Alfa Oil Pan

[xken]

Andy, I cannot get your pictures to enlarge; right now they are too small to appreciate.

Ken

[hot ford coupe]

That's a big ditto, Good Buddy. I'd really love to see how you did it.

[Andym]

Let's try that again... Sorry guys.

[xken]

Andy, now that is more like it. Do you have any pictures of the cutting process showing your set up and cuts? I assume you start with a block of T3 aluminum.

Ken

[Andym]

Ken - I started with 6061-T6 Aluminum bar. I have all the pictures of the build / machining processes and will post them tonight when I get home.

[xken]

Andy, AHHHH......you are using the pricey engineering grade stuff. Must be nice.

Ken

[Andym]

I like it because it responds well to wet sanding when I want a dulled look and, more importantly, polishes up almost like chrome when I'm going for the Pebble Beach look. I also think it's easier to work with on the mill and the lathe (but that's probably only because it's what I'm used to).

[Andym]

After experimenting with different techniques, I figured that making the oil pan in three pieces was the way to go. There were lots of little reasons, but the two big reasons for this decision were (1) it was easier to curve the ends of the pan if it was a separate piece and (2) drilling the holes in the bottom plate was much simpler.

I started with a block of aluminum. After making sure it was a perfect rectangle of appropriate size, I cut the top sides at a 3 degree angle on the tilt table on my mill.

In order to give the cooling fins the appropriate curve on the ends, after getting the basic shape of the pan, I rounded off the left and right edges (measured horizontally) using my belt sander and ever increasing grits of sand paper to get a nice smooth edge.

Next - and the last step before cutting the fins - is do drill and counter sink the drain plug hole at the front end of the pan. Again - this should be done before the cooling fins are machined.

Now that I had the pan shaped correctly, it was time to cut the cooling fins. A couple of words of caution here. First - it is highly recommended that you have a digital read-out on your mill for this step. Second - to get the proper number of fins, use a 1/16" flat tip end mill with each fin spaced 0.1250" apart. Third - GO SLOW. Forth - GO REALLY SLOW.

Now that the pan is done, it's time for the bottom plate. After two failed attempts I realized that this was never going to work out if I didn't cut the holes BEFORE shaping the plate itself. Because the holes are so close to the edge, it just made a lot more sense to cut the holes first. This step required a bit of creative thinking in terms of how to hold a piece of flat aluminum plate (1/8" thick) on the cross slide of the mill. I ended up notching a block of wood, screwing the entire aluminum plate onto said chunk of wood using machine screws and then setting the hole positions using an end mill chucked up in the Mill. Again - a digital read-out is helpful if not mandatory to get the holes spaced and aligned correctly. Once the hole positions were set, I used a jeweler's press with 0.00001" run-out to drill the holes using a #55 bit.

With the plate done, the final step was to cut the end piece. Given that the 1:1 prototype was cast, I had to figure out how to replicate the look with machining instead of casting . I think the picture speaks for itself and I'm pleased with the result.

A little epoxy resin to join up all the pieces, some wet sanding and polishing, and voila - an all-aluminum, scratch-built, 1:8 scale Alfa Romeo 8C 2300 oil pan.

Andy.

[hot ford coupe]

Way cooooool !! Thanks Andy for breaking that down. The process is crystal clear.

[Andym]

HFC - the funny thing is that even though I wrote everything down and took explicit notes with pictures and measurements, I'm pretty certain I couldn't do it again.