2.5 I4 -> 2.8 V6 swap questions

[sureshot007]

I have a camaro MPFI 2.8 to replace the blow 4cyl (don't bother telling me how bad of an idea this is, I already know). It's an 86 2wd with an ax4. I assume the ax4 will mate up no problem since the 2.8 that was available in the MJ used the ax5. My question is about the clutch - can I reuse the 2.5's clutch? Also, will the steering pump on the 2.8 work just fine? Any other detail I should be concerned about? I have the wiring harness and ecu from the camaro already. I'm only worried about it running and not powering the dash or anything.

[JeepcoMJ]

You won't get any positive info on this.

 

Sell the camaro motor and buy another 4 cylinder.

 

 

But theoretically everything will function together, however inelegant.

[Geonovast]

If you must get a V6 ( :ack: ), get a 3.4 out of a Camaro.

[sureshot007]

(don't bother telling me how bad of an idea this is, I already know)

Ok, I'm going to go over this just once, because I have done it too many times today.

 

Class rules limit displacement to 3000cc's, and engine must be available from manufacturer. Now, since I want to keep it rwd (and it must stay 2wd), my only options are the amc 2.5 or gm 2.8v6. Luckily, I don't have to use the same induction method, so I can ditch the carb'd motor for a more modern MPFI setup. This allows me to use the camaro 2.8, which maks 135 hp and 165 ft*lbs, which is better than the 4cyl. This also gets me a motor that enjoys revving a little more, because I have blown up 2 4cyl already. While not a great motor, and not a great power increase, it should be an easy swap, and I can stop using that POS 2.5L. The real benefit is that there are actual performance parts for the v6 available, whereas the 4cyl has nothing useful for me.

 

And don't worry. This setup is short term. I have a 5.2 to drop in the next chassis for the 2012 season :)

[JeepcoMJ]

Those numbers look umm...ok on paper. But they're not reality.

 

 

The 4 cyl is superior. Matter of fact, the 4 cyl power band where torque and hp meet is 3200rpm. It's a much better motor for high revving, and it, unlike the 2.8, is successfully internally balanced.

[Pete M]

the Jeep 2.8 is externally balanced. The Camaro 3.4L is internally balanced. does anyone know for sure which the 2.8 camaro is?

[sureshot007]

I do, and the large crank journal 2.8 is internally balanced.

 

Oh, and if the powerband on the 4 cylinder is so great, why don't you have one? :)

[Pete M]

prob cause he's not limited to 3000cc :D

 

I can't wait til you get that 5.2 fired up.

[JeepcoMJ]

I don't have one because I have a 4.0.

 

I don't have a 2.8 because I wanted a good motor. So I put a buick 3800 in it.

 

I got a 4 cyl after the 2.8 as a dd and had no problem. Loved it for dd. Sold it because I needed the cash.

 

 

Either way. To answer your question, if you want the camaro 2.8 you will need a mj 2.8 flywheel, get it neutrally balanced, and then it will work.

 

You will need an mj 2.8 oil pan, exhayst manifolds, and y pipe plus motor mounts.

 

The camaro may not have a block mounted fuel pump. If it doesn't, and you're going with tbi or mpfi, you'll probably want a 4.0 fuel pump to throw on the 2.5 sender.

 

The 2.5 radiator will work, but you'll need either an e-fan or a mj 2.8 mech fan and shroud.

 

 

Xj 2.8 perts work too.

 

That said, you're wasting your time.

[JeepcoMJ]

If you want 3000 cc, get a 3.1 and shave the deck. Raise compression, lower cc.

[Pete M]

If you want 3000 cc, get a 3.1 and shave the deck. Raise compression, lower cc.

 

 

that's actually not a bad idea. :brows: assuming it'd be legal.

[sureshot007]

I have a 2.8, and I'm not spending more money on buying another engine for a temporary solution.

[mvusse]

If you want 3000 cc, get a 3.1 and shave the deck. Raise compression, lower cc.

 

Shaving the deck will lower the volume of the combustion chamber, increasing compression, but it does not change the displacement. Only factors affecting displacement are number of cylinders, stroke length and cylinder diameter. A 3.1l engine with a shaved deck still displaces 3.1l.