Changing from pump gas to alky

[252wheelieking]

I wanted to change over from pump gas to alcohol & had a few guys tell me that all I had to do is switch the carbs over to alky carbs bolt on a fuel pump & GO! Then I had a couple of people tell me I had to change my 21cc gas domes over to alky domes with the switch of alky carbs. & fuel pump. I just wanted some safe suggestions on how to go about the switch. Thanks BHQ for all help.

[Josh Z]

I wanted to change over from pump gas to alcohol & had a few guys tell me that all I had to do is switch the carbs over to alky carbs bolt on a fuel pump & GO! Then I had a couple of people tell me I had to change my 21cc gas domes over to alky domes with the switch of alky carbs. & fuel pump. I just wanted some safe suggestions on how to go about the switch. Thanks BHQ for all help.

if you are gonna run alky you need alot of compression. like in the 180s. you do need to do carbs, a pump, and drill your fuel cap as well so you can get enough flow. and you want to start way rich and slowly lean it out. It only takes a second of running lean to really cause some damage with alky.

[tidos76]

thats correct you want at min 170lbs of compression. alky LOVEs compression higher the better. i had a friend running 205lbs on alky. not safe but it screamed. depending on your elivation i would run atleast 16cc domes. on a stock stroke/bore motor it should put you at about 180-190lbs.

 

you will need alky carbs. IMO atleast 35mm. you can buy carbs and have them changed to alky by any builder or just buy some that are already done. you dont HAVE to run a pump. if your staying wide open for a good period of time you may want one. oversized bowls will help also.

 

you will need a dual pingle and need to mod your gas cap to alow more air in. and change your plugs to a b9es and advance your timing to 6 as a starting point and go up from their.

 

keep in mind if you dont know how to tune DONT switch to alky. its not as easy as gas and will toast your motor FAST if you run too lean

[J-Madd]

You don't have to run higher compression or timing; but you won't get the full benefit of running alky if you don't. Is the motor ported? Not much to be gained on a non-ported motor. It can give you about 7% more hp, so If you've only got 40 or 50, it ain't worth the headache for 3 hp. It does run much cooler than gas, though - that can be a benefit; but you use twice as much, so you won't get very many miles per tank.

[KickStartMyHeart]

Buy lectrons. Im switchin my 421 cub to alcohol and picked up a set of 41mm lectrons. They are sooo damn easy to tune. It takes a lot of work outta drillin ur carbs for powerjets etc...