On a Holley NH, does the lower bowl gasket (the smaller one) go inside the bowl or outside ?
Jim Thode said - inside
Jack said outside???
I vote outside.
I vote outside also......
Outside. Unless you want it to leak.
Large one inside, small outside if it's our gaskets red inside, grey outside, Bob
Also on sale at Bob's Antique Auto Parts
An earlier post regarding a Kingston L4 said the gasket goes inside. I have always put mine outside (on my own L4 and on a L2) without leak problems.
I am new to the NH so I thought I would ask.
Maybe its different depending on the model carburetor ?
BTW only one lower bowl gasket in my rebuild kit.
It goes on the outside, but you can put one on the inside too, and it will still work.
Outside. No need for one on the inside
The reason for the inside gasket is when rebuilding them sometimes there is a small gap in them, that's why we supply it, also my father when he was alive and I rebuild them we also put them in as does Russ Potter, Bob
Yes, the inside one is just a spacer. Fuel behind it can leak down the threads and out if there's no outside gasket.
the difference is in where the gasket goes is dependent on how it is made. Kingston has a threaded stub which goes through the bowl. It has a flat on it which seals firmly against the inner face of the bowl. If you put the gasket on the outside, the fuel runs down the threads and out the carb...you have no effective seal...all you've done is keep the nut from scratching the bowl paint.
With the NH, you have essentially a threaded plug from the outside to the inside. With an NH, you want the seal on the outside, between the plug/drain and the bowl.
Depending on the abuse the bowl has seen in it's life, you may or may not want to use the extra washer as Bob Bergstadt mentioned above. If you reshape the seal area of the bowl to original shape, you will have a space as Bob mentioned. All too often, amature rebuilders fail to do this, and the mis-shaped bowl bottom is caved in enough that the extra gasket/spacer cannot be fit.
Anyway, that's the difference.
Sometimes the leaking problem is not just a gasket. Many times the bowl has been dimpled in, by over torquing the bowl nut.
I always use a brass hammer to flatten out the bottom of the bowl prior to re installing the bowl and/or nut or drain bolt.
You can also put the bowl in your press and use a deep socket to squash the bottom back to flat. Some of us hammer-control challenged individuals don't always hit where we mean to hit.
That's how flatten them also, Steve.
The bowl pictured above appears to be an L-4.