Quote:
Originally Posted by Flying Undertaker
I just had my '69 ZL-1 engine built by Brian Tilburg at Tilburg Racing in Trout Run, PA. All original 052 engine block that was bored .030 by previous owner. All NOS GM internals used, even .030 over GM pistons. Dynoed in Apr. 2019 (2nd pull) at 601 hp @ 6700 rpm limit that I had specified because of the age and rarity of the block. Brian said that the camshaft was still pulling hard, and had not reached its peak on the curve. He said it would have maybe 15-20hp more by 7300, as he had done several ZL-1's for NHRA Stock Eliminator AA/SA cars before. Race break-in oil and modern rings used. I have both dyno sheets. Same conditions as one stated above; good tune up, open headers, no air pump, no air cleaner or alternator!
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Ya you would have probably made more power 5-700RPM more. Those cam were rumored to pull well into the 7500/7800 RPM range, just not sure they were making more power or just hanging on better without the drop?
I looked at my ZL1 dyno sheet, @ 6700 I was at 785.1 Hp but it should have been higher. And you "probably" left 50 or so Hp on the table with you deal using the GM piston design and not pulling to 73/7500 range. Modern piston with 1/16 rings or better rings and not the 5/16 would have picked it up nicely too.
THEN one can look at the heads/valves and see what "could" be found there? I don't know what you did with your stuff, like better modern valve, back cut and valve job, but there is POWER there too.