Mikuni 44PHH Part #85 "Carb Cooling Body"

[EricB]

I've searche all over the prior postings and while I can many mentions of the carbs I don't think this particular issue has been addressed... If I missed a post and you have the link handy I'll take that rather than starting a whole new thread.

My set of 44 PHH came with part #85 fitted to all three carbs - have never used them - just fitted them with rubber plugs and left it at that. With the carbs temporarily out of the car they got me thinking...

From the description it's there to cool the fuel reservoir... But has anyone used this function? What did they cool the fuel with? The radiator COOLANT isn't THAT cold once at normal operating temp! ... Separate circuit of mystery XXX fluid with separate pump?

If I remove them altogether then I am forced to re-adjust my Pump Rod (#60) to the new shorter length, right?

What do you all think?

-e

[jmortensen]

I understood that the fuel coolers route fuel from the return line under the carb bowls to cool the carb, which is being heated by the exhaust. IME this is not necessary. I've run my car in stop and go with no heat shield at all, and have also run at a track in 114º without having the fuel boil in the bowls.

YMMV though...

[JLPurcell]

Eric,

I have found Todd Walrich at Wolf Creek Racing to be a great source of knowledge as well as parts for the Mikuni Carbs. You can email him from his web site:

www.wolfcreekracing.com

Hope this helps. JLP

[Victor Laury]

Mr. EB, I've never seen anything hooked to the "Mystery Nipples". My roadster (Dual 44's) runs just fine with these wide open. Don't bother eliminating them.

And Jerry is right! Todd is my ultimate Mikuni Guru.

[EricB]

I've had mine plugged up too for the past couple years I've had them on the car... this time though I just got to thinking about what they were there for... I'll get Todd's $0.02 for the heck of it...

-e

[Victor Laury]

Eric, Reply back after you call him and give us his advice.

[240znz]

Yes please, any info on 44phh will be very well received.

[EricB]

Todd confirmed that they were what we inferred... after the fuel feed line goes to each carb, the return line is indeed supposed to be routed to each carb via these "cooling bodies"... the flowing fuel is mean to cool down the carb body...

But again like the rest of us Todd has never seen anyone use this function of the Mikuni carb... That in itself almost makes me want to try it... then again I bet I'd be hard pressed to tell the difference...

I wonder if Alan has seen anyone use this function back in Japan?

Considering none of us have ever tried it, who knows maybe it's a night and day difference on a hot day?

-e