Ring Gap Effect on NA Power?
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Melting Slicks
Joined: Oct 2004
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Ring Gap Effect on NA Power?
I currently have a 383 in my Z06 that is setup for N2O. The diamond pro select rings are gapped at .026 and .028 and I am curious as to what effect this has on the motor when I am off the bottle. I understand the larger gaps are so they can expand with the increased heat from the nitrous, however, when off the bottle how does it affect the motor and how does it affect performance? All help is greatly appreciated.
Racer
Joined: Mar 2006
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From: silverdale washington
you will definitely get a little blow by with the larger gaps. and lose a minimal amout of horsepower due to this lost compression. Not sure of exactly how much power would be lost. We had a 396 ford small block w/ 15.8:1 cr that made 737 hp on engine dyno, then changed rings for nitrous and made somewhere around 660 hp on engine dyno. However it then made 1103 hp on engine dyno which was about a hundred more than it made with old rings. There are trade offs, but im sure at a modest cr your loss wouldnt be nearly as pronounced.
Thread Starter
Melting Slicks
Joined: Oct 2004
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thank you for your reply. other than reduced NA power, are there any other effects this has on the motor? is it causing more wear on the motor? does this change anything at all when I am calculating the static compression ratio or the DCR? all help is greatly appreciated as Im curious as I have never had a nitrous built motor before.
Pro
Joined: Feb 2006
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From: Vancleave Ms.
Over on the Hardcore 5.0 forum is a guy who owns Probe Industries. He has been hotrodding for more years than I have been alive. Mark O'Neal(owner of PI) did some testing of a big block with ring end gaps and found no difference in power to the wheels with larger gaps. I don't know exactly how scientific his studies were, but I trust him....I don't think the extra gap will hurt you. James
Racer
Joined: Mar 2006
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From: silverdale washington
It definitely will not hurt especially with a modest cr. It is the right thing to do for sure. I dont know if you can actually calculate the change in dcr or not. There will definitely be a change. If you use actually cylinder pressures you should see the change but like I said im sure its not much. It will actually cause less wear and tear on the motor due to less friction when na. This is why when most people do it they wont see a major change in the horespower because you are getting some blow by but you also have less friction on the cylinder walls, When you have big cr's though the blowby is alot more noticeable. Not sure what it would be like at 10.19 or 10.46 :1. never built a race motor to run on pump gas and a low cr. Dont have to much ls1 specific knowledge im sure some of these other guys that have done it would know more specific details.
Thread Starter
Melting Slicks
Joined: Oct 2004
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are there any other things I should do or be concerned with due to the increased blow by? Like I said, all info is appreciated as Im just curious on the subject and would like to learn more about it.
Racer
Joined: Mar 2006
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From: silverdale washington
Possibly vacuum, thats about all I can really think of. I know the ls1 has alot of good design characteristics that differ from older sbc's especially in how they breath on the bottom end. So that would be a more specific question that you might as someone with more ls1 specific knowledge.
