Author Topic: 836cc Cylinder walls?  (Read 1895 times)

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Offline racemx51

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836cc Cylinder walls?
« on: November 24, 2011, 05:42:38 PM »
Hey guys, Im getting ready to send out my cylinders to have it bored for the 836. Ive heard a few times that the walls are pretty thin after that much boring and I should sleeve it... What are your thoughts on this? Is that true or is it a bunch of crap?

Offline 754

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Re: 836cc Cylinder walls?
« Reply #1 on: November 24, 2011, 06:07:31 PM »
 Not really, you can still take em out to 850c..
 plus they are plentiful and cheap..
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline mick7504

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Re: 836cc Cylinder walls?
« Reply #2 on: November 24, 2011, 06:08:54 PM »
You'll end up with about 2.5mm of wall thickness after boring to 65mm (836)

These motors have been getting drilled out to 65mm for years and years and I'm unaware of anybody having any issues with that being done.

I guess that ideally, bigger/thicker sleeves would be better but "How much better and what will the benefits be?"

If the motor isn't going to be subjected to extreme use, I'd personally be inclined to bore out the stock sleeves.

Keeping in mind that if you decide to go with the thicker sleeves, the cylinder block will need to be bored first for the thicker sleeves and the top engine case will need to be opened up as well.

Mick
If I was you
I'd be worried about me.

Offline Big Jay

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Re: 836cc Cylinder walls?
« Reply #3 on: November 27, 2011, 07:32:10 PM »
We only recommended bigger sleeves to the turbo guys who were going to run a lot of boost.

Offline Hummel

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Re: 836cc Cylinder walls?
« Reply #4 on: March 07, 2013, 03:20:39 AM »
Found this old thread, saying 2,5mm in Wall thikness. Is that total for both sizes?

Is there a special type of The cb750 with smaller sleeves than The others ?

Offline Big Jay

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Re: 836cc Cylinder walls?
« Reply #5 on: March 08, 2013, 05:07:15 PM »
2 mm per side.  They are all the same.