What is the recommended piston ring gap or tolerance before it is time to throw away?
Cheers
dave
bigdave Officially Full-On Dubber
329 posts · joined Aug 2006 ·
Ring gap for 85.5 standard bore?
grumble Son of Jim - Creator of Good
2,672 posts · joined Jun 2008 ·
The recommended ring gap was .004" per inch of bore. Obviously if the bore is scored or lipped badly it is time to replace the units. When we are rebuilding normally we replace the pistons and barrels, this is the same as reboring an inline motor.
68AutoBug Beetle Restorer - Experience over 138\% - YIKES --
11,654 posts · joined Aug 2002 ·
Hi Dave,bigdave wrote:What is the recommended piston ring gap or tolerance before it is time to throw away?
Cheers
dave
I'm not an engine rebuilder but that is a strange request ...
it depends on the manufacturer of the rings I would say...
usually Pistons with new rings and cylinders are replaced all together...
check if there is a lip in the cylinder ...
where the rings don;t go -
this will be the original size of the cylinder...
You should be able to feel the lip with Your Finger...
cheers
LEE
- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---
vwo60 Veteran Volks Folk
2,036 posts · joined Feb 2007 ·
The ring gap is a major part of any engine build, you cannot trust any manufacturer , these need to be checked and filed to the correct gap when you install any piston rings,
Compression ring clearance new - .3MM to .45MM.
Oil scrapper ring clearance new - .25MM to .4MM.
Wear limit compression ring - .9MM.
wear limit oil scrapper ring - .95MM.
sizes taken from the factory manual
Compression ring clearance new - .3MM to .45MM.
Oil scrapper ring clearance new - .25MM to .4MM.
Wear limit compression ring - .9MM.
wear limit oil scrapper ring - .95MM.
sizes taken from the factory manual
matberry Moderator Go hard or go home
8,114 posts · joined Mar 2006 ·
I recommend .0045"/inch of bore for our engines
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
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