Engine Rebuild Stand

[Luke]

I decided to take a little time off from the 16V project for a month or so, to pay down some credit cards bills before I bought the rest of the valvetrain parts, but I also had some side projects I wanted to accomplish before I moved foward - one of which was a nice engine stand to rebuild the bottom end.

I have the nice factory service fixtures for mounting the engine, and a cheap engine stand I modded to hold the factory bracket, but it was a pretty crappy setup overall.

So i decided to build a basic but sturdy stand that worked better with the SAAB holding fixtures (I also have the transmission and cylinder head holding fixtures)

So I went to the local steel yard and picked up about $35 worth of steel and went to work.

I built a simple framework for the stand, the legs are spaced apart so that they can go around a rolling work table that I also just built - which will allow for easier tranfering of a block from a table to the stand.


Here is the rolling cart - built out of some old steel from some pallet racks and casters from an old tool box. I put a small bin shelf underneath it to hold engine components.



I also pressed bronze bushing into the pivot tube - probably overkill but it just seemed like the right thing to do.

[Luke]

Then a little paint made it look a tad more presentable.






The rear end of the pivot shaft is turned down to fit a worm gear set - so that I can fit a crank to position the engine at any angle I want.



And here it is in position around the rolling cart:

[Luke]

So this flange on the rear will hold the gearbox for rotating the engine.




I thought for a little while about how I wanted to build the gearset, originally I was going to build it out of some welded plate - then I thought about milling it from a big chuck of billet - but I decided the best and most economical option would be to cast the housing.

My dad had built a furnace a while back as experiment to try melt some bronze for some sculptures, etc and I figured it would have no problem melting some aluminum.



So I built a suitable pattern out of wood to hold the gearset - the corners smoothed and filleted to provide a clean release. I didnt take any pictures of the pattern in progress - but you guys can fill in the blanks - some sanding and filling with wood putty and then painting with primer and sanding.



Then the next

[Luke]

Then the next step was to pack the pattern in green sand. The sand is just a mix of fine silica sand, bentonite clay and water.






The sand is just piled in and packed firmly around the pattern and then smoothed off to the top of the wood flask (the wood box that contains the sand) This half of the mold is referred to as the drag.



Then the whole box is flipped over to reveal the bottom side of the pattern.



You wouldnt normally remove the pattern at this step - but I wanted to make sure I was getting a clean release because of the deep walls, so I pulled it just in case.




Yep, looked decent!



So I put the pattern back in and applied talc to the entire surface. The talc is provide a clean part between the two halves of the sand mold.

Then I filled the top half of the mold (called the cope) with the green sand and packed it tight.



Once this is done you actually pull off the cope half, which separates at the talc line, and remove the pattern. You also carve some holes called sprues and gates for metal to flow through into the mold.

[Geoff]

OK, I was going to say this is pretty awesome. Then I saw that you're in the process of casting your own gears and I decided you belong in a loony bin!

Are all your casters salvaged? They're typically the most expensive parts if you're building your own engine stand.

[Luke]

And this is where it starts to get fun!

For an aluminum supply I took some old gearbox parts and smashed them up into smaller chunks - I also added from chunks of 6061 scrap for filler - but you dont want to add too much of that as its not really a casting alloy.



Then we fire up the furnance!


Its fired on propane and gets very hot... heres my gauge about to peg out at 1100 deg. We only need to get to about 1350 or so.





See if any of you can recognize this part!









It is (was) a shifterhousing. Also note one more use of SAAB pliers, those things are the best!

[Luke]

OK, I was going to say this is pretty awesome. Then I saw that you're in the process of casting your own gears and I decided you belong in a loony bin!

Are all your casters salvaged? They're typically the most expensive parts if you're building your own engine stand.

The casters on the table were salvaged, they are some nice US made "faultless" ones - I bought the ones for the engine stand though.

Haha, no I'm not going to cast the gears - I got a cheap surplus set on ebay - but I am going to cast the housing.

[Jordan]

OK, I was going to say this is pretty awesome. Then I saw that you're in the process of casting your own gears and I decided you belong in a loony bin!

Are all your casters salvaged? They're typically the most expensive parts if you're building your own engine stand.

Luke is missing the part of the brain that says "you should/can not do this". I wish I was so lucky.

[Luke]

So once the stuff is hot I scooped out the dross (which is impurities and carbon and stuff that floats to the surface) and then its ready to pour.

[Luke]

So after it had cooled for a while I broke apart the mold to find out how much of a mess I had made...






Digging.....





Hey not too bad!



A little cleaning of the flash and some fly cutting and it should be usable.



Then I bored the cross hole for the worm gear and drilled and tapped the bolt pattern to bolt to the stand.





Pattern and the final piece.



And with the gearset installed.




And mounted up:


I still need to make a cover and a crank handle but otherwise its basically done.

[SwedeSport]

Is there anything you won't try?

Impressive!

[Luke]

Is there anything you won't try?

Impressive!

Jason, I'd like to think that there are quite a few things you've tried that I don't plan on trying.

[paulh]

nuts. Best engine stand on net, no joke!

Paul

[airsweden]

geez Luke? I'm starting to think you do this just to mess with us... wtf dude?

[Geoff]

Next up: Luke re-tools his garage to mimic the Trollhattan factory floor and it's suppliers circa 1978 complete with sheet metal dies, engine casting equipment, body welding jigs, etc.