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Discussion Starter #1
The wet kit I have requires a fuel pump. I have the proper pump it's like 4-7psi pump. My question is should I just run the fuel tank to the fuel pump then tee off to the carb and to the fuel solenoid from the pressure side? Basically making it a full time pressurized system.

Or should the fuel feed be split from the tank and a gravity feed the carb as before and gravity feed the pump inlet and only run the pump when nitrous system is armed?
 

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Discussion Starter #4
Thanks for the replies guys. I was just wondering if I could feed the carb with fuel from the pump as well as the fuel solenoid. Would the needle and seat on a super G work OK that way? I have a pingle single output pet cock a high flow. Does pingle make a dual output one?
 

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Thanks for the replies guys. I was just wondering if I could feed the carb with fuel from the pump as well as the fuel solenoid. Would the needle and seat on a super G work OK that way?
I wouldn't, it's not designed for a pressure system.


Does pingle make a dual output one?
Yes, that is why it was recommend twice. They even make a triple outlet.
 

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Discussion Starter #8
I have two 2.5lb bottles. Its all dynotune parts using a Tomahawk single nozzle drilled in just before the carb. Can be jetted up to 150hp shot. I'm only running a 50hp shot. It's going on an S&S V124 with 640 cams. Should be fun hopefully no go boom. I'm running a handle bar button switch that goes through a full throttle micro switch for safety. Opted not go for a window switch. Plan to hit the juice at 2500rpm and cut at 6000.rev limiter set at 6300 though I may move that to 6500
 

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Can you elaborate for us mechanically impaired?

Sent from here to there.
top rings need a larger gap than normal for nitrous although at a 50 shot occasionally I doubt it's really necessary.
The upper ring gap needs to be wider to account for the higher combustion chamber temperatures.

I'm going to disagree on the 50 shot not needing it. On an air cooled engine any amount of nitrous should have the gap opened up. And with these big motors having almost no skirt area, its even more important.
 

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So the larger ring Gap is for thermal expansion?

Sent from here to there.
 

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Discussion Starter #15 (Edited)
Oh boy...... At what horse power shot would you say is safe without that? Planned on occasional use but yah... I'm me... Ugh didn't think if I went with a 50hp shot it would need any mods. But your advice is well headed racing for the finish on the project in the next couple months a motor tear down isn't gonna happen now. But I'm not looking to blow $hit up for a missed step. I won't be hooking up the juice till after the dial in of the new G with thunderjet. Gotta get it tuned perfect, wasn't rushing for the juice right away. If would be wise hold off the juice till winter I'm fine. As always great to have you guys around lookin out thanks. Also got cold range plugs will that help?
 

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So the larger ring Gap is for thermal expansion?

Sent from here to there.
Yes.

Oh boy...... At what horse power shot would you say is safe without that? Planned on occasional use but yah... I'm me... Ugh didn't think if I went with a 50hp shot it would need any mods. But your advice is well headed racing for the finish on the project in the next couple months a motor tear down isn't gonna happen now. But I'm not looking to blow $hit up for a missed step. I won't be hooking up the juice till after the dial in of the new G with thunderjet. Gotta get it tuned perfect, wasn't rushing for the juice right away. If would be wise hold off the juice till winter I'm fine. As always great to have you guys around lookin out thanks. Also got cold range plugs will that help?
Plugs make no difference on the ring expansion.

The amount of nitrous is not the whole issue.

Its a heat and time issue. The time is under your control, the heat is not.

The nitrous is an oxidiser. And just like with air and fuel, a skinny mix burns hotter than a fat mix. The mix is more important than the amount of Nox added to the cylinder as far as ring are concerned.

Rather than blaze new trails on this, I would ask some of the companies that build Nox motors for advice as to how wide the gaps should be. The cost of adding some ring gap is a hell of a lot less than the cost of jugs and pistons.

You may find that that there is already enough gap on that 124. S&S tends to be pretty liberal with stuff like that on their street motors.
 

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Discussion Starter #19
According to S&S's own piston gap calculations it says for nitrous on a 4 1/8" piston it comes out to .00226 recommended gap. Still can't find what factory gap is set at
 

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Discussion Starter #20 (Edited)
S&s V124" max rpm? Right now set at about 6300 pulls good right to the limiter. Warranty is just about up so I'm clear to toy with settings. What would you figure "safe" max at? At what rpm do the 640 cams fall off? Or wise to keep it where it's at? Probably have it dyno tuned just be safe with the Juice mix ratio and make sure it isn't lean
 
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