Any body know anything about the cummins 3.9, was thinking about doing a swap into a mid to late 80's 4x4 s10 for a commuter truck. This will be in the future if and when I sell my house.

 

Their just like a 5.9, just missing two cylinders.

 

Biggest thing to keep in mind about the 4BT is thte fact that it is somewhat unbalanced in its opperation.

They do shake around a bit.

~Wes~

 

How much is a bit, excessive, will the whole truck be shaking? Also are the injectors the same? would it be easy to turn up?

 

You will be lucky to be able to see out of your mirrors with a stock 4BT installed. I had one mounted on an LN8000 Ford as an aux. engine that almost shook the entire truck apart. Cummins made a factory balancer option that was available for the early models that may help

 

mine shakes at idle, especially in gear (auto), but off idle it really isn't bad at all. it is Noisy though!

You can put one in front of a 700r4. I don't know how reliability in the long term will be, but if you aren't towing, it should hold up fine.

If you turn it up, well.... something more heavy duty may be in order. I'm looking at a 4l80e with a compushift controller. the NV4500 or ZF series transmissions would be good too.

 

Do yo have any pics?

 

If you guys turn the idle up slightly, it will cure most of the really bad shakes. I used to run a dynapac roller with a 4bt in it, and you could adjust the throttle ever so slightly and it would run smooth as silk.

 

yea shoot my mirrors vibrate just a tad with my old school 12v and just a little edge on the throttle and I can see faces in the mirror behind me.

 

I put a 3.9 in a 1994 dodge 1500, and just fired it for the first time yesterday and it didn't seem to vibrate that bad. to me it was just like the 5.9. and i have any kind of harmonic balancer whats so ever.

The 5.9 and the 3.9 have the same bolt pattern for the adapter plate to the trans.