E85 jet sizes emulsion tube (19mm HuaYi Carburetor on a 212)

#1
So .037" to .039" seems to be the "go to" jetting for a starting point on a typical 212 engine with the basic exhaust and intake mods. I'd like to run E85 on my setup. Does anyone have the basic guide for jetting? Idle jet and emulsion tubes as well?

I have read 30% is the norm. So .049 or so on teh main is where I was gonna start. And tips on teh idle jet or emulsion tube?

I've heard he 140 etube is standard. How would this change for E85? Is a 140 Etube .140? I'm not familiar with them. is this the diameter through the center of the tube?

.019" to .020" for the idle jet... So add 30% to these too? so .026?
 
#3
Wichita ks... not forced... But I love the stuff! Drag racer and run it in all my vehicles. Picking up 10-15% at the wheels on NA cars by simple swapping to e85. E50 has similar benefits without the carb "gel" issues associated with carbs as well. MAy end up on that. Just though it was odd there isn't much information on E85 or E50 jetting out there.

thanks!
 

65ShelbyClone

Well-Known Member
#6
You're multiplying the jet diameters by X% when it should be the orifice flow area increased by that amount.

If you have an 0.040 main, increasing the flow area 30% will require a 0.046 orifice.

Increasing the orifice diameter by 30% would require a 0.052 hole, which is an area increase of 69%. Big difference.
 
#7
You're multiplying the jet diameters by X% when it should be the orifice flow area increased by that amount.

If you have an 0.040 main, increasing the flow area 30% will require a 0.046 orifice.

Increasing the orifice diameter by 30% would require a 0.052 hole, which is an area increase of 69%. Big difference.

Thank you for the response, that makes sense. also explains why the engine ran horribly with my jetting. What formula are you using to calculate that so that I can figure out the idle jet as well?

Currently running .021 and .037 jetting on gas. And I have great idle and performance near as I can tell. I'd like to switch to E85 though.
 
#10
I tied originally with my incorrectly calculated jetting and it was a mess. I have not tried again as I didn't know the formula to calculate orifice flow area. wasn't sure how far to drill out my jets.
 
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