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Rings gap - 150 shot

Posted By: dart_73_br

Rings gap - 150 shot - 01/22/14 02:50 AM

Hello guys,

Need a help..

318 will run on ethanol + 150 shot..

Some ring makers says 0.0055" x bore size for 1st and 2nd rings....
But saw in a nitrous forum that should use a bigger gap in 2nd ring..

Cold you please give me your opinion...?

Thanks,
Posted By: Bigcube

Re: Rings gap - 150 shot - 01/22/14 03:05 AM

With a 4.440" bore this is how much I changed them for a healthy shot.

Top ring gap (N/A) .020
Top setting .032
2nd ring gap (N/A) .016
2nd setting .036
Posted By: Cab_Burge

Re: Rings gap - 150 shot - 01/22/14 06:16 AM

A lot wider is way better than a tiny bit to narrow, especially on NOS
Posted By: Crizila

Re: Rings gap - 150 shot - 01/22/14 04:42 PM

Quote:

Hello guys,

Need a help..

318 will run on ethanol + 150 shot..

Some ring makers says 0.0055" x bore size for 1st and 2nd rings....
But saw in a nitrous forum that should use a bigger gap in 2nd ring..

Cold you please give me your opinion...?

Thanks,

IMO, that aint gonna be enough. Follow the piston mfg's recommendations - and add another 3 - 4 thou to be safe.
Posted By: cheapstreetdustr

Re: Rings gap - 150 shot - 01/22/14 04:47 PM

it also depends on piston material.
forged aluminum has a different causation than
Hypereutectic pistons. i would look into what
your piston manufacturer recommends as well..
Posted By: dart_73_br

Re: Rings gap - 150 shot - 01/22/14 05:09 PM

Itīs KB KB399 hypereutetic one...

Iīve mailed their tech support but no answers so far... using moly rings with the hyper pistons...
Posted By: cheapstreetdustr

Re: Rings gap - 150 shot - 01/22/14 05:34 PM

i think the hypers end up with top ring gap at 25
i dont have my notes handy on that build...
KB will tell you the correct amount for sure.
Posted By: dart_73_br

Re: Rings gap - 150 shot - 01/22/14 05:38 PM

Found in their hyper catalog...

street nitrous:

TOP ring factor = 0.008 > 3.94 x 0.008 = 0,0315"
SECOND ring = 0.004 x bore > 0,0157"


I think thatīs it...
Posted By: Cab_Burge

Re: Rings gap - 150 shot - 01/22/14 07:28 PM

Quote:

Found in their hyper catalog...

street nitrous:

TOP ring factor = 0.008 > 3.94 x 0.008 = 0,0315"
SECOND ring = 0.004 x bore > 0,0157"


I think thatīs it...


No way in the world would I run the second ring that tight with your motor, maybe .031 or larger Most of the piston ring makers and the piston makers use to recommend numbers like that years ago, not now Almost all of the better companys recommend a bigger gap on the second ring than the top ring now The reason being is ring flutter at the upper RPM in a race motor
Posted By: mshred

Re: Rings gap - 150 shot - 01/22/14 11:20 PM

Quote:

Found in their hyper catalog...

street nitrous:

TOP ring factor = 0.008 > 3.94 x 0.008 = 0,0315"
SECOND ring = 0.004 x bore > 0,0157"


I think thatīs it...



That number for the second ring seems too tight to me, even on motor.

I followed my ring manufacturers instructions when gapping mine for the nitrous, and it recommended a larger ring gap up top then for the second ring...Then I posted about my gaps on another board, and was told by a bunch that the second ring gap should be bigger then the first to allow the trapped gases to escape.

I would say gap them larger then you actually want to spray, because you are going to want more pill size after a while, and the larger gaps really shouldn't hurt anything...but seeing your running hypers, I wouldn't push them too much...I'd be more comfortable spraying cast then hyper pistons, but thats just me.
Posted By: Cab_Burge

Re: Rings gap - 150 shot - 01/23/14 12:16 AM

Quote:

Quote:

Found in their hyper catalog...

street nitrous:

TOP ring factor = 0.008 > 3.94 x 0.008 = 0,0315"
SECOND ring = 0.004 x bore > 0,0157"


I think thatīs it...



That number for the second ring seems too tight to me, even on motor.

I followed my ring manufacturers instructions when gapping mine for the nitrous, and it recommended a larger ring gap up top then for the second ring...Then I posted about my gaps on another board, and was told by a bunch that the second ring gap should be bigger then the first to allow the trapped gases to escape.

I would say gap them larger then you actually want to spray, because you are going to want more pill size after a while, and the larger gaps really shouldn't hurt anything...but seeing your running hypers, I wouldn't push them too much...I'd be more comfortable spraying cast then hyper pistons, but thats just me.

Hypertitics(SP?) are cast pistons, they are not forged I'll bet you meant forged pistons for all out racing on NOS or any other power adder, yes?
Posted By: mshred

Re: Rings gap - 150 shot - 01/23/14 02:43 AM

Quote:

Quote:

Quote:

Found in their hyper catalog...

street nitrous:

TOP ring factor = 0.008 > 3.94 x 0.008 = 0,0315"
SECOND ring = 0.004 x bore > 0,0157"


I think thatīs it...



That number for the second ring seems too tight to me, even on motor.

I followed my ring manufacturers instructions when gapping mine for the nitrous, and it recommended a larger ring gap up top then for the second ring...Then I posted about my gaps on another board, and was told by a bunch that the second ring gap should be bigger then the first to allow the trapped gases to escape.

I would say gap them larger then you actually want to spray, because you are going to want more pill size after a while, and the larger gaps really shouldn't hurt anything...but seeing your running hypers, I wouldn't push them too much...I'd be more comfortable spraying cast then hyper pistons, but thats just me.

Hypertitics(SP?) are cast pistons, they are not forged I'll bet you meant forged pistons for all out racing on NOS or any other power adder, yes?



No, I meant what I said cab lol...As far as I know, cast and hypers are made from slightly different processes...I know both are touchy, but have always been warned that hypers are even more so and when they let go, it's a little nastier (although at that point, pain is pain lol).

Of course, I could be all wrong...I have only ever sprayed a forged motor- it was a safety net for an idiot like me lol
Posted By: 1967dartgt

Re: Rings gap - 150 shot - 01/23/14 02:45 AM

Hyper and moly rings not best choices for nitrous.
Posted By: Leon441

Re: Rings gap - 150 shot - 01/23/14 03:02 AM

150 is not that much... But, most people who intend to run 150 end up with more.

NO WAY IN HADEES I would run that gap on a second ring. But, that said I do not follow the flock with the larger ring gap on the second ring. The idea is whatever gets below the top ring should have extra room to get by the second. Ring flutter comes from pressure between the rings. Keep it up and eventually you put so much pressure between them with a little heat in the valve pocket and you lift the land. The top ring will always see more heat than the second. Which equals more ring expansion in the top ring. I set my gaps the same but, ran fairly large gaps.

Leon
Posted By: Bigcube

Re: Rings gap - 150 shot - 01/23/14 03:15 AM

The one thing to add is typically top ring and second ring are not the same material. 2nd ring is usually cast with a "good" top ring, be it Moly, or whatever.
Posted By: dart_73_br

Re: Rings gap - 150 shot - 01/23/14 03:20 AM

Guys, this juice stuff might be addictive but I know this hyper are crap for large nitrous shot so thats why I'm limiting it to 150. And thats what I have now.. So... Will put it together and have some fun....
Posted By: mshred

Re: Rings gap - 150 shot - 01/23/14 03:40 AM

Quote:

Guys, this juice stuff might be addictive but I know this hyper are crap for large nitrous shot so thats why I'm limiting it to 150. And thats what I have now.. So... Will put it together and have some fun....



Correction: not MIGHT be addictive but WILL be addictive.

Take it from me, especially if you have the pistons out and have not balanced them yet...Sell your pistons and rings, get a forged piston and non moly rings and put them in with a gap that is sufficient for say a 200-250 hit....When the addiction kicks in, you'll be glad you did it


Just my ...good luck and have fun with it regardless !
Posted By: Crizila

Re: Rings gap - 150 shot - 01/23/14 03:45 AM

Quote:

Quote:

Found in their hyper catalog...

street nitrous:

TOP ring factor = 0.008 > 3.94 x 0.008 = 0,0315"
SECOND ring = 0.004 x bore > 0,0157"


I think thatīs it...


No way in the world would I run the second ring that tight with your motor, maybe .031 or larger Most of the piston ring makers and the piston makers use to recommend numbers like that years ago, not now Almost all of the better companys recommend a bigger gap on the second ring than the top ring now The reason being is ring flutter at the upper RPM in a race motor

Both those #s are a little tight, but hypers have an expansion chamber between the top and second rings to address ring flutter. I have run those style pistons with .034 on the top ring and .017 on the second ring with no problems, A 150 shot will work with those pistons if you go easy on the timing and run it cold as you can - water injection, etc.
Posted By: D-50

Re: Rings gap - 150 shot - 01/23/14 03:55 AM

I used to run the KB hyper pistons in a 360 back in the 90's. I gapped the rings for nitrous like the instructions said . I never ran less than 150 shot and ran 175 some times. I had the kb 107's and J-heads. I always ran about 28* timing and 93 octane fuel.Never had any problems...

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