Topic: Resto Challenge – Salvage These Sandcast Cases? Looking for Suggestions

[kmb69]

It certainly looks good from the inside..
 I remember a guy welding aluminum pipes with oxy acet,  about 40 years back, I think using rod and flux.. much like welding cast iron.. and sometimes foundries would weld up small flaws in castings, to prevent scrapping them.
 I wonder if they ever did that on the sandcast cases, at the factory..

Had not thought of that but a very good possibility, Frank.

[Don R]

 I ran an injection die cast machine for a couple weeks making lawn boy mowers, aside from the danger of being burned up and hot all year round not a bad gig. It paid well.
 Those dies are constantly being repaired by welding and machining. Parts stick in them, the ejector pins make the round marks inside the castings. The dies must not be too hot or too cold. You spray a water oil mix between injections, if one part of the die gets too cold you get a cold lap or a pocket, if it isn't cool enough when the die opens you get a smear, if the inserts aren't perfectly seated you really mess things up when it tries to close.
 Long story short, all the funny marks in a part are due to all or some of those things happening. Any part I made that didn't pass QC got re-melted and put back into the pot. No repairs on those parts, it was quicker to melt it and try again. I'd imagine sand casting has core shifts and similar issues, I got a tour of a cast iron boiler plant and the sand molding was amazing.

 They had a design flaw and I got laid off, went back to Butler Mfg, picking nuts and bolts for pre-fab buildings. I missed the pay but not the molten metal stuck to my shoe, shirt, hat, hair, etc.

[754]

Dont forget, they were scrambling to get bikes out as fast as they could in those days..

[markb]

I put the cases together with the final driven shaft in place. Without the screws installed I was able to get a 0.005” shim between the cases in the shaft area. I put in the 4 screws  that are around the shaft and just barely snugged them down. Then I couldn’t even get a 0.001” shim in. Then I torqued the screws to spec and rotated the shaft. It was smooth and felt just like it did before tightening. I think I’m going to run it.

[markb]

I had one more issue that I hadn’t noticed before. I had two pins for the clutch cover that hadn’t been removed. After soaking and heating for a couple of days they still weren’t budging with pliers.


So out came the slide hammer. I put 1/4” screw on the tip which was a close fit on the inside of the pin. Then I used a vice grip to swish the pin into the threads of the screw.


Then I heated the area with the propane torch and a half a dozen light taps later they were out. Of course the soaking for a few days didn’t hurt. I haven’t found a better way to remove stubborn pins. It wrecks them of course but I always replace them anyway.

[Powderman]

I found out the hard way that damage and repair like that needs seriously devalues the cases. I sold all my sandcast parts to a guy who specializes in rebuilding them. I trusted him on the value of my crash damaged cases because he treated me very well on the mint frame and other SC parts. I was hoping to get around $2k for number 1535, but only got $550.

[kmb69]

I put the cases together with the final driven shaft in place. Without the screws installed I was able to get a 0.005” shim between the cases in the shaft area. I put in the 4 screws  that are around the shaft and just barely snugged them down. Then I couldn’t even get a 0.001” shim in. Then I torqued the screws to spec and rotated the shaft. It was smooth and felt just like it did before tightening. I think I’m going to run it.
.....

Looking good Mark. You might still consider swabbing a little Loctite around the OD of the bearing.

[kmb69]

I had one more issue that I hadn’t noticed before. I had two pins for the clutch cover that hadn’t been removed. After soaking and heating for a couple of days they still weren’t budging with pliers.
.....
So out came the slide hammer. I put 1/4” screw on the tip which was a close fit on the inside of the pin. Then I used a vice grip to swish the pin into the threads of the screw.
.....
Then I heated the area with the propane torch and a half a dozen light taps later they were out. Of course the soaking for a few days didn’t hurt. I haven’t found a better way to remove stubborn pins. It wrecks them of course but I always replace them anyway.
.....

Very clever trick! Wish I had thought of that a few times! Gonna put that in my toolbox. 

[markb]

That seems a little low. Was your damage from a chain break? Mine definitely has some issues but I don't think mine was. Either that or it wasn't seriously damaged or was repaired extremely well. At this point I'm feeling pretty optimistic about bringing this one back to life. Was it $550 just for the cases? Was that in unrepaired condition? If so then that's probably a fair price. I'm pretty determined to save it and I'm not doing it to sell it but does anyone else have an opinion on what these cases would be worth repaired?

[markb]

Looking good Mark. You might still consider swabbing a little Loctite around the OD of the bearing.

Thanks. That is my plan.

[754]

 Stuck Dowels. .?? Shucks I just run a tap in them and they turn right out, usually reusable too.
 But yours looked rusted in, heating them up wouod probably unstuck them.
 So I will stick with my method.

Great you can run the cases .. are you building a stocker ? Or ?

[HondaMan]

Nice job, Mark!
I've repaired many, but not sandcast-ers. They usually work fine. The only ones that worried me (unnecessarily in the end) were those where the cases still let in a (forced) 0.0010" feeler gage in the area where the chain broke out the face of the cases. I surmise that either the [thicker] Permatex #2 I used there worked fine or else the chain's goo plugged up the slight crack over time? Either way, they both never leaked oil there.

[Powderman]

Mine had chain break and crash damage, all of which was repaired previously. Unfortunately broken motor mount holes that were repaired were visible. I inherited the basket case and wanted to sell it to fund the Triumph build. Seems very little of the sandcast was salvaged after the wreck. I was hoping to make a whole lot more money on parting it out until I was informed "most" of what I had was from a 73 model.
I'm curious to what members here think your repaired cases would be worth for just the bare cases.

[markb]

Stuck Dowels. .?? Shucks I just run a tap in them and they turn right out, usually reusable too.
 But yours looked rusted in, heating them up wouod probably unstuck them.
 So I will stick with my method.

Great you can run the cases .. are you building a stocker ? Or ?

Another good idea I think for most pins. However, I don't think mine would have come out that way.

My plan is to just do a stock restore.

[Dunk]

If you use Loctite on the bearing or any other similar applications go with 640. It's bearing and sleeve retainer designed to retain bearings and such with up to .007" gap. I've used it in a few automotive transmissions with worn parts. Mixed results but mostly it has worked given proper prep, time to fully cure, and working with gaps toward the lower end of what they claim it's good for.

I have to pull the trans in my truck again for another issue, but the front case is NLA and the machined area for the countershaft bearing is a loose fit to the race. Loctite 640 worked to retain it even with towing and so forth. I'm debating when I pull and reinstall that race if I want to use 640 or break out the 660. Thing that sucks is any time you change any of the bearings you need to measure and shim that front race in the worn case. 660 is closer to a permanent bond and is supposed to work for massively worn parts up to .020" clearance.

[Bankerdanny]

I can understand how the repair would have some impact on the value, but in the end it is still one of only ~7100 sandcast cases and should still have substantial value, it's an engine case, not sculpture, why should it have to be perfect?

[markb]

it's an engine case, not sculpture, why should it have to be perfect?

I actually think of it as a work of art, but I agree it doesn't have to be perfect. 

[markb]

I pulled out the E1789 cases to compare the sprocket area. It has very similar markings E1490.


Even on the inside. I think they’re marks from the mold. Makes me feel even better about salvaging the E1490 cases. I'm convinced it's not repaired chain break damage.


I tried welding the nut on the broken stud. There wasn’t quite enough to hold it. So I had a local shop remove it. I also dropped the cases off at the welder. He’s going to repair the crack in the bottom case and fill in the gouges on the cylinder base surface. Then I’ll have it milled flat.

[BPellerine]

how did they get it out mark?great to have cases to compare,most only see one set in their lifetime.bill

[markb]

how did they get it out mark?

They just drilled it out.

I got the cases back from the welder. It was TIG micro welded with 5356 rods.


Here’s a close up.


Of course some of what caused damaged to the case also caused damage to the cylinder base. So that’s welded now too. The sleeves were pretty bad (they would have to be bored oversize) so I had them removed to make it easier to mill the base surface.


I put the cylinders on a surface plate and it was flat within 0.001” and the case looks pretty good too (in the areas with no gouges that is). I’m thinking of trying to take less than 0.003” from each surface for a total of 0.006” off the height. What is the maximum I can remove with affecting things like the timing, compression, etc.?

[kmb69]

.....
What is the maximum I can remove with affecting things like the timing, compression, etc.?

The absolute answer is -0-. But I know what you're asking. You will see little difference at 0.006" but even that will have some effect on the timing and compression. The easiest way to "fix" it is to use a 0.005-0.006" thicker base gasket. Pretty sure they're are available from Cometic.

[calj737]

At least with the weld beads proud of the surface, they can be milled flat/flush to the surface. I won't be surprised if some porosity shows up once they're milled though. Nature of the beast with welding cast alloy.

[markb]

This has been done for a while but I figured I should post an update. Here’s a pic of the cylinder base on the upper crankcase. My machinist put it on a sine plate on the mill. It took awhile to get it dialed in. It had to be shimmed to get it parallel to less than .001”. It took just barely more than that to clean it up. Same for the cylinders. I’m guessing total material removed on both was .002-.003”.

At least with the weld beads proud of the surface, they can be milled flat/flush to the surface. I won't be surprised if some porosity shows up once they're milled though. Nature of the beast with welding cast alloy.

You were right, I did end up with some pits but there is plenty of material out to the edges. The cylinder actually turned out much better. I’m thinking I might fill the pits with some JB Weld and then flat file it smooth. The dowel pin hole was rebored and the threads were retapped too and came out perfect.


My welder convinced me to weld the crack on the inside and outside. It just ended up being a lot more work for me but I think it was worth it. Here’s the outside…


and the inside.


I had to grind it down on the inside so the gear would clear.


I think the outside turned out great. I gave it quick sand blast to rough up the area. After it’s painted it will look even better.


By the way, after doing a good cleaning on the oil filter housing surface I think it will seal up just fine. I already Plasitgaged the crank bearings and I'm going to get the cases vapor blasted and painted and I will be ready for assembly. I have about $250 into just the cases (I'll have a bit more into the cylinders after they're sleeved and bored) but I'm feeling really good about how everything turned out.

[Stev-o]

Excellent...

[calj737]

Personally, I wouldn’t worry about the pitting on the mating surface. The gasket should seal that up fine. Others may disagree and have different input. But as long as they don’t cross the exterior plane, they should be fine.