Here is my problem. I have a stainless steel Rock Valley 15 gallon gas tank in my 1934 Ford Coupe. It has an aluminum gas cap with an "O" ring inside. The tank is an older unit with a bottom feed. The gas cap fits a two and a half inch neck. It has worn out, and it has fine thread. Upon calling Rock Valley I was told that they no longer make units with fine thread caps ,and that the cap I need is no longer available. Has anyone got a cap . Any info appreciated.
Know anyone with a manual lathe with the ability to cut threads? Any local machine shop should be able to help you.
If it's the threads that are worn take it to a machine shop to recut the threads Sent from my iPhone using The H.A.M.B. mobile app
2 choices--- 1- have 2 new caps machined (spare) or 2- remove the tank, clean the crap out of it and weld a new filler assy on it with somthing you can get parts for. Not a big deal to do either one
no idea what thread it is, but might be worth checking - http://fuelsafe.com/store/fill-accessories/fc250c.html
It is. Fuel Safe makes competition sanctioning body regulation compliant components for racing fuel systems, not random caps for hot rods. The fuel cell in my Porsche was about $2000, two decades ago.
Contacted them,they have the right size, but are coarse thread. They are going to check and see if they have any older stock which was fine thread. Appreciate the info.
What about looking into an adapter, from your tank to whatever the common cap is now? Might have to have one made, but then you wouldn't have this problem again.
The gas tank neck sticks out of the rear sheet metal several inches and as it is the gas cap is near the liscence plate assembly, not much room at all to work with. Appreciate the idea.
Could you get one of the ones with the smaller diameter and have it machined out to what you need? Is there enough meat there to do that? If you try to rethread your old one you will lose too much material.
The next size down in this style cap is two and a quarter inches in size, of no use as I need two and a half inches. Not enough material on a two and a half inch coarse thread cap to attempt to change it to fine thread.
They don't have the size I need, or the thread, and jump from two inches to three and four inches in size. Appreciate the info.
Fuel Safe just got back to me, they don't have any of their early fine thread caps left in stock. They no longer use them. Appreaciate the info.
Joe You need to determine what the thread lead is on the tank (threads per inch). Next you need to determine the diameter (actual) is of the filler. To get a close measurement you will probably need three wires that when they are put into the threads, one wire on one side and two wires on the other, they stand proud of the thread. Measure the diameter over these wires and the actual thread depth of can be determined from that. Now your machinist can cut a inside thread to fit without having the filler neck. If you have three drill bits the same diameter that works. You can measure over the tops of the threads on the filler but that pipe was probably under 2 1/2 to begin with which is why the threads in the cap don't work now as they had very little engagement to begin with. Hope this is helps Greg Sent from my iPhone using The H.A.M.B. mobile app
Joe Quick and dirty would be to wax the crap out of the filler tube threads and clean the cap with acetone. Mix epoxy and apply to the inside if the cap and put it on the filler tube. Just make sure you put plenty of wax on the filler threads. Teflon pipe tape would probably work better but only two or three wraps. Just thinking. Greg Sent from my iPhone using The H.A.M.B. mobile app
Is the "O" ring bad or the treads? You might try a tread file. Sent from my iPad using The H.A.M.B. mobile app
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