205 PSI compression??

[Brucetafer]

all 4 of my cylinders in my aq131a volvo penta have exactly 200-205 psi, wot, 5 compressions, 2 different snapon testers...

does this sound holy crap high????

 

[Don S]

Re: 205 PSI compression??

142 to 170 is book value. Makes me think possibly some engine work done in the past 25 years by a previous owner ?

 

[JustJason]

Re: 205 PSI compression??

My Soobie engine that I built as a high compression engine hit's 210 on my gauge, but I built it that way.
205 on a stock motor is way high, if it runs, you can dry decarbing it and see if it drops, but i doubt it would drop to the 150-170 range. If your running this engine, i'd reccomend going at least 1 colder in the heat range on the spark plugs.

 

[Fireman431]

Re: 205 PSI compression??

Is it possible that the pervious owner had some head work done? Any evidence of a previous rebuild?

 

[45Auto]

Re: 205 PSI compression??

When's the last time your compression gauge was calibrated?

 

[Joshua Nichols]

Re: 205 PSI compression??

Is it diesel?? May have had some head work done and had lots of meat taken off the heads?

 

[wca_tim]

Re: 205 PSI compression??

When's the last time your compression gauge was calibrated?

it wouldn't have to be off by much in terms of a calibration...

Also, a 200 psi cylinder pressure, in the context of the wide lobe angle separation / cam profile of most marine engines doesn't really need to correspond to more than about a 10:1 static comression ratio...

compression gauge a little off, tight engine, a little milled off the head during a good rebuild, block decked, etc... could just great.

How does it run? If good, then just run good fuel and enjoy it.