Oil lines, Too big???

[CTX-SLPR]

Howdy,

Ok, here's the setup. I have a custom gerotor oil pump that will need to feed oil to an external oil filter then to an oil cooler and finally back to the block. A friend of mine who was shop crew on a Craftsman truck team picked me up about 10ft of AN-12 fuel line off of a truck they were updating and I'd like to use that but the fittings on the block and oil pump are only 3/8NPT. Is there such a thing as too big of hose? I know if I was buying it I'd get AN-10 line but since I have 10ft of premium quality AN-12 line that I got for free, its high on the list of using it.

Thanks,

[Huskinhano]

Re: Oil lines, Too big???

I don't see a problem as far as pressure drop or volume but about the only two things I can think of are weight and the larger size of fittings. You'll have to drill and tap which could weaken the surrounding areas where the fittings go since they were designed for 3/8" not 1/2".

[CTX-SLPR]

Re: Oil lines, Too big???

Oh I'm not touching the fittings on the block and oil pump as they are all custom made. I'd have to run a 3/8in NPT to -12 adapters which are only offered I've found so far by Aeroquip in a steel 90º fitting. The filter and cooler have 1/2in NPT fittings there so not a problem with getting them. Weight doesn't really bother me that much, what does is that I really don't want to keep the braided stainless as I preffer the black textile hose and I'd rather buy the -10 stuff then so I'd have surplus -12 fittings that aren't cheap. Got some ideas on that front though I'm chasing currently.

[goat racer]

Re: Oil lines, Too big???

You can open up the ID of the -12 to 3/8 pipe fittings to eliminate some restriction. I don't see the -12 lines being an issue.

[Dynoroom]

Re: Oil lines, Too big???

I run a -12 x 3/8 fitting in a lot of my endurance engines. No problems at all.

Here are a couple shots of how I've done some on small blocks, the first one is before the fitting get drilled out to 9/16





And a crummy shot of the line going from the pump to the fitting

[CTX-SLPR]

Re: Oil lines, Too big???

Where do you get the 3/8in NPT to -12 AN straight fitting? All I've found is 90º fittings though a 45º would be perfect.

Thanks,

[Dynoroom]

Re: Oil lines, Too big???

Where do you get the 3/8in NPT to -12 AN straight fitting? All I've found is 90º fittings though a 45º would be perfect.

Thanks,

I buy mine from an industrial hardware store called McFadden-Dale. You can also find them from a hydraulic hose supply store.

[A/Fuel]

Re: Oil lines, Too big???

is that a fuel pump running off the oil pump?

[Dynoroom]

Re: Oil lines, Too big???

is that a fuel pump running off the oil pump?

Yep

[CDMBill]

Re: Oil lines, Too big???

Is this pump one that attaches to the stock location in the pan or is externally belt driven? I run a Peterson external pump and it used a -12 from the pickup which was welded into the pan to the suction side of the pump. I'm upgrading to one with two scavenge sections and the pickup side is now -16 to offset against the vacuum in the crankcase.

[CTX-SLPR]

Re: Oil lines, Too big???

Its a custom hybrid that "Ohio" George Montgomery and I built out of an 3800 Series II pump section and Stage 2 drysump cover and a custom billet feed tube that goes into the block through the old oil pressure sensor hole that has a 3/8in NPT external boss for the oil feed. The pump is capped with a block off plate with a 3/8in NPT hole in it where the oil filter adapter would have attached.

[CTX-SLPR]

Re: Oil lines, Too big???

Is the hex on an -12 hose end approximately 1in across?

[Dynoroom]

Re: Oil lines, Too big???

Is the hex on an -12 hose end approximately 1in across?

The wrench size of a -12 hose end is 1 1/4"

[CTX-SLPR]

Re: Oil lines, Too big???

Well that is good news, this one is right at an inch.

[Dynoroom]

Re: Oil lines, Too big???

Well that is good news, this one is right at an inch.

1" hose end is a -10