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can I convert a used alcohol carb to gas?

Posted: Fri Apr 18, 2008 11:30 pm
by bobbybigblock
I need a affordable used carb on the large side. I only found a 1,000cfm holley alky carb. Is the conversion complicated?

Posted: Sat Apr 19, 2008 12:33 am
by econo racer
IMO No! not without changing out a lot of costly stuff-Metering blocks etc :(

Posted: Sat Apr 19, 2008 12:51 am
by jmarkaudio
Metering blocks and boosters, air bleeds may have been changed. It would be almost easier to run Alcohol.

Posted: Sat Apr 19, 2008 2:07 am
by Ron Golden
Rejet it to an 1000cfm gas carb and try it. It may not be a BLP custom carb for your specific engine, but try it and see what happens. You have to remember that having the perfect carb, headers, gear, intake doesn't keep you from having fun, and you'll learn what works and what doesn't.

I'll bet all of us on Speedtalk started with a 4 barrel, headers, and a lot of gear and had a blast. Since then we've gotten smarter(?), spent a hell of a lot of money and didn't have any more fun..... we just go faster.

Ron

Re:

Posted: Sun Nov 01, 2020 2:53 pm
by n5ifi
jmarkaudio wrote: Sat Apr 19, 2008 12:51 am Metering blocks and boosters, air bleeds may have been changed. It would be almost easier to run Alcohol.
I had Pro Systems do one the exact opposite successfully for me years ago. I don't remember the cost but it wasn't a lot to do it at that time and it wound up being fairly close to correct right out of the box. It seems I had to change the idle jet size and maybe some bleeds to get it right.

Mark I quoted you in this thread hoping you are Tuner would see a post I have in engine tech.

Re: can I convert a used alcohol carb to gas?

Posted: Sun Nov 01, 2020 4:16 pm
by 1980RS
I switched one over to gas, just changed the metering blocks and the air bleeds, worked fine for me.

Re: can I convert a used alcohol carb to gas?

Posted: Sun Nov 01, 2020 7:30 pm
by swampbuggy
1980RS, Those metering blocks had to have had a Lot smaller Main jets for sure, Mark H.

Re: can I convert a used alcohol carb to gas?

Posted: Sun Nov 01, 2020 8:33 pm
by 1972ho
If they drilled those two extra holes above the meter blocks jets you will need another block and if they opened the main well also you need another block.

Re: can I convert a used alcohol carb to gas?

Posted: Sun Nov 01, 2020 10:18 pm
by 6.50camaro
I converted a Bolaws 650 I had picked up at a swap meet back to gas 25+ yrs ago before I know you couldn't . Got a old junker Holley from a friend .used the metering blocks from that and jetted it for gas and ran it that way for 3 or 4 yrs till I had the money to buy a better bigger 750 .Did it work the best ,I don't know it was the first engine I built and I could stay right with or finish better than my 2 byddies racing the same class so I has happy.

Re: can I convert a used alcohol carb to gas?

Posted: Mon Nov 02, 2020 8:31 am
by 1980RS
swampbuggy wrote: Sun Nov 01, 2020 7:30 pm 1980RS, Those metering blocks had to have had a Lot smaller Main jets for sure, Mark H.
They did as I know you need to go a lot less. I just used an old 650 QF HP E-85 over to gas as one of the boosters was bad from the factory. I put some A/D boosters in the pri side I had out of another carb in the Old QF body, added 2 QF gas metering blocks and it's done. Just never got time to test it out this year.