4.3 60šV6????

[Scott_68B]

Ran across this message on the MG Experience site today...anyone ever hear of the crankshafts this guy is talking about?

Whole thread is here:

http://www.mgexperience.net/phorum/read.php?40,667477

For your info. There are 4 cranshafts available from GM located in at the GM wearhouse which will convert the 3.4 to a 4.3 60 degree the prize is really reasonable $751 if you want stump puller power this is the one for you. It will replace the stock crank and some minor work done to the block.

-- Scott

[Joseph Upson]

There is a typo in there somewhere, I highly doubt there is enough room to stroke or bore a 3.4 L to 4.3L specs and it actually work long enough to drive around the block. The 3.4 will not clear the stock 3.5L crank without clearance work let alone additional stroking of that crank. The 3.9L is the closest to the 4" bore that's needed and it would probably be a serious compromise to bore it to that diameter so don't even think about boring the 3.4 block to 4".

They probably have some specs between the two engines mixed up.

[3100 MPFI]

or MAYBE..... He typed 4.3 when he meant to type 3.4?

Damn dyslexia.

[geoffinbc]

No they don't exist. The information is completely false. I don't think you could even stroke it that much without going through the oil pan rail or hitting the underside of the cam. You would need a 4.25" stroke. Stock stroke is 3.31" That a lot of additional stroke. Not to mention the rods would need to be shortened a lot giving a horrible rod/stroke ratio.

[CNCguy]

When I read that, I assumed that Bill G. had just misread or mistyped something.

[sharkey]

i figured it is possible with the 3900 to get to 4.3s. you need to bore the block .040" over, offset grind the crank to run the small journal rods, effectivly stroking it .250", ends up at 4.28L

[geoffinbc]

When I read that, I assumed that Bill G. had just misread or mistyped something.

Most likely the case.

[95 V6 J body]

maybe they meant a 3.8, not a 3.4? that would make a little more sense.

[Scott_68B]

Nope, he is serious about a 4.3 out of a 3.4.

http://www.mgexperience.net/phorum/read.php?40,669031

I have no interest in doing this by the way, just was very skeptical and wanted to run it past this forum.

-- Scott

[geoffinbc]

Ok well he better get some part numbers because I am still calling BS. I just don't think it is possible to add 0.940" of stroke without breaking through the oil pan rail or hitting the bottom of the cam. Both of these problems will require a modified block which does not exist.

[Superdave]

If this was possible we (the actual 60degree V6 comminuty) would have known about it years ago.

In for actual GM part numbers.

I bet he's confused with some weird stroker kit for the 3.8.. GM has a 3.8 block that can be stroked to a 5.2 V6 it's only $3800

[34blazer]

damn, a stage 2 block is $2200. a popular disp for that is 276 cid

[montess408]

i heard of a stroker kit for a 3.8 to make a 4.2 but nothing for the 3.4 i wish they would make somthing tho little bit more displacment is always a good thing

[Superdave]

i heard of a stroker kit for a 3.8 to make a 4.2 but nothing for the 3.4 i wish they would make somthing tho little bit more displacment is always a good thing

the problem is clearance.. you might be able to get away with a little increase but if you want to build a real stroker a 3500 block is the way to go. It's been clearanced for the larger rod journals.

[Ortie666]

LOL, with almost an inch of stroke added to a 3.4l your pistons would almost be coming out of the bottom of the bore.