New Engine: Aluminum Block L33 With 799 Heads

After lapping the valves, I did another leak-down test. The results were much better this time, but still pretty inconsistent. The worst cylinder had 25% leakage and the best 7%. I put a little engine oil in the cylinders to see if it would seal a little better, but I noticed no improvement. You could clearly hear the air passing through the piston rings. Since my build is on the budget, I decided not to continue with the cylinder job. The scrap yard was nice enough to take the engine back and give me a full refund. It was a little disappointing as I spent quite a bit of time on it.

LM4 after I was done cleaning it. Too bad it had to go back.

For the next engine I decided to spend a little more and get an L33 aluminum block. These came with 799 heads, which are pretty much the same as the ones that came on LS6 Corvette engine, minus the sodium filled valves. It was a little overpriced at $1200 CAD, but I couldnt afford to sit around waiting for a good deal. The engine looked pretty clean, and only had 80,000 miles.

L33 Aluminum Block from 2005 GMC Sierra 1500

Got straight to work

799 Heads