The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: coater87 on 20.04. 2017 01:51

Title: Large or small journal?
Post by: coater87 on 20.04. 2017 01:51
 I wonder if this is a large or small journal crankshaft, or if it's even BSA ?

 Does anyone recognize this?
Title: Re: Large or small journal?
Post by: duTch on 20.04. 2017 03:45

 Looks BSA without the flywheel; (if possible) have a look at the Stamps/numbers on the conrods, that should give an idea...??
Title: Re: Large or small journal?
Post by: coater87 on 20.04. 2017 04:08
Hi Dutch,

 I took a chance on this. I ran across the add on eBay about 3 minutes before the auction ended. I got it for $40.00 US, so cheap enough. But I didn't have any time to research it at all.

 I bought it maybe 3 hours ago, that's a picture right off eBay. The sludge trap plugs look pretty beat up. So it might be ground to +40, or maybe it's on standard and they had no idea how to get them out.

 Maybe it's a gold mine, or maybe I just got the shaft! ;)
Title: Re: Large or small journal?
Post by: duTch on 20.04. 2017 05:02

 Figured it might've been a rush job like that. ..I did much the same a couple of years ago at a swap meet,  when measured it was well past max (min) good paperweight though and the flywheel came too.
 it's a good price,  so good luck  *wink2*
Title: Re: Large or small journal?
Post by: coater87 on 26.04. 2017 01:28
 Nope, complete shaft with no gold. *sad2*

 None of the extra do-dads were brazed on, all were welded. Even the flywheel mounting hole to the sludge trap is welded shut.

 If that garbage would have been brazed, I think I could have fixed it. But once it was welded, I know its all over but the crying now.

 Even the rods are junk.

 Lee
Title: Re: Large or small journal?
Post by: muskrat on 26.04. 2017 20:50
G'day Lee.
Looks like it was modified for racing. It would have revved to 10 grand but not enough torque to pull the skin off a rice pudding!
Might be worth something to our Salt Flats combatants.
I lightened my racing A7 crank by a couple'a pounds (flywheel like Swiss cheese). Nothing under 4 grand.
Cheers
Title: Re: Large or small journal?
Post by: coater87 on 27.04. 2017 00:50
 Hi Musky,

 

 Yes, this thing would rev until it sounded like bees, but you would need washing machine gears and a clutch that could slip for days to get it rolling. I have not done a weigh-up, but whatever the crank weighs minus the fly wheel plus about 6 ounces would be close. *eek*

 I just wish they would have brazed this instead of NI-rod welding it. The welds will be hard as glass and the only way I know to get rid of it is completely grind all of the hardened material out. The heat from welding draws any carbon in the cast material straight into the weld making it non machinable on anything I use.  *sad2*