I have a 1935 Chevy with a 350 engine. The transmission went out so I'm replacing it. Pulled the grill and radiator to pull the engine and transmission together. The existing motor mounts did not fail but left a lot to be desired. Holes were egged. I designed foam mounts, here's a lineup shot. Glued and test fit. Joints waxed and coated with sheetrock mud. In the bucket, getting filled with sand. Cleaned up, drilled, and ready to go. I didn't account for shrinkage, and there was practically none on the height. If it cools from the bottom up and continues to take metal maybe it doens't shrink much. Re marked the ends of the cylinders for engine bolts and drilled hole from center punch front to center punch back. Used a lineup pin And aligned it with the drill bit then sat the center punch on the pin. The mounting bolts are pretty parallel even though the cylinders aren't.
Those look good Andy. Was the metal alloy known and any post treatment or as cast? Did I spy a third pattern (maybe accessory mount of some sort) not discussed Best, Kelly
Thanks! The metal was ingots I cast from previously cast engine parts and other castings, but primarily engine parts. I pulled them out of the sand as soon as I could without hot tearing and sprayed with water. They drill like a dream. I had failed pouring a trivet some months back using cast material. I poured to cold and was concerned about these pours. I had a lot of work making and fititng the patterns and did not want to fail so the third pattern was just some scrap I picked up to make a test piece. When it came out complete I went ahead and cast the real patterns, without failure. Thanks! I'm learning more every pour, especially with foam patterns. One mistake on this pour were areas with too much wax. It does not burn out as well as foam and crated some shallow voids. They're shallow and can stay but unsightly.
I hope they are far enough from the headers so the Aluminum doesn't get too hot and crumble. https://www.thefabricator.com/artic...minum-workshop-a-hotshot-s-guide-to-hot-short
Thanks for the link, some interesting stuff. I have urethane motor mounts so I have to install a heat shield but I was unaware of the low temperatures aluminum can be affected so I'll make sure my heat shield is large enough to protect the motor mount brackets too. Thanks again!
I filed and etched the test piece I poured to check for porosity. I was a little surprised. The lye turns the aluminum black so the pits show out, and also the file marks from aluminum stuck in the file. This piece looked clean before etching.
I've been using half and half toilet ring wax and paraffin. Applying it hot with a small brush. It seals the seals very nicely.
The reason I ask, as you may have previously read, I use Freeman fillet wax and that stuff is great to apply with heated fillet tools and has been burning out without a trace on my lost foam castings. In fact, when I put a torch to the stuff, I cant get it to light....it just vaporizes which may be why it works so well for detailing lost foam patterns. I'm not certain what you consider a lot of wax, but the fillet and embossment work on my water necks and manifolds I'd consider to be a lot of wax. I've discussed it here several times and if you search wax fillet, you'll get a few hits. Best, Kelly