BMW V8 dry sump from billet

[jim]

what are you going to do with the wax one when its finished?

i wouldn't be able to melt that work of art down!!

[AdeV]

Thanks again folks, it's always nice to know people are following along & appreciating.

Darren - I don't think the exhausts will get quite that hot... at least, I hope not! That said, the rest of the engine is aluminium, so it should be OK.

Dean - It's got a little bit of flexibility in it, which helps I think. Not a huge amount mind, as it will fracture quite easily. Watching the whole thing bounce when taking a slightly too-deep cut was a bit alarming, though!

Andy - Interesting idea about the magnet, but aluminium does strange things to magnets. If you've got a piece (sheet is ideal) and a neo magnet, do the following: Set the ali sheet up just off the vertical (say, 85^o), and slide the magnet down it.... That said, I don't know if your idea would work or not; I'll have to find a compass & give it a try.

Jim - I plan to keep it for posterity - especially if it ends up as the prototype for a lot of sumps However, I've got bags (literally) of swarf to melt down for future projects, so no worries on that score...

Right... back to the workshop...  

[John Stevenson]

Cast a new sump from it using the lost wax process.

John S.

[DMIOM]

......Darren - I don't think the exhausts will get quite that hot... at least, I hope not! That said, the rest of the engine is aluminium, so it should be OK.....

Ade - what Darren was referring to, and I was just about to post the same message but Darren beat me to it ..... we were wondering if the exhausts would melt the one you showed - i.e. the wax one !   

Dave

[andyf]

Andy - Interesting idea about the magnet, but aluminium does strange things to magnets. If you've got a piece (sheet is ideal) and a neo magnet, do the following: Set the ali sheet up just off the vertical (say, 85^o), and slide the magnet down it.... That said, I don't know if your idea would work or not; I'll have to find a compass & give it a try.

That's because the magnet is moving in relation to the aluminium, Ade, and thus setting up eddy currents which gerte a magnetic field which oppose the magnet's movement - Lenz's Law comes into it, I think. If the magnet is stationary, the problem shouldn't arise. But it was only one of my more harebrained ideas, and probably wouldn't work....

Andy

[CrewCab]

Brilliant Ade ............ brave man for sure  ........... really coming along now, good luck.

CC

[AdeV]

John S - That option disappeared today (see below). I'll still keep it I think, it'll be a nice memento at the very least.

Dave (and Darren) - Doh! Clearly, my irony detector was misfiring  this morning..... oops! Maybe If I cover it in aluminium foil, the heat deflection would be enough? 

Andy - It's still an interesting idea.... I've not owned a compass for nearly 20 years now (since I left the Scouts), but I'm sure my local tool shop will have some half-crock one I can buy for a few pence.... if I get chance this week, I'll do it.

CC - Many thanks It's been an adventure....


Right.... on with today's little update; and it is quite a short update, there's lots of thinking time been done, and more to come, before the tools come out to play again...

So, the first thing I did was whizz most of that big lump off the front. The extra clamp in the picture is shown because part of the front snapped off (at a pour interface):



Now, the plan was to make a separate block which will bolt/screw on the front of those three holes, turning them through 90 degrees. Unfortunately, there's simply not enough meat around the holes to guarantee a good seal. Worse than that, There's not enough space front-to-back to include all three pipes - with rubber hose attached - within the plan of the sump.

There's another problem - getting bolts into the piece without cutting through a pipe.... I wondered if I could slope the pipes upwards in my block, allowing me to get a couple of cap-head bolts in. So, set up a piece of scrap wax, using the sine bar & slip gauges:



It didn't work out; there just wasn't sufficient depth left in the wax to take a cap-head bolt.... and then it broke anyway.... ho hum...

Cue much headscratching, thinking, and planning... 

So, here's the result of the deliberations:



Instead of the separate block, with all the aggro of o-rings, bolts you can't reach, etc., the piece will be left on the front of the sump. The long holes will be capped off, and new holes will be drilled in from the side of the sump to intersect, at a slightly larger spacing (~25mm instead of 20mm); and starting a bit further back than I can manage with what I've got in the picture. Ignore the hole spacing in the temporary block, I got that the wrong way around...

In that picture, the black shaded parts are where I need to fill the drilled holes. Whatever technique I use has to be oil-tight, able to take a high heat (say, 200-250 degrees C to be on the safe side) while remaining oil-tight, and I must be able to mill/drill into it. I'm thinking, make a full-length (up to 100mm long for the longest hole) plug, which is a close sliding fit. Then, silver-solder this into the hole... The question is, with a 100mm long piece of aluminium, how far is the silver solder likely to penetrate? given that it has to go all the way down the hole, effectively making the piece solid again so I can drill into the side of it.

A second option, rather than rely on silver solder, would be to make a huge long threaded piece, and just screw it into the hole. Of course, the worry there is that one of the plugs unscrews itself over time, falls over & blocks the pipe... perhaps a combination of screwed & soldered?

Third option - shrink fit? If I warmed the sump & froze the plug, and the two were a close interference fit (1/2 to 1 thou, say), then that should make for a snug fit without over-stressing the metal too much, shouldn't it? Chances are it'd be a decent oil-tight seal too, without any further effort.

I'm throwing this one open to you, gentle readers... I genuinely don't know which of the above options (or some other option I've not considered) I should go with - please do suggest one...

Anyhoo - the final piece of the puzzle will be to add some spigots at the outflow points. The current plan for those is to mill a 1/2" to 1" long piece to 18mm ID, shove an 18mm OD steel tube in (it should be a nice wriggle fit), and silver-solder in place. These will then have standard rubber pipe jubilee clipped to them, which goes the short distance off to the oil pump.



Hmm, guess I'd better learn to silver-solder....


PS: I just did some expansion/contraction calcs: If I heat the sump to 150 degrees C, and cool the plug to freezing, the combined size difference of a 15.875mm (5/8" to you or I) hole/plug is a smidge over 0.0021". So, if I can turn a plug to within 1 thou accuracy (and not tapered), then a heat-shrink fitting would seem to be possible...

[jim]

to cap off the long holes, i'd be thinking along the lines of a gubscrew (taperd?)

loctite and then cross dill and pin/peg?


just a thought, are you going to run the sump on a "spare" motor before using it in anger???

i'd be gutted to hear that something went wrong ( and i've only read about it, not put a lot of hard work in!!!)

[John Stevenson]

You can't silver solder Aluminium.

.

[AdeV]

Hmm, that's a blow. What about soft soldering?

[Artie]

Gday mate, cant soft solder either BUT, this is the vacuum pick up? No pressure, cars have used screw in plugs for decades in oil gallery's under full pressure, that V8 will have some somewhere if you removed the bell housing or front covers. Screw thread and lock tite would work well.

If it comes to that, a press fit core plug WOULD do it.. but I'd prefer a thread myself.

Or you could have it welded.....

And ... great work Ade, if the final product looks anything like the wax, it sure to be a 'winner'...  

As an aside why cant you LIMIT the depth of each drill hole so that it only goes as far as it needs to be picked up by the 90 degree drilled cross holes? No holes to plug at all then. Simply a case of measuring and marking the drill bit before each hole.

[AdeV]

Cheers Artie - yes, this is on the vacuum side, the main thing is that the suction doesn't pull the fitting out, causing all kinds of pain.

I was just reading about aluminium & it's solderability. This alloy is 5082 (aka N8) - turns out that's considered "unsolderable" due to its magnesium content. Doh....

So, I guess I'll look at shrink fitting the long "core" plugs, and using a screw fitting + loctite for the pipework.

As an aside why cant you LIMIT the depth of each drill hole so that it only goes as far as it needs to be picked up by the 90 degree drilled cross holes? No holes to plug at all then. Simply a case of measuring and marking the drill bit before each hole.

Because I drill from the front of the sump, ALL of the holes pass through the fitting region. I could do the holes from the back, and just make a bolt-on piece to block the back of the holes; but then I'd have to drill all three holes to full depth (560mm); at the moment, only one needs to go long (470mm), each of the others is about 100mm shorter.

[Artie]

Believe it or not I was just in the 'bathroom' when I realised that and raced back in to delete the 'stoopid', but you beat me... You can buy screw in plugs that are quite narrow with a allen key head for just this application. They are steel and with the right loctite, they will never see the light of day again.

Good luck mate.

[DMIOM]

Ade,

if the sole reason for the shenanigans is to get better spacing for the screw-in terminal fittings, how about plugging the last bit where the entry hole is and then drilling in again on an angle? ( C-o-C below).  If that then doesn't leave enough for the thread, you could always mill a small flat at the entry point as a sort of counter-bore.  This way you only need two, long, plugs.  Also, if the drillings are too close to the surface for comfort, you could also make the new entry holes a little nearer the block ...



Dave

[Divided he ad]

Hi Ade,

I've been reading your thread for a week or so and just kind of caught up 

Not really had much to add, quite an engineering feat you've taken on..... Well out of my scope!


Anyway, I was just reading about the above crossdrill and plug issue and was thinking what about plugging the holes before you crossdrill in to the main oil ways.....

If you do this then you can loctite (or whatever pipe sealant you have) aluminium plugs into the holes and even drill and pin (roll pin,home made plugs/pins, screw or bolt) them into position through the main block. Leave for a day or whatever before drilling and they will be all fixed into position and sealed.

If it's pinned as well it'll never come out, it simply couldn't spin on the pin (that's if you only use one per plug) due to side wall thickness and shape.

Loctite stuffs are very strong and withstand a huge range of heats (they fix huge train wheels on with the stuff you know!!! Ask Stew.) you just have to buy the correct one for the application!


If I'm not making sense then C-o-C's can be rendered..... But I think you'll get what I mean?




Just thinking in text 






Ralph.

[AdeV]

Dave - I can't come out of the front of the sump with the pipework as pictured, because there's not enough room in front to fit the pipework. Even if I move the fittings as far back as possible, I'd still struggle to turn the pipes - the rubber hosing has a 25mm OD, and is not particularly flexible.

Ralph - I must have been unclear in my original post.... On the photo I posted above, the black shaded areas represent the original drill holes, which have been plugged to depth with a single piece of ali (locktited or shrink-fitted into place). Then: each sideways hole is drilled to meet its corresponding longways hole; so looking from the front, the nearest cross hole is drilled through two plugs to meet the left-most hole.

In other words pretty much as you describe, except it hadn't occurred to me to pin it as well.

For the Loctite, any suggestions? I'd wondered about 5399, which will take the temperature, but may not be the most suitable adhesive?

[AdeV]

Here's a c-o-c describing the plan I have in mind to turn the sump holes:



My writing is unintelligble at the best of times, so to save you struggling:

1) Drill main drain holes to full depth (i.e. as far as they need go).

2) Turn up 3 plugs, of the correct length, which will be fitted in the end of the holes. So, the first plug is the shortest, the last plug is the longest. Each is either an interference (heat) fit, or loctite, whichever is the most sensible.

3) Once the loctite has cured, or the sump has cooled down to the point it can be handled again, I can mount it up & cross-drill the holes - through the plugs (for the outer two holes)

4) (not shown) I'll turn a thread into the end of the cross-drilled holes, turn up some hose barbs, and screw them in using loctite to make sure they stay put.


Any thoughts? In particular, I'd welcome recommendations on which loctite to use, I think I have datasheet fatigue already...

[Artie]

Ade I cant see a problem with this method. Looking forward to seeing the unit in ali. Good to see someone thinking outside the box. Well done mate.

Artie

[John Stevenson]

I use high strength bearing fit for everything, it's kept Gert's knickers up for the last 8 years.

John S.

[AdeV]

Right, a quick spell in the workshop over lunchtime (working right next to the shop is great, but a terrible distraction  )...

First, hack off a piece of ali with my test hole in it. The pipe shown with it is a really nice snug "tap fit", so I'll make my ali piece about 0.001" bigger than it:



First, bung the main piece in the toaster oven, set to 265^oC, and leave until golden brown.



Next, turn up the plug. I'm using the same bit I made my drawbar spacer from. This has a 1/2" hole all the way through it, so when the heat fit is done, that'll probably end up a touch crushed. But that's not a problem, the object of this exercise is to practice heat shrink fitting:



Once exactly 0.634" is achieved, according to the micrometer, the piece is ready. First, check to make sure it won't go into the cold hole, by checking against the part i didn't hack off.




And, sure enough, absolutely no chance of that going in there, it simply will not fit (although, in fairness, I didn't try battering it with a hammer). So, into the freezer with the part, and wait a little while. About 15 mins, 'cos I'm impatient.

Finally, remove the receiver from the oven & clamp in a vice. Remove the plug from the freezer, align it with the hole, and wallop it with the Plastic Hammer of Destiny. And lo, it came to pass:



 

When it's all cooled down a bit, I'll hack off the disc & do a bit of trial machining work to see how it all holds up.

[AdeV]

Once I'd bandsawed off the disc, the tube was revealed:



Inset shows the faint line.

To see if I could move it, I stuck a piece of .625" rod in the other side of the hole & whacked it with a hammer a few times. It moved...:



But not all that much, really, and it'd really take a concerted effort to shift it. Dunno if it would grip better or worse as a solid piece...

Now, if only I could check it for oil-tightness...

[Darren]

Could you make a flat plate with gasket and bolt it on?

A lid if you like 

[jim]

I use high strength bearing fit for everything, it's kept Gert's knickers up for the last 8 years.

John S.

[Divided he ad]

Ade,

I'd have a bit of all the methods above myself, the heat fit will work fine and loctite on the insert before you (now lets copy and paste this to get it correct...)  "wallop it with the Plastic Hammer of Destiny"  This'll give very good leak stopping potential. Leave it to cool naturally (save issues with steam being created if quenched and creating fissures etc, and you could afford a few hours on a project like this to make sure it's all in place before machining couldn't you?)


As for the fitting of the barded hose connectors. I'd use PTFE tape.(Still very oil leak stopping on a good thread)
They're the kind of bits to get knocked and snapped during maintenance and you'd find it a lot easier to get 'em out than if they were sealed in! 


Oh and your C-o-C is exactly what I had envisioned 




Loctite..... I'd go with what John said  (is that the green or red stuff?)





Ralph.

[AdeV]

Hi Ralph - great stuff, I'll do a heat fit combined with loctite, then I think it's the red stuff that's temperature tolerant; but, then, for all I know ALL loctite is red!

I like the PTFE tape idea for the hose barbs too, provided it'll stand up to the 150-200 degrees temperatures which may occur down there... if not, I can always loctite them in anyway.  Once the sump is on & sorted, there shouldn't be much call to take it off anyway.

Ah, the Plastic Hammer of Destiny - a close ally of the Spanner o' Doom (seen recently near an angle plate) 

Darren - can't use a lid I'm afraid, I need each pipe to be separate. Now, one way to do that (with lids) would be to mill out a step in front of each tube, so it looked a bit like a staircase; then cap off each individual tube. However, to my mind, that would look messy & botched - I'd like people to look at this sump & think "it must be a casting..."

John S: Perhaps you need a bigger hammer? 

Anyway... no more sump work tonight; I was going to do some, then I thought I'd do 10 mins on another project. Measured three times, cut it wrong twice, gave up for the night, brain is clearly AWOL. Real work interferes for the next couple of nights, normal service should be resumed around Thursday.