B50 MX for Bonneville

Here you can publish Your projects bikes.
Only BSA singles

Moderator: minetymenace

User avatar
koncretekid
>620
>620
Posts: 629
Joined: Sun Nov 20, 2005 1:22 am
Location: Yarmouth, Nova Scotia
Flag: Canada

Re: B50 MX for Bonneville

Postby koncretekid » Mon Feb 13, 2017 12:52 pm

hwan wrote:tom - do you reckon that the ERC 110K was what Andy was using ?
:


Yes, ERC 110K. As for the free advice, it's what I like about land speed racing. With no prizes other than a certificate, everyone is there to help if they can.

Tom
life's uncertain - go fast now

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Mon Feb 13, 2017 6:50 pm

:grin:

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Feb 16, 2017 8:05 am

keeping the faith.
Attachments
018.JPG
014.JPG

stew79
>340
>340
Posts: 343
Joined: Tue Nov 05, 2013 10:26 pm
Location: norfolk
Flag: Great Britain

Re: B50 MX for Bonneville

Postby stew79 » Thu Feb 16, 2017 3:44 pm

hi andy looking lower and meaner ! ..........but whats that i see hanging up on the floor in the last pic ? the bing or delorto carb ? (must have been before it got cleaned up) i think they can work very well on a big single, as on the older husky 510,s, but the needles and jets etc must be spot on. how about putting together a 36 or 38 vm mikuni to keep as a spare carb, to perhaps swap over when it goes on the dyno ? (not much expense for a good second hand one ? and the needles, jets etc are very easy to get and work with)
stew

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Feb 16, 2017 4:24 pm

It is a 36mm Delorto and that's it after cleaning, i had just removed it from the box this morning to show brother John how much cleaner it wasn't :shock:
Don't forget it all about wide open throttle and the bike carburates and accelerates very cleanly in both the UK and the states. We expected problems getting of the line with the C/R box and high first gear but it turned out to be a pleasure with Marks clutch and touch of feathering.

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Feb 16, 2017 4:35 pm

How does the Delorto and Mikuni compare on size? as there is no room between the top frame tube and the top of the carb.

stew79
>340
>340
Posts: 343
Joined: Tue Nov 05, 2013 10:26 pm
Location: norfolk
Flag: Great Britain

Re: B50 MX for Bonneville

Postby stew79 » Thu Feb 16, 2017 5:34 pm

measuring from the top down to the spigot (engine side of a 38mm) its 48mm
stew

User avatar
minetymenace
Gerry1
Gerry1
Posts: 6651
Joined: Wed May 26, 2004 1:00 am
Location: Between Reading and Newbury, England
Flag: England
Contact:

Re: B50 MX for Bonneville

Postby minetymenace » Thu Feb 16, 2017 5:38 pm

Give Wal Phillips a call <096
Abyssinian Wire-Haired Tripehounds Gnash.

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Feb 16, 2017 6:26 pm

Gerry no fuel injection allowed so yes wal phillips would prob be ok <201

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Feb 16, 2017 6:48 pm

stew79 wrote:measuring from the top down to the spigot (engine side of a 38mm) its 48mm
stew

From the top of our Delorto down its 44mm but i have modded the plastic top and cable entry boss then fitted a tighter bend entry pipe secured from inside.I also pushed the carb as far forward as possible to gain clearance for the carb top, It would have been easier to put a scallop in the underside of the top frame tube but that is the part of the frame that the rules state cannot be altered in the modified class.I also removed the gusset from the same area but the rules state bracket can be removed
It was used to hold the side panels :roll:

beat
>1400
>1400
Posts: 5014
Joined: Sun Jun 04, 2006 5:33 pm
Location: Switzerland
Flag: Switzerland

Re: B50 MX for Bonneville

Postby beat » Thu Feb 16, 2017 8:14 pm

minetymenace wrote:Give Wal Phillips a call
Andy Chaos wrote:Gerry no fuel injection allowed so yes wal phillips would prob be ok


forget this very quickly please!
what you need is a excellent combustion, means a perfect atomizing of the fuel drops, - wich will never reached wit the Wal Phillips.

IMO, the flat slide from Keihin ore Mikuni is by far a better choice, - but not a easy go to set it up finely..... <201

beat <212

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Feb 16, 2017 9:32 pm

Worry not Beat
wal phillips <202 <202 <202 <202

User avatar
minetymenace
Gerry1
Gerry1
Posts: 6651
Joined: Wed May 26, 2004 1:00 am
Location: Between Reading and Newbury, England
Flag: England
Contact:

Re: B50 MX for Bonneville

Postby minetymenace » Thu Feb 16, 2017 9:43 pm

One day you will see the light, lots of fuel, lots of air, mixture only needs to be right at flat out throttle settings :ban
Abyssinian Wire-Haired Tripehounds Gnash.

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Fri Feb 17, 2017 10:51 am

Andy if you want a Mikuni to measure, don't forget i have 34-38mm VM's on the shelf....

Does anyone seriously think a Wal-Phillips 'injector' is any damn good other than as a door stop - really?
They were crap when they first came out, they were crap in the 70's when i tried them, they were crap on Rolands Vincent outfit on methanol in the 80's, same again on his Greenwood Vincent 3 wheeler (couldn't fit anything else) in the 90/00's and are still crap at Elvington last year as i watched some poor shumck struggle all day with one.......

I guess you could always use a fuel tap and a main jet, inline, and feed direct to the inlet port - but then again, it would be more sophisticated (with actual fuel metering) than the Wal-Phillips ..................................

Rant over :grin:

beat
>1400
>1400
Posts: 5014
Joined: Sun Jun 04, 2006 5:33 pm
Location: Switzerland
Flag: Switzerland

Re: B50 MX for Bonneville

Postby beat » Fri Feb 17, 2017 5:48 pm

hwan wrote: Wal-Phillips 'injector' is any damn good other than as a door stop


hi hwan

nothing wrong with the Wal Phillips !

as long as it is used as a boat anchor - why not :?:
DSCN1911.jpg
a tripple mess....


beat :lol:

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Fri Feb 17, 2017 7:37 pm

Cheers for the offer Whan but no intentions of changing from the dellorto.
It certainly works well on the CCM and have never twiddled a screw or even seen the main jet :thumb

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Fri Feb 17, 2017 8:20 pm

Not suggesting you move away from what works Andy - just though you were wanting measurements or something?

As for only need to work at full throttle - BOLLOX !

As Andy and anyone who as raced a bike knows - it needs to be able to pull up onto the cam (or pipe on a two-stroke) - n
When we raced Yam's, everyone thought we were running special cylinders or something and were very disappointed when they saw the porting ..... nothing special.
What they didn't appreciate, was the hours spent sorting the carburation and exhaust - that's why it pulled like a MX'er out of a hairpin, with Andy sat on the tank to stop it wheelying, while everyone else were slipping the clutch like an idiot, waiting/looking for the power ....................

Even in them days, Andy wasn't a racing snake - and we were officially the second heaviest side-car racer's on the circuits..........


Beat - we agree on something at last :thumb

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Wed Feb 22, 2017 9:59 pm

Had a day to myself today so set about making these.They will have to fly out with the bike so trying to keep them as small and as light as possible.
Attachments
20170222_171206_resized (1).jpg

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Sat Mar 11, 2017 9:31 pm

Had a day on the Bonneville bike today, engine back in, interspan rewired timed up and sparking.
Gauges remounted where i can see them with new lower riding position.
Almost ready to test the roller starter on road tyres and annoy the neighbors tomorrow :thumb
Attachments
20170311_200533_resized.jpg
20170311_200513_resized.jpg

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Sun Mar 12, 2017 4:27 pm

All back up and running and sounding sweet.
The repositioned AFR fluctuates between 11 and 13
Rev counter rock steady and giving an accurate reading, god only knows what it was reving to before we went out last year :shock:
Next job is to design a faired front mudguard that fits within the rules and back to the dyno :thumb
Attachments
029.JPG
028.JPG
The shiny part of the exhaust is the old location of the Lamda sensor.
027.JPG
The seat height is slightly lower than the top of the motor

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Sun Mar 12, 2017 7:09 pm

looking good andy :grin:

User avatar
Mark Cook
>1400
>1400
Posts: 4752
Joined: Fri Sep 10, 2004 8:45 pm
Location: CCM Britain HQ Goldthorpe South Yorkshire
Flag: England
Contact:

Re: B50 MX for Bonneville

Postby Mark Cook » Sun Mar 12, 2017 8:03 pm

You have a job to tell it was A-salt-ed <216

Hope your going to fit that missing sprocket bolt Andy :?:
CCM Britain motorcycles and spares manufactured exclusively by PES

+44 (0) 1709 894192
http://www.ccm-britain.co.uk (online shopping experiance)

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Sun Mar 12, 2017 9:43 pm

Mark Cook wrote:You have a job to tell it was A-salt-ed <216

Hope your going to fit that missing sprocket bolt Andy :?:

Well spotted Mark, The reason its missing is i just bought a new nut gun and thought i would test it on the rear sprocket bolts. worked great until the nut fell off inside :???:. Loads to do but off to hospital tomorrow although hoping to get a couple of days off to work on the bike and maybe the Dyno this weekend.
Mark I will pop in this week sometime to buy a new chain, you would never talk to me again if i fitted the rusty a-salted old one

User avatar
Mark Cook
>1400
>1400
Posts: 4752
Joined: Fri Sep 10, 2004 8:45 pm
Location: CCM Britain HQ Goldthorpe South Yorkshire
Flag: England
Contact:

Re: B50 MX for Bonneville

Postby Mark Cook » Sun Mar 12, 2017 11:10 pm

Enjoy hospital Andy, I'm sure your not their first. I like to use a 3/8 drive rattle gun as it makes me less dangerous. :mrgreen:
CCM Britain motorcycles and spares manufactured exclusively by PES

+44 (0) 1709 894192
http://www.ccm-britain.co.uk (online shopping experiance)

mlb50
>160
>160
Posts: 161
Joined: Wed Jun 25, 2014 4:25 am
Location: Perth, West Australia
Flag: Australia

Re: B50 MX for Bonneville

Postby mlb50 » Sun Mar 19, 2017 1:29 am

Hi Andy,

Love the project. One query - are you running with just the stock primary case breather? I can't see another. If only the one, I'd suggest tapping a BSP barb into the tacho cover plate with a hose to vent excess crankcase pressure. I can't say that would increase speed but it will reduce piston effort somewhat.

Cheers, Mick
B50 @ 10:1 - what's a leg between friends?

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Sun Mar 19, 2017 2:36 pm

Yes Mark [Edit by mm: that's Mick Andy, not Mark] that is the only breather at the moment put plenty of options to fit others if necessary.
While it was flat out on the Dyno i placed my hand over the end of the breather pipe and was surprised how little movement there was. On the other hand Stan has been at this years and always goes as big or as ugly as you can stand it. We should have been back on the dyno yesterday but i have not been able to put weight on one leg since an opp on monday, all being well next week should start to show some progress.

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Sun Mar 19, 2017 8:03 pm

MLB50 - like this i presume....

The one way valve is a £8 brake vacuum jobbie with an 8mm bore - slightly smaller ones are available in many Car Shops in uk.
Attachments
WP_20170319_18_55_15_Pro.jpg
WP_20170319_18_55_08_Pro.jpg

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Mon Mar 20, 2017 11:13 am

Andy Chaos wrote:Yes Mark [Edit by mm: that's Mick Andy, not Mark]


Thanks for that Gerry but you would get into bother in a school correcting work in red you should use a green pen as red is supposed to be to aggressive.
I couldn't get my breath when i was told. :shock: :cry:

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Mon Mar 20, 2017 11:35 am

Ah yes SCHOOL and red pens - that was such a good idea when i went teaching ................... :shock:

Seems the hot idea now are ....... technical colleges and a re-hashed OND/HND/ONC/HNC quatification ??

Marks baffled by his apprentice on some sort of Engineering qualification - he cannot do any (and i mean any) maths either, reminds me of trying to teach volumes and area's to a bunch of 'high level' (!!!) students - never got onto easy algebra :???:


I/m sorry Andy taking work ............ you keep you leg up for a couple of weeks, i'll bring you a bunch of flower and some grapes :grin:

mlb50
>160
>160
Posts: 161
Joined: Wed Jun 25, 2014 4:25 am
Location: Perth, West Australia
Flag: Australia

Re: B50 MX for Bonneville

Postby mlb50 » Tue Mar 21, 2017 2:31 am

Hi Andy and Hwan,

The standard primary breather pressure pulses can be felt by hand at idle, but due to the frequency of reverse pressure, it appears undetectable, more so as revs increase. What we are trying to address is reducing resistance in the crankcase to piston motion, as the engine is in effect, an air pump. Phil Irving cites - "put as big a hole as you can in to the cases without compromising structural integrity" Mr Irving was an expert in his time on single and twin cylinder racing motorcycles, and whilst modern technologies have superseded some of his ideas, his general opinions on 4 stroke design is sound and relevant to the generation of the B50. HPStan is onto this too.

The idea of a non return valve is good, as it induces negative pressure on the upstroke - if you want to prevent oil leaks from gaskets, and has some theoretical efficiency in multi-cylinder performance engines, i.e. NASCAR. But for a single piston engine, the balance of suction on the underside of the piston and ambient pressure above has some doubt of net benefit.

The B50 timing crankcase has 2 well sized and positioned holes for venting gas pressure. I'd suggest these are actually better than the opposite ones on the primary with or without the "insect" screens.

To advantage the expulsion of gases, the vacant tacho drive is perfectly located. In my fitment, I made a simple ally 6mm plate into the base for I think, a 3/16th BSP right angle barb fitting - but pointed upward as I can't see how putting it downwards would prevent oil fluid from wanting to escape. The breather hose goes up to the fuel tank base and bends back to run under the seat base and exit to atmosphere.
Its an easy job to fit, even more so if you use the standard tacho cover plate.

I've tried to attach some photos but the interweb here in China is not cooperating.

Cheers, Mick
B50 @ 10:1 - what's a leg between friends?

mlb50
>160
>160
Posts: 161
Joined: Wed Jun 25, 2014 4:25 am
Location: Perth, West Australia
Flag: Australia

Re: B50 MX for Bonneville

Postby mlb50 » Tue Mar 21, 2017 2:35 am

Im trying to get the photos uploaded, hope it works.

B50 timing breather.PNG
B50 @ 10:1 - what's a leg between friends?

User avatar
Mark Cook
>1400
>1400
Posts: 4752
Joined: Fri Sep 10, 2004 8:45 pm
Location: CCM Britain HQ Goldthorpe South Yorkshire
Flag: England
Contact:

Re: B50 MX for Bonneville

Postby Mark Cook » Tue Mar 21, 2017 9:39 am

37 years of experience obviously counts for nothing, best send the airline ticket Andy. I don't have a clue.
CCM Britain motorcycles and spares manufactured exclusively by PES

+44 (0) 1709 894192
http://www.ccm-britain.co.uk (online shopping experiance)

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Tue Mar 21, 2017 10:18 am

Mark Cook wrote:37 years of experience obviously counts for nothing, best send the airline ticket Andy. I don't have a clue.

As i replied Mark plenty of options if necessary?? and i don't think it is necessary.
But i do welcome input from everyone.
On another note this is the first day i have managed to put 2 socks on. :thumb

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Wed Mar 22, 2017 11:10 am

The only reason i've fitted the secondary breather is that i have discovered that if the screw holding the Wassel ignition sensors (or the Cam in a points system) is too long, it blanks off the OEM timed breather.

Currently i'm experimenting leaving this screw out, so it vents directly into the area used by the points and back-plate.

i'm trying to find out where last years smokey exhaust came from and seeing if i have excessive blow-by was the first thing to check, also any excessive oil in the crank-case should get thrown/blown out of the breather.

I also had the PCV spare from another project .................

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Wed Apr 12, 2017 10:36 am

Do we have any experts on air box design on the forum.
Just in the process of adapting an old 75 CCM one to fit. Sealed up the 2 side openings to prevent air rushing passed creating low pressure, but not sure weather to run an open top or make a lid with a scoop and try to create some pressure at speed. Plan so far is to run without a top and maybe try a scoop on the salt either way the motor should now get cooler air rather than straight off the motor.
Andy

User avatar
Mark Cook
>1400
>1400
Posts: 4752
Joined: Fri Sep 10, 2004 8:45 pm
Location: CCM Britain HQ Goldthorpe South Yorkshire
Flag: England
Contact:

Re: B50 MX for Bonneville

Postby Mark Cook » Wed Apr 12, 2017 11:06 am

Where's that head Andy, one change at a time remember
CCM Britain motorcycles and spares manufactured exclusively by PES

+44 (0) 1709 894192
http://www.ccm-britain.co.uk (online shopping experiance)

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Wed Apr 12, 2017 11:14 am

Will be off today Mark but needed the position of the carb to start on the air box will also allow me to run a much larger CCM filter :thumb
I can easily go back to the original filter and strap the interspan to a frame tube for a dyno run.

hwan
>620
>620
Posts: 626
Joined: Tue Feb 11, 2014 7:53 pm
Location: Doncaster, UK
Flag: Great Britain

Re: B50 MX for Bonneville

Postby hwan » Wed Apr 12, 2017 11:52 am

I don't know, he tries to do something about the state of the head after last year and you whittle at him - one thing at a time ........ :grin:

Re - idea about easy access to cam - just realized its not so easy for the B25/50 due to oil end feed, i was looking at the C15 t/s main brg feed arrangement.
May pursue it for the C15 as it could help learn something about cam's for 250's ?

User avatar
koncretekid
>620
>620
Posts: 629
Joined: Sun Nov 20, 2005 1:22 am
Location: Yarmouth, Nova Scotia
Flag: Canada

Re: B50 MX for Bonneville

Postby koncretekid » Thu Apr 13, 2017 3:59 am

Andy,
I tried making an airbox, about 5 times the size of the motor (2.5 ltres) with two 2" aluminum tubes running forward with entrances either side of the front fender. The first photo shows the airbox under construction. I used 2" aluminum on both sides, which reduced to 1-1/4" at the front so that the air would slow down before entering the box and develop more pressure (Bernouli's principle). I also connected a 1/4" fuel line to the gas tank which was theoretically sealed, so that the fuel would see the same pressure as the airbox. It didn't work. When I got to maybe 60 mph, the mixture went excessively lean and I had to shut down. I'm thinking the increase in pressure blew the fuel out of the bowl.

I have read that some people can make it work, but I think the air intake has to be well forward of the bike to intake clean air. I've read you don't get any benefit until you get to 100+ mph, and then it's something like 0.5 psi or 1 psi; can't remember.

Image

Image

Tom
life's uncertain - go fast now

Andy Chaos
>580
>580
Posts: 585
Joined: Fri Nov 24, 2006 11:33 pm
Location: Yorkshire
Flag: England

Re: B50 MX for Bonneville

Postby Andy Chaos » Thu Apr 13, 2017 10:10 am

Cheers Tom
The main reason for the air box was to stop the carb from taking hot air from directly behind the motor. I started to read up about resonant design air box's but from what i can make of it, its no concern with a single (good job as my brain was going to explode with the maths ).The top of the air box has a 8"x 4" opening which fits between my legs, so i make a sort of scoop with my body in the riding position but not enough to pressurise it. I may still make a lid with an intake scoop to try on the salt if all else fails.
As Mark say though one step at a time.


Return to “Project bikes”

Who is online

Users browsing this forum: No registered users and 4 guests