Holley alcohol carb

[Retroboy]

Howdy and help. I have what I was told is an 850 Holley methanol carb. Did Holley build such a thing? I can only find references to 750 and 950 for meths. It has no choke horn and on the primary metering body it has L 47812 stamped so a quick cross reference to the Holley number reference on their page tells me it's an 850. It has Annular boosters (the rears are loose which doesn't seem normal?), 50cc pumps 4 corner idle screws. It has P32 cast into the body and I know that smarter people than me know that means something but I suspect it's only going to tell me it's an 850. I had a look at the jets - primary are approximately .140" numbered 72 (re drilled?) and the rears are a hex shaped thingie that screws into the metering body with about .150" drilling. How do I know what size the needle and seats are they aren't numbered? but have 4 square openings about again about .150". I specifically told the guy I got it from it didn't want some bodgy home converted thing but I'm starting to think that's what I've got.
Can anyone tell me what the go is with this. It's been 30 plus years since I looked at a carburettor.
Cheers
Tony

 

[pishta]

alcohol carb jets are sometimes no jets at all, just the threaded bosses! The hex things are jets that are so big that the screw drive tangs could not be machined as the jet orrifice is so large. All ports are larger on an alcohol carb as its very low on the BTU scale or whatever is used for fuels so it requires like 3X as much for the same power, but the octane is like 150 (?) Loose boosters just need to be swedged again, can do it with a ball pein hammer, all they are are tubes pressed into a boss.

 

[Retroboy]

Well I've been thinking and the rear jets are a hex shaped thingie so they can be screwed in and out by a nut driver and they are longer so they are jet extensions. I don't know if it's a factory Meth carb but I measured the venturi and bottom butterfly and it is definitely an 850. Tightened the two loose boosters no probs so I'm just going to clean out the main body and the float chambers and call it good. Now I need to talk about the fuel pump but that's for another post.
Cheers
Tony