below is a picture of how far my fuel fitting will thread in. Shouldnt they thread in farther than that? they are speed inc. rails and Mr. Gasket fittings.

 

you are trying to screw a fitting with pipe threads into a rail made for a strait thread and o'ring seal...

If it's a pipe thread in the rail, and on the fitting, you may have to retap the rail, to move the taper on the threads further into the rail.
Pipe fittings will not screw all the way in to the end of the threaded area...

 

so if I'm trying to get a fitting that will screw all the way in and hook up to a 10AN line what fitting from summit will work. the only straight cut fittings I can find are AN to AN

 

The hole is tapered. It doesn't need to screw in all the way. I used teflon tape on my fittings for my Speed Inc rails and that's about how far they screw in. I've had them like that all summer and have had no issues with any leaks of any kind.

 

As long as you are using a NPT fitting, then all is well. My Speed Inc rails were 3/8 NPT. NPT thread are tapered for a seal. They will never bottom the hexed part out.

 

Speed inc rails here too, and I'm with carl. Mine look the same way too.
J

 

thanks then I wont worry about it.

 

NPT threads in a rail not only look like Fido's a$$, the load of the lines on the fittings can cause cracks in the root of the threads.
IMO, the rails should be tapped with straight threads, and AN fittings with o'rings should be used...
Doesn't cost any more to use a straight tap and fitting, than NPT stuff...
furthermore, the AN fittings with the radiused inner openings flow better than a pipe threaded fitting.

Again, just my $.02. Your results may vary.

 

I agree, I would have much rather had O-ring fittings. They also help with space by threading all the way in.

 

since I'm tapping illiterate. What kind of tap do I need to tap the rails for the oring fittings?

 

What size NPT thread is now in the rail? It may be that the drill size for that tap is already too large to allow the rails to be redrilled for a strait thread fitting.
As I recall, my rails are tapped for 9/16" threads...
I'll check in the Am, as I have a set in the shop, that I can measure..

 

3/8" is in the rail now

 

I just don't see why the need to go to all of the hassle to retap the rails, risk screwing them up, just to install some o-rings when there are numerous people, myself included, that have no problems with the rails as they are. Obviously Speed Inc uses them on customer cars with big power setups with no problems.

 

The post contained my $.02.... Buy into the logic, or not. My systems are done w/ the o'rings.