Magnum on nitrous!?

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Jonnylightening

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So after my teen ate its cam I found a Magnum 360. It's currently at the machine shop so I have some time on my hands. I'll be using the stock bottom end with new rings and bearings. My question is with a 125-150shot max what piston rings should I go with? Hastings has a set with a plasma-moly coated ductile top ring for around $80? Opinions on these?
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I have no idea, but I am so in for the answer.
I do know you will need to open up the ring end gaps some.
 
So after my teen ate its cam I found a Magnum 360. It's currently at the machine shop so I have some time on my hands. I'll be using the stock bottom end with new rings and bearings. My question is with a 125-150shot max what piston rings should I go with? Hastings has a set with a plasma-moly coated ductile top ring for around $80? Opinions on these? View attachment 1715552579
Double check the application of those rings. I thought the Magnum rings were different sizes than LA, and these look like LA sizes.
I may be wrong, but double check before ordering.
 
So after my teen ate its cam I found a Magnum 360. It's currently at the machine shop so I have some time on my hands. I'll be using the stock bottom end with new rings and bearings. My question is with a 125-150shot max what piston rings should I go with? Hastings has a set with a plasma-moly coated ductile top ring for around $80? Opinions on these? View attachment 1715552579
Somehow I think ring gaps are more of a concern at the upper levels of nitrous...
 
More power means more heat, more heat means things expand more.

Piston and ring land location is more important when gapping. Wouldn't hurt to add a couple thou to the gap, .004-.006. With a hyper piston, going from .024 to .030, isn't gonna do anything to hurt power. Forged piston from .016 to .020/.021. It won't hurt performance and will provide a margin of safety when juicing.

Used to be an issue with plasma flaking off when juicing. I think those rings will be fine.
 
More power means more heat, more heat means things expand more.

Piston and ring land location is more important when gapping. Wouldn't hurt to add a couple thou to the gap, .004-.006. With a hyper piston, going from .024 to .030, isn't gonna do anything to hurt power. Forged piston from .016 to .020/.021. It won't hurt performance and will provide a margin of safety when juicing.

Used to be an issue with plasma flaking off when juicing. I think those rings will be fine.
I was under the impression that the nitrogen had a cooling effect as well? I'm not thinking a compensating amount for the power received but some? Do you think there's a certain power level where this must be addressed?... And on the opposite side of the coin do you think there's a juice level that it doesn't matter?..
 
Double check the application of those rings. I thought the Magnum rings were different sizes than LA, and these look like LA sizes.
I may be wrong, but double check before ordering.

Isn't 5/64 5/64 & 3/16, LA not magunum? Like said double check.
 
The cooling effect happens as the nitrous hits your intake manifold making a cool dense A/F charge.
However the combustion chamber will ultimately be hotter as your spraying.

When the nitrous is in the tank it’s in a compressed liquid stage.When your solenoid opens the nitrous tuns into a gaseous state which in turn will be around -125*F.....
That’s why it’s important not to have your hand getting exposed to the nitrous purge discharge as that may result in frostbite.

I tend to gap my second ring slightly larger that my top ring. Supposedly this will stop ring “flutter”
Piston manufacturers have tech info on their website.
 
ueprint-series-the-how-and-why-of-setting-piston-ring-end-gap-2018-09-25_16-52-02_045553-960x275.jpg

These are the minimum recommended ring end gaps, per inch of bore, as recommended by JE Pistons. Other piston or ring companies may offer slightly different recommendations. Per this chart, a 4.500-inch-bore big-block Chevy that will see moderate nitrous would need a (4.50 x .005) = 0.0225-inch top ring gap and a (4.50 x .0055) .02475-inch second ring gap, rounded to .025 inch.

You may also notice that the second ring gap is recommended to be slightly greater than that of the top ring. Not all that long ago, accepted practice was to tighten the second ring gap over the top ring’s. However, testing has revealed that increasing the second ring gap relieves pressure buildup in between the top and second rings, which can partially unload the top ring and induce leakage.

Keep in mind that the primary job for the second ring is not to seal compression but instead to squeegee any remaining oil off the cylinder walls left by the oil rings. It’s is the second ring’s secondary job to help seal cylinder pressure.


From JE Pistons website
 
View attachment 1715553211
These are the minimum recommended ring end gaps, per inch of bore, as recommended by JE Pistons. Other piston or ring companies may offer slightly different recommendations. Per this chart, a 4.500-inch-bore big-block Chevy that will see moderate nitrous would need a (4.50 x .005) = 0.0225-inch top ring gap and a (4.50 x .0055) .02475-inch second ring gap, rounded to .025 inch.

You may also notice that the second ring gap is recommended to be slightly greater than that of the top ring. Not all that long ago, accepted practice was to tighten the second ring gap over the top ring’s. However, testing has revealed that increasing the second ring gap relieves pressure buildup in between the top and second rings, which can partially unload the top ring and induce leakage.

Keep in mind that the primary job for the second ring is not to seal compression but instead to squeegee any remaining oil off the cylinder walls left by the oil rings. It’s is the second ring’s secondary job to help seal cylinder pressure.


From JE Pistons website

Makes one wonder how gapless second rings work ! Mine have finally seated , ''I think." -----6'' of crankcase vacuum now , no tricks to get it .-------??
 
Makes one wonder how gapless second rings work ! Mine have finally seated , ''I think." -----6'' of crankcase vacuum now , no tricks to get it .-------??

Some Zero gap rings “overlap”

Some have a “rail” ring used in conjunction with a ring. So ultimately one would set the gap in the ring and the rail is providing the Zero gap function.

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55CBBDAD-0F6B-4C26-B95B-9C3ED15DCECC.jpeg
33D9401A-3E12-4B4B-8061-967FB81D6910.jpeg
 
Some Zero gap rings “overlap”

Some have a “rail” ring used in conjunction with a ring. So ultimately one would set the gap in the ring and the rail is providing the Zero gap function.

View attachment 1715553360
View attachment 1715553361 View attachment 1715553362

Yeah, I always wanted to try the childs and albert rings , but they are way more expensive than the total seal rings. I have had the gapless total seal rings in 3 engines now , no complaints . Always wanted to try the top gapless total seal too.
 
Yeah, I always wanted to try the childs and albert rings , but they are way more expensive than the total seal rings. I have had the gapless total seal rings in 3 engines now , no complaints . Always wanted to try the top gapless total seal too.

Yeah, I never used Zero gap rings but I like Total Seals system as the gap in the ring creates a void ( or a port) that allows the compression in and push the ring up against the cylinder walls.
Almost like a “gas ported” piston.
 
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