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View Full Version : 3/8' to -8 adapters?



dj3
03-16-2008, 12:39 PM
I have the stock fuel tank in my 69 Camaro and need to convert it to a -8 AN fitting to run the fuel system. Summit makes an adapter to convert 1/2" hard line to -8, but i cant find one for 3/8" to -8. Do I need to run a short piece of 1/2" and connect it to the 3/8 with rubber hose or is there a better way? Is there anyone that makes a 1/2" setup to replace the 3/8" line in the tank? Thanks for the help, dj

68sixspeed
03-16-2008, 12:52 PM
I ran a seperate 1/2" pickup tube in and then ran one of the 1/2" hard line to #8 male fittings. The nice thing is the 3/8" line is still available for a small nitrous system feed. (I'm thinking of a 250-300hp shot for fun...)

I've also read of people modifiying the pickups by changing the pickup tube and using JB weld epoxy or cutting up a new pickup and tig welding in a bigger pickup tube.

David Pozzi
03-16-2008, 08:10 PM
You should be able to flare the 3/8" tube to 37 degree flare and use an aircraft backup sleeve and flare nut, then use a -6 to -8 double male adapter.

dj3
03-17-2008, 06:04 PM
Thanks for the help guys, I should be able to get something together now.

Vegas69
03-17-2008, 07:13 PM
Whats the point of going from 3/8 to 1/2 inch? Your fuel system is only as good as your smallest segment.

another69
03-18-2008, 01:56 PM
I thought the same thing when I did pretty much the exact same mod as dj3. I cut off the factory roll on the sending unit and used a stainless 3/8" compression x 1/2" male adapter. I then used a 1/2" al female coupler to a -8 adapter with -8 line up to the mechanical pump. I opened up the insides of the male adapters with a unibit in an effort to get more flow, but I doubt it did anything. Why do it this way? I hope to upgrade the stock style tank one day, and when I do, I will already have the -8 line there. As for why go from 1/2 to 3/8- I figure until the tank upgrade the -8 will still add more volume. (don't hold me to that last statement) Either way, it's an upgrade over the factory 5/16 line!

dj3
03-18-2008, 04:20 PM
Whats the point of going from 3/8 to 1/2 inch? Your fuel system is only as good as your smallest segment.

My new engine combo is 600HP and the fuel pumps have the -8 inlets, so i figured a short run of 3/8 out of the tank wouldnt hurt. I was trying to put off buying a new tank with a simple fix. I probably should do what 68sixspeed said with the horsepower I have, since it looks like hes putting down some crazy number with a small block.

Vegas69
03-18-2008, 09:40 PM
Prodigy Customs told me I could modify a stock sender with a 1/2 inch line. You may want to consider that if budget is a huge concern. I said *** it and ordered a Ricks Tank with a -8 AN. Of course I am ALL IN.:2nd: I did get a really good price from Frank on my tank. Of course I think I am on the third tier above the top tier on the discount scale.:lmao: I still don't think you are gaining a damn thing even if you use a .25 of 3/8 line. That 3/8 line still has to keep that -8 AN full. In fact they recommend a larger diamter feed line to the pump the the output.

another69
03-19-2008, 03:14 PM
Is adding a sump to the rear of the tank out of the question?

dj3
03-19-2008, 06:11 PM
Is adding a sump to the rear of the tank out of the question?

Welding on gas tanks make me nervous.

CarlC
03-19-2008, 07:25 PM
In the latest PHR there is an article on the problems they had using a stock small-diameter fuel line in their 600HP Chevelle.

another69
03-20-2008, 08:44 PM
dj3-
Welding on a gas tank is really no big deal if it's new ('69 replacements are reasonable, about $120). If used, I think there are several ways to do it safely, one of which involves dry ice. I just finished adding a sump to a friend's chevelle (new tank), and I'm kicking myself for not doing it to my own car when I had the chance. We used a kit from C. E. , which showed how to "baffle" the stock tank- it's really simple and (seems) effective. We leak checked it with compressed air and soapy water. I MIG welded it, but TIG welding would have been better if I had the equipment. The nice part is the 1/2" npt ports that make it really easy to run AN lines.

Skip Fix
03-22-2008, 07:59 AM
Using the stock 3/8 pickup but -8 past the electric pump solved all my fuel issues. Pushing 575 HP 10.99@124. Maybe I can get that Chevelle in the magazine to spot me some lengths since I have less CI and less HP :)