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https://slantsix.org/forum/viewtopic.php?t=19636		 Page 2 of 2
Author:  argentina-slantsixer [ Sun Sep 17, 2006 9:47 pm ]
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Quote:
I run one about 500 miles or 50 passes, which ever comes first.

The motor in the car now got 1 street mile before making it's first pass, and it got a 100 shot in low gear before it had 1/2 mile on it.

If it's assembled properly, break-in is bullshyt anyway. :shock:
I assume you're talking about your racing engines wich you ain't keeping for safe and sound use anyways, if not, I respectfully disagree with you encouraging a regular john to go make 50 passes down the racetrack to break in the newly rebuilt motor...
Author:  sick6 [ Mon Sep 18, 2006 5:02 am ]
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okay, I bought some White Lubriplate and am still looking for cam break-in stuff.

any reccomendations?

also, I need advice on setting the ring gap. I have chrome moly rings, and can't see how to set a gap when its in the compressor for installation. don't they just squish down to a pre-determined size to fir the bore?
Author:  dakight [ Mon Sep 18, 2006 5:19 am ]
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The technique I've always used is to slip them into the bore to measure the gap. Then make necessary adjustments before installing on the piston. You'll want to be sure to keep the rings in the bore where they were measured in case there are small differences in the bore diameter. Bore diameter differences are multiplied by 3.14+ at the circumference so a bore size change of .001 will change the gap by .00314+ at the gap. Actual bore differences will be less than that in a fresh block but the same ratio applies so to be safe I measure and adjust them in the cylinder in which they will be installed.
Author:  Bren67Cuda904 [ Mon Sep 18, 2006 5:28 am ]
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Try different rings in different bores to minimize the "trimming" amount. To trim a ring use a double sided flat file and pinch it between the ring ends and drag the file out. Draging motion should be longways. Then recheck gap. Repeat if needed.
Author:  slantzilla [ Mon Sep 18, 2006 7:47 am ]
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Make sure the ring is square in the bore when you measure it. If the ring is crooked it will change the gap measurement. :shock:
Author:  sick6 [ Tue Sep 19, 2006 4:29 am ]
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okay, any ideas on the right gap for a .060 over 225 with chrome moly rings?

should I just go with stock?
Author:  dakight [ Tue Sep 19, 2006 5:19 am ]
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The factory spec on a '62 engine is .010 - .027 for compression rings in a standard bore and .015 - .062 for the oil ring rails. It doesn't give a spec for .060 overbore. It shows a Max of .040 compression and .070 oil rings for a .005 overbore but does not specify the minimum. Bear in mind that an oversize ring is longer than a standard and will therefore expand more when hot. An .060 ring is approximately .189 longer so I would open the gap a few thousanths to compensate.

I did a google search and found this page
http://www.aa1car.com/library/ring_end_gap.htm

they recommend .004 x bore so at .060 over you have a bore size of 3.46. Multiplying that by .004 you get about .014 for a minimum. They also recommend .005 x bore for ring #2 which comes to .017.

The FSM recommends measuring the gap with the ring 2" from the bottom of the bore, press it down into the bore with an inverted piston to be sure it is square in the bore. In a freshly bored cylinder the gap should be the same no matter where it is measured as long as the ring is square in the bore and the bore is uniform diameter top to bottom.
Author:  sick6 [ Tue Sep 19, 2006 10:36 am ]
Post subject: 
my 1975 FSM says the same thing for checking the gap.

I'll let you know how it turns out.


anyone know a good cam lobe goop off hand?
Author:  slantzilla [ Tue Sep 19, 2006 10:42 am ]
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General rule is .004" of gap for every inch of bore size. Allow extra for nitrous or hyperteutectic pistons on the compression rings. :shock:
Author:  sick6 [ Tue Sep 19, 2006 12:11 pm ]
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sorry slantzilla, no joy juice or boost here- I wanted it (boost) but I have been told I had too much cam for that......and no one can really tell me how much is too much....(my cam: http://slantsix.org/forum/viewtopic.php?t=13881&start=0 about halfway down).....so I decided for just carburation....maybe EFI if I can figure out how it works.
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