let the games begin - R69s engine rebuild

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wa1nca
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Re: let the games begin - R69s engine rebuild

Post by wa1nca »

Very nice
Well done
Good luck with the crank
Tommy
Tommy Byrnes
54 R51/3 55 R50/Velorex 560 sidecar 64 R27 68 R69US
Ashfield, Ma
USA

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

Thanks Tommy..... for your response/s.

Well today I started on the prep for the reaming of the bushings of the cam followers.
I am installing over sized followers and so need to ream the brass bushes to the correct size.

Anyone here have experience doing this as I have never done any precision reaming.
Any advice welcome.

See the attached photos for my attempt to do what ever I can to avoid any unnecessary stuff ups caused by my inexperience.


Mal
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MAL_0921.jpg
MAL_0918.jpg
MAL_0915.jpg
mal - R69s
Toowoomba- Australia

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

The technical advice I have received is to use a spiral flute reamer of the exact required size.

Oh well back to the piggy bank.

Mal
mal - R69s
Toowoomba- Australia

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

I am sure many of you run into this problem.

The bike is sitting neglected because I have all these other tasks I have to undertake prior to being able to focus on the bike.
So there has been no progress with the bike because as you can see I have been using the workshop to do other stuff.
MAL_0934.jpg
MAL_0929.jpg
MAL_0928.jpg
MAL_0927.jpg
Battery box for my son's new ute, a test part for my brother in law's rear diff housing project.
So the bike has had to lie under wraps.

Mal
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MAL_0936.jpg
Last edited by malmac on Mon Sep 07, 2020 3:03 pm, edited 1 time in total.
mal - R69s
Toowoomba- Australia

scottiesharpe
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Re: let the games begin - R69s engine rebuild

Post by scottiesharpe »

Hello Mal, I am very much enjoying your posts. It's enjoyable to learn from other mechanics, and you are doing such a fine job of it. One little tip I'll pass along, in case it is helpful to you. I do not align crankshafts using two v-blocks, one on each main bearing journal. Rather I use two v-blocks, one inverted upside down, such that the v-blocks are holding only the front crank web by the nose bearing journal and the main bearing journal. Putting the crank nose in the the lathe would also suffice. In this way the metrology components of the front and rear pins can be isolated and measured separately. I used to align cranks with two v-blocks as you show it, but found it impossible to isolate measurements to determine front or rear pin movement. I was pulling my hair out till I came up with this method. Hope that will save you some time. Best regards from San Jose CA!
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Scottie Sharpe, Proprietor
Scottie's Workshop, Santa Clara CA
Full Service repairs, maintenance and restoration workshop for vintage and classic BMW Motorcycles http://blog.scottiesharpe.com

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

scottiesharpe wrote:
Mon Sep 07, 2020 1:04 am
Hello Mal, I am very much enjoying your posts. It's enjoyable to learn from other mechanics, and you are doing such a fine job of it. One little tip I'll pass along, in case it is helpful to you. I do not align crankshafts using two v-blocks, one on each main bearing journal. Rather I use two v-blocks, one inverted upside down, such that the v-blocks are holding only the front crank web by the nose bearing journal and the main bearing journal. Putting the crank nose in the the lathe would also suffice. In this way the metrology components of the front and rear pins can be isolated and measured separately. I used to align cranks with two v-blocks as you show it, but found it impossible to isolate measurements to determine front or rear pin movement. I was pulling my hair out till I came up with this method. Hope that will save you some time. Best regards from San Jose CA!
Good advice is hard to come by and I sense your advice is good.

I have high quality lathe will look at testing the cranks with both methods to see how they can compliment each other.

Do you test the pin offsets as per the video on Salis's website?
I guess there is no reason that could not be done in the lathe.

One of the things I find frustrating is magnetic dial gauge stands. They don't seem robust enough for my liking.
That is why I have built short, strong arms which are adjustable but pretty damn rigid.
I would have to conceive of how to build in the same repeatability into the measuring devices.

I very much appreciate your advice and it is working away at my mind as I type.

Regards


Mal
mal - R69s
Toowoomba- Australia

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

Battery box is a bit big for the bike, but I have learned some things which will come in handy.

Mal
MAL_0939.jpg
mal - R69s
Toowoomba- Australia

flyingtpot
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Re: let the games begin - R69s engine rebuild

Post by flyingtpot »

For the lifter bushings....

An adjustable reamer is not efficient or accurate in this application.

A reamer that is to the finish size diameter is also not that efficient or accurate in this application.

One issue with using reamers is their ability to ream to size. Most often than not, the reamer you use is designed to remove material and produce the required surface finish when removing a set percentage (2-3%) of material. That is, for a bore diameter of these lifters, going to an oversize of .01mm or .04mm is a very slight amount of material to remove. The reamer size you choose is going to be basically just getting pushed through the bore without cutting as it is designed.

The factory technicians were masters at using reamers and other such tooling. If necessary, you can also do it accurately if carefully setup with the proper procedure and tooling.

An alternative to reamers in this application is going back to the stone age. This is an application where early man techniques can be efficient. I use a technique/procedure via a honing process. In this application, tooling such as the Sunnen Honall's work ideal. The bores can be sized with diameter accuracy, straightness and the proper surface finish.

Nice to read your posts on the custom tooling and processes.

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

flyingtpot wrote:
Tue Sep 08, 2020 6:16 pm
For the lifter bushings....

An adjustable reamer is not efficient or accurate in this application.

A reamer that is to the finish size diameter is also not that efficient or accurate in this application.

One issue with using reamers is their ability to ream to size. Most often than not, the reamer you use is designed to remove material and produce the required surface finish when removing a set percentage (2-3%) of material. That is, for a bore diameter of these lifters, going to an oversize of .01mm or .04mm is a very slight amount of material to remove. The reamer size you choose is going to be basically just getting pushed through the bore without cutting as it is designed.

The factory technicians were masters at using reamers and other such tooling. If necessary, you can also do it accurately if carefully setup with the proper procedure and tooling.

An alternative to reamers in this application is going back to the stone age. This is an application where early man techniques can be efficient. I use a technique/procedure via a honing process. In this application, tooling such as the Sunnen Honall's work ideal. The bores can be sized with diameter accuracy, straightness and the proper surface finish.

Nice to read your posts on the custom tooling and processes.
This is an interesting approach.

Is this exactly what you are referring too?
It would certainly handle the dimensions I require and probably have other uses as well.
Thank you very much for pointing it out to me.


Mal
Portable-Honing-and-Accessories-17.jpg
mal - R69s
Toowoomba- Australia

flyingtpot
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Re: let the games begin - R69s engine rebuild

Post by flyingtpot »

Hi Mal,

Oops.... I meant to include the Sunnen part numbers of their portable mandrel drivers for your review. The P-180 and P-200 are the units to use in this application. The initial upfront cost of the tooling usually is the reason not to take this process path. Yet, it is an excellent tooling approach to have available especially if you have other uses for it in your shop.

Now that high quality carbide reamers are readily available, and the norm in some speed shops, I've tapered off on some use of my Sunnen equipment while switching over to reamers. Yet, there are still times when stones are the path to take. The Honall and Sidewinder are not for large bores (over ~35mm).

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