BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
  JWood Auction  
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Photo posting tutorial

Member Spotlight
Ron C
Ron C
Ohio
Posts: 23
Joined: August 2017
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
219 registered members (57nortonmodel77), 1,807 guests, and 537 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Brian Ellery, Jon Andrews, Berni Ernst, johnguppy, michael morgan
9955 Registered Users
Top Posters(30 Days)
btour 189
koan58 100
Stuart 84
NickL 67
Popular Topics(Views)
437,348 mail-order LSR
Forum Statistics
Forums33
Topics65,274
Posts632,183
Members9,955
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate This Thread
#319815 - 06/23/10 11:45 am b33 cams  
Joined: Jun 2010
Posts: 37
kye Offline
BritBike Forum member
kye  Offline
BritBike Forum member

Joined: Jun 2010
Posts: 37
queensland
hi
i have got a 1950 bsa b33 i have just finished rebuilding
it has standard cams .020" standard compression piston, rebore new bearings
standard magdyno i think the valves are standard but they
have been replaced and reseated it has a AMAL 932 Concentric with this setup it runs beautifully
my question is
i have got hold of some cams intake 65-2438 and exhaust 65-2436
i want to know if it will run with these cams with std compression
i understand i have to change valve springs and change timing to 1/2" is there anything else to do or should i not bother untill i up my compression
thanks kye

#319979 - 06/24/10 4:58 am Re: b33 cams [Re: kye]  
Joined: Dec 2004
Posts: 8,887
kommando Online content
kommando  Online Content


Joined: Dec 2004
Posts: 8,887
Scotland
If those are Goldie cams then it was a common upgrade back in the 50's. You will get a performance increase with just the cams but more again if you increase the compression. However with an iron head you will increase the heat if you go too far so try the cams only first before adding the increased compression.

#319996 - 06/24/10 8:32 am Re: b33 cams [Re: kommando]  
Joined: Jun 2010
Posts: 37
kye Offline
BritBike Forum member
kye  Offline
BritBike Forum member

Joined: Jun 2010
Posts: 37
queensland
thanks kommando (once again!)
will give it a go
the book says these are early 48-51 goldstar race cams
for dope
i suppose our fuel is better quality and higher octane these days
i will let you know how it goes
kye

#320005 - 06/24/10 10:29 am Re: b33 cams [Re: kye]  
Joined: Feb 2003
Posts: 2,884
Rickman Offline
BritBike Forum member
Rickman  Offline
BritBike Forum member

Joined: Feb 2003
Posts: 2,884
Ohio
Is the term "dope" [ which I have heard about for DECADES! ], an old term for alky-hol? Or is it a term for nitro-methane based drag race fuels? Or WHAT?

#320028 - 06/24/10 1:22 pm Re: b33 cams [Re: Rickman]  
Joined: Sep 2002
Posts: 7,812
Alex Offline
BritBike Forum member
Alex  Offline

BritBike Forum member

Joined: Sep 2002
Posts: 7,812
Seattle
Dope is that old-timey term for Methanol...or, as one guy with a JAWA flattracker at british in the blue ridge had on the signboard in front of the bike in the show had it "runs on menthol". I wanted to find him to ask if it ran on Lights, too...


A smattering:
'53 Gold Flash
'67 Royal Star
'71 Rickman Metisse
'40 Silver Star
'37 Rudge Special
sixtyseventy Lightboltrocket road racer...and many more.
#320031 - 06/24/10 1:54 pm Re: b33 cams [Re: Alex]  
Joined: Sep 2008
Posts: 129
Tim Lynch Offline
BritBike Forum member
Tim Lynch  Offline
BritBike Forum member

Joined: Sep 2008
Posts: 129
Devon, UK
AS Kommando says, raising compression too much will create problems with standard B33 iron head. I did this with mine and experienced pinking and overheating problems. I now run a modified B31 head with big valves and a decompression plate and a 90mm piston. This gives a more compact combustion volume which is currently at about 9.75:1 and it runs fine. It is possible to convert the head to twin plug (10mm plug behind pushrod casting) but it is a tight squeeze.


1949 BSA M33
1952 JABSA 652 Sprinter
2009 Honda VFR 800
#320247 - 06/26/10 1:06 am Re: b33 cams [Re: Tim Lynch]  
Joined: Jun 2010
Posts: 37
kye Offline
BritBike Forum member
kye  Offline
BritBike Forum member

Joined: Jun 2010
Posts: 37
queensland
hi tim what is the 90mm piston out of?
is yours the early long stroke engine?
kye

#321547 - 07/04/10 5:12 pm Re: b33 cams [Re: kye]  
Joined: Sep 2008
Posts: 129
Tim Lynch Offline
BritBike Forum member
Tim Lynch  Offline
BritBike Forum member

Joined: Sep 2008
Posts: 129
Devon, UK
Kye,
Piston is a JE one but originally it had quite a large dome. Machined piston to remove dome top and around outer areas and fitted decompression/squish plate to improve combustion volume. I now have a flat top JE piston which is 90.5 mm which will go into my next engine. Current engine has modified M20 crank so bore + stroke is 90 x 94 = 598cc. Conrod is an early B33 long rod at the moment. See bike in BritBike Gallery, BSA M33 1952.

Tim.


1949 BSA M33
1952 JABSA 652 Sprinter
2009 Honda VFR 800
#322824 - 07/13/10 5:00 pm Re: b33 cams [Re: kye]  
Joined: Apr 2010
Posts: 8
dalton w Offline
BritBike Forum member
dalton w  Offline
BritBike Forum member

Joined: Apr 2010
Posts: 8
canada
I have an iron engine in a swing arm frame that I use for vintage track days. The cases are ZB33 and the top end is M33. The piston is CB34 Goldie and the cams are Goldie Touring. I shot-peened the conrod and use a Goldie crankpin and lightened flywheels. Valves are standard, carb is 32mm Concentric (jetted on the rich side) and exhaust is a Goldie trackpipe with a megaphone style muffler. Ignition is battery and coil.
I've used the bike for trackdays for many years and it's been very reliable. It pulls nice high gearing and runs suprisingly cool. Performance is quite adequate for an old fart like me.

#322834 - 07/13/10 6:23 pm Re: b33 cams [Re: dalton w]  
Joined: Aug 2001
Posts: 1,851
dave - NV Online content
BritBike Forum member
dave - NV  Online Content
BritBike Forum member

Joined: Aug 2001
Posts: 1,851
Elko, Nevada USA
Tim Lynch ... Thank you again for your info building a performance 'iron' BSA. A question I have ...
You mentioned boring a B33 cylinder and fitting a liner with a 90 mm bore. Is there enough material in a B33 cylinder to allow such a large oversize?

BTW ..
Those of us with 90 bore road Goldies have fitted the special cast up cylinders from Phil Pearson. This works great and you have a 560cc GS that 'pulls like a train' and loves to rev. I like that.

Our GSr pal Ron Halem aka GStarRon has modern custom design 90 bore forged pistons by Venolia he supplies many of us. Pearson also stocks 90 bore pistons. I also like to use Total Seal 'gapless rings'.
Only a few passes 'right on by' those pesky twins makes it worthwhile. Nice. It would only be more fun to do it with a olde iron motor. yeah ..

Last edited by dave - NV; 07/13/10 6:24 pm.

dave - NV
#323247 - 07/16/10 7:47 am Re: b33 cams [Re: dave - NV]  
Joined: Sep 2008
Posts: 129
Tim Lynch Offline
BritBike Forum member
Tim Lynch  Offline
BritBike Forum member

Joined: Sep 2008
Posts: 129
Devon, UK
Dave, My iron barrel is a small fin 500 fitted with a liner so when bored to 90mm it ends up with quite thin wall thickness but as it is supported all round by the barrel there is no problem. Later big fin barrels are a larger diameter casting under the finned area so 92mm piston would probably be feasable. I toyed with idea of 94mm piston bored straight into small fin barrel but casting wall thickness goes down to about 2mm. Hmmm, not good. Opening out crankcase mouth also gets a little close to cylinder bolt hole threads but I plan to fit 94mm Ducati 916 piston into linered Jawa aluminium barrel with DOHC 4 Valve cylinder head, grafted onto B33 bottom end. I'll post a picture of modified engine soon.


1949 BSA M33
1952 JABSA 652 Sprinter
2009 Honda VFR 800
#323269 - 07/16/10 1:16 pm Re: b33 cams [Re: Tim Lynch]  
Joined: Sep 2008
Posts: 129
Tim Lynch Offline
BritBike Forum member
Tim Lynch  Offline
BritBike Forum member

Joined: Sep 2008
Posts: 129
Devon, UK
Not finished yet but getting there...



1949 BSA M33
1952 JABSA 652 Sprinter
2009 Honda VFR 800
#323453 - 07/17/10 5:40 pm Re: b33 cams [Re: Tim Lynch]  
Joined: Nov 2009
Posts: 2,048
Peter R Online content
BritBike Forum member
Peter R  Online Content

BritBike Forum member

Joined: Nov 2009
Posts: 2,048
Netherlands
Very interesting project Tim,
I look forward to watching your progress.


Peter.
1974 Commando 850
1972 Trident T150T
1961 Goldie DBD34
1969 Benelli 250 sport special
#323659 - 07/18/10 8:44 pm Re: b33 cams [Re: Peter R]  
Joined: Sep 2008
Posts: 129
Tim Lynch Offline
BritBike Forum member
Tim Lynch  Offline
BritBike Forum member

Joined: Sep 2008
Posts: 129
Devon, UK
More pictures at:-

http://s426.photobucket.com/albums/pp346/tdl1325/JawBsa/

Perhaps these should be on a new post as no B33 cams in here!


1949 BSA M33
1952 JABSA 652 Sprinter
2009 Honda VFR 800
#324674 - 07/25/10 7:44 am Re: b33 cams [Re: Tim Lynch]  
Joined: Jun 2010
Posts: 37
kye Offline
BritBike Forum member
kye  Offline
BritBike Forum member

Joined: Jun 2010
Posts: 37
queensland
tim that thing is an animal
very very cool

#652534 - 05/12/16 10:12 am Re: b33 cams [Re: kye]  
Joined: May 2016
Posts: 1
antonis643 Offline
One time poster
antonis643  Offline
One time poster

Joined: May 2016
Posts: 1
Cyprus
Hello guys.I know this thread is quite old but i couldnt find a more relevant one. I ve taken apart my b31 (1953)for a complete restoration. I ve been reading that the easiest way to increase the power is to fit a T140 piston. My question has to do with the cams. Is it correct that the next easiest thing is to install the goldstar clubman ones?
I know that these matter has been raised quite few times but i would really appreciate it if i can have details regarding the exact cams to install.
Finally after taking these two steps whats the next thing on the list taking always into account that the engine will still run smoothly.

KR

Antonis



Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.103s Queries: 15 (0.006s) Memory: 0.9029 MB (Peak: 1.1569 MB) Zlib disabled. Server Time: 2017-11-21 17:07:44 UTC