Author Topic: Low percentage of Nitro with Carb  (Read 5205 times)

Offline alkyal

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Low percentage of Nitro with Carb
« on: October 16, 2015, 10:11:26 AM »
Like others, Need a little extra power. Running pure methanol thru an Alky Specific Carb. Currently the Carb is set-up to run on the rich side. Only want to run approx max of 10 % . Due to components in Engine. Biggest factor being the CAST Hyper pistons and the PM rods. Have access to nitro and have a FIE hydrometer set-up. Thanks

Offline Spud Miller

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Re: Low percentage of Nitro with Carb
« Reply #1 on: October 16, 2015, 10:18:12 AM »

 Sure, your system will do it and you'll see a power gain. I'd start with 5%. If things look ok, try increasing a couple of percent at a time. I think you'll find that you need to richen the jets and idle in the carb. So, if you're prepared to do that, 10% shouldn't pose a problem.

Keep in mind that reducing timing a few degrees to start with would be a good idea. Also running some toluene in the fuel (one quart per 5 gallons) would help to reduce the chances of destructive detonation. That's been covered in other threads here.

If you start detonating, it could make quick work of those rods and pistons.

 Spud

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Offline alkyal

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Re: Low percentage of Nitro with Carb
« Reply #2 on: October 16, 2015, 12:26:00 PM »
Thanks for your quick reply. Flat Top 350 engine With CI heads. Running locked ignition now @ 34 deg total. What amount would you recommend for total timing. On pure Alky the best HP-TQ on the dyno was @ 36 deg total timing. Will for sure add the Tol. as per a previous post of yours. Thanks again for your help. Al

Offline Spud Miller

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Re: Low percentage of Nitro with Carb
« Reply #3 on: October 16, 2015, 12:30:33 PM »

 34 degrees outght be fine for flat tops. Try a couple more later after you know things are working.

 Spud

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Offline ricardo1967

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Re: Low percentage of Nitro with Carb
« Reply #4 on: October 16, 2015, 07:31:44 PM »
Prediction... once you get hooked, you won't stop at 10%...

What the compression ratio?

Offline alkyal

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Re: Low percentage of Nitro with Carb
« Reply #5 on: October 17, 2015, 09:46:22 AM »
C/R is approx 9.2 to 1.  dont know if we will even get to 10% Its a one time deal with this engine and dont want to hurt it. I know what you mean about wanting to "tip the can". Have been around nitro since the late 60s, I just havent been in this situation. This should be fun, as this group hasnt been subjected to the Nitro Bug! Will post how it went.

dreracecar

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Re: Low percentage of Nitro with Carb
« Reply #6 on: October 17, 2015, 11:02:11 AM »
Unless rule prohibate , why not a simple 50hp shot of Nitrous,  no mixing, no temp variance, no hydrometer, consistency, simple when needed push button on steering wheel. Jetting in the carb remains the same

Offline alkyal

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Re: Low percentage of Nitro with Carb
« Reply #7 on: October 17, 2015, 07:47:16 PM »
Cant do Nitrous in this case. Already have access to more Nitro than we need. Thanks for your input.