ADVrider

ADVrider (http://www.advrider.com/forums/index.php)
-   Airheads (http://www.advrider.com/forums/forumdisplay.php?f=85)
-   -   Airhead stud tool dimensions (http://www.advrider.com/forums/showthread.php?t=743311)

Bill Harris 11-20-2011 07:28 PM

Airhead stud tool dimensions
 
Does anyone have, or or know of an online source for, the distances between the cylinder studs on a BMW R-bike? I'm working up a stud repair drilling jig.

robtg 11-20-2011 10:37 PM

Quote:

Originally Posted by Bill Harris (Post 17347337)
Does anyone have, or or know of an online source for, the distances between the cylinder studs on a BMW R-bike? I'm working up a stud repair drilling jig.


Oddly enough, the stud spacing is really close to the same spacing as the holes in the cylinder, head gasket,and the cylinder head. Although you may
want to use an actual crankcase for an exact fit. :D

batoutoflahonda 11-21-2011 12:06 PM

I'm pulling the jugs off mine this weekend. I could measure, photo, etc if you like. But you are probably looking for engineering drawings. I recall see it some where. I'll look around.

Bill Harris 11-21-2011 01:30 PM

I'll use a head gasket or a /5/6 base gasket for a "template", though there is the possibility of dimensional errors that can creep into transferring measurements from the gaskets. The better way would be to use a bare case and measure the stud distances. I'm doing my top end as we speak, but it's going through it's second stud-thread repair and I'm sure that some creep has crept since I've not always used a mil-spec drilling jig. Just double-checking-- I'm sure that the "correct" dims will be to the nearest millimeter.

I recalled seeing that stud dimension layout, along with the transmission shim plate dims at one time.

For 30 years I've used a drilling jig that you have to index to the stud you're repairing, and currently am using a rental jig from Northwoods, but I thought I'd make myself a nice self-indexing jig. Not hard, a couple of dims and a Bridgeport & a lathe and you're done.

And I might go commercial develop with a nice mahogany or teak drilling jig for the connoisseur... :eek1


Oh, this top-end work is coming along so nicely...

wirewrkr 11-21-2011 01:52 PM

no need bill, I've got plenty of open engines on the bench at the moment.
I'll go measure and be right back.......................

wirewrkr 11-21-2011 02:11 PM

1 Attachment(s)
I'm reading 72mm x 93mm center to center.
I agree with ROBTG about using an actual block though.
I have an R65 block that threw a rod, I'll see if one side is good enough for a jig.
Maybe I could even cut out the section and send it to you for the shipping.
I'll check and see, it's in the bottom of my scrap metal drum.

wirewrkr 11-21-2011 05:10 PM

1 Attachment(s)
So here ya go Mr Harris,
went through 3 sawzall blades to get'er done, but was worth it.

datchew 11-21-2011 05:20 PM

Robert.

You just brought a new level of awesomeness to this forum.

Bill Harris 11-21-2011 06:01 PM

Omygosh, how neat. If you're wanting to part with that prize, I'll take it (check your PM for address).

93x72mm sounds right (I measured mine, in inches, and those numbers are in the shop at the other end of the house now). I'll check later. The spigot is 97mm for pre-nikasil and 99mm for Nikasil cylinders.

baldwithglasses 11-21-2011 06:19 PM

wirewrkr, what datchew said.

Awesome. Sublime.

disston 11-21-2011 06:31 PM

Quote:

Originally Posted by Bill Harris (Post 17354194)
Omygosh, how neat. If you're wanting to part with that prize, I'll take it (check your PM for address).

93x72mm sounds right (I measured mine, in inches, and those numbers are in the shop at the other end of the house now). I'll check later. The spigot is 97mm for pre-nikasil and 99mm for Nikasil cylinders.

Actually the Nikasils are 99mm but there are some pre Nikasils also 99mm. The division is the last year of /6. 1975 and older are 97mm. 1976 and up are 99mm. So some iron cylinders are 99 but can be updated to Nikasil.

Nice looking slice from your block. If you welded them back in at an angle you could make it a Moto Guzzi.

wirewrkr 11-21-2011 06:57 PM

luckily, the stud holes are all the same distance from 1970-96.
This chunk is from a 79 R65.

wirewrkr 11-21-2011 07:04 PM

Bill, PM ed you the info.

Mugwest 11-21-2011 07:35 PM

Cool ++

That R65 block gave itself to the Larger Good :nod

Bill Harris 11-22-2011 03:44 AM

More than cool. This is art!


Charlie, thanks for the extra info. I remembered that the early cast iron cylinders were 97mm and the later Nikasil were 99mm and assumed that the division was by cylinder type and not model year.


Times are GMT -7.   It's 01:55 PM.

Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014