It`s it`s The Ballerum Blitz. Room for another Beeza?

[Rasmussen]

Hi all

New guy from Denmark here, who just did an intro after being a lurker for 3-4 years. Went to Speedweek in 2012 where I had the pleasure of joining Bill Anderson (Nortonist) who has been an online friend for years. Right after getting home I started building the bike I hope to bring over this year with the help of Bill and his crewchief Joe, who has both been a tremendous help in making this happen.
Bike is currently being tested, and although it looks finished there`s still a bunch to do (isn`t there allways?).
The stupid name? Well it seems like every LSR bike needs a name, So thought I might as well make it a "sweet" one. The pics should explain the somewhat far reached logic behind it




A few basics:1967 350cc BSA ex Danish army bike. 300cc Aisin blower fed through a 38 mm Mikuni butterfly carb off a Sportster. B44 intake valve and ported head. Welded crank and lightened rockers, but apart from that pretty much a stock engine.

Not hoping to be the new Burt Munro or anything like it, but just following an old dream of racing at Bonneville.

[Rasmussen]

Almost forgot! First teststart:
https://www.dropbox.com/s/3341r6de55pjzdo/20131229_134738.mp4

[tauruck]

Great stuff.

The bike looks great.

Thanks for the pics.

[Koncretekid]

Welcome,
The BSA B40 was the highly underrated poor stepchild of the earlier 350 Goldstar.  With its short stroke design, it has a lot of potential, especially with the welded crank.  Unfortunately, a few years too new for vintage class, but the records are yours for the taking.  Are you a member of the B50 forum (http://www.b50.org/index2.htm)?  All the BSA single cylinder experts are on that site.  The addition of the supercharger is stunning on the old bike.  When you come (and I hope you do) I hope you stay for the BUB speed trials.
Tom 

[Briz]

Excellent! The more the merrier! Look forward to seeing you there.

[Nortonist 592]

Looks and sounds great Ivan.   Looking forward to seeing it blitz the salt!!

[Koncretekid]

I'm interested in your supercharger drive.  Is it chain or belt?  If it is belt, how are you oiling your clutch bearings?
Tom

[Rasmussen]

Thanks Bill and Tauruck

Briz: Likewise! I actually had the pleasure of speaking briefly with you in 2012 when admiring the Weslake. Had been following your build here, and it was one of those bikes I just had to see for myself. Was really impressed with it, as I am with the Salt Flash. Wish I had that sort of talent.

Tom: Thanks a bunch for the encouragement. Your build has been a great inspiration too, and am truly impressed with the kind of speed you have managed to get that old girl up to. I totally agree on the B40 or the B models in general being way underrated. Always supposed the bad rep here comes from the military having a bunch of them in a very low state of tune, when in fact with a little tinkering they can be made into very reliable and fun bikes.
Not totally sure I get what you mean by lubricating the clutch bearing? The basket just runs on greased rollers normal Brit style. The clutch seems to work just fine in dry state, at least for now. The only problem I see is the primarychain running dry. A belt would probably be the right thing, but failing that I believe bringing an extra primarychain should get me through the week. Recall you saying something in your build diary about the B50 sharing gear and primary oil? is that right?, then I believe that explains your question. The B40 has separate primary and gearbox, so it really doesn`t present a problem running the blower off the crank. Please let me know if this is what you asked, and if not I`ll do my best to give you a proper answer.
For the drive I chose a single v belt for 2 reasons. I wanted to keep it narrow and most importantly, stepping on new ground here, wanted to be absolutely sure, that in the case of severe blowbacks I wanted to have a little "give" in the system and not having my lobes shift destroying the blower. I would never run a chaindrive like some do, being the cautious type . The belt should be good up to at least 5 HP and at the moderate power I´m aiming for believe that will be sufficient, fingers crossed.
Will try uploading a few pics of the setup.
BUB`s is unfortunately not likely to happen. Have talked my mate Lars into joining for a 3 week vacation. The deal is we go to SW, and he decides where we`re going after that. but who knows, he may be getting saltfever and want to go back to Bonneville. Would love to come by and have a chat.

[Rasmussen]

First mock up:

Machining the beltwheels (proper term?) out of a couple of lumbs of aluminum. Took forever as I didn`t have any round stock, but had to work from a piece of thick plate cut out with an angle grinder:

A little further. Mounting the drive on the crank turned out to be very simple. Where the alternator magnet used to sit, the axle was 3/4" which is approx 19,05 mm`s, or close enough to use a 19 mm double sided taperlock and a straight bored drivewheel. The nut is only there for show. The beltwheel holds the primary drive sprocket in place just fine:

Milling the stock primary cover:

And it all fits nicely:

In order to keep everything tight and within stock width (and thereby be able to use the stock footrests) I had to move the blower slightly outwards to have the belt clear the frame. Total offset of drive is approx 3/8". Read on a chart somewhere on the net that with this fairly long belt this should give me a drive of 95% or thereabouts efficiency. I can live with that, especially considering how much work it saved in the rest of the setup

[Rasmussen]

A little background information may be in order. Here`s a couple of scans of some old pictures. As bought in 1984 from a military surplus dealer:


The bike was painted all black, and given a quick overhaul, but was pretty much left as was until 2000 when turned into a dragbike to compete in the annual all British sprint held here in Denmark. It was given (almost) the full threatment at that time. Fresh bore, high comp, ported head, oversized valves, new bearings all through and so on. Raced it once where I came last against the 500`s in the street legal up to 500 cc class. After 500 miles of riding, a good friend made me an offer I couldn`t refuse. An even swap for his 1939 500 cc BSA all in boxes. My friend Jørgen had a heart condition, wasn`t really well, and realized he probably never would get the 500 assembled, so he`d rather have a less desirable but complete bike in his garage.
Jørgen sadly passed away in 2008, unfortunately he never got to ride the B40, not even once.
His mother found it fitting to let me have the bike for free, rather than to just sell it to someone who wouldn`t appreciate it, and I made a promise to never sell it again.
Having more bikes, I realized that I would probably not really get much riding done on it, and after sitting again for 4 years, except for a couple of trips down the dragstrip being ridden by friends, I found turning it into a LSR bike would be the right thing to do. Also as a sort of way to remember my old friend.
Sorry about the sob story . Just feels it`s an important part of the reasoning behind making this my preferred choice of projectbike

[Koncretekid]

Ivan,
The clutch hub bearings are the ones I was concerned with.  You say they are greased, but because the bearing is not sealed, the grease might potentially get thrown off.  I've looked at a couple of clutch hubs and clutch chain wheels where these bearings were starved of oil and started skidding which ruined both parts.

As for the B50, it is like the B40 and does not share primary oil with the transmission.  However, the B50 main crankshaft bearing is unsealed and there are holes drilled in between the primary case and the crankcase, so the B50 breathes thru the primary case and the oil can move back and forth thru the main bearing and thru the breather holes.

I believe you can further modify your primary case by separating the primary drive chain from your supercharger drive pulley with a flat aluminum plate with a seal between the two drives. Cut away all the primary case outboard of this plate back to the clutch.  You may have to use an idler pulley on the slack side of the belt to get it to clear the bulge at the clutch.  The belt will run outboard of this welded in plate, the chain will run inboard and can therefore be within the then sealed primary case which can then contain oil which will lubricate both you chain and your clutch hub bearings. Similar to the photo I show below, but the drive pulley can be moved back closer to the motor if you cut away part of the primary case.

Another question I have is that of your fuel supply. It appears to be gravity feed.  Will the boost created by your blower prevent fuel from flowing into the carb? 

By the way, the B50 is nothing more than an expanded B25/B40/B44, and uses the same clutch (extra plate) and transmission, which obviously becomes the weak link.

Tom

[Rasmussen]

Hi Tom
Ok, now I get it, must have gotten it all wrong when reading your diary. Sorry about that  . Mine has a seal on the driveside of the crank. I know there are a few differences between the WDCO cases and civilian versions, this may be one?. Another funny thing is, all my bearings are metrics, suppose that could be a difference also?
I actually worried more about having grease thrown into the clutchplates, but I do see the potential risc of failure here. Still, it's not that different from what is on the old Albion box on my BSA M21 that runs an open primary, or even my Shovel that runs a belt, and therefore a dry primary. Your suggestion sounds like a brilliant mod, and I'll keep it in mind. Just don't feel I have the time to start over at the moment Will have a look when there's a few miles on it and see if there's any problem
The pictures are just mockups with the old carb in the normal place. I run a suck through setup, so should be fine.
Now you have me scratching my head and wondering how the h... my cases are breathing. Honestly never given it much thought. You believe there could be a horse ot two hidden here by relieving the pressure? Would it do any good to drill and put a hose on the rear valve cap, and let some air out through the pusrod tube?
Are you still considering supercharging yourself?

[Koncretekid]

Your B40 likely breathes thru the camshaft with a "timed breather" hole that allows the crankcase pressure to exit into the timing cover, and then out thru a small hole in the upper timing cover.  I don't know the exact location, but these timed breathers never worked very well, and eventually with the B50 they just decided to let it breath thru the primary case with a breather tube exiting under the rear fender.  Is there a cover on the front of the timing cover for  a tach hookup, like the later ones? You can use this as well and let it breath thru a one-way valve, reed valve is best but a PCV valve will work.  You may need this, as with the blower, you'll probably get more blow-by past the rings than the timed breather can handle - - read lots of oil leaks!  Once again, the B50 forum guys have all the answers for single cylinder BSA's.

As for supercharging, I'm just in the watch-and-see mode because there are a couple of new ones coming on stream (including your friend Bill Anderson, I believe (Nortonist?).  I don't know if a bored out B50 motor, clutch, and tranny can handle that much hp.  In fact, I was considering building a 350 motor based on a set of B50 cases which are better with a 3rd bearing on the crankshaft and bigger studs.  I'll be watching your performance closely.
Tom

[wobblywalrus]

Ivan, thanks for sharing the history of your bike.  There is nothing to be ashamed of by paying tribute to the past.  All of us race in the shadows of those that have gone before.  This is something you really feel when you are on the salt.

[generatorshovel]

Looking GOOD Ivan 
This forum's members have a wealth of information that comes from experience, I know , sometimes this creates a head spin while you try to digest it all, , , ,
I'm still sorting my 250 out, but getting there
 
Tiny