help on 220 compression

2tines

Well-known member
i just checked compression on my 220, starting at the prop on the left side they are 150,162,115 and on the right 145,125,145. also on the left bank i have black smut and when you crank it you can hear it popping a little when its cold. which of these numbers are normal and how close should they be? seems to run and idle great. i would like some advice from you guys on what i should do.
 
I only do the differential compression checks on my aircraft type engines. Those automotive reading don't tell as much. 20% difference with the automotive test is a suspect cylinder. Go to this site and it gives a very good explaination on checking your cylinders:

http://www.littleflyers.com/engcomp.htm

The popping noise is never good. Try to isolate which cylinder it is and check further. Use 2 feet of garden hose to listen to each cylinder and that might help. Could be lifters. Need more information.
 
Des Moines is right you need to do a leak down check on your cylinders. This will tell you what type of defect's that your cylinders have from exhaust & intake leak's ,to blow by on your ring's. Its the best way to inspect an engine for prior to purchase.


Rick
 
my experince with all ground pounder in past check oil every stop till you know the motter well dont run over 3000 rpm wfo fix the exaust leak and run it like you stole it till it is time to rebuild/ps change oil every 50 hrs it will run for your grandkids!!:arrow:
j.mcdonald[swampsoldier]
 
thanks guys, im going to run it this weekend but monday i will be taking it to a friend that works on a/c motors. he has a the tools needed to do all the checks.
 
update: i checked all cylinders with differential gauge and #1 was no good, so i put new rings in all cylinders,honed all cylinders and rebuilt holley 500 carb,plus all new seals including intake tubes. i run it last night and it did ok on power but it had a little fire popping out of the left bank and still smoking a good bit out of that bank. this morning i fixed the exhaust leak on this bank( i think this may be cause of the fire) but it is still smoking. i checked compression this moring with automotive gauge and they are from 150psi to 130 psi. anyone have an idea on where the smoke is coming from?
 
MY 220 just started popping on cold start ups and found it to be one of my exaust valves was sticking. Was told to replace before the valve actually drops out of seet.
 
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