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Discussion Starter #1
I know zippo about welding so I brought this to a buddy to tig tack for me. First thing he commented on was the cast pump being so porous and not the best for welding, especially with a steel pickup tube (two different metals). But after cleaning off the oil with some laquer thinner and a small bit of grinding to smooth things up, he got it together. Was on there about 7 seconds and it didn't get too hot on the spring side. Looks good to me but I have no idea if he did a good job or not. Doesn't move, that's for sure. Wondering if I should grind away some of that "tail" section or at least smooth it down. May not be necessary. Would like some opinions before I button up this motor. Also going to bring this to my machinist for his review as well. thanks guys!



 

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Is there any heat distortion on the tube, I am not seeing it. To me it look like a superficial weld, as in it's connected, but barely, where if you twist is a bit it's gonna break apart. Where I would think that with a tack you want a little more holding power in this case.(vibrations) I have welded a few things like this, and from my experience they can look like they are well attached and not be.

What I am looking at specifically is how the the bead kind of sits on the tube and doesn't "flow" into it at all.

See how it flows into the metal, and has heat distortion? That's what I am talking about. Could just be me, but I look for this when I tack, as I know it will hold.
 

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looks like its cracked already. I would grind it out and have some one braze it in place or tig it.
 

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You should remove the pump cover and clamp it to the welding table. The pump relief spring should be removed. that weld looks cracked and didn't flow properly. I use a nickle rod to TIG weld cast iron to steel.
 

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Discussion Starter #6
As at least two of you surmise, there is definitely a small crack. Can't tell how deep it goes. I can not move this thing at all. Couldn't before the weld either, got it pretty tight with a drop of loctite. I really only want to do this once so need to fix this now before it gos in the car. That bolted connection seems ok but not sure I want to chance that nut coming loose. With the comments so far I will probably remove this weld and leave it alone or get it brazed. I had a dozen people tell me it would be ok to leave the spring in there as long as it didn't get too hot so that's what I did. Is removing the cover as simple as 4 bolts or can I expect anything to pop out if I do? Thanks for the feedback.
 

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As at least two of you surmise, there is definitely a small crack. Can't tell how deep it goes. I can not move this thing at all. Couldn't before the weld either, got it pretty tight with a drop of loctite. I really only want to do this once so need to fix this now before it gos in the car. That bolted connection seems ok but not sure I want to chance that nut coming loose. With the comments so far I will probably remove this weld and leave it alone or get it brazed. I had a dozen people tell me it would be ok to leave the spring in there as long as it didn't get too hot so that's what I did. Is removing the cover as simple as 4 bolts or can I expect anything to pop out if I do? Thanks for the feedback.
Yes,:yes: Removing the cover is as easy as (4) bolts.
It's safe insurance (easy too) to remove the spring. By the looks of the weld that your welder was trying not to get it too hot. Lot of good that did.:D
TIG it with a good nickle rod and sleep easy.:yes:
 

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You used loctite and then welded? What happens to the loctite when you apply heat to it? It melts and then crystallizes.

Tig welding is very hot but localized. Brazing is even worse.

The spring and piston MUST be removed before welding. The welding current that runs through to ground can heat up that little spring and anneal it. Plus the heat can carburize any oil which can lead to the piston sticking.

We've seen a lot of pump problems over the years on this forum. Pickup tubes that people thought were "tight", eventually worked themselves loose and fell off.

I used to build and weld pumps for site members but unfortunately I'm still stuck in Iraq otherwise I'd fix that thing.

I built a fixture to properly press-in the pickup tube to the correct distance, Tig weld them, then resurface the lid flat, After porting the passages, I set the gear clearance. Piston gets polished for smooth operation and a new 55 psi spring installed.
 

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Discussion Starter #12
I will certainly redo this thing. I will politely tell my friend the situation. I'm sure he will be cool about it, and hopefully learn something.

Thanks for the info and offer Paul. I'll grind off that weld, pull the cover off and see what's what. If we screwed up the loctite I'll need to pull the pickup (if I can - maybe stick it in the freezer? lol) and see what lies beneath. Will get out to the garage as soon as I finish cooking dinner!
 

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Trying to think of a way to avoid the weld between cast iron and steel...

How about making a small steel bracket that is retained by one (or two) of the pump housing bolts, and welding the bracket to the pickup tube? Not as nice as welding the tube to the housing, but...much easier to manage the welding.
 

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did this on my pump,(bad picture),
tig welded pick-up to pump, 3/8" weld both sides of tube,
also welded bracket to tube then bolted to pump base,
 

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patman, seems like your idea is pretty similar to what CDAN mentioned.....



Any thoughts on this product? I am not a welder and I like to do things on my own. Bolting this in is something I can do. p.s. you guys are great
I used that peice on my wifes vette pump. So far, no problems. I guess it's the next best thing to welding it on:)
 

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Discussion Starter #19 (Edited)
Well, the good news is the spring and piston seemed fine, operated smoothly without issue. The bad news is that I chipped the piston a bit. You can see it in the pic. I'm not too worried. This was a small lesson for me as I have never opened up an oil pump so at least I now have a feel for it. I chipped the piston when I had it almost out.....slipped a needle nose plier inside of it then opened it up a bit to grab it internally. piston just chipped. This was a $20 M55 Melling pump. My first thought was that maybe there is a small repair kit available but now I'm thinking to just get a better pump. Why would someone go with a high volume or high pressure pump? Is that upgrade needed for my mild 350 engine? (355 4 bolt, steel crank, 9.5:1, 1.94 world heads, Crane LT-1 spec hydraulic cam)

Browsing thru my summit catalog I see many options. One that caught my attention is a made in USA summit pump with the pickup already tacked on!!!!! Great but I can't help but think, how will I adjust the pickup height in conjunction with my pan.

Another thing...Paul mentioned a kind of "blueprinting" of the pump. When I look at the main oil passage I don't think I'd be too happy putting it back in without at least burring down the edges a bit. You can see in the pic how rough they are. good idea?



just found the in depth melling article in the 'best of' section. can't seem to figue out how to cut and paste a link fom my wife's laptop here but very good info on that thread. Tried to see Paul's blueprinted pump pic but the link is bad. so....hat's the final verdict on the new m55? should I get one or avoid? personally, I don't want a 20 dollar pump in my engine.
 
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