Gen1 3.0L specs are 143HP @ 5000 rpms/168 lb-ft @ 2500 rpms.

Gen2 3.0L specs are 151HP @ 5000 rpms/174 lb-ft @ 4000 rpms.

CAPS shows the original Gen1 3.0L driver side cam to be MD126155, superceded by MD145656.... which is the same cam shown for the Gen2 3.0L. Does anyone have the OE specs for the Gen2 cams?

Does anyone know how the change in the curve was accomplished to get the higher rating? The ECU is different, but weren't the intake and exhaust manifolds the same?

We have a '94 in the yard..... I'm thinking about pulling the cams to compare them to the Gen1.

Frank

Could this be the change from radius to roller followers?
From my 92-96 engine book.
Truck Cam ID,G In 19-59 258* Ex 59-19 258*
FWD Cam ID,H In- 16-66 262* Ex 56-26 262*

The Air filter setup and MAF setup are different. Not sure about the exhaust. The gen 2 3.0 has the plastic flat type air filter box with a diffent type of MAF sensor behind it. Not sure but I remember reading that this updated intake is what increased the HP.

Charlie - your specs are the same as I show for the cams. The US spec 3.0L Monteros all had roller followers..... it was the Chrysler variants that used the 3.0L engine before 1990 that made the changeover to rollers.

Justice - maybe that's the difference - along with a different fuel/ignition map, but I don't understand the jump in torque peak to 4000 rpms unless it's a slight increase at higher rpms after a major curve rise to ~2500 rpms. The trucks need the lower rpm torque with the weight and transmission gearing, so maybe the Gen2 curve is about the same as the Gen1 with a slight increase above 2500 due to better air flow. I'll take a look at the air box on the '94 here and see what gives.

Frank

Yes - the air box is the flat type..... everything else appears the same...... so I think I'll grab the heads, coil assembly and a few other goodies.

Frank

Exhaust manifolds look exactly the same. I have not taken mine out to compare. Air plenum and lower intake is the same too. Fuel rail and injectors I am pretty sure are the same. Different cruise control.

what are the titles on these engine books ???

Mitsubishi Motors
Service Manual
MONTERO
1992-1995
Volume 1
Chassis and Body

and the same for the Galant, probably for the fwd motor...

aka, the "FSM"'s...

Hey Frank, I remember reading that the minvan 3.0's went from a 2.25" exhaust manifold outlet to a 2.5" outlet for some increased power...maybe the Monty's did the same?
From Allpar, under History

Interesting - I haven't compared the Y-pipe/collector between the Gen1 and Gen2 3.0L variants, but when I cut off my collector to replace with a larger one to accept 2.5" exhaust pipe, I did find the Gen1 collector to be very restrictive.

I'm in New Orleans now but will take a look at the Gen2 Y-pipe when I return to the Atlanta yard.

Thanks,
Frank