For you Rover nuts.

[robertf03]

Originally posted by AgDieseler
The 3.9s can put some 500 lb-ft to the ground with an HX35, mild tuning, and no internal mods.

so then why did he replace it with a diesel?

[jerryg79]

I'm guessing he lost a bet....

[eight]

Originally posted by robertf03
so then why did he replace it with a diesel?

4bt is 3.9 liters. And weighs just as much as that 6.5.

[Graystroke]

I've read that a 4bt weighs in around 700lbs, a cummins weighs a little over 1000lbs. what does a 6.5 weigh? has to weigh more than 700lbs. for reference that 3.9 rover engine the guy took out weighs 315 pounds in long block form!
Anybody know where some 4bt's are? I'm looking for that or an Isuzu 4BD1T (also 3.9L). I've heard the 4BT's will shake your teeth out and that you have to pull over every couple hundred miles or so to tighten all the bolts back up on the truck.
I've also heard that the afore metioned only applies to heavily modified (tuned) 4BT's and that stock ones aren't that bad. Anyone know?

[bburris]

Look for a Frito-Lay or similar truck. I think most come with 4BTs.

[eight]

In high school I knew a guy that had a 6.5 with a marine pump on it and it could hang with my stroke. The marine pump was mechanical too so it would be an easy swap into something else, and they use the standard chevy bolt pattern so plenty of trannies bolt up. I have thought about putting a 6.5 in my jeep, as it's probably only 100 lbs more than the 4.2 in it. But then I've thought about putting lots of motors in it.

Here's a post from a buy that put a bunch of diesels in a YJ:

The diesel engine that you will want for a Jeep, will greatly depend on what you plan on doing with the Jeep.
It really sucks when you go through all the work of putting a diesel in your Jeep (and it is a lot of work) and you take it out the first time and you have that feeling in your stomach that this is just not what you expected. I have been there twice now.
Back in 1990 when i first built my Jeep, I installed a brand new 4 cylinder Isuzu in my stock CJ7. This engine did not have a turbo on it and was very gutless on the road. It would only do about 55 with a tail wind. Off-road it was acceptable, and it did get 20 mpg consistently.(with 31" tires and 3.54 gears)
After I got sick of that engine i replaced it with a 6.2L diesel. Off-course the 6.2 was better, but it still did not impress me. It would go faster on the road, but it still took it awhile to get there. Off-road it also did very well, and also got close to 20 mpg. (31" tires and 3.07 gears)
After that engine busted a valve, I replaced it with a 4 cylinder Perkins diesel. This is a very tall engine, so that is when i had to go SOA, just to get it to fit. This engine had some issues and I only put about 2000 miles on it before i replace it. It sucked on the road (top speed was 65) and i never tried it off-road. It did get close to 24 mpg though.(31" tires and 4.11 gears)
Next came the current 6.5L turbo diesel. IMHO, this is the best engine to ever put in a SWB Jeep. It weighs about 150 lbs more than a SBC, will so 0-60 in about 10-11 seconds, will do 100+mph, and still gets between 18-24 mpg. It has had the stock axles in it, so it has not went off-road, but I cant see any drawbacks there either.

The problem with the diesels that have already been mentioned. The mercedes and VW-hard to mate a tranny to it. The Cummins and Perkins 4 cylinder is a very heavy engine(close to 800 lbs), a much slower engine (redline 2500-3000) and does not have the hp or torque of the 6.5L diesel.

So if you are planning on only using the Jeep as an off-road vehicle a 4 cylinder diesel would be sufficient. But if you want a Jeep that will be a DD and off roader you would want a higher speed diesel, I would not go with a 4 cylinder, unless it has a turbo on it.

[BigRedFord04]

Originally posted by AgDieseler
After I extract all the torque I can from my 6.2L and build my dad's 300 hp 6.5L, it will be time to move on to something else. I'm thinking alond the lines of a 12V Cummins with 950+ lb-ft and 20mpg.

driving a diesel offroad is like running in the special olympics...even if you win, you're still retarded

[AgDieseler]

The 4BTs do vibrate quite a bit! When you think about it, it's the same HUGE connecting rods and rotating assembly as the 6BT which already vibrates a lot. Missing those two extra cylinders just makes for a motor that won't run as smoothly as the full sized version. The displacement per cylinder is so high (4.02 x 4.72) that it's no wonder why it rattles itself apart!

As far as weight goes, the 6.2/6.5 is the same weight as a BBC - around 655 lbs dry. The 4BT is around 800. The marine DB2 pump is really pretty nice. It flows about twice as much fuel as I am running now, and you have to run 18:1 or lower compression a big ass turbo with a matching intercooler in order to take advantage of it, but it's a solid recipe for 300 hp.

The plans for my dad's 6.5L with be a DS4 at 340 hp, 17.5 or 18:1, and probably a Holset turbo with a 9cm or 12cm housing plus a matching Cummins intercooler. That should give 550 lb-ft in the least. That isn't much when you take into consideration that the new 2004.5 Cummins will out 590 in stock form, but it's plenty for towing the 8000 lb Airstream. These engines are nice since you can spin them up to 4100 rpms without balancing. We balanced my motor, and it didn't shake in the least at 4000.

The guy that put the 6.5 in his YJ used a GM6 van turbo - very clean. It's really nice; here's more: http://www.thedieselpage.com/readers/fleming.htm
I wonder if he's related to anybody we know?

BTW: If a big block is called a rat motor, and small block a mouse, then I guess the 302 would be some kind of gerbil. Maybe a lemming.

[BigRedFord04]

Originally posted by AgDieseler
BTW: If a big block is called a rat motor, and small block a mouse, then I guess the 302 would be some kind of gerbil. Maybe a lemming.

wanna race?

[bburris]

Hell, I'll even race David.

[AgDieseler]

Originally posted by BigRedFord04
wanna race?

I'll run you off the road with my black smoke screen. Remember Spy Hunter?

[BigRedFord04]

yes, but for that you'd have to be IN FRONT of me....wont happen....unless you use BOTH pounds of boost, then i might be scared.....no....prolly not.

[AgDieseler]

I'll just have to settle for suffocating you through the window.

[BigRedFord04]

HAHAHAHA....you think you could keep up.....

[AgDieseler]

It sounds like it's time for another day at the redneck race track. Let's let the stopwatch quantify the embarrassment.