welding oil pump pickup

[10secBu]

Need to weld a mild steel pickup tube to a cast iron oil pump body. This is for a GM big block chevy oil pump.

In the past, I just used an ER70S-6 1/16" filler rod. I'm a bit concerned about the heat input needed for welding, even though I do remove the bypass spring & plunger.

One engine builder told me he used a stainless steel filler rod, but no mention of the alloy used. I also have heard of a silicon/bronze alloy rod which is supposed to melt at lower temps?

What would be the appropriate rod for the application of joining mild steel tube to a cast iron oil pump body? It would be two or three 1/4" long tack welds more than likely, unless the silicon/bronze was cool enough to weld the complete way around the tube (approx 3/4" diameter tubing slip fit inside the cast iron pump body.

thanks
Todd G

[imported_Blackplague]

The filler to use would be

309 stainless to join your cast to mild steel. I'd get .045 if you can get it, if not 1/16'' will work.

[tooldude56]

I have used braze and an O/A torch on these for years in race engines,marine engines and street engines,with not one falure.I use just standard flux coated 3/32" brazing rod and braze all the way around the tube.I got this advice from Ray Baker of Baker enginering,many many years ago,when I was racing in Michigan.I still know many people that are building engines and they still use this old,but proven method.This worked so well that I never had a reason to try anything else.

tooldude56

[10secBu]

brazing

I have used braze and an O/A torch on these for years in race engines,marine engines and street engines,with not one falure.I use just standard flux coated 3/32" brazing rod and braze all the way around the tube.I got this advice from Ray Baker of Baker enginering,many many years ago,when I was racing in Michigan.I still know many people that are building engines and they still use this old,but proven method.This worked so well that I never had a reason to try anything else.

tooldude56

Well, that would have worked, but I just returned my Oxy/acetylene bottles a couple months ago. Got tired of paying the yearly rental fee for the little use they saw. That's why I was lookng at the silicon/bronze rod for Tig.

Can you braze with a small propane torch, or possibly MAP gas?

[Sundown]

I would use 309L SS rod to do that, either .45 or 1/16 (as said before) would work ok.

[dyn88]

when I worked for MOROSO performance products we welded hundreds of these things. we used 1/16 silcon bronze and our tig machines set on a/c with the hf on continuos(its next to imposible to clean the cast, thus the a/c
) 3/32 tungsten with a sharp point(not pure). You should find this to work for you. I would avoid using stainless rod as the joint between the cast and the filler is brittle and cracks easily(especially under the stress of harmonic vibrations found in bottom ends at high rpms)

[10secBu]

when I worked for MOROSO performance products we welded hundreds of these things. we used 1/16 silcon bronze and our tig machines set on a/c with the hf on continuos(its next to imposible to clean the cast, thus the a/c
) 3/32 tungsten with a sharp point(not pure). You should find this to work for you. I would avoid using stainless rod as the joint between the cast and the filler is brittle and cracks easily(especially under the stress of harmonic vibrations found in bottom ends at high rpms)

That's good information. I'm using a Lincoln Squarewave 175 Pro machine which has almost no adjustments other than amperage and your polarity switch. Do you remember what amperage you used at Moroso?

[Paul Seaman]

Any time I've welded cast iron I used Ni rod and have had very good results. I would only worry about vibration and the dissimilar materials wanting to expand and contract at different temps.

just my .02

[dyn88]

We used old lincoln 300/300 a/c d/c tig, set at medium (75-150 Ithink). Use your foot pedal and introduce the rod untill the base accepts it.

[glockdoc]

I second LFB with O/A, maybe even silver braze as it is a lower temp process (but more money). Not only will it not fall out but will also be airtight.

[Portable Welder]

Glock dock maybe on to some thing, it works like braze but melts at a lower temputure.He's right about it being pricy.
I had to repair a very thin corroded condencer made out of stainless and found the silver solder worked great, I have also used it to weld the carbide back into drilling bit tips.
The other ways will probally work fine but if money was no object I would pop for the silver solder with an oxy/ acet. torch.

[J hall]

O/A and 1/8 coated bronze rod are about all I have seen used on engine oil pump pickups and hydraulic lines, maybe because it is easy, but I have never had a failure.
jh