Author Topic: Mercedes-Benz W165 Grand Prix engine in 1:3 scale  (Read 151612 times)

Offline fumopuc

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #135 on: July 07, 2017, 08:00:19 PM »
Hi Mike good to see you back in the shop. The engine pictures, impressive like always.
Kind Regards
Achim

Offline Art K

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #136 on: July 08, 2017, 02:54:14 PM »
Mike,
The work looks great. I saw some of the cylinders & such from the Guilford show photos, very impressive. I am in the process of trying to decide what to do with Photo....et. I don't object to paying just putting my info out on an insecure site.
Art
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Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #137 on: July 14, 2017, 05:05:28 PM »
Part 9        Crankcase

I was able to find a longitudinal and a traverse cross section drawings of the W165 engine in my copy of the British Intelligence Report number 1755 published in 1948. From these two cross section drawings I produced the 1/3 scale drawings in AutoCAD, from which I could work. The W165 crankcase was cast in magnesium and was of a fairly conventional 90 degree V8 layout with the added interest of the supercharger and accessories drives at the front end. At the rear, two outriggers bolted the engine to the chassis tubes The crankcase was quite robust in construction, which is probably due in part to the use of welded and fabricated cylinder blocks. The crankcase has to provide most of the engine's stiffness.

Another factor may be the speed in which the new engine and a new, smaller, race car was produced. The history books tell us that Mercedes undertook this feat of engineering in just eight months. Even working round the clock, it did not leave much time to design a completely new engine, produce the foundry patterns and commit them to the foundry to be cast in super lightweight magnesium. In order to achieve these time scales, the Mercedes engineers would have relied heavily on the existing designs and drawings for their highly successful 3 litre V12 engines. The new engine was reduced in length from 12 to 8 cylinders and slightly reduced in scale. The engineers also decided to include a significant bulge on the left hand side of the crankcase block. I assume this was intended to house the multiple oil pressure and oil scavenge pumps, which were favored in those days. In the event, the bulge was never used and the oil pumps were eventually located low down in the dry sump. A case of having to live with an early engineering decision?






I have no foundry facilities, so the decision was made to machine the crankcase from solid billets of 6084 T6 (HE30 TF) aluminium. I decided to make the crankcase in two halves, to be joined together on the centre line, by five M5 steel bolts passing through the main bearing webs. The heads of the bolts could be buried and later capped out of sight by aluminium plugs. The  two part construction allowed the undercuts inside the crankcase sides to be machined, these features would have been next to impossible to achieve if a single piece billet had be used.

The overall length of the 1/3 scale crankcase was 192 mm, the maximum X axis travel of my EMCO F1 mill was 200 mm (8 inches). With some very careful positioning of the billets, I would be able to machine both ends of the blocks and use a 8mm diameter cutter. A very tight fit, but do-able. 



I realised there would be the need for multiple set-ups and numerous machining operations, so the first item to be made was a fixture plate with both dowel pins and the cross bolts to locate and relocate the billets. The fixture plate could be mounted at any necessary angle by using pairs of bolt-on angle plates.





A start was made by accurately drilling the bolt holes and dowel pin holes in all of the aluminium billets. Each block measured 8" x 4" x 2" and weighed 2.6 kg (5.8 lbs). The billets were then transferred to the fixture plate, which remained in place on the mill for the entire duration of the crankcase manufacture.








The machining started by milling out the interior detail of the crankcase. I used a 8 mm ball cutter to pocket out the space between the main bearing webs. The ball mill produced nice looking fillets where the cross webs meet the crankcase sides. The centre bearing and rearmost bearing webs are slightly wider than the intermediates.








The 45 degree slope under the cylinder face and the pocket for the supercharger gear drive appear next. The billet is beginning to reduce in weight already.






The semi-circular space for the main bearing is roughed out along the entire length of the embrio crankcase. The bearing locations will be line bored at a later date when the two sides of the crankcase are finally bolted together and all the removable bearing caps have been made and fitted. This delay will give the machined blocks time to stress relieve and settle. All that is required to do now is to repeat the above for the opposite side of the case and then again for my second crankcase.








These two views show the the left and right halves for two engines after the completion of this first stage of machining all the interior detail. A bucket-full of chips has been produced and there is plenty more still to be machined away before the job is complete.

This machining activity was my first use of LinuxCNC in anger. It was a fairly painless transition from my previous DeskNC controller to LinuxCNC. I was very impressed by the stability and reliability of LinuxCNC. The learning curve was not too steep and everyday I am discovering new hidden features. LinuxCNC only controls the machine,  it does not produce the tool path code. I still do that with DesKAM and by hand. I am not into 3D modelling yet, way above my pay scale. All my machining is done by pocketing or profiling (contouring) at a fixed depth. It's called 2.5D machining.

These images were hosted by Coppermine , generously provided for MEM use by Ade. Thanks Ade, it's a much nicer place than 'Photo....it'

Stay tuned.........

« Last Edit: July 14, 2017, 07:18:27 PM by Vixen »
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Offline Ye-Ole Steam Dude

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #138 on: July 14, 2017, 05:50:07 PM »
Incredible machining. Really enjoying following along.
Thomas

Offline Admiral_dk

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #139 on: July 14, 2017, 07:30:22 PM »
Glad to see you back on this amassing project Mike :praise2:

Are the halves milled as "perfect mirrors" of each other so far ?

If so, could you use a command that did it for you or was it manually done ?

Best wishes

Per

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #140 on: July 14, 2017, 07:52:03 PM »
Hello Per,

I am further along with the project than with the build log. I am trying to catch up with actual progress with regular weekly postings.

The left and right side of the engine are similar but not identical, the left side bulges out much further. So no perfect mirror is possible. Also due to the peculiarities of the G-code tool command system, it is only possible to mirror straight line moves. You only need to change the sign (+ or -) of one axis to do the mirror. Unfortunately, that is not possible when circles, curves or arcs are involved. Then it is safest and easier to recreate the opposite side toolpath from the mirrored drawing. That can take quite some time to do and you still have to 'prove' the new toolpath by cutting metal. Can be a nervous time when you have already invested time and effort in the part being made.

Mike
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Offline steamer

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #141 on: July 15, 2017, 12:20:53 AM »
Looking good Mike!!!! New shop layout is starting to come together....I hope to get back out there soon....

Dave
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Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #142 on: July 15, 2017, 07:39:02 AM »
Hi there Dave,

Thanks for looking in.

I heard about the major upheavals in you workshop, "out with the old and in with the new".
Nice that your young daughter could help with the new storage and furniture. That sort of help is priceless.

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline michelko

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #143 on: July 15, 2017, 08:39:38 AM »
 :praise2: very nice.

Michael

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #144 on: July 15, 2017, 08:54:22 AM »
Hello Michael,

When it's finished, We can race it against your Bugatti, they were both from a similar era

Mike
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Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #145 on: July 21, 2017, 09:41:26 PM »
Part 9B    Crankcase: roughing the outside

In the previous installment from Vixen's Den, I described the first steps of machining the inside of the crankcase from two very solid billets of aluminium. This week I will show some of the very long process of machining the outside of the billets, in the hope that an engine crankcase will emerge.
I started by bolting and clamping the two mating halves of the embryo crankcase together and securing them directly to the milling table. The positioning had to be precise as the two billets measure a fraction under 8" x 4" x 4" and the maximum travel of the mill's table is only 8" X 4". You don't want to hit the travel end-stops during the machining!





With the crankcase inverted, I machined the features on bottom face of the crankcase. The main bearing  webs down to the bearing cap split line and the inside and outside profile of the sump gasket face. I drilled and tapped the main bearing stud/bolt holes and the sump screw holes during this set-up The sump face is a wide T section on the bottom of the crankcase casting and adds considerably to the stiffness of the final item. My initial Datum Points at the lower right corner of the billet are about to be machined away, I will need to reference off the jig plate during future machining.







With the individual crankcase halfs re-positioned on the jig plate I made a start at roughing out the side faces of the billets. I milled away a considerable amount of material at the front of the crankcase in 0.1" steps. The 30 degree downward facing flange for the engines auxiliary drive can be seen emerging. There is still a minimum of 20 thou. to be removed from all the roughed faces and obviously over 0.1" at the crests of each step.






The 45 degree slopes for the cylinder base flanges were removed next. Again the excess material was removed in 0.1" by 0.1" steps from both sides. It is unbelievable to see the mountain of chips that were once part of the billets. On the top of the casing are the four apertures which will eventually become the air/oil mist separation plenum chambers, part of the crankcase breathing system. At the front the top flange for the supercharger is also emerging.








These last two photos summerise progress so far. A considerable amount of material has been removed from the initial aluminum bricks, the shape of the crankcase is starting to emerge. Many hours of machining are still required to refine the shape of all the external features, but confidence is growing that a true replica of the Mercedes W165 crankcase will eventually appear.

Stay Tuned

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Ye-Ole Steam Dude

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #146 on: July 21, 2017, 09:48:39 PM »
Beautiful.
Thomas

Offline steamer

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #147 on: July 21, 2017, 11:40:30 PM »
Nice work Mike!!!

Dave
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Damned ijjit!

Offline Sven

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #148 on: July 22, 2017, 05:57:13 AM »
I am waiting kindly for the Crankshaft making.
Realy nice work.
I got an similar project

 Regards Sven
(Hamburg Germany)

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Online Jo

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #149 on: July 22, 2017, 07:51:15 AM »
 8)

I assume you will be taking the engine to the Bristol show in a couple of weeks so we can see your progress. (Bristol - Another show I can't go to :disappointed: )

Jo
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