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speight1823
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The R47 engine overhaul is progressing at a snails pace. This is undoubtedly the most difficult BMW engine I have worked on due to the condition of the engine and difficulty in getting spares.
The latest difficulty presented to me is the tappets These are supported by 2 special roller bearings . The inner race is the tappet shaft . ( Originals badly indented ) The outer race is slipped over one tappet end and moved into position and the rollers inserted.
The other problem is that the push rods are not in the center of the push rod tubes . I suspect these tappets are from another model . Possibly the R57 ?
The previous over hauler made up split brass inserts but these did not work well .
I will probably end up making better fitting tappets . Quite a bit of work but possible but making roller bearings is definitely beyond my expertise and equipment.
I am at loss for a solution and would appreciate any suggestions.
Bill

  • r47-2.jpg
  • r47-4.jpg
Darryl.Richman
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Surf City, USA (Santa Cruz, CA)
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According to the R47 parts

According to the R47 parts book (see attached pages), the original rockers each have two outer bearing races (#254, Lagerringe) that are clamped to the head, with the area of the head (#241) and clamp (#251) having some material left separating the two bearing races. Although your photo shows one race, it looks to me like this is just one of the two that should be with that rocker. The book also says that each of these bearings takes 10 rollers (#255, 80 total).

I have been told that a lot of the reproduction rockers are merely cast, but to stand up to the twisting forces on the rockers here, they should be forged pieces. I also know of an R63, where these roller bearings were replaced with bronze bushings, but these turned out to be much too soft and wore quickly, again because of the twisting forces applied to the rocker.

  • r47_head_1.jpg
  • r47_head_2.jpg
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speight1823
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R47 engine

Thanks for the input Darryl . I find just discussing the problem helps me see a solution.
I am sure I will win if I think about it enough.
One thing you could help me with is to let me know where I could get a spare parts list as clear as yours. I have the same parts list as your but mine is very fuzzy . I make quite a few small Items by measuring off the spare parts list with an eye piece with measuring lenses but it is very difficult to see detail with my list.
I am getting quite excited about this rebuild as I can see the light at the end of the tunnel. I have had this bike for about 30 years now in parts . This must be some sort of record for the longest restoration.
All the best
Bill

Darryl.Richman
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Surf City, USA (Santa Cruz, CA)
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If you think the scan I

If you think the scan I pulled this from is clearer than yours, yours must really be bad.

Actually, I think the copy that's on the R47 model page here is even clearer. Just click BMW Models over in the left sidebar, then click on the R47. I uploaded scans from BMW Group Classic to the bottom.

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speight1823
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R47

Yes much better than my copies and with facilities to blow up the pictures . Did not know this existed. That is great.
Thanks Darryl
Best regards
Bill

Darryl.Richman
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Good luck with your project!

Good luck with your project! It's these small things that really make you pull your hair out (I have to resort to other measures). I've had ongoing issues with the hardness and position of the gear on the transmission input shaft on my R52.

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Luigi bmwR68
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ITALY
Joined: 05/22/2008
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Hello Bill I'm not start to

Hello Bill
I'm not start to restore the R47 engine, but if you are looking for some pictures or information (if you understand me, I don't speak very well English ) write me.

  • 20140712_120713.jpg
Peter D. Nettesheim
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Joined: 01/27/2006
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R47

Bill,
The Rockers must be forged, then ground. If you have original sets that are worn, you will need to grind the surface upon which the rollers ride. You will then need to fit new rollers of a larger size and then confirm that the inner portion of the outer race is not only in good condition but sized correctly. Then you will need to confirm the retaining bridge properly squeezes the outer race as the bridge is tightened. If the bridge does not squeeze the outer portion of the race, you will need to make and then have hardened a new outer race.

I spend 6 months on a complete restoration of an R69. I have spent three years on just a restoration of an R16 transmission. Pre war is a completely different game.

Good luck.

speight1823
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Thanks for the replies . I

Thanks for the replies . I have managed to get the threads on the exhaust on the heads welded up and re-cut these in my lathe . The set up was quite a job . My last obstacle is the tappets . I have made these by machining from Bohler Steel K110 and had them vacuum hardened . I have redesigned these to accept modern sealed bearings , which should solve the lubrication problem which was bothering me . Will post pictures if you are interested. After this I can finally assemble the engine . This overhaul has really tested me.
I am quite excited by the progress . The gearbox and cardan drive should be easy by comparison .
All the best
Bill

  • img_0261.jpg
Luigi bmwR68
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ITALY
Joined: 05/22/2008
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Motor parts

This is reconstructed
I still have one but I did not have time to disassemble it

  • whatsapp_image_2017-05-02_at_09.11.591.jpeg
  • whatsapp_image_2017-05-02_at_09.11.59.jpeg
speight1823
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R47

Thanks for the photo,s and sketch sketch Luigi. I can now make these.
I am a time served metal machinist and have been making parts for most of my life but I must admit that making bearings for the tappets is beyond me . I have taken the easy way out and modified them to accept modern bearings .
Bill

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