BidRedUgly

When I say repower, I intend to do an engine swap. I'm just undecided on which engine to swap in. Also, are there any considerations to make such as the truck computer, air compressor swap, or any other things to take into consideration? Is it a plug and play operation in other words?

Looking at repowering my 07 CHN613. Currently, it has an AC380/410. Which engine is the better choice to move into, the 427 or 460. I have 4.10 rears behind a 13 speed. I don't know the final ratio of the tyranny. Anyway, the 380/410 is underpowered for what I do, which is a mixture of light and heavier loads. I occasionally run out west into the mountains, but I'm mostly midwest 'flat land'. I need more power, but torque is nice on the hills. The 380/410 has that nice steep torque curve. As I understand it the 460 has to be revved up to 1800 to maximize torque and hp. Is the 427 a better compromise? Asking for me!

I thought it seemed like a long shot. I'm on turbo number 4 since I bought the truck. It did fine for the first 8 months, then I got the "Utah curse". Without fail, going out to Utah (3 for 3) the turbo would start pushing oil out the turbine side which would exit the turbine/exhaust coupling. Then the nozzle position sensor code would pop, boost would fizzle (15-20 lbs), and she couldn't pull herself downhill. I suspect a blowby issue, but a Mack tech told me he never heard of a turbo going before front and rear seals due to excessive crankcase pressure. So, a trip to the dyno is in order. Good times!

I currently own a 2007 chn613 that has an AC 380/410. I found a 2007 MP8 for sale. I had read that late in the 2007 build year, some CHs were fitted with egr-only MP8s. My question is this: if this is true, and the engine I found is an egr-only MP8, is it possible to swap in the 2007 MP8 in place of my AC 380? I've read numerous places that the MPs are better engines, and frankly, I'm tired of the turbo issues with my engine. Thanks for your feedback.

Sorry I took so long to reply with results. Okay. One more R&R of the EUPs later and the fuel leakage has stopped. The deck was still getting wet around the EUPs but no fuel smell anymore. Culprit? Exhaust manifold studs. I discovered a broken one causing an exhaust leak, so while repairing I pulled the others and replaced using hi-temp RTV to seal the lowers due to the partial thru-bore of the stud bore (per service bulletin). The engine is now dry as a popcorn fart! Thanks for all the help

Ok. So I got the seal kits installed on all the EUPs. As I said earlier, they were all supposedly new remans when I got the truck. I've only put on about 50,000 mi. Since April. Most of the seals removed were pretty stiff, not pliable like new ones are. Without fail, every backer plate on the rear of each EUP was wet on the inside. I'm assuming (and hoping) that means the round o-ring under the 'plug' was leaking on each one which would weep fuel around each EUP from the rear making it look like the upper bore o-ring was leaking. I won't have any results until after Christmas when I'm back out, but this is what I've found, so far. Thanks again for the suggestions.

Supposedly all these unit pumps were reman units not long before I bought the truck. It sounds like a dentist mirror and a little investigative action is the order of the day! Thanks for all the help, guys. I will let you know what I find.

They all were and still after the new O-rings, which is why I question my methods. I made sure the bores were clean before (no residue on the bore walls of any kind) I re-installed the EUPs. It took a few days, but they all started showing signs of fuel on the block. 2007 CHN613. AC380/410. Is there some trick to getting the upper O-rings to seal in the block to prevent fuel from weeping down the outside of the block? I pulled all six of mine in sequence and replaced the O-rings. When I did that, I cleaned the grooves (upper and lower) and oiled the groove and installed the O-rings making sure they weren’t twisted. I applied a thin coat of oil to the top of the bore and the O-rings and reinstalled. I used a barring tool to rotate the engine, and using new bolts, I ran them down evenly on both sides of the unit pump. Still have the same fuel leakage issue that I had before new O-rings. Thoughts?

2007 CHN613. AC380/410. Is there some trick to getting the upper O-rings to seal in the block to prevent fuel from weeping down the outside of the block? I pulled all six of mine in sequence and replaced the O-rings. When I did that, I cleaned the grooves (upper and lower) and oiled the groove and installed the O-rings making sure they weren’t twisted. I applied a thin coat of oil to the top of the bore and the O-rings and reinstalled. I used a barring tool to rotate the engine, and using new bolts, I ran them down evenly on both sides of the unit pump. Still have the same fuel leakage issue that I had before new O-rings. Thoughts?