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

[Admiral_dk]

Me too  :'(

Mike it looks more and more like a mix between Art, Watchmaking and Jewelry         

Hope that your good times will last 

Per              

[Kim]

That's wonderful that you're going to be able to make the show, Mike!   As others have said, I wish I could be there, but that won't be possible for me.  Hopefully others can take pictures and share them.  Your engine is a work of art!

Kim

[steamer]

Simply Magnificent Mike!!

 

[gadabout]

Mike, just fantastic!
To the others that have commented , there are TWO engines here not one!

Regards
Mark

[RReid]

Wonderful to see the progress, Mike, even if the latest parts are hidden (why didn't you use that transparent seethrouminium alloy?). So happy to hear of your "sort of a remission state", I do sincerely hope that continues for a very long time to come.

[Vixen]

Part 44   Making 64 Inlet and Exhaust valves

Thank you all for calling in.

Mark is correct, there are two identical engines being built. Normally making two engines means making two of everything but when it comes to pistons and cylinders that number shoots up to 16 of everything. But when I come to the valve gear, which is the next big task     the numbers become enormous. There's four valves per cylinder, that's 32 valves per engine, then multiply that by two again. It's not just the 64 valves, there are 64 of everything: valves, springs, spring retainer caps, cam finger followers etc.          Should keep me occupied for a while.

I am considering using ground drill rod for the valve stems with a separate piece of steel screwed and silver soldered in place to form the head. Do any of you have experience with making this type of fabricated valve? What happens to the drill rod during the silver soldering, does it become flint hard while cooling, which will prevent any further machine work. A heat treating oven would be a 'nice to have'. I could then control the post soldering cooling rate or do an annealing cycle.

Just a thought; To harden drill rod you need to rapidly quench the red hot steel in water. What happens to the hardness if the steel cools more slowly in the brazing hearth, say over a minute or so?

I have also decided to do away with any valve gap clearance adjustments. Instead, I will simply grind the length of each valve stem on an individual basis.   Set it, then forget it.
Sometimes, I wish I had bought a plastic kit to assemble. 

Cheers   

Mike

[RReid]

I am considering using ground drill rod for the valve stems with a separate piece of steel screwed and silver soldered in place to form the head. Do any of you have experience with making this type of fabricated valve?

Hello Mike,
Regarding your question above, I have made fabricated valves successfully, but in my case used 303 stainless steel rather than drill rod, so hardening wasn't the same concern. Mine are not screwed, just a socket to center the stem and soldered. I don't quench, just let them cool among the warm fire bricks. In the case of drill rod, I believe cooling in this way should leave them in more or less the same annealed state as received. Grind to fit lash adjustment has worked fine for me, although I've never had as many to keep track as you will!

For an example of what I did, see reply #227 below:
https://www.modelenginemaker.com/index.php/topic,11109.225.html

[Vixen]

Hello Ron,

Thanks for that valuable feedback. I knew I had seen fabricated valves somewhere on the forum... but where? now I know, it was in the 'Halfa' build. The tip about adding that extra length of large diameter rod to make it easier to heat the joint from below, will be especially useful. I can get the valve head to red heat for the silver soldering, and not need to worry about bringing whole length of the stem to the same temperature. Good call.

With such a large number of valves to make for the W165, I need to consider some sort of production line approach and perhaps some sort of fixturing to reduce the number of separate operations. I had considered using accurately ground drill rod as opposed to drawn 303 SS for the valve stem as one way of eliminating a valve stem diameter finishing opp. How did you get on with the 303 SS? Did you find it 'round enough' as delivered, or did you need to lap or polish it to fit the valve guides. I am guessing that some sort of tubular shield over the valve stem during the silver soldering stage would help reduce the amount of scale and the clean up required to remove it.

If I can reduce the time spent on each valve by say 10 minutes, it will save many hours overall. I need to get into an American production line frame of mind, rather than the traditional British hand-crafted approach.

All suggestions welcome.

Cheers   

Mike

[Dave Otto]

Hi Mike
You can purchase percision ground 303 stainless steel stock, I buy mine from McMaster Carr here in the states.

Dave

[Vixen]

Hello Dave,

Precision ground 303SS would probably be a better choice than drill rod. I did know you could buy 303SS precision ground.

I am going to need 8 or 9 feet of it at 3.0mm dia. Could you be kind enough to enquire (or look up) the price and shipping from McMaster Carr.  Meanwhile, I will try to source some here in UK.

Cheers

Mike

[RReid]

Hi Mike. Glad my info is helpful, it's great to feel like I've returned the favor in a small way. I didn't do anything to shield the valve stems during soldering, and they cleaned up nicely with some fine wet/dry paper while spinning in the lathe. That is a good idea though, and I may try it next time. If I remember right (not always a safe assumption ) I used the ground 303 that Dave mentioned. No problems at all in the valve guides.

I made the valves for the Curtiss K in the same way. A few more pics and comment here, starting with reply #146:
https://www.modelenginemaker.com/index.php/topic,11498.135.html

[RReid]

Here is the relevant page from McMaster:
https://www.mcmaster.com/products/round-bars/material~303-stainless-steel/tight-tolerance-easy-to-machine-303-stainless-steel/

Unfortunately I have heard others comment that they flat refuse to ship outside the US.

[Vixen]

Here is the relevant page from McMaster:
https://www.mcmaster.com/products/round-bars/material~303-stainless-steel/tight-tolerance-easy-to-machine-303-stainless-steel/

Unfortunately I have heard others comment that they flat refuse to ship outside the US.

Thanks for that Ron,

I have also heard they wont export out of the US. Not to worry, because I think I have found a UK supplier.

The Curtis K pics are also very helpful. I think I can see a mass production plan coming together.

Cheers   

Mike

[Dave Otto]

I have no way to determine what the shipping would be.

Dave

[Vixen]

Thanks Dave,

Ron says they will not export out of the US, I have heard that from other sources. I think I may have found a UK supplier

Cheers

Mike