Anyone with any good 2.8 info?

Well since this is a new forum for the MJ and all and I just got one, I am looking for info on the 2.8 other than the fact that it blows!

















oh and i wanted to be the first to post! :laugh3:

p.s. Someone spelled Comanche wrong!

Swap it out with a 3.4 GM motor.

http://www.lunghd.com/Tech_Articles/Project_XJ/Project_XJ.htm

Im not sure where I got this link, but I made sure to save it to favorites for future reference. Good info here about the 3.4 swap.

The 2.8l in general isn't a bad engine. IMO it was the carb that killed it,many GMs ran the same engine with MPFI and they typically hold up pretty well and have decent power.

cruiser54 said:

Swap it out with a 3.4 GM motor.

Click to expand...

Thats option number one.

dasbulliwagen said:

http://www.lunghd.com/Tech_Articles/Project_XJ/Project_XJ.htm

Im not sure where I got this link, but I made sure to save it to favorites for future reference. Good info here about the 3.4 swap.

Click to expand...

Awesome, i've heard about this thread. We are gonna crack it open and see whats knocking next week. If its too bad i'm gonna find a 3.4.

My mom had an 86 S10 with the 2.8. The engine ran great and never gave us any problems. So...find a GM version?

GM version of the 2.8 is the same. The 2.8s just weren't as robust as the 3.4s.

Darky said:

My mom had an 86 S10 with the 2.8. The engine ran great and never gave us any problems. So...find a GM version?

Click to expand...

Same engine. From what i hear the carb'd ones were bigger piles. I may just swap the intake onto a 3.4 and run it carb'd.

They say that some of the 2.8 had a defect in design of the oiling system, that was corrected on later models of the 2.8 and subsequently the 3.1 and 3.4. Gm still uses a version of this motor today.

For what it's worth....we've offered motor mounts for the 2.8 MJ for 3 years now. Only sold two pair....the second pair went to a guy who didn't know there were any other 2.8 MJs still running. You have a rare bird!! (I think!)

Brown Dog said:

For what it's worth....we've offered motor mounts for the 2.8 MJ for 3 years now. Only sold two pair....the second pair went to a guy who didn't know there were any other 2.8 MJs still running. You have a rare bird!! (I think!)

Click to expand...

I have been looking around and the 2.8 mounts work on a 3.4 which is most likely what i'll be putting in there.

Oh and be expecting a call from me come monday!

Its suprising how many 2.8l MJs are out there,I find 86's with the 2.8l all the time.

At the current cost of scrap, they are worth $55 or so

You'd be surprised how much research I'll do just to be a smartass....

www.60degreev6.com, I think, for general information.

Swap it out for an S-series drivetrain built around around the 3.1L or 3.4L V6 - it's a direct swap (bring along the electronics, the FI is also a significant improvement,) you'll bring along the THM700R4 - picking up an overidrve gear - and the NP231C transfer case - which has a wider chain than the NP231J.

Also, the 1988-up THM700R4/4L60 is a basic improvement in strength over the "baby" A904 - and the only real "fabrication" work you end up having to do is relocation and likely modification of the transmission crossmember.

If you only want to swap the engine, check the FWD donors for an unused starter motor mounting pad on the rear of the engine (as mounted.) Goodwrench Service Replacement blocks were machined with starter motor mounting pads on both sides - a dedicated FWD block will have only one starter motor mounting pad on the front of the block (as mounted) - which is the wrong side.

Either way, bring across the fuel injection setup - yeah, you can swap the intake from the 2.8L over and take the Weber 2V, but why? MPFI is a significant improvement over carburetion, you have more tuning options available (getting a GM PCM reflashed is relatively simple,) and the Weber 2V isn't very good anyhow.

For the 2.8L itself. MPFI > TBI > EFBC. But the 3.4L can be had cheap. 4.0L can be had just as cheap.

Johnnie Walker said:

For the 2.8L itself. MPFI > TBI > EFBC. But the 3.4L can be had cheap. 4.0L can be had just as cheap.

Click to expand...

True - but the 3.1L/3.4L will be an easier swap than the 4.0L - plus the THM700R4/4L60 doesn't require an electronic swap (it's hydraulically controlled.)

Yes, the AW4 will compare favourably to the 4L60 - in strength and durability, I tend to think of it as a THM350 + OD - but a good 4L60 is plenty for a stock 3.4L - it's put behind the SBC fairly often. And the overdrive range in the 4L60 will end up saving enough fuel to pay for the swap anyhow.

Flex, if the engine runs good, you might as well leave it alone.

The compared to todays setups, the engines suffered from attempts to make them smog free. The exhaust manifolds are tapped for air injectors, the carb with a couple of do hickys to prevent NOx generation during deceleration and an EGR valve that is probably clogged. The engines generated good power starting around 2800rpm and with a set of 4.56 gears really hum on the hwy.

The most irritating thing about the 2.8L that Jeep bought was that they bought old stock GM engines with carburetors. The Rochester carbs suck off-road. Anytime you get at an extreme angle pointing anywhere but up, it will spill over the fuel bowl and flood the engine. The #1 thing you can do to a 2.8L is to swap out the intake and carb with a TBI unit from a GM. That alone will improve the performance and reliability of the Jeep 2.8L for the least amount if wrenching.

One of the guys in our club swapped in a fuel injected 3.1 (3.4?) out of a Camarobird into his 2.8 powered XJ. It transformed the Jeep to the point that his engine was no longer a liability.

He was going to do the swap and then then sell it to get a 4.0 Cherokee but once he did the work and had it drivable again he didn't feel the need (he was already geared properly for his 33s).

Zuki-Ron said:

Flex, if the engine runs good, you might as well leave it alone.

The compared to todays setups, the engines suffered from attempts to make them smog free. The exhaust manifolds are tapped for air injectors, the carb with a couple of do hickys to prevent NOx generation during deceleration and an EGR valve that is probably clogged. The engines generated good power starting around 2800rpm and with a set of 4.56 gears really hum on the hwy.

The most irritating thing about the 2.8L that Jeep bought was that they bought old stock GM engines with carburetors. The Rochester carbs suck off-road. Anytime you get at an extreme angle pointing anywhere but up, it will spill over the fuel bowl and flood the engine. The #1 thing you can do to a 2.8L is to swap out the intake and carb with a TBI unit from a GM. That alone will improve the performance and reliability of the Jeep 2.8L for the least amount if wrenching.

Click to expand...

Oh it runs good, Besdies the CLACK CLACK CLACK CLACK CLACK noise it makes. My buddy and I are gonna drop the pan this week and see if we can save it. Obviously if i can spend $40 on bearings and have my buddy put them in, I'll do that and wait for it to finally give up.

cruiser54 said:

GM version of the 2.8 is the same. The 2.8s just weren't as robust as the 3.4s.

Click to expand...

FlexdXJ said:

Same engine. From what i hear the carb'd ones were bigger piles. I may just swap the intake onto a 3.4 and run it carb'd.

Click to expand...

Yeah, I know they're the same, I was just being a smart ass...