Mac
Member
I'm checking ring clearance and preparing to assemble a new motor. Wiseco recommends .004 per inch of cylinder.
A 780 bore measures 2.870 close enough to 3 inch. Clearance should be .012 (twelve thousanths). With a feeler guage I measure .01 (ten thousanths) Instuctions even say "Additional end gap may be necsessary for moddified engines" What size should I set the gap? Should I leave ten thousanths? Nosboy no hijacking please!!! --mac--
A 780 bore measures 2.870 close enough to 3 inch. Clearance should be .012 (twelve thousanths). With a feeler guage I measure .01 (ten thousanths) Instuctions even say "Additional end gap may be necsessary for moddified engines" What size should I set the gap? Should I leave ten thousanths? Nosboy no hijacking please!!! --mac--
Ring gap
I assume you placed the ring at least a ½” to ¾” down in the cylinder bore and measured the gap. Correct. You should have about 0.010 to 0.025 thousand of inch. I just did a stock viper 700 with oem parts and I have a gap of 0.013 and all is good. Now with after market parts. It would be wise to follow parts supplier recommendations. As I understand it after market parts heat up differently and at different rate than oem’s, I believe the extra clearance is for expansion, as aftermarket expands more, now this said and you are in fact running aftermarket you have to remember to warm up your engine before hammering it and let Idle a few minutes after a long pull. Failure to do this you will be rebuilding it again…Good luck …
I assume you placed the ring at least a ½” to ¾” down in the cylinder bore and measured the gap. Correct. You should have about 0.010 to 0.025 thousand of inch. I just did a stock viper 700 with oem parts and I have a gap of 0.013 and all is good. Now with after market parts. It would be wise to follow parts supplier recommendations. As I understand it after market parts heat up differently and at different rate than oem’s, I believe the extra clearance is for expansion, as aftermarket expands more, now this said and you are in fact running aftermarket you have to remember to warm up your engine before hammering it and let Idle a few minutes after a long pull. Failure to do this you will be rebuilding it again…Good luck …
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Mac
Member
Are you recommending .04 (fourty thousandths) to .09 (ninty thousandths) and .08 ( eighty ) sounds like way to much. I was thinking .014 (fourteen) to .016 or there about. Where are all the motor heads when you need them?
jwiedmayer
New member
An old snowmobile mechanic friend of mine told me .005 per inch bore a LONG time ago.. This may not be applicable for new engines. He was a snowmobile mechanic in the 70s. He now build race car engines.
vibeline
New member
ring end gap
yamaha SRX service manual says .014-.022" (thousandths)
so that .005" sounds pretty close.
SRX bore=2.7165" (69.00MM)
2.7165*.005 = .01358" so lets round it off to .014"
yamaha SRX service manual says .014-.022" (thousandths)
so that .005" sounds pretty close.
SRX bore=2.7165" (69.00MM)
2.7165*.005 = .01358" so lets round it off to .014"
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theblues said:
I just did typo corrections on the thousandths...sorry a little too much
last nite
.014" gap is plenty