BMW V8 dry sump from billet

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Divided he ad:
:ddb:

Back on it :headbang:

Looks like it'll be very nice, very soon :thumbup:

I'd leave it at the 8mm.... 5mm thick ali will take a bit of debris knock a lot better than a 2mm bit will..... Definitely!

Right... Bed me thinks!

Ralph.

Dean W:
Fitting up time, and it's all looking good, Ade. Some to go yet, I know, but it sure is getting close.
What a job!

I like your "arty" shot, too.

jim:
i'm looking forward to this being finished, good work!

NickG:
Great to see you back on this Ade. Nice to see the trial fit too :thumbup:

AdeV:
Thanks chaps for the kind words, always appreciated :D You'll make a metal mangler of me yet...

Speaking of which, it's time to look at the bit I've been putting off all this time (yes, even right back to the wax mockup)... that chunk at the back. The original sump has a fairly intricate casting which covers the flywheel & bolts to the gearbox bellhousing. This adds strength to the engine/gearbox unit, and keeps the crud & gravel off the flywheel. Whilst I won't be able to replicate the casting, I should be able to come up with something which at least acts as a cover, and adds some extra strength to the whole affair.

The first job, then, was to take one of the big arced pieces of ali I cut out of the original round piece, & chop it down to a more manageable size. Fortunately, Evolution do a range of TCT (Tungsten Carbide Tipped, I believe) blades which are rated to slice ali, at up to 3000 rpm. The blades are supposed to go in an Evolution circular saw, but keeping that thing straight whilst chopping into a 2.5" thick piece of ali proved to be nigh on impossible.... so, I stuck a blade in a broken down old table saw I found in the basement. It took 2 passes, but it did the job.

Next up, I used a tip handed to me by Bogs - and stuck a similar circular saw blade into a slitting saw arbor, and mounted it in the mill. Dial the RPMs up to 2300, and let 'er rip!

You can go through a piece of aluminium that big faster than a vindaloo goes through a dog. In fact, the only reason I didn't cut it full width in one pass was because it was too tall to clear the quill.

There are only 2 drawbacks to this method of cutting metal: 1) it makes a hell of a racket (good ear defenders are essential), and 2) the chips are officially hotter than the surface of the sun, so you really need an asbestos neck. In the photo above, I'm actually standing about 10 feet away from the mill, and using a garden sprayer* to fire occasional bursts of WD40 at the blade, hence the smoke coming out of the back side.

Anyway - long story short, before you know it the block is roughed to size & ready for the next bit of headscratching. This next photo shows you what I'm trying to achieve:

Basically, I shall cut the ali to approximately the radius drawn on it. It will be bolted into place where shown, and slots milled down where required. I'll also hollow out the back of it so it's a bit lighter.

So now all I have to do is chip the rust off my maths skills, work out the diameter of the circle from the chord I have (350mm across by 122mm high in case you're wondering) which will tell me where it has to go on the rotary table so I can cut a nice smooth arc.

More tomorrow!

PS:

* - Another of John's excellent tips. One of these things: is great for firing WD40 about the place. You can set it to a really fine mist; or screw the nozzle out to send firehose-sized blasts at an overheating cutter...

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