B32 competition accidently purchased.

[Wildebeest90210]

I didn't mean to buy this but at auction at Stafford recently it came home in my van. I'm new to BSA's but not at all new to building bikes. I intend to check it over and run it as is, have got the top end off and discovered it has been running methanol for a start which I'd like to continue. I will need help and have questions but first does anyone recognize it and have any history for it? It may have belonged to Martin Lampkin recently but the auction catalog was not clear on that, it's a '49 frame (that should be plunger) and a '53 engine, gearbox has no marking. Last run at the 2007 Thunder sprint? Thanks, Joe.   

[scifi]

Looks great...   You do realise that Methanol requires the carb jets to be almost 3 times larger than Petrol.  For a 250 they would go up from 140 to 400 size, and the needle and tube would be different as well.   The Compression Ratio could have been maxed out as well, so don't be tempted to run it on petrol.   Also check what oil it is using, it could be Castrol R or Millers CB40 castor oil for these methanol engines.   The cam could have been changed for a sprint cam, if that was what it was used for.
Hope you can run and bump it, or maybe you have the starting rollers....  Best of luck, hope you take it to a few events.

[Wildebeest90210]

Looks great...   You do realise that Methanol requires the carb jets to be almost 3 times larger than Petrol.  For a 250 they would go up from 140 to 400 size, and the needle and tube would be different as well.   The Compression Ratio could have been maxed out as well, so don't be tempted to run it on petrol.   Also check what oil it is using, it could be Castrol R or Millers CB40 castor oil for these methanol engines.   The cam could have been changed for a sprint cam, if that was what it was used for.
Hope you can run and bump it, or maybe you have the starting rollers....  Best of luck, hope you take it to a few events.

Thanks, very happy with it so far. The main jet is a 900 and needle to suit. It has the 13:1 piston, exhaust cam is a common one but the inlet is just marked 48 and has a measured lift of 0.355". I'm going to make some rollers that run off one wheel of my van just for added danger  Pics to follow.

[Wildebeest90210]

Pics

[neil1964]

Well done on the purchase.  Looks like a serious bit of kit.
The cams are later cams (65-2449in and 65-2450ex that you expect on DB onwards tourers or racers (I have the same cams on my 51 ZB34 top end).  The piston is 13:1 so definitely for running dope (mine is only running 7.5:1).
Your carb appears to be a later GP type. 
Correct for your year would be the ill thought of RN type of 1 3/16".  The year earlier would have been a 1 5/32" TT but I guess the later cams, high comp piston, megaphone exhaust will have their own settings and requirements that someone will have found by experimentation and experience.  I expected the main jet to be around 1000 (vs my 500 has a 10TT9 settings of 360 main jet, 106 needle jet, needle position 3, slide 7). 

[neil1964]

Sorry wanted to edit:
65-2448 inlet cam

[Mike40M]

I'll be a bit suspicious if it has run on Castrol R. Could be that old R has solidified, blocking oil passages. Wasn't a problem when you stripped the engine between races. Modern castor based like Morris C40 has inhibitors. Run my Manx for six years on C40 without taking engine apart. Molnar changed his recommendation for his Manxes from castor oil to synthetic oil a couple of years ago. Changing needs a complete strip and cleaning. When I changed from a JAP speedway bike to JAWA in 1970, I also changed from R to a multigrade oil. The JAWA only needed a complete tear down twice a year. With synthetic oil you don't new so much warm up time before riding.

[Wildebeest90210]

The oil drained pretty clean considering the time it had been stood, it had wet sumped but no surprise there. Some corrosion on the steel fittings on the fuel system and a little white powder from the dope.

[Wildebeest90210]

This is what I found lurking in the cylinder head, any ideas? Modified? Inlet has been polished and exhaust appears treated and over size maybe. Numbers are not clear, some battle scars that have been dressed back so I'll probably leave them. I'm thinking dope runs cooler so not like a two stroke looking for sharp points for detonation.
 

[neil1964]

There are two inlet valves of that size:
65-1842 (1.6")
65-1611 (1.599")
The details will depend on stem diameter and collet type - sure you know two types of GS collet.
The exhaust looks to be a special.
65-1644 is 1.524"
65-1759 is 1.53"
65-1630 is 15547"
It will be interesting to see the condition of the stems, top surface and which collets were used.
Similarly the condition of the crank and flywheel tapers/rivets.
Looks like it should the first type of short rod BB 6 7/8"  con rod to match that piston.

[ducati2242]

Really good write up on valves on the britbike forum .https://www.britbike.com/forums/ubbthreads.php/topics/929282/1

[Wildebeest90210]

I stripped the clutch today for inspection. Does this look like a standard unit? The ring round the outside is something I've done before on diaphragm clutches but I guess it helps the basket here as well.




The bearing was wobbly for sure but I guess with rollers this narrow that might be expected. Even so there is play  of maybe 15 thou, not measured it yet but it will need looking at.





Can anyone help ID the gearbox? I cannot find any marks anywhere, is it original to the '53 motor? I've looked for stamps in all the places the 'internet' says to look.

[V500]

That's a later (and reputedly better) four spring clutch unit.
The gearbox is the same as my '51 ZB32.

[Wildebeest90210]

Thanks, does the gearbox have a designation code for ID should I need to get spares?

[V500]

Possibly, but I don't know it.
It's the same gearbox as on the equivalent B31/33 so finding the correct part from Drags (if they're not on "back order"!) should be simple enough.