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Question about ring gaps
Thread Starter
Pro
Joined: Nov 2005
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From: Bardstown Kentucky
Question about ring gaps
I am getting ready to start filing the rings for my 383 LT4. I am running Mahle pistons and rings. I thought about going ahead and opening them up just a little more in case I want to run a 100 shot in the next year or 2. This is with a 4.029" bore.
Their recommendations
Street Strip
Top ring - Bore X .0045" = .018"
Second Ring - Bore X .0055" = .022"
Nitrous to 150 HP
Top ring - Bore X .0060" = .024"
Second Ring - Bore X .007" = .028"
It just seems like a big jump in size. Would I be sacrificing any power running the Nitrous gap for a while?
Their recommendations
Street Strip
Top ring - Bore X .0045" = .018"
Second Ring - Bore X .0055" = .022"
Nitrous to 150 HP
Top ring - Bore X .0060" = .024"
Second Ring - Bore X .007" = .028"
It just seems like a big jump in size. Would I be sacrificing any power running the Nitrous gap for a while?
Race Director
Joined: Feb 2004
Posts: 12,518
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I am getting ready to start filing the rings for my 383 LT4. I am running Mahle pistons and rings. I thought about going ahead and opening them up just a little more in case I want to run a 100 shot in the next year or 2. This is with a 4.029" bore.
Their recommendations
Street Strip
Top ring - Bore X .0045" = .018"
Second Ring - Bore X .0055" = .022"
Nitrous to 150 HP
Top ring - Bore X .0060" = .024"
Second Ring - Bore X .007" = .028"
It just seems like a big jump in size. Would I be sacrificing any power running the Nitrous gap for a while?
Their recommendations
Street Strip
Top ring - Bore X .0045" = .018"
Second Ring - Bore X .0055" = .022"
Nitrous to 150 HP
Top ring - Bore X .0060" = .024"
Second Ring - Bore X .007" = .028"
It just seems like a big jump in size. Would I be sacrificing any power running the Nitrous gap for a while?
Thread Starter
Pro
Joined: Nov 2005
Posts: 536
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From: Bardstown Kentucky
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From: Good health is merely the slowest possible rate at which one can die
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Wha? There ya' go, casting aspersions at me again.... 
Great site and a frequent reference for me. Lots of handy info there. 
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From: CLT, North Carolina
Go with the .024/ .028 gaps recommended. The increase in blowby would be nill; you would have difficulty measuring it. Do spend a little time carefully deburring them afterwards. Measure your ring ends with a micrometer to be sure you have removed the burrs. When ring ends are ground or filed it raises a burr along the trailing edge which will prevent the ring from sealing against the ring land in the piston. Of more significance is your choice of top ring, the quality of the pistons and thus the quality of the top ring lands and the straightness and roundness of your honed bores. It is absolutely imperitive for any performance small block buildup to use honing plates while finish honing the bores. Not using them would be a much greater source of blowby than just about anything else. The quality of your work and exactness of your measurements in machining and preparing components for the shortblock is the foundation of any engine build and will determine the success of the job.
Last edited by Greg Gore; Jul 1, 2007 at 04:14 PM.
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Go with the .024/ .028 gaps recommended. The increase in blowby would be nill; you would have difficulty measuring it. Do spend a little time carefully deburring them afterwards. Measure your ring ends with a micrometer to be sure you have removed the burrs. When ring ends are ground or filed it raises a burr along the trailing edge which will prevent the ring from sealing against the ring land in the piston. Of more significance is your choice of top ring, the quality of the pistons and thus the quality of the top ring lands and the straightness and roundness of your honed bores. It is absolutely imperitive for any performance small block buildup to use honing plates while finish honing the bores. Not using them would be a much greater source of blowby than just about anything else. The quality of your work and exactness of your measurements in machining and preparing components for the shortblock is the foundation of any engine build and will determine the success of the job.
I couldn't agree more. There's an old saying I remember from back in my oval racing days. It's called "The Five Ps." Prior Preparation Prevents Poor Performance.
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Pro
Joined: Nov 2005
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From: Bardstown Kentucky
Go with the .024/ .028 gaps recommended. The increase in blowby would be nill; you would have difficulty measuring it. Do spend a little time carefully deburring them afterwards. Measure your ring ends with a micrometer to be sure you have removed the burrs. When ring ends are ground or filed it raises a burr along the trailing edge which will prevent the ring from sealing against the ring land in the piston. Of more significance is your choice of top ring, the quality of the pistons and thus the quality of the top ring lands and the straightness and roundness of your honed bores. It is absolutely imperitive for any performance small block buildup to use honing plates while finish honing the bores. Not using them would be a much greater source of blowby than just about anything else. The quality of your work and exactness of your measurements in machining and preparing components for the shortblock is the foundation of any engine build and will determine the success of the job.
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