[Public-List] Piston Ring Blow By / Smoking......Doubling Head Gaskets

crufone at comcast.net crufone at comcast.net
Thu May 13 15:28:44 PDT 2010



Michael, 

One does not have an issue with poor rings on an automobile until the oil consumption gets to be at about a quart every 500 miles.  To convert to boat motors let's use 45 miles an hour, thus 11.11 hours to reach 500 miles.  So check your oil consumption, top it up exactly on the line in calm water and see how many hours to burn off a quart of oil. If you are burning a quart in let's say 10 hours of operation then you might be loosing significant engine power in addition to polluting the atmosphere big time.  If everything else is decent with the engine, it is not likely to fail on you due to poor rings. Check the plugs and see if they are becoming oil fouled, carry an extra set or two on a long trip. 

Better yet, SAIL the damn boat...................just a joke ok. 



Oh yeah another thing Gord, when an engine just begins to burn oil the smoke can appear very very light blue or white...ish, especially when back lit with the sun in your face. Blue smoke comes along when you are really really burning oil like at the one quart/500 miles point.  You can run the engine at 2200rpm for a minute then back off quickly to an idle, when engine reaches idle perform very hard acceleration.  This is a easy check for poor rings. Running at 2200 rpm normalizes the engine. Fast deceleration sucks in more oil than can normally be burned. Then hard acceleration allows the burning oil to be viewed much more easily. 



An engine with poor compression, i.e., poor rings, is more difficult to start when hot. Folks doubling up the head gaskets are also lowering the compression ratio, loosing power, making for less efficient engines and harder to start when hot engines. Better to mill the head and block to get flat surfaces and use one gasket. Normally gaskets are designed to mate against a flat smooth surface and not against each other. Double gasketing head gaskets is a band-aid approach and not a very good one at that. For a boat component in which you wish to rely on I would not do a band-aid fix. 



My two cents, 

Michael #133 
  
 Just catching up on the list (should be working). 

 Your smoke sounds a lot like what I developed late last season. My head 
gasket is only two season old, so I really don't think that's the issue. 
I also replaced my valve springs and cleaned up valves and seats then, 
so I am willing to believe that my valves are better than my rings.   


 When starting up this season I had uniformly lousy compression. I 
poured Marvel Mystery Oil into each cylinder , turned it over and left 
it for a week. Then I came back and ran it full throttle for a 14 mile 
trip, and it felt better and better through the day, and even better on 
the next long motor. It still smokes, but not a lot. 

  I suspect that I am burning engine oil, and not leaking cooling water. 
The question is how long until I do a ring job? 
I am kind of planning on pulling the engine within 2 years, and hope it 
lasts until then! 

  Moyer Marine sells Marvel Mystery oil $7.79 for 32 oz. 

Mike 





More information about the Public-List mailing list