#1 low blow by on 75H?

Rvators,

my #1 is showing low in comparison to rest on 75H and I hear hissing at the oil filler and breather during its blow by test.

73,78,79,80,78,78 (1..6) Over 80

It is new IO-540 straight from Vans. After first test I took the airplane out and flew it hard for 30 minutes. EGT and CHT normal. Retest Blow By, Same result on #1. The airplane is now 1 year old.

I am an experienced kitbuilder, but not engine man. So is this something to be concerned about? I'd like to fly away to a holiday destination this coming weekend, but a little concerned on #1 result comparitive.

Any advice or additional tests appreciated?

Rudi

PS: In hindsight I should have taken tests on 25H, 50H oil changes too, but never thought required on a new engine, and required before its 1st annual test. So sorry I dont have a trend.

Go fly, 73/80 is nothing to worry about

It is true. I have experienced such things simply resolved by the next oil change. I learned to calibrate my arm for a quick check before flight.

In general a 73 would not concern me on an older plane, but it is out compared to the rest on only 75H

If I had no other symptoms, I'd fly it like the other guys say Rudi - I can make a jug read up or down by five or more psi just by exactly where the prop is resting when I take the reading.

Likely a stuck ring. Marvel mystery oil will take care of it. Just because its new doesn't mean something can go awry.