bad rings or bad valve stem gasket?
Nov 13, 2007 | 04:40 PM
#21
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I don't know what stock 22RE's do at sea level but 140psi sounds about right for 1 mile+ above sea level. Altitude makes a huge difference.
Here's a post on another forum that shows the math:
http://www.eng-tips.com/viewthread.c...169417&page=15
It basically shows that a reading of 160psi @ sea level is about 113psi @ 7800 feet.
That's where turbo's come in handy..
Here's a post on another forum that shows the math:
http://www.eng-tips.com/viewthread.c...169417&page=15
It basically shows that a reading of 160psi @ sea level is about 113psi @ 7800 feet.
That's where turbo's come in handy..
Nov 13, 2007 | 07:51 PM
#22
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From: austin, tx
Rings correctly installed and gapped?
Once a cylinder has been bored, it's honed to a final size that is correct for piston to wall clearance. *Most* 22R motors, by the type they need a rebuild, will no longer be in cylinder to wall specs. The bores tend to not wear the same across the bore.
Still, I'd do a leak down test to confirm rings... Cam profile can cause differences in compression...
The miss below 1800 is interesting also.. Try pulling one cylinder at a time, see if you get an RPM drop. You're looking for the cylinder that doesn't cause a drop - that's the one with the miss...
Nov 15, 2007 | 05:29 PM
#23
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update
Did you measure them or a machine shop? IE - confident they were measured correctly?
Rings correctly installed and gapped?
Once a cylinder has been bored, it's honed to a final size that is correct for piston to wall clearance. *Most* 22R motors, by the type they need a rebuild, will no longer be in cylinder to wall specs. The bores tend to not wear the same across the bore.
Still, I'd do a leak down test to confirm rings... Cam profile can cause differences in compression...
The miss below 1800 is interesting also.. Try pulling one cylinder at a time, see if you get an RPM drop. You're looking for the cylinder that doesn't cause a drop - that's the one with the miss...
Rings correctly installed and gapped?
Once a cylinder has been bored, it's honed to a final size that is correct for piston to wall clearance. *Most* 22R motors, by the type they need a rebuild, will no longer be in cylinder to wall specs. The bores tend to not wear the same across the bore.
Still, I'd do a leak down test to confirm rings... Cam profile can cause differences in compression...
The miss below 1800 is interesting also.. Try pulling one cylinder at a time, see if you get an RPM drop. You're looking for the cylinder that doesn't cause a drop - that's the one with the miss...
I did not get a chance to do a leak down test. However, I did do another compresion test and found out that when I added a teaspoon of oil the readings went from 140 to 150. Not a significant jump, but does that mean that the rings are indead bad?
Also all the spark plugs where nice and black and sooty. Is this from oil getting into the combution chamber?
Nov 15, 2007 | 08:21 PM
#24
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From: Port Coquitlam, B.C.
I did not get a chance to do a leak down test. However, I did do another compresion test and found out that when I added a teaspoon of oil the readings went from 140 to 150. Not a significant jump, but does that mean that the rings are indead bad?
Also all the spark plugs where nice and black and sooty. Is this from oil getting into the combution chamber?
Also all the spark plugs where nice and black and sooty. Is this from oil getting into the combution chamber?
Nov 15, 2007 | 08:31 PM
#25
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From: Victoria, BC
if its consuming oil then the rings are bad
it shouldnt take that long for the rings to seat. My rebuild stopped using oil after 400 miles
Also if the plug are black and sooty that means its running rich. If the plugs are black and wet, then its consuming oil
it shouldnt take that long for the rings to seat. My rebuild stopped using oil after 400 miles
Also if the plug are black and sooty that means its running rich. If the plugs are black and wet, then its consuming oil
Last edited by BC_4runner; Nov 15, 2007 at 08:33 PM.
Nov 16, 2007 | 10:33 AM
#26
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Running Rich?
The plugs were all dry and black. There was a little oil by the threads of the plugs, but the plug tips were dry. How do I get it to stop running rich?
Nov 16, 2007 | 07:59 PM
#27
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From: Victoria, BC
If its a "sooty black" then its running rich but if its just a dry black and it hasnt been run for awhile then its oil.Try pulling the plugs right after running it if they are wet then you know for sure
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