T O P I C R E V I E W
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asskickn88
Member # 4957
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posted
I have a standard bore block with aftermarket TRW forged pistons. I'm running a blower so I have been told the gaps should be a bit bigger.
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JohnB
Member # 969
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posted
Yes, it would be a good idea. Your ring manufacturer should have specs and guidelines for your application.
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asskickn88
Member # 4957
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posted
quote: Originally posted by JohnB: Yes, it would be a good idea. Your ring manufacturer should have specs and guidelines for your application.
The rings are already in the motor. Its very low mileage, I just pulled it apart to clean and check the ring gaps. I dont have the original specs though. I did check the gap and its at .026 and I have been told thats too big but they were never filed any larger. Will I run into problems if I leave them with the gap that large?
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Fostang
Member # 3752
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posted
How about you buy new rings. It's already apart.
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asskickn88
Member # 4957
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posted
the pistons and rings only have around 150-200 miles. I only pulled it apart because the short block has been sitting for a couple years. I dont want to replace perfectly good rings if I dont have to. I got the rings new and know that they were never filed so I dont understand how it could be too far out of spec.
If I need to replace them I found these from Summit and they seem to be a decent set... any ideas?
Summit [ January 25, 2007, 02:05 AM: Message edited by: asskickn88 ]
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JohnB
Member # 969
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posted
That gap is fine, as long as both (top and 2nd) are not the same. If you've pulled it apart, hone the cyl's and put new rings in it. Obviously something was bothering you or you wouldn't have pulled the engine apart.
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phil a
Member # 6951
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posted
like what john said - new rings with a new hone. don't waste money throwing a set of new rings on with an existing hone as ring seal will be compromised
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93PONY
Member # 60
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posted
Run it. Don't sweet it. .022-.024 is the proper gap for a 600RWHP 4" bore blower setup with *most* moly rings. .002-.004 extra is the width of a piece of paper... There will not be any adverse issues with running a .026 gap vs .022. Slightly less cranking compression & slightly less vaccum at idle (probably not even noticable), but at WOT there will be absolutely no difference in performance. Same with daily driving.
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asskickn88
Member # 4957
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posted
quote: Originally posted by JohnB: That gap is fine, as long as both (top and 2nd) are not the same. If you've pulled it apart, hone the cyl's and put new rings in it. Obviously something was bothering you or you wouldn't have pulled the engine apart.
I only pulled it apart to to clean it up. I built the motor a few years ago, put it in the car and only put a few hundred miles on it, pulled the heads and sold them to get some AFR's. My daily driver was stolen and I parted out most of the project to buy another car. The block has been sitting for a long time so I decided to pull it apart to clean and recheck the ring gaps. The motor was NA before but because I'm installing it in a blown car I wanted to open the gaps up a bit for that. From what I have seen, a 4" bore needs about a .014 min ring gap so what would be good for a blown car? Also, how much larger do I need to gap the second ring than the first? thanks for the help all, I might go with the rings I posted above.
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