Mercedes-Benz W165 Grand Prix engine in 1:3 scale

[Jo]

And hopefully we will see it finished

Jo

P.S. I'll be good and let you post the first picture of it 

[scc]

PHENOMINAL engineering of the highest level I'm spellbound with every instalment.       Terry

[Vixen]

Thanks for you kind comment Terry

Yes Jo completing Danny's build is my intention, but don't hold your breath, it will not be the work of five minutes. Besides, I have other big projects on the go.

At the moment I am having a beer on a ferry, in the middle of the oggin, half way to France

Cheers

Mike
..

[steamer]

Thanks for you kind comment Terry

Yes Jo completing Danny's build is my intention, but don't hold your breath, it will not be the work of five minutes. Besides, I have other big projects on the go.

At the moment I am having a beer on a ferry, in the middle of the oggin, half way to France

Cheers

Mike
..

Good to hear!   Especially the beer part!

Dave

[Vixen]

It's not everyday you get the chance to sit in a £6,000,000 replica of a Mercedes Benz W125.

All thanks to Dick Crosthwaite at Crosthwaite and Gardner Ltd

Mike

[b.lindsey]

Great pictures Mike!!  What a thrill that must have been 

Bill

[Vixen]

Yes Bill, it was quite a thrill and a privilege.

The car was huge. The cockpit was spacious, with little to keep the driver in except a strong grip on the wheel. The bonnet (hood?) went on for ever.

Mike

[sco]

I see your W125 and raise you a W165 :-)

Simon.

[Vixen]

Snap,

That's the only running W165 in the world, the only other W165 is a static exhibit in the Stuttgart Museum.



Here is my two stage supercharger on top of the real thing

Mike

[michelko]

wow 

Whats the Status of your Project? When will it runn?

Michael

[Vixen]

Hello Michael,

The Mercedes W165 journey is long and progress is always slow during the winter months. You can heat the air in an outside workshop but the iron machines remain cold and that's hard on old hands and fingers.  Also I have been distracted by the Bristol Jupiter radial engine, you may have seen my other posts.

Our larger scale historic racing engines never get much feedback, compared to smaller more popular projects. I guess that's to be expected, as little is known about pre-war European racing engines on the far side of the pond. Even more so with the secretive way Mercedes Benz work, I don't suppose there are more than half a dozen living engineers, in the whole world, who have seen inside the MB W165 engine.  And they are not allowed to tell.

Mike

[Vixen]

Part 11D  Cylinder Heads

It has been a while since I last updated the build progress on my Mercedes Benz W165 GP engines. Sorry for that, but I have been concentrating on another engine; the Bristol Jupiter, nine cylinder radial engine. I will try to make amends with this rather long installment from Vixen's Den

We left the cylinder heads with the majority of the internal geometry machined, ready to start on the external surfaces. Here is a reminder of how far I had progressed




The next operations require the cylinder heads to be mounted back on the 28* angle plate, ready to start work on the three sides of the valve towers. I prefer to make precision angle plates for each set-up, easier to handle and less risk of an error compared to adjustable angle plates or sign bars. The cylinder heads are located against a reference face and secured by four bolts, through the spark plug holes




With the top and side faces machined, I was able to drill through from the outside into the water jacket cavities between the combustion chambers. This increases the size of the water coolant space and allows the coolant to reach up in between the pairs of inlet and exhaust valves. The drilled holes were then tapped 40 tpi for shallow blanking caps which were screwed in and sealed with JB Weld epoxy. You will notice there are two overlapping plugs sealing each water space. The second set of coolant holes were drilled and tapped after the epoxy securing the initial set  had cured





When all the epoxy had fully cured, I machined the top surface flat, to the finished dimension, then thread milled (40 tpi) each of the valve pockets, ready to accept the screw-in valve inserts.




Next, I machined the shallow recess in the top of the valve tower. before drilling and tapping the 18 off M3 threads for the studs which will eventually secure the cam boxes in place.





All this work was repeated on the opposite side and then on each of the four cylinder heads in turn. You can just make out the sealing caps on the completed side. This was a long demanding session in the shop but very rewarding.




The cylinder heads were transferred to a 90* angle plate so that the inlet and exhaust ports could be machined into the sides of the valve towers. The ports were first bored and then thread milled 40 tpi. That single tooth thread mill has achieved an amazing amount of work without the need for resharpening.




Exhaust and inlet stubs were turned on the lathe and the correct type screwed into the cylinder head, again secured and sealed with high temperature JB Weld epoxy.




Here the exhaust stubs are faced off, the internal ports opened up to an oval cross-section and the external flange profiled to shape, before being drilled and tapped for the M2.0 studs.





This just about completes this stage of the work on the cylinder heads, prior to the installation of the bronze screw-in valve seats.
As you can see. there is not much of the original billet left






Stay tuned, there's more to come.

Mike

[Jo]

Getting side tracked on the Jupiter was totally understandable 

Looking good, I hope those are not Royal Snail elastic bands - if they are be warned they biodegrade, you don't want your cylinder head dropping off and getting a ding 

Jo

[sco]

Awesome work Mike - loving following this build.

Simon.

[Art K]

Mike,
That looks great. It's also great to see you and your model next to the real thing.
Art