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Board of Directors (Jay)
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Discussion Starter #1
Here's a picture of what happens when ring end gap is not set correctly for Nitrous. The ring end gap went solid, and broke the piston part above. This is a fairly rare picture, as the piston came down on the ring, and locked it in the closed position.
 

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Board of Directors (Jay)
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43,454 Posts
Discussion Starter #2
Here's a picture of what happens when ring end gap is not set correctly for Nitrous. The ring end gap went solid, and broke the piston part above. This is a fairly rare picture, as the piston came down on the ring, and locked it in the closed position.
 

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Stu
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21,131 Posts
Here's a question for you Jay. A stock 5.7 hemi piston and rings, running 10 psi boost. What should the ring gap be at least? Or, running a 125 shot of NOS? These questions just popped in my head when I looked at that piston.
It makes me want to pull my engine out, take it apart, and add at least .015 more to my ring gaps.
 

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Board of Directors (Jay)
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43,454 Posts
Discussion Starter #4
Nitrous Street, .005 per inch of bore.
10 lb. boost, .006 per inch of bore
Nitrous Race, (250 horse, or more), .007 per inch of bore.

The above numbers are not "cast in stone", as other factors can come into play!
 

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Premium Member
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3,519 Posts
Another question Jay,

2010 Hemi Ram 9,400 miles Shifting 5950. Rev limiter 6200.

How large a shot of nitrous can I handle safely w/WOT switch over 3,000 rpms?

On Diablo Perf tune they say 3 degrees advance timing for that. So I'll deduct that first & 2 degrees @ every 50 hp shot.

Is my figuring correct? If not please enlighten me "Oh Knowledgeable One".
 

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Board of Directors (Jay)
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43,454 Posts
Discussion Starter #6
With the key word here, being safely, 100 shot, maybe 125. I'm sure we'll hear from members that have so far successfully used more. In yer case, the motor is just broken in. Still tight factory clearances. As a motor wears, cylinder bore will increase, thus making larger ring end gap. You need to clarify yer timing statement better, for me to answer.
 

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Premium Member
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3,519 Posts
To clarify my timing question:

DS claims to add 2-3 degrees in their canned perf tune.

I thought I should pull DS's 3 degrees before I pull an additional 3 degrees (6 total) for a 75 shot.

What do you think? Soon as I can find some decently priced headers I'll get a custom tune.

Thanks in advance.
 

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Board of Directors (Jay)
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43,454 Posts
Discussion Starter #8

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Board of Directors (Jay)
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43,454 Posts
Discussion Starter #12
How much NOS was the engine running with Jay? And was it the stock ring gaps?
Stu, I don't remember what I did yesterday, let alone a motor from a year ago.
 

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Board of Directors (Jay)
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43,454 Posts
Discussion Starter #13
The picture below shows an H beam rod, from a 600+ inch, big block Chevy. Customer ran well all last year with a 250 shot. The last run of the year he tried a 500 shot. As expected, rings went solid, locking piston to cylinder. You can see the elongation of the small end of the rod, as crank tried to pull it down, till the rod bolts let go. Four cylinder sleeves later, he's back up and running.
 

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Board of Directors (Jay)
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Discussion Starter #15
 
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