ALCOHOL CARB QUESTIONS ??

Posted By: mrplymouth

ALCOHOL CARB QUESTIONS ?? - 12/05/09 03:31 AM

Hey guys, need some help, we just finished a 540 cid B1-Bs head piece, its right at 13.3:1 comp and we are thinking about running it on Alcohol....Questions, What is the exact or proper name for the alcohol being used, ??? Is it Methanol ??? How much cooler can we expect the engine to run ??? How much more timing can we give it ??? I've never been past 36 Degrees with a big inch mopar before....Also, what type of power gain is normally seen with alcohol over say c-12 or c-16 ???And where roughly do I need to start with jetting an alcohol carb ??? Any and ALL help would be great.

Posted By: WILD BILL

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 04:11 AM

Man I wish I could help you with all that. I do know that the alky is methonal and that it will run cooler (when in proper tune)

Hopefully this will at least get the ball rolling.

Posted By: W5Dart378

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 04:22 AM

Some where close to a .200-.210" main,metering blocks and boosters and needle and seats to support the flow.. You will pick up a good bit of torque around 5000 to 6500 and loss a little in the upper rpms. My need to drop a tooth or two on the ring gear.

Posted By: MR_P_BODY

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 04:35 AM

Methanol or E-85, I run E-85 with 14.1:1 and see about
20* cooler water temps vs 112 octane.... just the carb
change(the rest of my fuel system could handle the
30% increase in flow)

Posted By: MegaDart

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 12:24 PM

Quote:

How much cooler can we expect the engine to run ???

A lot cooler, in fact once properly tuned you will only use your fan on occasion. Getting heat in it is more difficult then cooling, I would suggest a leanout valve and a vac pump to suck out the condensation/alky.

Quote:

How much more timing can we give it ??? I've never been past 36 Degrees with a big inch mopar before....

It may not want more then 36. I would start a few * low like 32-33 make some hits and read the strap on the plug and et slip to see where it is happy

Quote:

And where roughly do I need to start with jetting an alcohol carb

without knowing who's carb you have that one can not be properly answered. No 2 carbs are built the same. I had a Rupert 1050 on a motor similiar to yours that ran 164 jets. Same motor with APD carb had 192 jets. Best to get a good carb from a reputable builder and use what they say.

Posted By: mrplymouth

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 01:52 PM

OK, thanks for all the info, I am sure our fuel system will cover the 30% difference /increase in fuel flow, we have a Magna fuel pro 500 pump and regulator, -10 line, etc.

2 more questions, what do we start with as far as plug heat range's ??? NGK 7,8, or ???

We do have a vac pump on the car and will change the oil very very often, say every 5-6 passes, but has anyone seen any signs of premature wear or bearing failure do to the alcohol ??? Maybe thats a stupid question, but I dont know anything about this and for years we've ran C-12 and felt like we had a really good handle on things, never had any oiling issues and tried very hard to stay on top of everything. Now I feel like one small change and I'm kinda lost, thanks for all your help.....I am looking at a 1250 Rupert, but I think it might be a little too big for my 540 ???

Posted By: MegaDart

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 02:20 PM

Quote:

OK, thanks for all the info, I am sure our fuel system will cover the 30% difference /increase in fuel flow, we have a Magna fuel pro 500 pump and regulator, -10 line, etc.

2 more questions, what do we start with as far as plug heat range's ??? NGK 7,8, or ???

We do have a vac pump on the car and will change the oil very very often, say every 5-6 passes, but has anyone seen any signs of premature wear or bearing failure do to the alcohol ??? Maybe thats a stupid question, but I dont know anything about this and for years we've ran C-12 and felt like we had a really good handle on things, never had any oiling issues and tried very hard to stay on top of everything. Now I feel like one small change and I'm kinda lost, thanks for all your help.....I am looking at a 1250 Rupert, but I think it might be a little too big for my 540 ???

you've got plenty of pump for sure.
As for plugs I like to run a cold plug but IMHO NGK -8 or -9 would work well for you. If you have room for a projected tip it is worth a few hp. I am running AR3932 in my alky carbed 555ci 1000hp. Rupert 1250 is a GREAT carb, I won first time out with mine. It may be too big for your combo though. I ran a Rupert 1050 on my 540ci and it rocked! Talk to George he will set you up right. You will not need to change oil that often once your setup is right. I change mine 20-30 passes. First freshen up at 300 runs showed no premature wear on any parts due to alky

Posted By: 440Jim

Re: ALCOHOL CARB QUESTIONS ?? - 12/05/09 02:21 PM

I agree with MegaDart.
The 30-40 percent is for E85, for methanol it should be sized for double the flow of gasoline, IMO. The pump must be designed for methanol (alky) for material/seal compatibility.

At 13.3 CR, I would start with an NGK -9 heat range. But you might be able to run one step hotter -8.

And if the fuel/air mixture is setup right, and you use a lean out valve in the pits, put proper heat in the water, etc, then you won't have oil problems and 20-40 passes should be fine. Especially with a vacuum pump pulling moisture out of the crankcase. Check the oil a few times when you first start running alky to make sure.

And run a top end lube in the alcohol.

IMO, you will see the most ET gain in the hot weather (85-90 degrees F), and less in the cooler weather (50-70 F).

Posted By: mrplymouth

Re: ALCOHOL CARB QUESTIONS ?? - 12/06/09 05:04 PM

Thanks for the info....The only reason I was thinking about the 1250 carb, is there is one thats almost brand new and the fellow wants it sold.....