Early LA eng by pass hose

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66dartgt

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Looking at the by pass hose set up on a 66 273, versus the later model small blocks. It looks to me like the bypass hose needs to have a smaller ID on the water pump side vs the inlet to the manifold, and this is not a small difference, the cast iron pump has a thread that will end up being about 3/4inch od and the inlet to the manifold is about 1 inch od.

Anyone notice this before?

I am wondering if I need a special by pass hose for this thing or what.....Hmmm.

I suppose I could cobble a bushing to bring the pipe size up on the pump. But I'd rather use the "correct" stuff to do this.

Thoughts and opinions appreciated.

:book:
 
my 72 340 used a 3\4" brass Iron pipe size nipple that was 1" OD. It was a standard nipple that I got from my assorted plumbing fitting box, I just cut it down to 1 1\2" and put er in there. Sounds like thats what you have.
 
my 72 340 used a 3\4" brass Iron pipe size nipple that was 1" OD. It was a standard nipple that I got from my assorted plumbing fitting box, I just cut it down to 1 1\2" and put er in there. Sounds like thats what you have. Then I got the hose from the local NAPA store, the only thing is I wanted something to make it nice like some stainless braiding but this size is unique to SB Mopar engines.
 
The factory fittings in the sb intakes? I used stainless NPT nipples cut to length.... That way there is no corrosion factor. You could also use galvanised. But over time, the black steel nipples will rust out...


Triggerjay
 
Thanks for the replies. I am going to post on the engine portion of the site and see what I come up with.
 
Go down to your local NAPA. On the HELP board they will have hose nipples with various size threaded and hose ends. You should be able to find some thing that will work.

Using a pipe niple is kind of cheesey when for a $1 or so you can purchase the correct fitting.
 
I didn't just use a pipe nipple, I used polished stainless....
Doesn't matter though, the Edelbrock stuff is on its way now...

Triggerjay
 
For those interested: I did some research and found that there is a special by pass hose for the earlier LA engines. The inlet on the water pump side is smaller than the inlet on the intake size. Learned something new !
 
I have the opposite problem, the inlet on the intake is smaller than the water pump one. I just sqeezed the hose smaller with a clamp, but one day I might upgrade.
 
The water pump on my '69 273 has a fitting that is 1/2" npt by 1" hose. It looks like the factory fitting to me so it uses the same hose as the late LA.
 
I use a 273 intake on my 318, with late water pump...I just cut 1" off the 273 bypass hose, slipped it on the intake fitting, then slid the late model bypass hose over the (Bushing, per say)...Takes care ov all ya problems, cheep, and U kan't even tell it's in there!!!...

U also kan use a nipple in the intake, and a coupler over it, then use late model hose!!!

P4180566.JPG
 
They do sell both dia. stainless fittings for the intake. 69 on back with the lower hose on the left take the smaller dia. hose. 70 and up with the aluminum pump and the lower hose on the right take the larger dia. Some one switched something on your car . but if your car has a cast steel pump it should take the smaller hose. I have used the rubber bushing in the past with no problem a NAPA part. Today I would get the right hose , Only because if your going to do it right use what it came with. But thats just me.
 
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