Best motor

[Circus Master]

I need some help with what motor to use. We are building a rock buggy for competition on the east coast. To my knowledge a 3400 is what we want to use. What would be the best year motor to use. Keep in mind horse power and torque are not that important. Durability, simplicity reliability are the big issues. Being able to adapt a stock wiring harness and computer are important.

Clayton

[3100 MPFI]

3400 (or 3100 for that matter) would be a good choice. They can be run on the older computers WITH TUNING.

A 3500 would require some extra parts. To use the older computer, you would have to replace the wiring harness on the engines, but with the 3500, you would also have to adapt a throttle body, and fuel rail, as well as the crank trigger for a DIS.

You could probably even use the older 2.8 (GEN 1) computer and run a distributor, or something, if that is what you want.

Personal experiance is with the 3100 (just a small bore 3400), and they are pretty easy to get to do what you want.

[Circus Master]

Are there any better years to start with? There is a 2002 3400 at a local junk yard with 70,000 miles on it. There is also a 2005 with 38,000 on it. But the harnesses are cut up and the computers gone. What would be my options for a harness and which is a better motor to start with?

[Superdave]

i'd grab the '05 3400 as long as it's not the equinox engine or whatever. Then grab an engine harness from a 1991-1994 V6 Cavalier/Sunbird along with the computer.

the newer motor is better to start out with, it will have the better LIM gaskets, Headgaskets, coated piston skirts and possibly better exhaust manifolds (If you are lucky).

Tuning the computer to run the engine isn't hard but for your application there are probably much easier ways since you don't need it perfect. Grab an adjustable FPR and crank the pressure down so that it dosen't flood, then use a wideband to get the AFR's in the 12.x range at WOT. If you want a chip for the computer that will run it w/o the redneck tuning there are a few people that can help you out with that.

What tranny are you planning on using?

[Circus Master]

We either want to run a power glide or a 904 because they are small and we need to put a transfer case on for 4 wheel drive. Any advice would be great. The motor will have nothing to do with the motor. We will be running a manual valve body.

Here's a link to what we are going to be doing.

http://www.pirate4x4.com/forum/showthread.php?t=576381&highlight=badlands

Here's a link to my current buggy with a Jeep 4.0L in it. That motor weights about 500 lbs and the total vehicle weight is 3300. So we are looking to loose about 500 lbs in the next buggy we can pickup a good 150 lbs with the 3400 motor.

http://www.youtube.com/watch?v=2zhfaTwP7mw

[Jeepbeater]

Clayton,

sent you a PM

John

[Piper106]

Jeep refers to the auto trans used behind the 1990's 2.5L 4 cylinder engines as a 30RH, but don't let that fool you, it is a lock-up version of the 904 TorqueFlite just with a new name.
Also recall that the Jeep 2.5L 4 cylinder has the same bell housing bolt pattern as the GM 60 deg V6.
Bottom Line, a 30RH from a 1990s 4 cylinder Cherokee or Wrangler will bolt right up to a 3100 / 3400 / 3500 V6.

Piper106

[Circus Master]

Here are a couple choices.
2005 3500 saturn vue 35,000 miles complete with computer and harness
2005 3500 not sure what car 31,000 miles
2002 3400 impala 73,000 miles

[sharkey]

the 904 would be a great choice of tranny for you. they are already 4wd, fairly small, and have a good 2.74 1st gear ratio. about the only other automatic that would bolt up to the motor and is a 4x4 is the 700r4. its a bit longer, heavier, and more rotating mass than the 904. the th200c is another choice, used in early 80s s10/blazers.

id recomend against a powerglide. they never came in a 4wd application, however im sure there are adaptors out there for it. only being a 2 speed with a 1.84 low gear would mean you need substantially lower diff gears or a lower t-case low range.

[silvergtjrad]

Here are a couple choices.
2005 3500 saturn vue 35,000 miles complete with computer and harness
2005 3500 not sure what car 31,000 miles
2002 3400 impala 73,000 miles

The saturn VUE doesnt have a 3500, its a 3.5 SOHC honda engine.

[Circus Master]

Yeah I found that out about the VUE

[Piper106]

I have read that another auto trans option would be the Aisin Warner four speed automatic overdrive that Jeep refers to as the AW4, Toyota calls the A340E. Lots these trannies available from 4WD Cherokees with the 4.0L inline six engine. Get rid of the 4.0L bell housing (it bolts on) and get an Isuzu 3.5L V6 automatic bell, and you have the 60 deg V6 (3100 / 3400) bolt pattern.

That is all I think I know.

Piper106