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Why the difference in power?

ring seal due to the differences in the expansion rate between the aluminum block and steel sleeves is what I have been told. I heard this from a relaible source that has used both types of block that the aluminum block would only hold minimum (less than 5 inches)vacume on start up cold and end up with positive crankcase pressue at the end of the run, 45 seconds to a minute and fifteen seconds later The iron block holds 17 inches on start up and crooses the finish line at 15 inches or more depending on how many runs are on the rings and pistons. This is on a boosted 2000+ HP motor IHTHs



Completely agree there is a loss with Alum blocks but i'm wondering how much closer a solid alum block is to a iron one compared to the water ones.

Both my TS engines have solid KB blocks. (but if i had the choice and there were iron 4.840bs blocks out there i probably would have gone with steel.