Funny thing about wax casting- I have a customer of mine who does museum reprodutions of all kinds, (you name it they do it). Called Sanders Museum Services. Members of the guild practice the art of lost wax casting at his shop on Shepherdstown, WV. I watched a bit of the process. It is very, very cool. I totally respect artisans with that kind of ability.

You may know them (or some of the artisans), Sterling. Craftsmen travel from all over the country to work on some of his projects..

(Sorry to digress- just thought it interesting it came up)

BTW- I cannot wait to send my Nikki for the 'rebuild'. Yesterday I took my RX7 out for the first time since October..It told me it WANTS it, BADLY. I cannot dissapoint the rotary gods! (There- something for the benefit of this thread!)

 

Interesting about lost wax casting. You're giving me thoughts. Well, okay, I had thoughts before but... ah hell, I'll just say what's on my mind.

I've been thinking about slide carburetors, as seen on motorcycles. Specificially the Keihin FCRs, which use a flat slide on roller bearings. For those of you not familiar with what I'm talking about, these are called variable venturi carburetors, as the bottom of the slide is part of the venturi, and the area of the venturi varies with throttle position. Fuel metering is via a tapered rod that goes into a fuel jet... actually, parts of it work a lot like the old SU carbs. There's an accelerator pump too, and some other stuff.

Various people have put the Keihins on Toyota 4AGs, and it seems like they're pretty hot ****; they efficiently meter fuel across the whole powerband and flow a lot. I was thinking of a couple for a peripheral port rotary only... well, the FCR is only made in sizes up to 41mm.

So now I've been kicking around the idea of making my own clone, embiggened, in 2-barrel form. Honestly, mostly just to see if I can, though it would be nice if it worked really well. I think I have all the worky bits figured out for that, and I'm going to go set it up in a CAD program approximately whenever I get around to it.



Yeah, this is sort of off topic... sorry. Sterling and Carl are probably two of the most knowledgeable people about carbys that I know, and it just brought my mad scientist scheme to mind.

 

Wow, I didn't mean to send this thread so off-topic.

Carling, I'd like to know if your carbs can work on full BP engines. I won't ask about half BP, because the Nikki likes to have primaries and secondaries comunicating for some reason. Do you think I'd be better off with an IDA? I'd prefer a Nikki of course.

Maybe I'll just keep the streetport size, the side plates currently have, without modification (or maybe I'll extend them a little?).

 

Well RB sizes a 600CFM Holley for a 12A BP. When my prototype is flowed, lets see what numbers we get. I'm fairly confident we'll get some high numbers. Of course youll need to do extensive porting to the manifold to get all the benefit.

 

Since this thread got hyjacked- I posted pics here-

https://www.rx7club.com/showthread.p...hreadid=272479