BMW V8 dry sump from billet

Gallery, Projects and General > Project Logs

<< < (35/73) > >>

AdeV:
OK, so there we have it. 3 plugs...

First, load some 1" ali bar in the 4-jaw chuck. I've given up with the 3-jaw, it's impossible to maintain concentricity within 10-15 thou. It's bad enough with the 4 jaw, I can usually get that down to 1 thou runout given enough time & patience:

Next, turn down the correct length (plus a couple of mm spare) to 0.625", again plus a gnat's to take into account the drill chatter. I think I ended up with most of the plugs at 0.630", and they're an easy sliding fit (would fall out if you turned the piece on end). Hopefully the loctite will make that up & bind them firmly in place with no leaks. In the pic below, I'm taking a facing cut to bring the plug to length:

So, once the plugs are finished, part them off leaving a thin flange. I can't seem to get parting off sorted on this lathe, dunno if it's the tool, the technique or what. So I used the tool to dig as deep as I could, then finished off in the bandsaw. Then, put the plugs back in the lathe the other way around, and face the flange so it's a bit neater. No special reason for this, but it's all practice. So here's the end result:

And here they are, snug as bugs in a rug, in their respective holes (and in this pic, you can see why I had to cut the flanges; I used the bandsaw, which is why they're all at jaunty angles):

Once glued in, the flanges will be milled off, leaving the plugs flush with the front of the sump.

And finally, a picture showing how they work. The black shaded lines represent the holes inside the sump, drilled in through the side & through the respective plugs:

Obviously that's a bit crap-o-cad, the real version will have equal pipe spacing, etc. So, by the time I'm finished, that long plug will have been chopped into three separate pieces. Someone, somewhere on this thread, suggested pinning them (by which, I assume, they mean a pin inserted vertically which intersects the plug and block, thus preventing the plug from either rotating, or moving) - this is an idea which appeals to me, and I will probably do it.

Day off tomorrow, so the next update will be Monday.

andyf:
Ade, I'm no expert on high-temp Loctite, but the datasheet for 648 http://www.loctite.sg/sea/content_data/93769_Loctite_648_Retaining_Compound.pdf
shows it stronger than 668 until about 175°C (you quoted 150-175°C as the most you expected) at which point its strength is on an increasingly downward curve. The graph for 668, though getting down to 50% strength at lower
temperatures, seems to hold that strength as the temp increases to 200°C.

You pays your money and takes your chance, but perhaps it's best not to get too blinded by science. Drain plugs in sumps traditionally consist of a bolt with no more than three or four turns of coarse thread clamping down a fibre washer under the bolt head.

This sump is for a competition car. If the plugs face forward, air pressure will keep them in place if you go fast enough :lol: :lol:

Andy

Dean W:
Wow, Ade. I missed a day, and you really went to town.
The light you showed at the end of the tunnel is a beautiful thing, in this case! (At least it's not a train.)
It's coming along so well, and I'm happy for your success.

Dean

Divided he ad:

--- Quote ---Someone, somewhere on this thread, suggested pinning them (by which, I assume, they mean a pin inserted vertically which intersects the plug and block, thus preventing the plug from either rotating, or moving) - this is an idea which appeals to me, and I will probably do it.
--- End quote ---

:wave:

Yep, pin down intersecting each plug section so it can't slide/pop out. As the side walls themselves would prevent them twisting on the pins, keeping 90+% of the flow contained even if the loctite fails. (belt and braces!)

Hope it works now!! :)

Looking good, and lots more answers on the loctite front..... Isn't the internet brilliunt!? :nrocks:

Ralph.

jim:
i'd loctite and pin each section.

i'm looking forward to the next update!

Navigation

 Message Index

Go to full version