The Stovebolt Site Forums The Shop Area Engine Shop Oil Pump to Block oil feed line???

Ok, here’s one for ya. Getting ready to button up my rebuilt 216 and when ever I do anything to my Stovebolt I look at it with an eye on the future. Should I ever need to replace the Oil Pump to Block feed line on an engine I’ve got here, I’d like to have some tube and fittings in stock. Soooo I goes and gets me trusty McMaster Carr catalog to order some tubing and fittings thinking it looks like 3/8”. But when I lay a piece of 3/8” fuel/brake line up next to just to make sure I find that it’s a bit bigger than 3/8”. In fact when I measure it I find its 7/16” and I’ve verified this in the parts book pn 839203 oil pipe 7/16 x 4 7/8.
Guess what, there taint now 7/16” tubing or 7/16’ compression fittings in McMaster or Grainger or any place else on line. And there taint no pump to block feed line in Chevs of the 40’s, JC or any other vendor that I’ve looked at.
Does this mean that should I ever need one of these lines or fittings that I have to find a junk engine and steal one????

Denny Graham
Sandwich, IL

You might check with Fastenal.. They have some 7/16 Brass fittings you could use with copper line.. Not sure about the tubing though. Mine looked pretty durable when i assembled mine so hopefully they hold up as long as there crimped well

Unless you're hung up on a bone-stock buildup, why not step up 1/16" and plumb the line with 1/2" tubing? The end fittings are 1/4" pipe thread, right? It won't hurt to use readily-available pipe-to-flare fittings and adapt the line to 1/2" tubing instead of something that's so hard to find. If you need to drill the flare fittings out for a slightly larger internal diameter, there's plenty of material available to do that without weakening anything.
Jerry

Denny,

HrL's good advice might be the only answer. Fastenal does not seem to have 7/16" copper tubing (in soft-flex tubing or refrigeration tubing).

Denny,
I ran into the same problem— couldn't find anyone with replacement parts in stock. It's such an oddball size! Thankfully I had a friend on The ChevyTalk message board send me a used on in great condition as mine was pretty banged up.
Stepping up to 1/2" makes sense, I wish I had thought of that earlier!

Yeah, that would be the easiest way out, I've looked everywhere. Not that I need one Mark, I just like to be prepaired next time it comes up and I or someone I know need to replace the line.

I don't know where GM came up with these odd ball sizes on some of this stuff. You see it in a lot of places. The transmission clutch shaft for instance, why .5895" instead of .5625" or .625", I mean .012" on a side either way wouldn't really make all that much difference. I would have thought that they'd have picked standard fractional sizes for their projects.

I think the oil feed line could go either way also, 3/8" would probably work just as well as 1/2" for that feed line.
I’d have to do some figuring on flow rates to see if 3/8” would handle the volume. The rate from 3/8” to ½” almost doubles.
http://www.pbase.com/dennygraham/image/135751729/large
http://www.pbase.com/dennygraham/image/135751709/large

DG

Bigger is almost always better- - - -once the line fills, the diameter won't have any effect on pressure, but the flow rate will improve, and there will be less pressure drop due to friction.
Jerry