The Jalopy Journal

1941coupe · 05-08-2012, 01:53 PM

i picked up a 1950 303ci olds engine and have no past history other than its been sitting a loong time ,it has a small ridge at top of cyl,pistons came right out no problem,no cyl scoring,im hopeing it just needs new rings and bearings, i plan on having it miked,my motors manual says 10 thousand min ring gap so my question what would be the max ring gap allowable..thanks

**mctim64** · 05-08-2012, 02:15 PM

.004" for every 1" of bore is a good "rule of thumb" so figure .015", over .020 is a lot.

Marty Strode · 05-08-2012, 02:16 PM

The bore on a 303 is 3. 3/4"

**Mr48chev** · 05-08-2012, 02:22 PM

Make sure that you cut out that even minimal ridge at the top of the cylinders though as the new top rings could catch on it and break if it is left in the engine. I've seen the results leaving a ridge on a "rebuilt" engine a couple of times and it isn't always pretty.

**48fordnut** · 05-08-2012, 02:32 PM

what 48 chevy said, I like .017 myself.

05-08-2012, 01:53 PM	#1
1941coupe Grenade Inspector Join Date: Jul 2010 Location: ny Posts: 154	303 olds ring gap i picked up a 1950 303ci olds engine and have no past history other than its been sitting a loong time ,it has a small ridge at top of cyl,pistons came right out no problem,no cyl scoring,im hopeing it just needs new rings and bearings, i plan on having it miked,my motors manual says 10 thousand min ring gap so my question what would be the max ring gap allowable..thanks

05-08-2012, 02:15 PM	#2
mctim64 Alliance Member Join Date: Dec 2008 Location: California, somewhere just below Fresno. Posts: 5,011	Re: 303 olds ring gap .004" for every 1" of bore is a good "rule of thumb" so figure .015", over .020 is a lot. __________________ Y-Block Powered Model A Tudor project http://www.jalopyjournal.com/forum/s...d.php?t=667198 "it looks just like a Tellafunkin U-47" http://yblockguy.com/

05-08-2012, 02:16 PM	#3
Marty Strode Senior Member Join Date: Apr 2011 Location: North Plains, Oregon Posts: 1,117	Re: 303 olds ring gap The bore on a 303 is 3. 3/4"

05-08-2012, 02:22 PM	#4
Mr48chev Alliance Member Join Date: Dec 2007 Location: Yakima Valley, WA Posts: 15,437	Re: 303 olds ring gap Make sure that you cut out that even minimal ridge at the top of the cylinders though as the new top rings could catch on it and break if it is left in the engine. I've seen the results leaving a ridge on a "rebuilt" engine a couple of times and it isn't always pretty. __________________ Definition of a "work car". One you have to work on all weekend so you can drive it to work the next week.

05-08-2012, 02:32 PM	#5
48fordnut Alliance Member Join Date: Nov 2005 Location: mid ga Posts: 2,338	Re: 303 olds ring gap what 48 chevy said, I like .017 myself. __________________ Will Rogers'' Common sense is not as common as you think Southern Slingshots

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