M1078 engine swap complete!

[Awesomeness]

Just finished swapping out my engine, with the cracked block, on the M1078, with a 290HP replacement from an M1088. It took 2-5 of us 5 full days (~9AM-8PM), plus 4 days after work (~4:30PM-9PM). It took a lot of work, but we'll be ready for the 4th of July parade tomorrow!



It started right up, with just a couple hoses that needed to be tightened back down. One remaining issue is that there appears to be coolant dripping from the transmission cooler VERY slowly (like it leaves a drop or two after driving it). I can see the coolant drip/wetness on one of the clamps in the middle of it (had to cut the original off, and am temporarily using 5 large hose clamps), but I don't find any wetness around the 4 actual hose connections. It could be just coolant trapped between the bracket and cooler from when the upper coolant hose was leaking at initial startup, or it could be something else.

Besides the cracked block from the broken u-joint, some of the bellhousing on the transmission is broken. It's going to have to do for now, but I'll replace the transmission someday.



I also found this little gem inside the engine bellhousing. I don't know what it is. It looks like it could be a link of small chain, that has been folded over and mangled by the starter ring gear. Or perhaps the nose of the engine speed sensor (which was damaged), though it looks way too big for that.



Also, after I pressure washed the new engine, the temperature sender seems not to be working. That thing is strange anyway. You have to screw on the cable, but in the process you have to twist up the cable 100 times. Even if you start it twisted completely in the other direction, it seems to not be enough and it ends up twisted into a little pig tail. I might cut off the connector, crimp on a ring terminal, and put it on with a nut. Anybody have any better ideas?

 

[coachgeo]

Congrats to you and your friends for getting the swap done.

 

[TNriverjet]

You're going to like the 290 Hp engine.

 

[Awesomeness]

You're going to like the 290 Hp engine.

LMTV definitely shows a noticeable improvement in pickup. It seems like the transmission is waiting a lot longer to shift up now though. I don't know how that is related to the engine swap, because we didn't really do anything to the transmission. For example, I think I use to be in 7th gear by maybe 40MPH (while at cruising speed on city streets), but now it won't go to 7th until 50MPH.

 

[TNriverjet]

I wonder if it has to do with the throttle linkage adjustment (slack). The shift points can easily be influenced by this from personal experience. Also, is there a throttle position sensor that would be different based on engine HP. There may be some communication issues between that and the transmission.

 

[Awesomeness]

I wonder if it has to do with the throttle linkage adjustment (slack). The shift points can easily be influenced by this from personal experience. Also, is there a throttle position sensor that would be different based on engine HP. There may be some communication issues between that and the transmission.

Yeah, those are possibilities. I did have to adjust the throttle linkage quite a bit from where it was (moved the stop nuts ~3/4") before I could get it to contact both stop screws (relaxed, and gas pedal fully depressed) as the manual instructed.