atblis
04-18-2008, 08:04 AM
Background
Jeep 4.2 with 4.0 head. The motor is cobbled together. Basically, I had an okay running 4.2, that needed a crank (PO stripped the fly wheel bolts). Put a new crank in it. Basically just took a crank out of another 4.2, polished it, mic'd it, and than threw it in (it was at the small end of spec for standard bearings). At the same time, I went ahead and did a 4.0 head swap. It has a different cam, new lifters, new pushrods,etc. The block was not hot tanked, I just used several cans of brake cleaner and a toothbrush.
So what's interesting is that before I put the new crank in I had this pretty sharp slap/knock. Only audible at idle. After the partial rebuild, the exact same knock was still there. The only part that didn't get changed/replaced were the pistons and rods.
The other day while wheeling, my electric fan croaked. I ended up overheating the jeep pretty good getting it off the trail. Basically I ran it pretty hot for a good while (maybe an hour). Boiled it over twice.
After over heating it.
The knock is gone!
The motor sounds fine, and seems to run just fine.
My coolant looks like it's full of rust now. Curious.
My oil pressure seems lower. Not troubling low, just a bit lower.
Anybody got any ideas. Did I cook out a oil passage blockage of some sort?
________
One vaporizer reviews (http://vaporizer.org/reviews/vapir-air-one/)
Jeep 4.2 with 4.0 head. The motor is cobbled together. Basically, I had an okay running 4.2, that needed a crank (PO stripped the fly wheel bolts). Put a new crank in it. Basically just took a crank out of another 4.2, polished it, mic'd it, and than threw it in (it was at the small end of spec for standard bearings). At the same time, I went ahead and did a 4.0 head swap. It has a different cam, new lifters, new pushrods,etc. The block was not hot tanked, I just used several cans of brake cleaner and a toothbrush.
So what's interesting is that before I put the new crank in I had this pretty sharp slap/knock. Only audible at idle. After the partial rebuild, the exact same knock was still there. The only part that didn't get changed/replaced were the pistons and rods.
The other day while wheeling, my electric fan croaked. I ended up overheating the jeep pretty good getting it off the trail. Basically I ran it pretty hot for a good while (maybe an hour). Boiled it over twice.
After over heating it.
The knock is gone!
The motor sounds fine, and seems to run just fine.
My coolant looks like it's full of rust now. Curious.
My oil pressure seems lower. Not troubling low, just a bit lower.
Anybody got any ideas. Did I cook out a oil passage blockage of some sort?
________
One vaporizer reviews (http://vaporizer.org/reviews/vapir-air-one/)