Author Topic: 1909 Mercedes Aero Engine  (Read 26216 times)

Offline Old Bill

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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  :) 

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #61 on: December 22, 2018, 10:28:09 AM »
Well, I had an hour out in the shed this week and some more proress has been made. The spark plug angles are shown on the drawing and look OK so I tried setting the dividing head to the appropriate angle. Unfortunately, I hit a snag....



After trying to win some height with a collet chuck, I gave up and set the mounting plate in the machine vice. It did the job but setting the angles was a lot more challenging. I put a dummy scriber in the chuck, picked up off the centre line of the block and then indexed across, remebering to lift the scriber before winding!





I made up a prop using a bit of rod with a bolt in the end to help stop it moving and then started off with a small slot drill to give myself a flat surface (Thanks Mike). A centre drill followed by pilot and tapping sizes were fine.



Finally a full-size spot-face.



Then index across and both were done. They even came out the other side in the right place!



I just have to tap all the holes and the block will be done. Unfortunately, I had my new taps sent to Father's address which was daft but I shall pick them up this weekend and then it will be time to start on the liners.

Now I must do the other block!

Happy Christmas everyone!

Steve    :)

Offline Dave Otto

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Re: 1909 Mercedes Aero Engine
« Reply #62 on: December 22, 2018, 10:30:47 PM »
Looks good Steve!

Dave

Offline Ye-Ole Steam Dude

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Re: 1909 Mercedes Aero Engine
« Reply #63 on: December 22, 2018, 10:59:49 PM »
Hello Steve,

Good job and it is looking really good.

Have a great day,
Thomas

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #64 on: January 04, 2019, 03:19:48 PM »
Happy New Year everyone!

Well, I did get some workshop time over the holidays and started off by tapping the spark plug holes. I used my mounting plate to get the holes vertical and hold the block securely and, for anyone else contemplating this engine, I would say that the time spent making it was well worth it.



Then it was onto the liners. A very nice piece of cast iron is included in the kit.



Then it was a case of rough turn the outside before holding in my self-centring four-jaw and boring and turning to size. I used the four jaw as it doesn't get a lot of use and is still unworn. It also has a larger through-hole so I could bore without risk to the chuck!







I made up a mandrel from a nice piece of free-cutting steel before turning the liners to size.



I did remember that I had over-bored one cylinder so I started with that one, just in case. In fact I got them all right first time but that was luck! I gave them all an interference of 0.001"





Then it was just a case of pressing them home.





All successful! Valve guides next, from phosphor bronze. Horrible stuff!

Steve   :) 

Online Vixen

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Re: 1909 Mercedes Aero Engine
« Reply #65 on: January 04, 2019, 03:37:57 PM »
Hello Steve,

Have you considered using SAE 660 Bronze bar for your valve guides?

If you do, you will find it a much more enjoyable experience than using PB.

Have a look at post 247 of my Mercedes Grand Prix engine build.

Cheers

Mike T
It is the journey that matters, not the destination

Offline steamer

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Re: 1909 Mercedes Aero Engine
« Reply #66 on: January 04, 2019, 06:21:28 PM »
Coming along great Steve!
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #67 on: January 06, 2019, 10:38:02 AM »
Thanks for that Mike. I hadn't thought of that. I am using stock from the drawer and have persisted but I wouldn't like to use the stuff for the quantity you have made! I always fancied a V-12 but I think I will stick to the straight four!

The guides were a straightforward turning job but I did set up my dividing head on the mill so I could do a quick change with the chuck for the cross-hole. That head was a very good investment.





Then it was just a case of pushing them in. I used a drop of Loctite on the one where the reamer had picked up, not to secure it but to make sure that it was sealed.











I ran a nice new reamer through for the valve stems and the job was done.





This looks like a nice straightforward job but still took longer than anticipated. Never mind. It is the journey that counts. It will, after all, only be an ornament once completed!

Steve   :)


Online Vixen

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Re: 1909 Mercedes Aero Engine
« Reply #68 on: January 06, 2019, 11:21:29 AM »
This looks like a nice straightforward job but still took longer than anticipated. Never mind.

Steve   :)

Ha ha, isn't it always that way? Now it's done and they look nice, the job's a good 'um  :ThumbsUp: :ThumbsUp:

What material are you proposing to use for the valves?

Mike
It is the journey that matters, not the destination

Online Jo

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Re: 1909 Mercedes Aero Engine
« Reply #69 on: January 06, 2019, 11:43:24 AM »
Looking good Steve :)

This looks like a nice straightforward job but still took longer than anticipated. Never mind. It is the journey that counts. It will, after all, only be an ornament once completed!

I totally agree its the making that is the fun bit  :cartwheel:

I bet you are finding machining in a warm workshop nicer than being outside playing with your lorries at this time of the year  ::)

Jo
Enjoyment is more important than achievement.

Offline steamer

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Re: 1909 Mercedes Aero Engine
« Reply #70 on: January 06, 2019, 02:42:18 PM »
Looking good Steve :)

This looks like a nice straightforward job but still took longer than anticipated. Never mind. It is the journey that counts. It will, after all, only be an ornament once completed!

I totally agree its the making that is the fun bit  :cartwheel:

I bet you are finding machining in a warm workshop nicer than being outside playing with your lorries at this time of the year  ::)

Jo

It would for me for sure!
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Roger B

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Re: 1909 Mercedes Aero Engine
« Reply #71 on: January 06, 2019, 04:20:15 PM »
Looking good  :ThumbsUp:  :ThumbsUp: Did you align the holes with the ports by eye or do something cunning?
Best regards

Roger

Offline Dave Otto

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Re: 1909 Mercedes Aero Engine
« Reply #72 on: January 06, 2019, 07:38:35 PM »
Nice update, the family shot looks great!

Dave

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #73 on: January 06, 2019, 09:33:20 PM »

What material are you proposing to use for the valves?

Mike

Funny you should say that Mike. The drawing specified 'silver solder' which is a bit of a surprise! I take it as a misprint and am using silver steel. In fact, I have spent my time today trying to sort out a manufacturing process for them and, after consulting this fine forum, have taken the advice and made a prototype. They are secured with E-clips so I ground up a tool on the bench grinder to cut the groove. I then brought the stock out of the chuck and machined the final diameter in steps, leaving them about 0.0005 oversize to be cleaned up with emery. This worked out OK in the end and I have one almost-acceptable valve.





As you can see, I left a boss on the face and cut a screwdriver slot to help me lap it in.



This week's project it to make eight more, preferably all the same.

Steve   :) 



Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #74 on: January 06, 2019, 09:36:06 PM »
Looking good  :ThumbsUp:  :ThumbsUp: Did you align the holes with the ports by eye or do something cunning?

Nothing cunning, I'm afraid, Roger. I looked down the top of the block and put two pencil marks in line with the edges of the ports, just by eye. I then aligned the the port in the guide with the pencil marks before pushing it home. They seem to be good enough but we shall see!

Steve   :)