Author Topic: 1909 Mercedes Aero Engine  (Read 2514 times)

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
1909 Mercedes Aero Engine
« on: November 26, 2018, 08:14:32 PM »
I can't quite believe it but it was November 2012 when I signed up having bought a set of castings for Heinz Kornmuller's Mercedes aero engine from The Engineer's Emporium. My intention was to finish off my Thornycroft lorry and then have a go at something smaller. Well, I have almost finished the lorry and have started on the engine! I have been taking some photos which I would like to share. The first is Heinz original engine so that you can see what I am on about.

« Last Edit: November 26, 2018, 08:42:39 PM by Old Bill »

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #1 on: November 26, 2018, 08:23:36 PM »
Hello Stranger,  ;)

 :headscratch: I am sure you just showed me your castings but they seem to have gone again. Have you been talking to Jason?

Jo
Usus est optimum magister

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #2 on: November 26, 2018, 08:26:20 PM »
Hi Jo. None stranger!

I am struggling to drop photos in with captions at the moment. I will get it sussed shortly. Any advice please?

Steve

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #3 on: November 26, 2018, 08:28:22 PM »
The photos need to be hosted on a photo hosting site like photosuckit and the links dropped into the post between the text.

Jo
Usus est optimum magister

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #4 on: November 26, 2018, 08:31:16 PM »
Thanks! I will return!

Steve

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #5 on: November 26, 2018, 08:38:25 PM »
That's what they all say to me as they gather up their castings and run  :-\

Jo
Usus est optimum magister

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #6 on: November 26, 2018, 09:00:08 PM »
OK. Got it!

I decided to start with the crank case. Now, all of the castings for this engine are a devil to hold.



I dogged the top half to my Taiwanese mill and skimmed the ends to give myself a datum. I also ran a mill along the feet for another straight edge.



The a bit of messing with the height gauge to find the centres.



Then drill and bore for the con rods. Now, the drawings for this engine could be a bit clearer and show more of the detail. Fortunately, I was switched-on enough to think of the block hold-down studs and took the opportunity to centre for them and the push rod bushes by coordinate drilling. In other words, by counting the numbers on the dials. One day, I am going to invest in a DRO!



Then I turned it over and skimmed it to thickness using a pile of slips and a clock gauge to measure it.



Spot face and hold-down holes.



First component well on the way!



I must admit that I am enjoying this one. It is so nice to be able to lift everything and to be able to fit it onto the machine with space to spare! Sump next. Then I am going to be looking for some advice as to how to drill the crank and camshaft holes.

Watch this space!

Steve    :)

Online sco

  • Full Member
  • ****
  • Posts: 1520
  • Location: Northants UK
Re: 1909 Mercedes Aero Engine
« Reply #7 on: November 26, 2018, 09:10:29 PM »
Looks like some nice castings Bill and I can appreciate the challenge in holding them for machining.  Are the drawings in metric or imperial?

Simon.
Ars longa, vita brevis.

Offline Ye-Ole Steam Dude

  • Full Member
  • ****
  • Posts: 995
  • Deep East Texas on Sam Rayburn Lake
    • Ye Ole Steam Dude
Re: 1909 Mercedes Aero Engine
« Reply #8 on: November 26, 2018, 09:34:48 PM »
Hello Bill,

Beautiful castings and some fine machining also, this will be a fun project to follow.

Have a great day,
Thomas

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 3388
  • Boise, Idaho USA
    • Photo Bucket
Re: 1909 Mercedes Aero Engine
« Reply #9 on: November 26, 2018, 09:51:42 PM »
Cool engine and nice work on your part Steve.
I'm looking forward to following along with your project.

Dave

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #10 on: November 26, 2018, 09:53:23 PM »
Looks like some nice castings Bill and I can appreciate the challenge in holding them for machining.  Are the drawings in metric or imperial?

The castings are quite nice and haven't been over-fettled. I would much rather clean them up myself as foundries tend to be a bit brutal to say the least! The drawings are all metric. However, my workshop is imperial so my calculator is now sitting on the bench. I am making the engine in metric units to drawing but am using BA threads as they are what I have and am tooled up to handle.

Steve   :)

Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12421
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: 1909 Mercedes Aero Engine
« Reply #11 on: November 26, 2018, 10:31:35 PM »
Great start Steve. Following along as well.

Bill

Offline stevehuckss396

  • Full Member
  • ****
  • Posts: 1311
  • Sterling Heights, MI
Re: 1909 Mercedes Aero Engine
« Reply #12 on: November 27, 2018, 01:00:19 AM »
Good work. I'll be following along. I like the engine as far as how it looks. Great project.
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline Art K

  • Full Member
  • ****
  • Posts: 928
  • Madison, Wisconsin USA
Re: 1909 Mercedes Aero Engine
« Reply #13 on: November 27, 2018, 04:23:10 AM »
Steve,
I must admit having a soft spot in my heart for aircraft engines. So I will be following along.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #14 on: November 27, 2018, 07:14:20 AM »
You are off to a good start and thanks for taking the trouble to host the photos externally so that you can post in the thread, it makes it so much easier and enjoyable to follow like that.

Online Fowellbox

  • Full Member
  • ****
  • Posts: 38
Re: 1909 Mercedes Aero Engine
« Reply #15 on: November 27, 2018, 08:20:26 AM »
This looks to be an interesting project (not that I need another one) but I tried to find details on The Engineers Emporium and there's nothing about it on there. Is another company doing the castings and drawings?
Brian

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #16 on: November 27, 2018, 08:36:12 AM »
Engineers Emporium still do the castings and a whole lot more but don't put them on their website :facepalm:

Best to ask for a copy of their catalogue

Online sco

  • Full Member
  • ****
  • Posts: 1520
  • Location: Northants UK
Re: 1909 Mercedes Aero Engine
« Reply #17 on: November 27, 2018, 08:44:49 AM »
Engineers Emporium still do the castings and a whole lot more but don't put them on their website :facepalm:

Best to ask for a copy of their catalogue

Useful to know - I had a look on their website and gave up in the end as it's a complete mess.

Simon.
Ars longa, vita brevis.

Offline RayW

  • Full Member
  • ****
  • Posts: 360
Re: 1909 Mercedes Aero Engine
« Reply #18 on: November 27, 2018, 11:42:39 AM »
Hi Simon,
Their October 2017 price list shows castings, gears and drawings at 315. Their code is MER1C

Ray
Ray

Offline RayW

  • Full Member
  • ****
  • Posts: 360
Re: 1909 Mercedes Aero Engine
« Reply #19 on: November 27, 2018, 11:50:49 AM »
Ray

Online sco

  • Full Member
  • ****
  • Posts: 1520
  • Location: Northants UK
Re: 1909 Mercedes Aero Engine
« Reply #20 on: November 27, 2018, 12:11:02 PM »
Thanks Ray!  Apologies for diluting your build thread Steve - please keep up the good work on the build log :-)

Simon.
Ars longa, vita brevis.

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #21 on: November 27, 2018, 05:59:06 PM »
 8) How much spare was there on that casting? Mine seems to have about 5mm top to bottom but the other measurements look tight.

Have you thought about your crank Steve? Are you going to do a made up one like the drawings show or make from solid?

Jo

P.S. Best tell Father Xmas that your milling machine needs a DRO  :mischief:
Usus est optimum magister

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #22 on: November 27, 2018, 09:23:24 PM »
Apologies for diluting your build thread Steve - please keep up the good work on the build log :-)

Simon.

That's quite alright Simon. I see a forum as a bunch of mates sitting in a pub talking about whatever the subject may be, asking for advice and wandering off down all sorts of alleyways. It's all part of the fun! I am certainly going to be asking for advice!

In the meantime, Jo, the castings are not very generous but are OK. One has to be careful as I have already found and will tell you about in a day or two. The crankshaft is pressed together with all of the bearings and rods fitted but I have not yet thought it through how to do it. That is another discussion to have shortly. Meanwhile, the next part will be the sump.

Steve  :)

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #23 on: November 28, 2018, 09:39:46 PM »
The sump is also an awkward casting to hold. I gave in in the end and simply gripped it gently in the vice whilst I skimmed the joint face.



Then turned it over and skimmed the other faces.



The two castings match and line up very well so it was simply a case of centre popping the bolt holes by eye and spotting through before tapping. I will make some proper studs eventually but, for the moment, they are held together with bolts.



Now, this brings me to the first major challenge. How do I put the crank and camshaft holes through and keep all three holes in line? The crank shouldn't be too bad, in fact, as the reaming size is 1/2" dia. This should be big enough not to wander too much in the centre bearing if I am gentle. However, the camshaft holes are to be reamed 8mm and the last hole is 150mm from the first. How should I go about keeping them in line? My current plan is to use the vertical slide on the Myford to hold the case and use the dials to control the centre distances. I can start the holes in the right place OK but where they go after that eludes me. I would value some advice please!

Steve  :) 

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #24 on: November 29, 2018, 07:23:53 AM »
Drill them out to 12mm an 7.5mm respectively and then make up a couple of between ctr boring bars. A 10mm or even 11/16" dia one should not be a problem to make but for the cam use some 7/32" rod, you won't have room for a grub screw from the side to retain the bit so drill in from one end say 25mm long 2.5mm and then tap the first 10mm or so M3. You can now slip in a bit of 7/32" stock and then use a M3 grub screw to push that against a small HSS toolbit.

In use the bar can be used to do one end almost to size, then swap it end for end to open up the other end and then finally take that to size. Then without altering the tool bit swap it back round to do the first hole which will ensure they are both the same size.

Probably do similar with the crank as it saves having to have a bar that is at least twice the length of the block.
« Last Edit: November 29, 2018, 07:50:16 AM by Jasonb »

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #25 on: November 29, 2018, 08:23:45 AM »
Morning Steve,

As the case is a difficult shape to hold I would start by mounting it on a jig which would give a nice large flat reference/clamping surface that is square to the casting  ;) Then the centres of both the crankshaft and camshaft can be marked & Centre popped.

Using an angle plate mount the cylinder, centre on the crankshaft hole then drill/bore. Turn end over end and do the other crankshaft bore (this keeps the offset distance to the bottom of the crankshaft equal). Using a long drill, drill a hole in the centre bearing around 10.5mm leaving space to line bore shortly. Do the same for the camshaft holes drilling the centre bearing 6.5mm.

Turn up 4 bronze bushes to fit the four outer holes, bored to fit the between centres boring bars which are going to be used to cut the centre bearings =10mm and 6.35mm dia respectively. As the centre bearings are bushed it is not critical to get it spot on as you can turn the bush to fit, what is important is getting it in line  :)

The between centre boring bars can now be made as short as possible with the bushes reducing the unsupported length of the boring bars to about 140mm. You can use your vertical slide, if you wish, to hold the case still on its jig for boring.

Jo

P.S. If you make both the crank and cam solid the centre bearings will need to be split  ::)


« Last Edit: November 29, 2018, 08:34:09 AM by Jo »
Usus est optimum magister

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #26 on: November 29, 2018, 08:44:32 AM »
Jo have you modeled the inside of the crankcase to see if there is room to swing split big ends? looks to me to be rather tight on the cam shaft and the oil pan will probably need modification too.


Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #27 on: November 29, 2018, 08:56:27 AM »
Heinz in his instructions says it is possible if you reduce the big end diameter to 10mm which is more than adequate for the bore/stroke.

I am currently modelling a Tulip  ::)

Jo
Usus est optimum magister

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #28 on: November 29, 2018, 10:20:20 AM »

I am currently modelling a Tulip  ::)

Jo

Don't forget you can always ask any questions about Alibre in the thread on ME relating to the 6month free trial :LittleDevil:

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #29 on: November 29, 2018, 10:57:58 AM »
That sounds like an advert  :ShakeHead:, I am more interested in Steve's build of his engine  :)

Jo
Usus est optimum magister

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #30 on: November 29, 2018, 09:50:41 PM »
Thank you Jo and Jason. Plenty of food for thought there. The one that is challenging me is how to put the middle hole in for the cam shaft as I can see it wandering all over the place. The hole will go through the joint line between the casting and the bearing cap and i don't suppose that they will be flush. No doubt it will become obvious in due course.

Steve   :) 

Online steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 9384
  • Central Massachusetts, USA
Re: 1909 Mercedes Aero Engine
« Reply #31 on: November 30, 2018, 12:20:44 AM »
Thank you Jo and Jason. Plenty of food for thought there. The one that is challenging me is how to put the middle hole in for the cam shaft as I can see it wandering all over the place. The hole will go through the joint line between the casting and the bearing cap and i don't suppose that they will be flush. No doubt it will become obvious in due course.

Steve   :)

Drill undersize, and then bore the middle.   Start with a good stiff spotting drill, and it won't wander around.   Boring bar will bring it to size and assure proper position...a drill just makes a hole.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #32 on: November 30, 2018, 07:21:20 AM »
Get yourself a long series centre drill, or loctite an 1/8" one in the end of a bit of rod.

Though a small amount of wander won't be so critical as unlike reaming the between ctrs bar won't try and follow the hole.

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #33 on: November 30, 2018, 07:10:03 PM »
The one that is challenging me is how to put the middle hole in for the cam shaft as I can see it wandering all over the place. The hole will go through the joint line between the casting and the bearing cap and i don't suppose that they will be flush.

The cam is in solid metal, the crank on the joint line - Yes highly unlikely the two bits will be flush  :facepalm: Maybe file/grind the two castings as close as you can true then drill undersized and bore a little more off between centres. At least on the crank you have more to play with so can use a larger diameter boring bar to keep it true :)

Jo

Usus est optimum magister

Online Vixen

  • Full Member
  • ****
  • Posts: 978
  • Hampshire UK
Re: 1909 Mercedes Aero Engine
« Reply #34 on: November 30, 2018, 07:36:19 PM »
+1 for ensuring the two castings a truly flat and fit correctly BEFORE you drill and bore the journals. Use some engineers blue to test for flat and fit.

Mike
It is the journey that matters, not the destination

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #35 on: November 30, 2018, 08:08:45 PM »
Fot the two part crank ctr bearing You could bolt on an over width cap and then mill either side of the cap and the part in the main casting to flush up both sides and bring to final width.

I assume there is a boss cast in for the cam ctr bearing which you should be able to mill the sides of with a small cutter.

You can always but a facing cutter into the between ctrs boring bar to flush things up after pilot drilling.


Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #36 on: November 30, 2018, 08:23:27 PM »
You are quite right, Jo, the camshaft goes through a solid divider in the middle of the crank case. It is in the corner though so it will take a bit of care.

I like the idea of the extended centre drill. I did buy an over-length one but it is just not quite long enough. Lots of good ideas and thoughts here.

Many thanks,

Steve

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #37 on: December 01, 2018, 10:38:04 PM »
Now that I have a crank case, I thought I would have a go at the cylinder blocks. Again, these are most awkward castings to hold!





There are very few good datum faces on the things so I held them by the base flange in the vice and took a skim across the top.



Then turned them upside down and dogged them to the table. This worked out OK but there is very little meat on the base flange so  so I had little room to manoeuvre.



I skimmed them to height across the base and then ran around the periphery to clean to size. Using the wonderful edge finder, I datumned off the corner and drilled the stud holes. Then it was simply a case of boring to depth, or so I thought....





One core was slightly off-set so the casting only just had enough metal to clean. What I didn't realise until later was that I hadn't quite got the casting upright when I skimmed the top and, of course, this compounded the core problem. To clean up properly, I have bored it oversize by 1.5mm and will have to make a thick liner. Not insurmountable but annoying carelessness on my part.





Still, at least the stud holes lined up!



Then the next googly. The dummy core-plug bosses fouled so that I couldn't put the blocks close enough to bolt them both down.



These were removed and I polished the ends with a needle file so that you wouldn't know they were missing.



Well, it is beginning to look like an engine, anyway!



The centres of the blocks need to be in line so that the rocker shaft lines up across the tops. First job was to find a centre line. This was another puzzle due to the difficult shape. However, With the base flange on one parallel and a second underneath a clean part of the water jacket, I scribed an approximate centre line before turning the block over and repeating from the other side giving me two lines quite close together.



At least I can see the problem. One block lies 1.3mm out of line with the other.



Whilst I ponder what to do about it, I have removed the pattern marks.



Five minutes with the Dremel and that is something else ticked off.



I have been out playing trains today and have guests tomorrow but hope to pick the job up again in the week.

Steve   :)

Offline Ye-Ole Steam Dude

  • Full Member
  • ****
  • Posts: 995
  • Deep East Texas on Sam Rayburn Lake
    • Ye Ole Steam Dude
Re: 1909 Mercedes Aero Engine
« Reply #38 on: December 02, 2018, 12:56:15 AM »
Hello Steve,

Looking real good. :ThumbsUp:

Have a great day,
Thomas

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #39 on: December 02, 2018, 09:36:19 AM »
 :thinking: Could you gently file the bottom clamping surface to adjust the angle to pull the top of the cylinder over in line?

I was allowed to fondle my cylinder castings this morning and there seems to be about 5mm top to bottom spare and 2mm on the clamping flange along its length. The width has nothing spare  :ShakeHead:

I know you have been aging your castings for a while Steve, I seem to recall the earlier cylinders did not have the water jacket cast in does yours? I don't think the slightly thicker liners will effect the water jacket  :)

Jo
Usus est optimum magister

Offline Roger B

  • Global Moderator
  • Full Member
  • *****
  • Posts: 3541
  • Switzerland
Re: 1909 Mercedes Aero Engine
« Reply #40 on: December 02, 2018, 12:13:53 PM »
Excellent progress  :praise2:  :praise2:  and some fun challenges with the castings  :ThumbsUp:  :ThumbsUp:  :wine1:
Best regards

Roger

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #41 on: December 02, 2018, 07:51:34 PM »
Thanks Thomas and Roger. The moral support is always appreciated!

I had been thinking about just filing a slight run across the base but I would rather machine it if I can work out how to hold it.

These castings have the water space cast in and the liners are pressed in to seal. (Wet liners). The thicker liner will be fine and even if it is left a whisker leaning once I have skimmed the base, then that will be of no consequence. I hope to have an evening in the shed this week so we can see how it goes.

Steve  :) 

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #42 on: December 02, 2018, 08:15:08 PM »
machine a bit of 1/4 flat with the desired angle which can be done easily by packing in the vice or pack the base of the vice.

Now clamp it down onto your tapered packer as you had it for machining the underside and bores.

Alternative would clamp it down to the mill table with a feeler gauge under one side to give it some tilt. Or pack a solid steel plate with feeler gauge/shim stock to get teh angle an dclamp the head down onto that, less likely to mark the top as it will be supported over whole area.

Agree machining will give a far flatter surface then filing.

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #43 on: December 07, 2018, 05:46:41 PM »
Well, I have managed to find a couple of workshop hours this week and took the opportunity to bring the blocks into line. As Jason suggested, I took a piece out of the drawer and machined a run across it using some shim stock under the edge.



Then set it up and checked with the DTI to make sure it was right. (It wasn't!)



After that, it was quite simple.



Success!



Next job is to start putting some holes in the top so I have clamped a datum to the table to allow for quick setting up and movement should it be necessary.





The valve holes are partially cored in so I used a nice new slot drill as a pilot. One of the nicest things I am finding with this job is that I have put away a number of brand new cutters over the years and saved them for 'best'. Well, this is 'best'!



I have also treated myself to some new reamers as I don't have any metric tools. This one turned up on Wednesday, just in time. I am doing something wrong with it though as it 'picked up' in two of the holes despite my best endeavours to keep the flutes clear.



I also managed to mis-read my dials and get one hole 0.010" out of position which is annoying for the sheer carelessness. I should know better by now. Oh well. I shall have to take Jo's advice and treat myself to a DRO.

A few more holes this weekend with a bit of luck.

Steve  :) 

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 11779
  • Hampshire, england.
Re: 1909 Mercedes Aero Engine
« Reply #44 on: December 07, 2018, 06:13:03 PM »
 :)

A few more holes this weekend with a bit of luck.

 :o

Its the weekend Steve and you are thinking about machining a model engine  :hellno: The weather looks to be  good.... are you not going down to stroke one of your lorries?   :noidea:

Jo
Usus est optimum magister

Online Vixen

  • Full Member
  • ****
  • Posts: 978
  • Hampshire UK
Re: 1909 Mercedes Aero Engine
« Reply #45 on: December 07, 2018, 07:59:56 PM »
The weather looks to be  good.... are you not going down to stroke one of your lorries?   :noidea:

Hello Stranger

Nothing wrong with that, considering the number of years you have put into each of them.

That was an excellent fix on the base flange of the errant cylinder block.

Do you have any Trefolex cutting paste? It is perfect for stopping drills. taps and reamers and even milling cutters from picking up in softish aluminium castings.

Mike
It is the journey that matters, not the destination

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #46 on: December 07, 2018, 09:29:54 PM »
Hi Mike and Jo.

The lorry I mentioned in my intro in 2012 has taken 29 years to get to this stage and we plan to finish it over Christmas. A few more days are neither here nor there! In the meantime, I am thoroughly enjoying machining something that is smaller than the mill and cutting 7BA instead of 1/2" BSW. It is great to do some model engineering indoors in a heated workshop. (Perhaps I am getting old...) Living 200 miles from the lorry doesn't help much either. I'll post some recent pictures on my intro in a moment and some more engine this weekend if I have no disasters!

I tend to use WD40 as the cutting agent on aluminium and that seems to work quite well for general machining. I think I let the flutes choke on the reamer and should have stopped the machine to clear them half way through the cut. It is all part of the learning process.

Steve   :)

Online Vixen

  • Full Member
  • ****
  • Posts: 978
  • Hampshire UK
Re: 1909 Mercedes Aero Engine
« Reply #47 on: December 07, 2018, 10:41:16 PM »
Hello Steve

Agreed, WD40 is fine for general machining, but for those high load conditions such as threading, reaming or key way cutting a little Trefolex cutting paste significantly reduces friction and the risk of aluminium cold welding (picking up) to the steel tool. Try it, it's got to be better than white spirit with a dash of mineral oil. AKA   WD40

Mike
It is the journey that matters, not the destination

Online Vixen

  • Full Member
  • ****
  • Posts: 978
  • Hampshire UK
Re: 1909 Mercedes Aero Engine
« Reply #48 on: December 07, 2018, 11:49:21 PM »

A few more holes this weekend with a bit of luck.

Steve  :)

Wasn't it 'Old Bill' who said, " If you knows a better 'ole..... go for it"

Mike
It is the journey that matters, not the destination

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6034
  • Surrey, UK
Re: 1909 Mercedes Aero Engine
« Reply #49 on: December 08, 2018, 07:17:28 AM »
You are also using a hand reamer in the mill so run it slowly as the longer cutting edge puts more load on it.

On long small holes you need to clear the flutes quite often, though this will depend on the size of your pilot as to how much is to come off.

Good to see the cylinders all lined up now.

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #50 on: December 08, 2018, 08:09:46 AM »

Wasn't it 'Old Bill' who said, " If you knows a better 'ole..... go for it"

Mike

Quite right!

Steve   :) 

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #51 on: December 08, 2018, 08:12:24 AM »
You are also using a hand reamer in the mill so run it slowly...

Thanks Jason. It is a while since I did this sort of thing and I forget. You are quite right about it cold welding. Notjhing I can't get over but annoying all the same. Hopefully, I will be back up to speed by the time I finish!

Steve   :)

Online sco

  • Full Member
  • ****
  • Posts: 1520
  • Location: Northants UK
Re: 1909 Mercedes Aero Engine
« Reply #52 on: December 08, 2018, 10:09:30 AM »
Following your build closely Steve.  I've put one of these casting kits on my Christmas list so fingers crossed  ;D

Keep up the good work,

Simon.
Ars longa, vita brevis.

Offline john mills

  • Full Member
  • ****
  • Posts: 83
Re: 1909 Mercedes Aero Engine
« Reply #53 on: December 08, 2018, 10:43:57 AM »
I would rather use one of the soluble cutting fluids normal coolant if you can flow plenty down the hole it can flush
the chips out as well.if you can contain it to the machine.i have found a work shop when working one of the contractors using wd40 machining alloy the workshop was un usable for the rest of the day with the fumes
they would burn your eyes.why not use a proper cutting fluid.it does work.

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #54 on: December 09, 2018, 08:33:02 PM »
I don't machine aluminium very often so I am not really set up for it. I do have soluble suds oil that I use with steel. Would that be appropriate with aluminium?

In the mean time, I have made a very little progress with the cylinder blocks. First job was to finish drilling the holes in the top so the coolant holes and the holes for the rocker shaft pillars were completed.



Then it was on to the exhaust ports. These were milled off using the drilling set-up and then marked across with the height gauge to keep them in line. Finally, the block was held square against and angle plate and simply supported with a piece of wood whilst I put the holes in.



All uneventful.



Now it is time for the more difficult angled holes. I have been puzzling how to achieve these for a while. Eventually, I decided on a mounting plate with a spigot that I could hold in the dividing head. I made the plate slightly longer than the base of the block so that I could get a good hold of it in the vice.



I faced off the water inlets and drilled them through.



The mixture inlet holes are at a compound angle, defined in the drawings as 18 up and 34 rotated. I set up my dividing head and elevated it by 18 and rotated it.



Unfortunately, the alignment doesn't look quite right to me so I need to think some more on this one. It is essential that the port comes out above the valve seat of course!



I am also pondering on whether to drill the valve guides before inserting them or by drilling through the ports. There are a few challenges in this engine!

Steve   :) 

Offline john mills

  • Full Member
  • ****
  • Posts: 83
Re: 1909 Mercedes Aero Engine
« Reply #55 on: December 09, 2018, 09:33:56 PM »
with coolant i have never changed the coolant on a machine to cut alloy or different materials.

Offline Art K

  • Full Member
  • ****
  • Posts: 928
  • Madison, Wisconsin USA
Re: 1909 Mercedes Aero Engine
« Reply #56 on: December 09, 2018, 11:12:36 PM »
Steve,
Still following along. Never built an engine from castings yet. But I can see where it would be frustrating to see the assigned angle dimensions don't line up. How are the rest of them, do they all mismatch in the same place?
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #57 on: December 16, 2018, 08:42:54 PM »
Hi Art.

The dimensions on the drawings are accurate but are a bit scant in places. There is a note next to these inlet holes which says to check the casting and I feel that the position of these is very susceptible to casting variation. In the end, I have laid it all out on the drawing board at five times full-size after measuring the actual castings and have calculated the angles to suit.

I managed to find a couple of hours this afternoon and tried setting it up to the new numbers. It looks a lot better.



Then it was just a case of using a centre drill and taking my courage in both hands.



Fortunately, it worked satisfactorily although I do seem to be a whisker off-centre. Nothing I cant live with.



I finally faced the flange (at yet another angle) and drill the holes for the studs.



I'll do the other tomorrow and then only the spark plug holes will remain.

Making progress if a lot slower than I would like. This earning a living business seriously gets in the way!

Steve :)

Online Vixen

  • Full Member
  • ****
  • Posts: 978
  • Hampshire UK
Re: 1909 Mercedes Aero Engine
« Reply #58 on: December 16, 2018, 08:58:47 PM »
Hello Steve,

Using a centre cutting end mill or slot drill is sometimes a more accurate way of starting a hole at an acute angle to the surface. Even a stubby centre drill will try to deflect to one side due to the angled point,  An end mill does not have this problem.

You will also get deflection if you try to enlarge the angled pilot hole with a larger drill, again an end mill or slot drill will avoid this deflection.

Mike
« Last Edit: December 16, 2018, 09:08:31 PM by Vixen »
It is the journey that matters, not the destination

Offline Art K

  • Full Member
  • ****
  • Posts: 928
  • Madison, Wisconsin USA
Re: 1909 Mercedes Aero Engine
« Reply #59 on: December 17, 2018, 03:12:14 AM »
Steve,
I'm with Mike even if you only use the endmill to give you a flat spot to keep the hole from walking. Sounds like you have to make due with a lack of good prints that actually match what you have for print dimensions. I'm not sure what I'd have done in your shoes. Looks good.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Old Bill

  • Full Member
  • ****
  • Posts: 31
Re: 1909 Mercedes Aero Engine
« Reply #60 on: December 17, 2018, 09:49:30 PM »
Thanks Chaps.

All good advice there. I have still to do the spark plug holes and they are on an awkward angle as well with a large spot-face to boot. If I do the spot face first, I will have a flat surface to drill which should help, just as long as it doesn't move. It is only held down with six 7BA bolts and I am a bit chary about using such a big cutter on it. I shall have to treat it very gingerly.

If I did this again, it would be a lot better!

Steve  :)