I bought a built low compression b20 motor off ebay, had almost no compression(cyl 1-60/2-60/3-20/4-60) when I received it. I took the head off and the head gasket was badly blown. The sleeves look good from what I can see. The head and the valves are fine also, I had them checked at a shop. Does anyone know of a way to check the piston rings without putting the head back on? Thanks for any help.

 

The only way to check the rings is either with a compression test or by removing the pistons. And if there IS a compression problem, it might be a problem with the ring lands on the pistons and not the rings themselves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tjbizzo &raquo;</TD></TR><TR><TD CLASS="quote"> And if there IS a compression problem, it might be a problem with the ring lands on the pistons and not the rings themselves. </TD></TR></TABLE>


Get a new headgasket and recheck the compression. If it still horribly low pull the pistions and see how bad the ringlands are. You said that it is a "built" bottom end. What pistons are in it?

Phil

 

The pistons are Custom-Ground CP Forged Pistons (Full Floating Wristpins). Thanks for your help.

 

I don't know if this will help with the troubleshooting, but here is a list of what is done to the motor.

Custom-Ground CP Forged Pistons (Full Floating Wristpins)
Eagle H-Beam Connecting Rods w/ ARP 2000 Waveloc Bolts
Polished Stock Steel Crank
Balanced and Blueprinted Bottom End
Ferrea Competition Plus Super-Flo Racing Valves
Darton Sleeves (Professionally Installed and Machined, Bored To Match Each Piston)
3-Angle Valve Job
Shimmed Valve Springs
New Valve Guides, Seals, Retainers, Keepers
All New Seals In Entire Engine
Entire Block and Head Oil Galleries and Water Passages Cleaned
King Rod and Main Bearings (Type H Conformity)