924Board.org

[MikeJinCO]

The fuel system I made using Weber carbs is all Earls -6 AN flexible tubing from the fuel cell except for the main fuel filter (stock Bosch)and pressure regulator which have pipe threads. When I put it together I could not find much information on what to use as a thread sealant, I figured not to use any tape as pieces might break off so I just used good teflon old pipe dope.

When I cranked it up for the first time this year last week I had to shut it down due to a fuel leak in one carb. A second shot at just running the fuel pump and gas sprayed out of the pressure regulator. I went on line and found the marine folks use Permatex #3 on all pipe threads. So the other day I did the same. There was almost no trace of the pipe dope left on any of the threads. That could have easily lead to a fire.

Permatex also makes a sealant called Motoseal that I used to replace the bottom gasket in my '77 fuel tank, but is seems to be more of a gasket type material than thread sealant.
_________________
Mike
Poco a Poco, #033 '78 Vintage racer, SCCA Dp-81
'77 924
cricketdesigns.com

[924RACR]

Yeah, pipe dope/teflon (including tape) is no bueno for automotive. The teflon is of course a lubricant; turns out its purpose is to help you jam the NPT threads tighter to get them to seal - but the seal is metal on metal, not the teflon.

I was recommended to use Permatex #54540 on my racecar after having one AN fitting vibrate loose (admittedly, probably badly torqued first time wround). Cost me a motor and made one helluva mess on track. The 54540 is purple liquid that works both as a thread locker and a sealant.

No problems since. Can even be used on both the face of AN fittings and the thread (I just use it on the thread).

https://smile.amazon.com/ESM-180-54540-Permatex-Pneumatic-Hydraulic/dp/B002JQK8NW

This looks like it might be similar, much less expensive:
https://smile.amazon.com/Vibra-TITE-440-Hydraulic-Pneumatic-Anaerobic/dp/B0026GOWUK

Seems like Loctite 545 is comparable too?
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[MikeJinCO]

Thanks, looked up both Aeroquip and Earls and not much mention of sealants. On the oil cooler side there are many fittings and a lot of pipe theads with the block bypass, remote filter and cooler plus a couple of fittings that just want to seep a little. I'll get the Permatex coming. My local FLAPS is somewhat independent and many times is a better deal than Amazon. Plus we need to support our local businesses now.
_________________
Mike
Poco a Poco, #033 '78 Vintage racer, SCCA Dp-81
'77 924
cricketdesigns.com