Comments on these leak-down test results

[David R.]

Sounds like it might be time to pull engine and go through it. Might just need freshened up. Hone cylinders, rings, lap valves and check clearances?

[alexiskai]

Originally Posted by David R.

Sounds like it might be time to pull engine and go through it. Might just need freshened up. Hone cylinders, rings, lap valves and check clearances?

Problem is, that is well beyond my abilities or toolkit. Would have to have a pro do it, so then we're into the big bucks. I agree that the engine would see significant improvement from new pistons/rings/honing, etc., but it's hard to justify, especially in this economic climate.

Originally Posted by Patrick L.

Have you checked the valve lash ? If so, what is it ? I think that needs to be done. The valve may not yet be burnt as it would then show zero compression. Work on just that valve may be all thats needed.

Haven't pulled the valve cover or the head yet.

Originally Posted by rotorwrench

Leakage past the exhaust valve could be a damaged valve or seat face but it could also just be some carbon keeping the valve from seating all the way. The rings & cylinder walls likely have a good bit of wear for the overall low compression readings... If it still runs on all four and doesn't use too much oil then it's still operable for a time. If it would double as a mosquito fogger then it might be time for an overhaul.

Oil consumption is low, no smoke when it's running.
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So it sounds like I should pull the head and check out the exhaust valve on #2, looking for damage or buildup. If it looks OK there, I should pull the valve cover and measure the lash. I'm extremely conscious of the potential to make problems worse by trying to fix them, so I want to proceed cautiously.

One thing this is making me question is my plan to eventually put in a HC head. With the cylinders in this poor condition, it really seems like I'd get much less benefit from a HC head than I was expecting unless I have the cylinders repaired at the same time.