BSA B50 -500 APG Build

[Old Scrambler]

Very nice Tom

You accomplished more than I did while on vacation.

I'll be watching from the forum this year...................but have 100% plans for BUB in 2013..........with a few ideas gleaned from you

[Koncretekid]

Thanks for the compliments!  I painted the bike on Sunday and re-assembled yesterday and today.  Had trouble getting it started on account of high compression and old K-Car starter.  Finally, with the help of a new battery, she started. I have tomorrow to get ready.  I leave early Wednesday for Loring, with a stop in Sussex, N.B. for a little Dyno work (timing and jetting).

We had trouble painting a third coat on some of the parts on account of fruit flies.  They started landing in the sticky paint, so we decided the third coat would have to wait.  It's a shame, but maybe I'll get it resprayed in time for BUB.

[wobblywalrus]

It won't be hard to find in the pits.  Good job.  It looks like some serious aero research was done and is applied.

[salt27]

Fruit flies= vortex generators.
Your fairing looks great.
Thanks for doing a diary, it has inspired me to try my hand at a fairing.

   Don

[coloradodave]

Turned out great, I can't wait to hear how fast she goes.

[RidgeRunner]

Slick!

I'm looking forward to checking it out up close this weekend.

Ed

[MattGuzzetta]

Oh my goodness Tom, that really turned out nice!    It is always a ton of work, but a great accomplishment.  Can't wait to hear the numbers....
Just keep up the good work

Matt Guzzetta

[Captthundarr]

How fast was it going when you took the photo....Looks real good.

[Graham in Aus]

Stunning Tom, thanks for sharing your build, looks awesome! 

Not a bad finish for a concreter!   

Best of luck for fast times! 

[Koncretekid]

I just got back from Loring, Maine with Good News and Bad News! The bad news is that the screws behind the outboard bearing plate backed out, grabbed the clutch, stripped all the teeth off the clutch wheel, ripped out all six screws, and spit the primary chain out thru the cases, taking part of the cases with it. I also see that the exhaust valve hit the piston and jammed the follower up into the case where it is now stuck, and blew the end off the exhaust pushrod. I don't yet know if the valve is bent or what is jamming the follower in the up position.

I'm open to suggestions on how best to restore the broken case and stripped screw holes in time for BUB Speed Trials. 

I had ignition gremlins during the first four runs, and some handling problems at 125 mph on run number 3 (weaving).  Run number four went as planned with the tach showing 8500 RPM's at the timing lights.  We got greedy and put on a smaller rear sprocket for the fatal run # 5.  My head temperature gauge and oil pressure gauge lasted one day, and my air/fuel ratio gauge never started working this year so I don't have anything to report on the cooling system except I don't appear to have overheated the motor (head off, no unusual discoloration but I see the exhaust valve hit the piston on over rev, probably when the primary chain went bang at 8000 RPM's and full throttle.  I'm probably lucky to have anything left after that.

The good news is that the crank still turns, the piston still goes up and down, and we went 136.7 mph.  So now I am almost as fast as a CanAm 125!

Tom

[Peter Jack]

Welding and Heli-Coils should fix the cases. I hope you're able to repair or replace the rest of the parts quickly.

Good luck!!!!

Pete

[Old Scrambler]

Not only does it look fast.............IT IS FAST

Too bad about the cases.............Maybe fill and re-tap for added strength..........think about running a much lighter chain on single-sprockets to reduce mass.............consider a chain-tensioner/idler on the slack-side when under power..............lots of teflon lube between runs may be sufficient so no oil drag and minor need to have an oil-tight case & cover.

Six weeks is a long time when your having too much fun

[Koncretekid]

Welding and Heli-Coils should fix the cases. I hope you're able to repair or replace the rest of the parts quickly.

Good luck!!!!

Pete

Peter,
Cases were originally made to support a rubber seal only and are thin, maybe 4mm, so helicoils have not proven to be very substantial, especially because we now use an outboard bearing which theoretically is lined up with a perfectly straight mainshaft and two other bearings.  I believe there are stronger inserts than helicoils but I can't remember the name.  I might also add six more.  To weld in a new back half case, which I have, will it be sufficient to weld from outside only?  I can't get to inside without splitting the cases.

Not only does it look fast.............IT IS FAST

Too bad about the cases.............Maybe fill and re-tap for added strength..........think about running a much lighter chain on single-sprockets to reduce mass.............consider a chain-tensioner/idler on the slack-side when under power..............lots of teflon lube between runs may be sufficient so no oil drag and minor need to have an oil-tight case & cover.

Six weeks is a long time when your having too much fun

Yes, six weeks should be sufficient, except it takes me the better part of a week to get there, and then there are the relatives, and the wife, and the honey-do list, etc.

Single chain on lighter sprockets?  I have already snapped two duplex chains with the torque of this motor.  I've heard that belt drives don't hold up either with a big thumper.  The main reason for this failure was the screws behind the clutch which backed out (in spite of red loctite being applied only an hour earlier - - maybe not enough time for the loctite to harden up?) and grabbed the clutch wheel.  All six of them were pulled right out of the case. And no chain tensioner is required, as the new duplex chains are a precision fit, almost banjo tight. As for no oil, don't forget the 25 tiny roller bearings on which the clutch rides.  They will flat spot without oil.

And yes, I'm pretty happy with the speed increase with the fairing, although in all fairness, there was a tailwind.  Bonneville will be the real test.

Tom 

[saltwheels262]

Keenserts are solid threaded inserts.( internal and external threads ).
after being installed they are locked into the material
with on board "pins".
the jergens company might be the manufacturer.

bill

what was the increase in mile an hour with the fairing ?

[DND]

Hi Tom

What type of screws do you use now?  Have you thought about flat head allans as they hold pretty good with the area of the countersink.

And maybe use 10 or 12 in your cover and drill & tap it in a mill if you can so they all line up perfect, then with some thread locker it should be good to go.

Don