L31MaxExpress
I'm Awesome
I pulled apart the 2 bolt 880 Vortec I had at the shop this evening. It is surprisingly clean for something that sat over a year with coolant in the oil from cracked heads. I am putting this one back together with factory GM Mahle lightweight LT1 pistons and a L30 nodular iron marine crank. Also using a $100 GM steel roller cam and some form of aftermarket Vortec head that was on the 99 Tahoe when I bought it. The only markings I can find on the heads are DD where the typical GM casting number is and what appears to be a serial number stamped in the end. I think they may be Speedmaster. The castings are much heavier than even a Mexican vortec but I had to do some cleaup work on the bowls, around the vane on the guides and the very coursely cast chambers.
Was not too bad for a 110K mile engine. Very little sludge other than the coolant gunk in the bottom of the pan. The rings were still sharp and the oil control rings and bottom of the pistons near perfect. I am shocked that even the cam bearings are near perfect. The rod bearings were very clean as well. The mains look nearly perfect. I am probably going to put new rings that I had laying around the shop on the LT1 pistons, new rod and main bearings and toss it back together. I checked the new rings in a couple of cylinders, got 0.018" upper ring gap and 0.024" 2nd ring gap straight out of the package. The rings on the LT1 pistons had 0.032 upper and 0.040" 2nd ring when I checked. Ao maybe there is some truth to a heavily used engine being pre-gapped for boost from wear, lol.
Was not too bad for a 110K mile engine. Very little sludge other than the coolant gunk in the bottom of the pan. The rings were still sharp and the oil control rings and bottom of the pistons near perfect. I am shocked that even the cam bearings are near perfect. The rod bearings were very clean as well. The mains look nearly perfect. I am probably going to put new rings that I had laying around the shop on the LT1 pistons, new rod and main bearings and toss it back together. I checked the new rings in a couple of cylinders, got 0.018" upper ring gap and 0.024" 2nd ring gap straight out of the package. The rings on the LT1 pistons had 0.032 upper and 0.040" 2nd ring when I checked. Ao maybe there is some truth to a heavily used engine being pre-gapped for boost from wear, lol.
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