Alky Carb Setup

I am thinking of making the switch to an alky carb setup for drag racing only. I have some knowledge on this topic & my cousin runs alky on his drag zilla. My question is what size of carb to start with? I was thinking along the lines of a lectron, but not real sure....40mm?
Right now, my motor is a 330 w/ CT pipe & 38mm airstriker.

Thanks for any help...let me know if more info is needed.

[zedicus00]

41mm is pretty common carb size for that size engine on alky. actually 39 - 41 is the common range. you will c lots of bored carbs too, like a 39 can be taken to 40.5mm. and usuaully the drag crowed straight bores there carbs instead of taper boring.

[TRX370R]

I picked up a alky carb for my 370, it's a 40.5mm.......haven't really did much tunning on it very much only tried it a couple times but when I did....what a difference over the race fuel. Did have a problem of starving for fuel on the top end in high gear due to lack of flow though the stock petcock, will have to install a fuel pump or just blow though the vent tube haha.

[beerock]

yea i believe a fuel pump is needed for alky.

[JeremyKS]

if you take the stock petcock off you can get by without running a pump unless your hill shooting...another thing you got to watch on the Pro X pistons is that you will have trouble keeping the piston together, I believe ESR has made a special piston now that is lasting much longer than their regular piston.

[wilkin250r]

BIG jets.

I think your logic is backwards. I don't think alcohol favors a particular carb "size". Rather, alcohol is generally used only in drag-racing, and drag-racing favors larger carburetors, since they generally don't care about low-end power or throttle response.

If anything, I would imagine alky would work better on a smaller carb, because it would increase intake velocity. However, a smaller carb will also reduce top-end power, which is counter-productive.

So, alcohol or not, for drag racing you want a large carb, I'd say at least 40mm for a 330.

[methyman]

Originally posted by JeremyKS
I believe ESR has made a special piston now that is lasting much longer than their regular piston.

I must correct you on that. Wiseco reinforced the piston on the big bore pistons around the intake window and the piston pin area. I know because I have the old version piston and the new one and I can see the difference. Jay at ESR told me that Wiseco changed it and it was not ESR that changed it. Wiseco did it on there own. The new design is now holding up to the Methanol with out and problem like cracking like the older design. Also a Pro-X piston will not stay together on methanol.

[methyman]

Originally posted by CT_330R
I am thinking of making the switch to an alky carb setup for drag racing only. I have some knowledge on this topic & my cousin runs alky on his drag zilla. My question is what size of carb to start with? I was thinking along the lines of a lectron, but not real sure....40mm?
Right now, my motor is a 330 w/ CT pipe & 38mm airstriker.

Thanks for any help...let me know if more info is needed.

I have a Packard Lectron 44 MM carb on my 330 ESR motor that is gasoline. I talked to Dennis Packard about going to Methanol and he said he used the exact same carb for methanol but changes the needle and make it a dual power jet. Any carb 40.5 mm to 44 mm I would think will be ok. You need to either run a pingel fuel valve or drill ouit your stock one, remove screen. Drill and tap the side of the cylinder to put an fitting for vacum for the fuel pump. I like the lectron because of the ease of tunning it. Simple.

[JeremyKS]

sorry I thought it was esr that had a new alky piston. I new the orginal pro X pistons were not lasting more than a few hrs on alky but didn't realize it was wiseco that had made the changes to the pistons. but it makes sense.