Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesSRM EngineeringLucas Classic MotorcycleHepolite PistonsIndustrial tec supply

Upgrade your membership to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Welcome to BritBike Forum!
Britbike forum logo
Member Spotlight
Grandad
Grandad
The Crypt - South East England
Posts: 1,117
Joined: February 2008
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Previous Thread
Next Thread
Print Thread
Joined: Oct 2020
Posts: 77
Likes: 4
S
S-NJ-W Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Oct 2020
Posts: 77
Likes: 4
The subject of running two right hand rods came up in Adam M's thread about his friends high mileage '72 A65, where he said he friend had blocked the drilled oil holes on the left hand rod. I notice that in the 'Thunderbolts & Lightning' book it's mentioned (page 84) that the BSA competition department recommended using two right hand rods instead of the drilled left hand rod.

I don't see the advantage of the drilled rod, except maybe spraying oil into the underside of the left hand piston and gudgen pin. Was that a problem that needed fixing? I don't know. I can see the advantage of not using the drilled rod, to keep as much oil pressure in the big end as possible.

Has anyone run two RH rods and developed problems as a result?

Steve.

Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Joined: May 2013
Posts: 7,567
Likes: 94
Britbike forum member
Offline
Britbike forum member
Joined: May 2013
Posts: 7,567
Likes: 94
The drilled rod was a sticking plaster apoach to a problem which eventually raised its head as the problematic 4CA points. They just never changed it back again after. The idea was to spray oil up the bore on the left cylinder.

The map rods have grooves cut away at the side of the rods instead of the holes.

Thunder engineering rods have 1 hole drilled (unless you spec differently)


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Joined: Oct 2020
Posts: 77
Likes: 4
S
S-NJ-W Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Oct 2020
Posts: 77
Likes: 4
Originally Posted by Allan G
The map rods have grooves cut away at the side of the rods instead of the holes.

Thanks Allan. It looks like both the MAP rods have 'notches' cut into them at the TDC point.
Visible here and the 'blurb' goes on to say :

"Innovative machined piston oil squirting notches"
and
"Unlike the stock BSA rods, these rods have been designed without a big end oiling hole because it is not necessary. Other oiling systems take place of the hole in the big end."

Did the steel capped rods used in the A70 have the oil holes drilled?

S.

Joined: Apr 2005
Posts: 2,693
Likes: 9
Britbike forum member
Offline
Britbike forum member
Joined: Apr 2005
Posts: 2,693
Likes: 9
Rods can split through that drilling. I use them but I would prefer them without, and would not buy them. Two non drilled steel capped rods are very good. So are the rods supplied by MAP which are steel and virtually as light.

The holes are not needed. Having motors run extensively without.


mark
Joined: Oct 2020
Posts: 77
Likes: 4
S
S-NJ-W Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Oct 2020
Posts: 77
Likes: 4
Originally Posted by Mark Parker
Rods can split through that drilling. I use them but I would prefer them without, and would not buy them. Two non drilled steel capped rods are very good. So are the rods supplied by MAP which are steel and virtually as light.

The holes are not needed. Having motors run extensively without.

Thanks Mark. I am heading towards the MAP rods for my re-build.


Moderated by  Allan G, Jon W. Whitley 

Link Copied to Clipboard
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor






© 1996-2021 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5