750 cylinder barrell very flat top
- Thread starter pierodn
- Start date
- Status
lcrken
VIP MEMBER
- Joined
- Mar 15, 2009
- Messages
- 4,979
Thanks for posting the pictures, Pierro. That has to be the worst quality casting I've ever seen for a Norton cylinder. It is visibly different in several ways from any factory cylinder I've seen. What should be the foundry mark and the serial number are almost unreadable. I don't see how it could be anything except a cheap knockoff. That doesn't mean you can't use it, as long as everything fits up properly.
Ken
Ken
- Joined
- Nov 10, 2012
- Messages
- 3,154
Hipete.v said:It almost looks like it has not been machined yet. Rough! Maybe it is just the picture. Wipe the surface clean and send another photo.
Other than that, it looks good.
You said +0,20, it appears to be +0,40 by the stamp on the piston.
Sorry, is +0,40.
Is not rough, only oil!
Thank you.
Piero
lcrken
VIP MEMBER
- Joined
- Mar 15, 2009
- Messages
- 4,979
I just ran across an interview with Les Emory, in which he mentioned that his new Commando cylinders were cast at a local foundry in Brierley Hill, but didn't mention the name. The only one I could find by searching is Brockmoor Foundry, but there could be other foundries in the same area. There were other foundries there back in the Black Country heydays. I'm wondering if Pierro's cylinders could be one of the ones Les supplied. Has anyone here seen on of the Fair Spares/Norvil cylinders, and do they look like Pierro's?
Ken
Ken
lcrken
VIP MEMBER
- Joined
- Mar 15, 2009
- Messages
- 4,979
Hi Piero,
That's pretty far back (25 years). I'm not sure when the aftermarket iron cylinders I'm thinking of first appeared. I thought it was somewhere in the '90s, but it could have been earlier. In any case, it is certainly an interesting piece.
The rough part I was referring to was the quality of the casting, not the machined surface. It just doesn't look as well done as the factory cylinders. But pictures don't always tell the story, and I could be wrong.
I can't quite read the name on the casting mark, or the cast-in part number. Can you read them off the actual cylinder? The part number appears to end in 937, but I can't make out the rest. On a factory cylinder the foundry mark would probably read "BIRCO".
Ken
That's pretty far back (25 years). I'm not sure when the aftermarket iron cylinders I'm thinking of first appeared. I thought it was somewhere in the '90s, but it could have been earlier. In any case, it is certainly an interesting piece.
The rough part I was referring to was the quality of the casting, not the machined surface. It just doesn't look as well done as the factory cylinders. But pictures don't always tell the story, and I could be wrong.
I can't quite read the name on the casting mark, or the cast-in part number. Can you read them off the actual cylinder? The part number appears to end in 937, but I can't make out the rest. On a factory cylinder the foundry mark would probably read "BIRCO".
Ken
- Joined
- Aug 8, 2005
- Messages
- 2,678
pierodn,
Pictures are good !
If you are going to use the flame-ring gasket then be sure you have no valve to piston contact and you may need a base gasket spacer to give you your desired compression ratio and clearances.
Check here. http://www.jsmotorsport.com/products.asp scroll down to middle of the page for copper base gaskets.
Hope that helps,
Cheers,
Thomas
CNN
Pictures are good !
If you are going to use the flame-ring gasket then be sure you have no valve to piston contact and you may need a base gasket spacer to give you your desired compression ratio and clearances.
Check here. http://www.jsmotorsport.com/products.asp scroll down to middle of the page for copper base gaskets.
Hope that helps,
Cheers,
Thomas
CNN
lcrken
VIP MEMBER
- Joined
- Mar 15, 2009
- Messages
- 4,979
One of the reasons for copper is that Jim supplies his copper base gaskets in a wide range of thickness. Another is that it deforms to seal irregular surfaces a lot better than steel. Also, I don't know of anyone supplying the steel base spacers in a range from thin to really thick.
Ken
Ken
- Joined
- Oct 19, 2005
- Messages
- 18,978
Alu tends to moosh flater over time more so than copper, so looses clamp force and in the case of head gasket I found out why Norton service notes say its taboo to use - because the alu mooshed out to rub on pistons till piston come apart. Alu sealing washers seal better than copper for the banjos feeding oil pressure and I had to switch to Alu banjo washers to seal my 1st Combat when copper flame annealed washers would not. Seems I remember steel base plates available but don't know as I gave up on base plates or regular gasket there a long time ago but did not have the stack height issues you do. I do not know if steel is better than copper for base plate - and reason I asked here. I'd check with the major vendors as they would know more about what works best for base plate.
lcrken
VIP MEMBER
- Joined
- Mar 15, 2009
- Messages
- 4,979
pierodn said:
Andover Norton has base spacer plates here, in .030" thickness
http://www.nortonmotors.de/ANIL/Norton% ... mit=Search
Also available form RGM here
http://www.nortonmotors.de/ANIL/Norton% ... mit=Search
And from a variety of other suppliers. Just use the AN part number to search.
Ken
http://www.rgmnorton.co.uk/buy/barrel-b ... mm_147.htm
grandpaul
VIP MEMBER
- Joined
- Jan 15, 2008
- Messages
- 13,247
I do not think there is a problem, if you can verify that the overall height of the cylinder from the bottom of the base flange to the top of the deck is within specification listed in the manual for that year model (probably the same over a range of years).
- Status