If you wanted to pressure test your engine with a screw in (Via the plug hole) pressure tester. Do you know what would be a good / medium / poor -Reading from the guage.
cylinder pressure testing for condition?
-
Ian5913
- Posts: 225
- Joined: Mon Jan 01, 1990 12:00 am
- Location: BERKSHIRE UK
-
Rohan B.
- Posts: 136
- Joined: Wed Oct 12, 2005 10:45 pm
- Location: AUSTRALIA
cylinder pressure testing for condition?
Pressure testing can only ever give a very general indication of engine condition. Pressure should be tested with the engine HOT, throttle wide open.
Older low compression engines obviously give lower readings than newer hi-comp motors, and old worn carboned-up motors may actually give surprisingly high readings.
If you get anything more than 100psi this is good for an older single, newer models may give 120+psi . A very late model twin may reach 170 psi. If you have a twin it is more important that each cylinder is within 5psi of the other reading, this makes for smooth even-running.
If a reading is low, add a spoonful of oil and turn the engine over a few times and test again. If the reading improves then your rings are worn, if the reading doesn't improve then a valve(s) leaks.
hopethishelps,
Rohan.
Older low compression engines obviously give lower readings than newer hi-comp motors, and old worn carboned-up motors may actually give surprisingly high readings.
If you get anything more than 100psi this is good for an older single, newer models may give 120+psi . A very late model twin may reach 170 psi. If you have a twin it is more important that each cylinder is within 5psi of the other reading, this makes for smooth even-running.
If a reading is low, add a spoonful of oil and turn the engine over a few times and test again. If the reading improves then your rings are worn, if the reading doesn't improve then a valve(s) leaks.
hopethishelps,
Rohan.
-
Ian5913
- Posts: 225
- Joined: Mon Jan 01, 1990 12:00 am
- Location: BERKSHIRE UK
cylinder pressure testing for condition?
Thanks for you reply
I am trying to diagnose suspected sticking rings.
I keep losing compression coupled with lots of smoke (Oil usage) which following a wait The compression comes back next start up and the smoking has gone also.
If it is sticking rings what do you clean them with
Does redex work or is it a strip down and clean
I am trying to diagnose suspected sticking rings.
I keep losing compression coupled with lots of smoke (Oil usage) which following a wait The compression comes back next start up and the smoking has gone also.
If it is sticking rings what do you clean them with
Does redex work or is it a strip down and clean
-
33d6
- Posts: 43
- Joined: Wed Oct 12, 2005 10:45 pm
- Location: AUSTRALIA
cylinder pressure testing for condition?
Hi Ian,
I must admit that sticking rings would be a fair way down my list with the symptoms you describe. I am also a believer in doing the easy checks first. A loss of compression when hot is often associated with the tappets being a smidgeon too tight. Especially with AMC singles with their zero tolerance tappets. I would first check whether you have tappet clearance when the engine is hot. As for the smoke that can be a variety of issues but I would check for a sticking exhaust valve first. This is a frustrating condition to check for as the valve unsticks when the engine cools down. Hopefully I've given you a few ideas and helped a little, Cheers BOB
I must admit that sticking rings would be a fair way down my list with the symptoms you describe. I am also a believer in doing the easy checks first. A loss of compression when hot is often associated with the tappets being a smidgeon too tight. Especially with AMC singles with their zero tolerance tappets. I would first check whether you have tappet clearance when the engine is hot. As for the smoke that can be a variety of issues but I would check for a sticking exhaust valve first. This is a frustrating condition to check for as the valve unsticks when the engine cools down. Hopefully I've given you a few ideas and helped a little, Cheers BOB