke
3.4 = 3.62 bore and 3.31 stroke

is this possible and will it affect my PCM also what type of cam would work with the PCM and still be emmision legal? Thanks

-William

 

Too much to bore, and it's probably cheaper to buy the HT 3.4 GM crate engine which is meant to replace the 2.8.

http://www.gmgoodwrench.com/crate_en...istv6_ht.shtml

 

okay, so if i do decide to do that then what do i have to change ( pcm,wiring harness, fuel injection, etc. ) and how much is it going to cost, roughley? I have about 2,000.00 total, to spend on the entire project.

 

Hey look, something in Advanced tech that I can speak with some authority on!

If I remember right, the HT3.4 is designed for auto trans usage only. There's no clutch boss on the block.

You CAN bore/stroke a 2.8L motor to the 91mm bore that a 3.4L requires. It's been done, but there are several reasons not to do it.

As OldSS said, you'll get some really thin cylinder walls which WON'T stand up to high compression or boost for long.

There are crank differences in the older/newer V6-60 motors, mainly pertaining to how well oil makes it to the bearings. It's much better to have a later crank (87+) and an early one.

Here's some information that could be useful to get your answers.

What year 2.8L is your core? HO660 (F-body, Fiero, Citation X series) or truck block/heads?

If you're going NA, how much compression do you want to run? What redline are you looking for?

In a 2,000 budget you'll probably be running your existing carb/injection system. Need to know what car this came out of.

I'm assuming we are talking about a RWD V6-60. If it's in a FWD car, RWD 3.4L block can be converted to FWD by drilling starter holes and removing material on the opposite side.

Finally, when all is said and done, would it have just been cheaper to put a V8 in your vehicle?

EDIT: I just looked at your sig, I'm assuming the motor is coming out of that car, correct?

 

Yes it is this car that im pulling the motor, but since the time i have posted it i have decided to bore it to 3.53 ( 30 over ) and install 3.1 pistons and a 3.1 crank ( 3.31 stroke ) and hope to get --> 9.0:1 and be done with it. And maybe get a msd ignition and flowmaster and that is about it. But any info on me doing this is needed, cause i am new at buliding motors. Thanks

-William

 

You'd save yourself some work by getting a used or rebuilt 3.4L shortblock from a 93-95 Fbody. I *believe* the T-5 in 3rd gens and 4th gens are the same. Check before you buy though.

Your heads will bolt on, just clean up the ports a little bit while they are off. Gen I 2.8L heads should give ~9.25:1 compression on a stock deck height 3.4L block using a standard thickness head gasket. Using your existing heads also allows you to keep your existing EFI system. Buy some 18# injectors though.

You won't make huge power, but more than you did. You'll probably have a little money left over as well. You can build from there.

 

You can get a rebuilt 95' 3.4L long block (put together heads to crank) from crate-engines.com for $1699, free shiping, no core charge.
The 3.1's were over $2000 from them, so I got the 3.4.
Re use the old fuel injection system with 19 lb hr injectors.

 

I have a 1982 2.8 M4, any ideas about putting a carb and the M-4 on the 1995 3.4? I should prob find a T-5 and put on it...