let the games begin - R69s engine rebuild

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malmac
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Location: Toowoomba, Australia.

Re: let the games begin - R69s engine rebuild

Post by malmac »

The tweaking of the crank has stalled for the moment.
I got to a point where I thought I needed to regroup and let the situation soak for a bit.
Here is the problem I face.
MAL_1076.jpg
So I have turned my attention for the moment to the Sunnen hone.
Step one was to calculate the dimensions I needed to allow the adjustment required.
sunnen no 1.jpg
So I have started by turning up the first stage parts.
MAL_1101.jpg
So far, so good.


Mal
mal - R69s
Toowoomba- Australia

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malmac
Posts: 463
Joined: Sun Jun 29, 2014 2:10 am
Location: Toowoomba, Australia.

Re: let the games begin - R69s engine rebuild

Post by malmac »

Bit more work on the honing mandrel today.
Here is first view of the inside mechanism.
MAL_1108.jpg
Here is the 2nd view of the inside workings.

MAL_1109.jpg
The mechanism assembled, but still missing the drive yoke.
MAL_1107.jpg
Mal

PS. Here it is finished.
MAL_1112.jpg
mal - R69s
Toowoomba- Australia

flyingtpot
Posts: 32
Joined: Fri Oct 27, 2006 3:00 am

Re: let the games begin - R69s engine rebuild

Post by flyingtpot »

Greetings Mal,

Wow, you really took the Sunnen honing idea seriously. I was only joking on that, and figured you'd continue on with reaming the bushings. :o

Ok, your design and machining is moving along nicely! My recommendation is to practice on identical bushing material before tasking on the actual engine parts. There are also some excellent docs available on the Sunnen site describing in detail the honing procedure and technique. You'll want to avoid 'issues' like bellmouth, barrel shape and incorrect Ra finish. A speed controller on your drill is also an ideal feature to have for better control of the process. What type and grit stones did you get?

Maybe you're done already?

Carl

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

flyingtpot wrote:
Fri Nov 27, 2020 2:49 pm
Greetings Mal,

Wow, you really took the Sunnen honing idea seriously. I was only joking on that, and figured you'd continue on with reaming the bushings. :o

Ok, your design and machining is moving along nicely! My recommendation is to practice on identical bushing material before tasking on the actual engine parts. There are also some excellent docs available on the Sunnen site describing in detail the honing procedure and technique. You'll want to avoid 'issues' like bellmouth, barrel shape and incorrect Ra finish. A speed controller on your drill is also an ideal feature to have for better control of the process. What type and grit stones did you get?

Maybe you're done already?

Carl
Carl


I went down and had a look at the Sunnen P180 system. The dealer was very helpful and unlike a lot of folk, was not negative about my partial purchase.

So the home made version of the P180 seems promising. However I have not done the job yet.

Grit size Y20J67 - if that means anything to you. It is a reasonably fine grit, maybe about wet and dry 600 grade. Just guessing. It was the grade the rep recommended.

First step is to dress the edge of my stone with a diamond file, which I have.
Then to run a precision sizing exercise to calibrate the desired diameter.
Then run a couple of test runs as you have suggested.
Then I am into the real territory - do the job.
I guess if I stuff it up I will just need to push in new bushings and start again.

How critical is the speed of the hone? I dont have an electronic device to measure RPM on my cordless drill.
I guess with a couple of trials I will get a feel for what feels smooth and controlled Vs sluggish or at the other end over revving.

mmmmmmmm........ it is an adventure after all is said and done.

Mal
mal - R69s
Toowoomba- Australia

flyingtpot
Posts: 32
Joined: Fri Oct 27, 2006 3:00 am

Re: let the games begin - R69s engine rebuild

Post by flyingtpot »

The 'J' series stones are correct for bronze. They are silicon carbide. The issue is that J67 stones are coarse at 280 grit and used for quick material removal. That grade also will not achieve the desired Ra finish. Coarse stones, if not used carefully/properly, can also lead to honing issues like bellmouth and barrel shape bores.

Depending on the undersize of the bore, the process may only require a stone type like Y20-J95 or Y20-J97. Those are rated at 500 grit. They also produce a more desired Ra finish.

You'll also want to use a truing sleeve on the mandrel before starting any bore processing.

How are you going to flood the bore with honing oil when processing the bores?

For the speed of the mandrel....That bore size, if using a vertical machine hone, would be processed in the ~800-1000 rpm range. Maybe the drill you're using has a low/high range selector. Using that feature can get you close to determining the actual drill rpm.

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

Well, I did one bore this morning.
I now have a neat fit for the new cam follower, however I think I will revisit the bore when all the others are a neat fit and make a call on the right amount of final clearance.

The finish in the bore seems quite reasonable, though I am sure I could get an even better finish with an even finer grit stone.
I might just give it a polish with some 2000 wet and dry.

Thank you very much for your advice and expertise. I am glad you are not here to see that I have not achieved the standard that I am sure you would be capable of achieving.

I have opted to leave the block in the engine stand with the block tilted to give about a horizontal entry. I tried the test piece vertical and found it harder to control holding the drill.
I have compensated by running the RPM at around 50 to 100 rpm and steadying the body of the mandrel where it is smooth in the fingers of my left hand.

Is it perfect? Well of course far from it.

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 »

Well the jobe went along quite well.
Tomorrow I will review the clearances, as one is just a smidge tight.

Crankcase tilted on engine stand.
MAL_1119.jpg
Using the honing device.
MAL_1132.jpg
The custom tubular feeler gauge ready to test dimensions.
MAL_1133.jpg
The bore checks out OK based on fit of the gauge.
MAL_1136.jpg
Well it some time and patience to get past the hurdle of fitting the oversized cam followers. Happy with the finished job.
Thank you to Carl for your advice along the way. Much appreciated.

Mal
mal - R69s
Toowoomba- Australia

vav
Posts: 2
Joined: Sat May 23, 2015 8:39 pm

Re: let the games begin - R69s engine rebuild

Post by vav »

Mal thanks for your posts I do enjoy them. I came across this post on you tube How I changed the crankshaft seals on my 1970 Kawasaki H1 500 triple. This was posted by Allen Millyard. He is an amazing engine builder who makes 3 cylinder bikes into 4 cylinder bikes and 4 cylinder bikes into 6 's. In this particular post he disassembles a crank and reassembles it.
Just an unassuming Englishman working in his shed out the back.The Barber museum has bought and displays a couple of the bikes he has built. Cheers Vince( Perth WA)
VAV

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malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

vav wrote:
Sun Nov 29, 2020 5:52 am
Mal thanks for your posts I do enjoy them. I came across this post on you tube How I changed the crankshaft seals on my 1970 Kawasaki H1 500 triple. This was posted by Allen Millyard. He is an amazing engine builder who makes 3 cylinder bikes into 4 cylinder bikes and 4 cylinder bikes into 6 's. In this particular post he disassembles a crank and reassembles it.
Just an unassuming Englishman working in his shed out the back.The Barber museum has bought and displays a couple of the bikes he has built. Cheers Vince( Perth WA)
Hi Vav
Yes I have checked out some of Allen's youtube videos - brilliant man that is for sure.
Trust me I am not planning to marry together two R60's into a 1200cc flat four.
You can rest assured.

For actual hands on advice for the person wanting to do the job I found this youtube video mre useful.

https://www.youtube.com/watch?v=6lKLKtzWPQI

Thanks for the comment. Sometimes I wonder if I am wasting my time posting stuff up if it is of no use to anyone.
I get a lot of benefit from the posts of other folk and I feel I should contribute not just take.

Cheers


Mal
mal - R69s
Toowoomba- Australia

User avatar
malmac
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Re: let the games begin - R69s engine rebuild

Post by malmac »

So good to have the cam followers ready for reassembly. Now for the crankshaft runout, alignment and clearances.

Clearances on the rear conrod are to spec. .07mm Good
Front conrod, way out at .2mm one side and .15mm the other side of the crank pin.

So I needed to press the front web closer to the centre web.
Here are some pics of what I did to achieve the goal.

Mal

Plasma cut 16mm plate.
MAL_1142.jpg
Machine out so I get clearance for the centre web.
MAL_1145.jpg
Next cut out a spacer to hold the con rod from having pressure applied.
MAL_1146 1.jpg
Set it up in the press and carefully press it to the desired clearance.
MAL_1147.jpg
mal - R69s
Toowoomba- Australia

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