Laust Pedersen

This question comes up quite often: “Can I use my block with these cylinder scratches?”

A good way to evaluate this is realizing that the main goal is to minimize the leak-down. A very good engine has about 2% leak-down, which mainly comes from the ring gap. So multiply the ring gap with half the piston-cylinder clearance and you have the approximate leakage area A0 for the 2% leak-down (another more accurate way to do this is to empirically find the orifice diameter that gives 2% leak-down).
Then multiply the width and depth of the scratch to get the added leak-down area A1 and compare that to the area for the 2% leak-down. Make the crude assumption that the leak-down is proportional to the leak area and you can use this formula to assess the resulting cylinder leak-down 2% x (1+A1/A0).

Also, since low leak-down is the goal, it should be obvious that any use of sandpaper is a “no no”.

Btw, on the face of it, your leak-down numbers look terrible if done according to FAA specification http://en.wikipedia.org/wiki/Leak-down_tester , but there are some cheap low pressure testers give different numbers and may not provide adequate pressure to properly seat the rings.

Laust

Lightningmcnulty

Ok good news guys it's together and works and no smoke! It seems to make good power but I don't really have anything to base that on!

Now the bad/weird, I have a water leak, I think it's down to a clamp that I didn't do up quite enough, I tightened it but haven't tested yet.

Second I have the dreaded balance belt noise so I have to go back in and address that.

Here is the weirdest thing. My power steering belt turned onto its side then eventually came off, why is this happening? To tight to loose?

Thanks

Kim