I'm thinking of putting a 4cyl. cummins in a 79 chevy shortbox 4x4. The gas motor I put in it gets really poor fuel mileage, so it don't drove much. I am still debating on leaving 3 speed auto or putting a 5 speed manual in it. I have heard with some good injectors and turbo you can push around 300 horse with them. Is that true? What kind of fuel mileage should I expect out of this engine? Any idea on how much a low miled 4cyl cummins would be? I don't know just one of my ideas so I can get rid of my car and won't have the upkeep of 2 vehicles right now. Any help would be greatly appreciated!

 

25-30mpg is common.Bout $1500-2500. check out 4btswaps.com and search ebay and your local craigslist.

 

Ok ill give it a try. Thanks for your help!

 

I'd stick with the 3-speed, it's a durable old transmission and will work well with a turbo-diesel 3.9L. Plus the price is right. Look for a turbo (4BT) with an inline pump if you want to look for more power. It may get a little over 25, but there's the physiscs of weight and aerodynamics working against you to get over 29 - 30, which would be excellent!

 

Compared to 7-8 now, that would be awesome. But will this thing have any power without sticky a lot of money in it?

 

yeah you could get it around 250-300HP easy basically the same as moding a 5.9L 12v

 

Try dovebid.com for a 4BT.

Nick

 

I wouldnt do the th-350 or th400 if i were you, there is no overdirve. Your RPMs would be screaming, which equals poor MPG, Id def. do the 5 speed.

 

I have a 79 GMC 3/4 ton 4X4 with the 4BT and 4 speed, I don't worry about power STOCK...... Ok, it might be a tad slow in the midrange, but I sure wouldn't consider turning it up to 300 Hp........ 150 Hp would be MORE than enough to get you killed in a 4X4.

26 MPG in mine.

 

Oh yea, almost forgot, since you are doing the Chevy thing, don't piece the kit together, buy a complete P30 Chevy based stepvan. With that setup, you use everything, even the air filter........and it bolts right in.

You have to trim one of the front crossmembers and dinge the under side of the hood a bit, but other than that, straight bolt in.

 

There was a good thread on 4BT swaps on DieselPlace not long ago. Search, "Looking for a Diesel car."

Nick

 

Wahts your point not trucks come from the factory making alomost double that 150 hp mark......so why not turn it up agian the power output has nothing to do with staying alive factor its the mental output from the driver behind the wheel that controls that

 

Cummins, that is true, but the main goal of most 4BT swaps is good performance with exceptional economy, and at 300 Hp from the 4BT, Economy is certainly going to suffer greatly, especially in the VE equipped variants.

If you are after power, just drop the 6BT in.

 

Not always true. In many 4WD situations, what you want is a good degree of control and having a turned-up engine could contribue to an out-of control situation when you least expect/desire it. I would say it depends upon the intended use as to turing it up or not. It's usually best to see how it performs stock, then adjust to suit your needs and taste afterwards.

 

Granted, I have no experience with VE equipped engines, but why is the mileage gonna go south if he turns up the engine? I'm sure most of us have turned ours up and have had the same or even better mileage when driven normally.