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No these measurements are in the ring travel area. I rotated the bore gauge in about 8 different spots to get a variety of readings. I usually measure them horizontally, then vertically, then on a 45 each way to get a few different readings. I do this at the top of the ring travel, and at the bottom. Not saying that’s right, but how i’ve always done it, to determine taper and as close to accurate as I can.
Correct, the bottom bore is only .001 out, which is fine. Its the top, which is worn .010 that i’m worried about, as that cylinder had over 20 psi less than the other on the compression gauge.
The owner doesn’t want to spend the money to rebuild it anyways, so ill just transplant another powerhead on it. Ill likely still rebuild this myself. I hate to toss blocks. I have a bunch of rebuilt ones on my shelf that are too expensive to sell now, but are ready to go anyways!
I have had members come over and offer me 50 bucks for a fully rebuilt powerhead. Yeah, Ill just keep it thanks 😉