I have 8 holley 94's set up on my 392 hemi by a vendor in Florida, and it uses banjo fittings with hard nylon or teflon sealing washers. I have trouble with them leaking. I can't tighten them enuff to seal reliably without stripping threads. The vendor says he hasn't had any trouble with them, and repaired the stripped threads at no charge, but they still leak. What is the solution? There must be a better washer. Also, I was thinking about abandoning the whole banjo set up and switching to individual -6AN lines going to fuel logs. I'm looking to tap into the m***ive HAMB brain trust for suggestions! I know some of you guys must have been thru this already. PS, I know the carbs are backwards. That's just the way the intake was when I got it. THanks, Joel
Maybe try copper washers? There's a ton of them out there for banjo brake fittings in all sizes, and thickness'. Maybe a try before you swap over?
Those appear to be Speedway Motors aluminum banjo fittings (which do use the nylon crush washer). You could always try Clive's Stromberg nitrile gaskets for his banjo fittings (or better yet, his banjo fittings too).
Cory, that looks like a good idea. Those will fit the carb end of the fitting with the .500 inside diameter. How about the outer end, under the head of the fitting? THose are 5/8 I.D. I think I'll look up Clive, Thanks Invisible, I did try solid copper washers and copper crush washers, both leaked. Either the washers are too hard, or these fittings are junk.
At least you gave it a shot! Copper is very forgiving, so might be the fittings.........Hope you find the answer.
have you checked the sealing surfaces for flatness? run the banjo fittings on fine sandpaper on something flat and see (could also use a sharpening stone) ..
The sealing surfaces for banjo bolts and washers usually have raised concentric rings to bite into the washers. That creates multiple seals within one washer that need to be breached before there is a leak. Without the rings the sealing surfaces need to be dead flat and smooth because there is only one surface and it needs to be perfect- the carb the fitting and the bolt. A thicker fiber washer might be better because it's more pliable than a Teflon or plastic washer. You'll probably need a hard washer between the bolt and the soft washer. There's just a few lbs of pressure so is bet the sealing surface defects should be quite obvious. Another thing is what size is the transfer hole in the banjo bolt ? What's able to p*** thru that hole Is all the fuel volume the carb will ever see. There's math and charts for volume flow thru orifice size at given pressure. Don't matter if you run a 1/2 line or a 2" line up to the itty bitty hole either
Joel. I had the same problem years back with the banjo fittings. I installed copper washers and it was much better however still had some slight seeping. I went to AN fittings and that was the end of the slight leaks.
The Stromberg banjo fittings use the same size nitrile gasket on the inboard and outboard sealing surface. The gasket is centered mostly by the recessed bore in the banjo fitting. I happened to still have some Stromberg gaskets, and measured them at approx 0.760" OD and 0.495" ID.
You might check out Parker Stat - O - Seal. It's a washer with an O - ring molded into it. Don't know if this will help, just throwing it out for consideration.
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