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Moded BSA B33 motor, cams valves crank pics. Q's
#330819
08/30/10 9:15 pm
08/30/10 9:15 pm
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Joined: Aug 2005
Posts: 99 UK
maxwell
OP
BritBike Forum member
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OP
BritBike Forum member
Joined: Aug 2005
Posts: 99
UK
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Hi there I have got a B33 motor. Here in the uk they are hard to come by. I have been trawling the forums for advice regarding the head being welded. This has been done. Here are pictures of what I found when the engine was dismantled to examine/repair (it's been in a yard for years). It's a lightned crank with a polished conrod (excuse the watermark) And work done on the rockers Also has posh valves As well as these there was a high compression piston and nice cams. Here's a list Cams 65-1891 65-2442 piston 65-1267 1/2mm os inlet valve 65-1632 (g2 on it) exhaust vave is hard to make out, I can just see bsa & g2. I have a couple of Q's Does anybody recognise the cam partnumbers? I have seen 1 of them on pearsons site. Are these touring? or what? any advice from others in this field would be apreciated cheers
Last edited by maxwell; 01/29/11 9:07 pm.
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: maxwell]
#330951
08/31/10 5:03 pm
08/31/10 5:03 pm
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Joined: Sep 2001
Posts: 2,792 Comox BC Canada
Gordo in Comox
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BritBike Forum member
Joined: Sep 2001
Posts: 2,792
Comox BC Canada
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According to Bacon's Singles Resto book the 65-1891 was used around 1954/555 for exhaust on some 350 and 500 Clubman, some 350 Tourers, at least one 350 scrambler and some 54/55 Race machines. The timing is 60 85 85 60. These are all CB or DB engines.
Gordo
Without frequent roadside repairs there is no fun in riding!
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: maxwell]
#330964
08/31/10 5:57 pm
08/31/10 5:57 pm
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Joined: Aug 2001
Posts: 1,871 Elko, Nevada USA
dave - NV
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BritBike Forum member
Joined: Aug 2001
Posts: 1,871
Elko, Nevada USA
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The 65-1891 exhaust cam is listed for the 350 Clubman. It is designed to be fitted with the 10 degree advance pinion. It has a longer duration than the more typical 65-2446 cam many of us use in both race and road GSs.
That all being said, I've tried using the 1891 a couple of times over the years with poor results in my 500 DBDs. However the 350 GSrs really like them. hmmm
For sale: 65-1891 cam and a 10 degree advance pinion
dave - NV
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: Stephenrc45]
#330988
08/31/10 8:43 pm
08/31/10 8:43 pm
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Joined: Aug 2005
Posts: 99 UK
maxwell
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BritBike Forum member
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OP
BritBike Forum member
Joined: Aug 2005
Posts: 99
UK
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Correction inlet is 65-1632 The crank looks almost identical to the Gold Star ZB crank fitted in my ZB34.
The rockers are ZB Gold Star items having the lightened body with exhaust valve lifter foot also being cut down.
65-2442 is a clubman inlet cam and normally runs with a 65-2446 exhaust cam. I can't help with 65-1891 at the moment but will dig though some notes. I think it was a 1950-1951 clubman exhaust cam. Has that crank You speak of been lightened or did it come like that as standard. (standard b31 crank has a lip on the flywheels) the conrod looks to have been polished also. Re: the 10 degree advance pinion, I see no visual difference in the one from this engine, and a standard b31 item, apart from one has 7 stamped on it.
Last edited by maxwell; 08/31/10 8:59 pm.
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: maxwell]
#331068
09/01/10 11:33 am
09/01/10 11:33 am
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Joined: May 2004
Posts: 3,674 Sydney Australia
BSA_WM20
BritBike Forum member
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BritBike Forum member
Joined: May 2004
Posts: 3,674
Sydney Australia
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Drive shafts for alloy chaincases were just a smiggen longer than drives for tin chaincases but they are same at the other end so it is easy to get them mixed up. Drives for stationary engines or for non motorcycle applications were also longer. BSA made engines for all sorts of things other than motorcycles. They made them on the same lines with the same tooling so they will look like they fit till you try and line things up when suddenly the primary is 1/2" too far out or so close that the clutch can not line up. We buy stuff for swaps or on evil bay from traders who have either no idea or just a rough working knowledge then wonder why they don't actually fit. DID you measure it from end to end first ?
Bike Beesa Trevor
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: maxwell]
#587479
02/26/15 2:29 pm
02/26/15 2:29 pm
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Joined: Feb 2015
Posts: 135 UK
flowboy
BritBike Forum member
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BritBike Forum member
Joined: Feb 2015
Posts: 135
UK
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Looks interesting tho'! :-) The iron motor can be made to go pretty quick. Maybe with slightly softer cams than these? They also run very hot (on petrol) when highly tuned. Oh yes, they go BANG as well! The long rods aren't safe much over 6000rpm (they are all 50-65 years old now) Seems to have built to something like B34 competition spec. But the crank is not B33. It looks very much like ZB32GS - if not genuine it would be fairly straighforward to convert B31 flywheels to that spec. All the B33/34 cranks were the heavier castings (very similar to M20 wheels). I always assumed this to be due to it being easier to balance the assy. with heavier 500 piston & workload. There is another recent & useful thread on early / ZB crank ID. Goldie long rods are 66-1321 not the 66-483 B31/3 but I suspect they were the same rod but polished!? (Never seen a numbered ZB GS rod). No GS cranks I've seen have had numbers stamped. Early cases are all the same timing side. ZB34 drive side cases I have are heavier with more strengthening webs than ZB31/2/33 which are the same number as B32GS up to 1951 - GS then got a stronger drive side. You must check that valve springs dont get coil bound at full lift. They will with these cams! The very high lift 1891 & + 10 deg. pinion is the best racing exh. cam for CB-DB350's. Without the pinion you can't adjust the valve timing any less than +/- 20deg.
Last edited by flowboy; 02/26/15 2:33 pm. Reason: detail
na
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: flowboy]
#587482
02/26/15 2:47 pm
02/26/15 2:47 pm
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Joined: Feb 2015
Posts: 135 UK
flowboy
BritBike Forum member
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BritBike Forum member
Joined: Feb 2015
Posts: 135
UK
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See the Gold Star forum; "Distinguishing features of ZB and BB cranks?"
Also looks like your crank could be GS as it seems to have the big cankpin nuts = Goldie crankpin. Check the shafts aren't loose!
na
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Re: Moded BSA B33 motor, cams valves crank pics. Q's
[Re: Boomer]
#587543
02/26/15 8:10 pm
02/26/15 8:10 pm
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Joined: Feb 2014
Posts: 417 Cork Ireland
chaterlea25
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BritBike Forum member
Joined: Feb 2014
Posts: 417
Cork Ireland
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Hi, This is shown as a 500cc Clubmans inlet valve in the 49-52/3 BSA spares book HTH John
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