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1971 Challenger fuel system, gas cap and venting

Started by GrandpaKevin, July 16, 2017, 08:52:28 AM

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GrandpaKevin

Double checking our 1971 Challenger's fuel system.

The car had it's vapor return line setup and rubber hoses to the fuel tank nipples removed many years ago and I don't plan on replacing it.

Currently has new SS 3/8 factory bent fuel supply line from tank to mechanical fuel pump on engine.

Installed new Spectre 1971 gas tank with the 4 nipples on passenger side of tank.

I'm using this locking Stant fuel cap under the factory flip open gas lid.
From what I can find this cap is an emissions cap and is supposed to be vented?
https://www.summitracing.com/oh/parts/snn-10571/overview/?cm_mmc=pla-google-_-shopping-_-srese1-_-stant-products

So is it OK to put rubber caps on the 4 nipples on the gas tank? Should I cap all of them? Some of them?

Thanks.



Cuda Cody

Does your filler tube have the vent nipple?  There were two different filler tubes used based on what tank you had.

1 Wild R/T

Quote from: Cuda Cody on July 16, 2017, 09:16:33 AM
Does your filler tube have the vent nipple?  There were two different filler tubes used based on what tank you had.

A 71 wouldn't have the vent nipple.... 

Kevin, if you still have the vapor separator that mounts in the RF corner of the trunk you should connect the four hoses from the tank to the separator then just leave the fifth nipple open..


GrandpaKevin

I'm not exactly sure what the vent nipple looks like but I don't think the car has it.

This Challenger has a January 1971 SPD and has a 1970 style trunk with the access plugs for the rear shocks on top instead of horizontal like my other 1971 Challenger which has a June 1971 SPD.

GrandpaKevin

Quote from: 1 Wild R/T on July 16, 2017, 10:01:05 AM
Quote from: Cuda Cody on July 16, 2017, 09:16:33 AM
Does your filler tube have the vent nipple?  There were two different filler tubes used based on what tank you had.

A 71 wouldn't have the vent nipple.... 

Kevin, if you still have the vapor separator that mounts in the RF corner of the trunk you should connect the four hoses from the tank to the separator then just leave the fifth nipple open..

Thanks.

I think most of that is still there.
I'll need to source some new hoses, they appear to be different sizes.

Would it be OK to just cap the nipples on the tank for now just to get the car up and running?

1 Wild R/T

leave at least one open... Or plug them all & leave the cap loose...

Cuda Cody

That's where I was going.  If you want to run a 1970 style system then you need to vent it with the nipple in the filler tube that has the hard lines that run down through the floor of the trunk pan.  If he has the 1971+ style filler tube then I agree it's just easier to use the nipples on the tank.   :alan2cents:

Quote from: 1 Wild R/T on July 16, 2017, 10:01:05 AM
Quote from: Cuda Cody on July 16, 2017, 09:16:33 AM
Does your filler tube have the vent nipple?  There were two different filler tubes used based on what tank you had.

A 71 wouldn't have the vent nipple.... 

Kevin, if you still have the vapor separator that mounts in the RF corner of the trunk you should connect the four hoses from the tank to the separator then just leave the fifth nipple open..