Second compression ring gap
Thread Starter
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Second compression ring gap
Building a 383 with Probe forged pistons and Speed Pro Moly rings.
The recommended gaps are:
.016-.018 Top ring
.020-.022 Second ring
They don't specify the gap for the oil ring
Out of the box (no filing at all) measured gaps are:
.018 for all of the top rings
Second rings are all over the place
2@ .020
1@ .021
2@ .023
1@ .024
1@ .026
1@ .028
Oil rings are all .028
These are non-file fit rings, but I was told to expect that they would still require a little filing for proper gapping.
I understand that it is good to have a larger gap in the second ring than it the top ring, but isn't .010 difference between the two a little too much??
What kind of problems could I expect if I were to install these rings as-is with the large difference in the gaps of the second rings?
What should the proper gap be on the oil rings?
Thanks in advance.
The recommended gaps are:
.016-.018 Top ring
.020-.022 Second ring
They don't specify the gap for the oil ring
Out of the box (no filing at all) measured gaps are:
.018 for all of the top rings
Second rings are all over the place
2@ .020
1@ .021
2@ .023
1@ .024
1@ .026
1@ .028
Oil rings are all .028
These are non-file fit rings, but I was told to expect that they would still require a little filing for proper gapping.
I understand that it is good to have a larger gap in the second ring than it the top ring, but isn't .010 difference between the two a little too much??
What kind of problems could I expect if I were to install these rings as-is with the large difference in the gaps of the second rings?
What should the proper gap be on the oil rings?
Thanks in advance.
Thread Starter
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Originally Posted by comp
have you tried in different hole's????
The gaps remained virtually the same no matter what hole I put the rings in.
I'm going to take them back to the machine shop on Monday and see if they can swap them for file-fit rings.
Thread Starter
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Originally Posted by comp
yep thats the thing to do 
I just measured the new set and they all have a .015 gap. Now I just hope I don't screw up on the little bit of filing I have to do.
