CaptainChrysler

Ok, I am getting ready to do a LP upgrade. Have read the sticky(s), have a few questions.
-Are all 3 fittings (fuel inlet to head, fuel oulet from head, fuel inlet to pump) 12mmx1.5?
-Is a 3/8 fuel line going to be big enough? Is it worth going to 1/2"?
-I plan to use the 2nd gen LP with a bypass reg, will the stock return line handle this, or do I need to upgrade that as well?

FYI I just called Cummins and was quoted $84.29 for a 2nd gen LP.

Thanks

BC847

1 - Can't remember.
2 - If you run a daily driver as a weekend warrior, 3/8" is plenty big in my opinion.
3 - If you're gonna do the fuel line upgrade, use the original fuel supply line as the regulator's bypass return. As such, the OEM return should prove plenty good.

Hope this helps some.

smokin95

why go to a factory lp... a holley blue pump is only a little more...

ofcmarc

LP outlet is a 14mm.

CaptainChrysler

David, you are saying to leave the original return alone and plumb the regulator return to the original feed line? What about inside the tank, do I just fashion a tube from the original feed to dump the fuel towards to bottom of the tank? If it just sprays back in from the top of the sending unit, won't it create alot of foam?

smokin95-
I would feel better with a mechanical pump, its the whole reason I bought a 1st gen. Plus there is no wiring to worry about.

ofcmark-
You are talking where the tube threads into the lp right? It is a metric flare?

Thanks for the help guys.

CaptainChrysler

Another thing, I am planning on using the simflo regulator, anyone see a problem with this?
http://www.vulcanperformance.com/ser...gulator/Detail

bgilbert

That sounds like a 24 valve electric pump. The 2nd gen piston pump runs anywhere from $150-$200 from Cummins. Be sure it's 3936316.

VE pump is 14mm iirc, the rest are 12mm. The lift pump outlet is some weird reverse flare type fitting.

I prefer leaving the entire stock fuel system alone and building a separate suction and return for your new fuel system. The stock return will function the same, and the stock supply/suction will be there in case of a failure, an ah-oh or if you want to sell it and put it back to stock etc.

CaptainChrysler

Ok, so If it put in another return can it just dump back into the tank? Or should it be extended down the the bottom of the tank?

bgilbert

Yep you can dump it back into the top of the tank anywhere you like. Tee the vent, overflow, drill a hole, install a bulkhead fitting you name it.

That price also sounds like a 1st gen stock LP. You'll know when you see it.

BC847

What Bill said.

Keep in mind that when I did my fuel line upgrade, I modded the internals of the fuel pick-up assembly. As such, the OEM fuel supply line was there unused for the purposes Bill mentions. When I got to the regulator thing, I just took advantage of the existing line there for the bypass return. No big whoop.

CaptainChrysler

BC847, your write-up is responsible for my big line dream.

What do you guys think about this:
http://www.vulcanperformance.com/ser...2%84%A2/Detail
It appears to be compatable with our sending unit.