B65 Mongrel

beat · Post by **beat** » Thu Sep 30, 2021 8:29 pm

Well, - what the balance pipe SHOULD BE FOR - I guess I got it in theory , yes.

BUT - what IT IS FOR it seams to me is still unknown

IMO, - if it should help, it needs a surtain angle in the connection banjo to reach a injector effect AND it should be in accordance to the mufflers resistance for the gases of each cylinder.
but what do I know........

beat

beat · Post by **beat** » Thu Sep 30, 2021 8:33 pm

B44Claus wrote: ↑Thu Sep 30, 2021 8:26 pm The A65 engine is ugly? No way!

s.s.s.s.sorry, - but I prefere the look of a Bantam

unknown

B44Claus · Post by **B44Claus** » Thu Sep 30, 2021 8:54 pm

Hi Beat,

The balance pipe was introduced to make the British parallel twins quieter without sacrificing power. By connecting the header pipes each cylinder can make use of the combined full volume of the whole exhaust system. Each silencer could be more restrictive but since both sides were connected to each cylinder the back pressure wasn't increased and power not affected.
It's not theoretical but works in real life. A friend of mine installed 1972 A65 silencers to his 1967 A65 and it ran like crap, it wouldn't rev out and was down on top end power. Fitting header pipes with a balancing pipe from a later A65 brought the power back(at least most of it).
Not all the BSA A65's had balance pipes in front of the cylinder head, if you look at the pictures I just posted the balance pipe is just in front of the silencers. Which is another reason why I like the high pipes better

I don't think there is much ejector effect from the balance pipe as it's perpendicular to the gas stream.

Regards,
Claus

B44Claus · Post by **B44Claus** » Thu Sep 30, 2021 9:05 pm

s.s.s.s.sorry, - but I prefere the look of a Bantam

: Bantam.jpg (11.78 KiB) Viewed 6798 times

So do I Beat

Regards,
Claus

beat · Post by **beat** » Fri Oct 01, 2021 8:07 pm

SteveS · Post by **SteveS** » Thu Oct 07, 2021 5:00 pm

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I've spent a bit of time cutting up bits of stainless tube and then getting my friendly welder to stitch them back together to form a couple of exhausts. The silencers are cheap Chinese ones off ebay. Not had a chance to run the engine with the system in place so not sure how good the silencers will be at limiting the exhaust noise.............
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: OS

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: NS

Also need to give some thought on the workings of the brake pedal as the left exhaust now runs through the intended mounting position

beat · Post by **beat** » Thu Oct 07, 2021 8:10 pm

a exhaust like a ALPHORN

( not sure this ugly engine has such a lovely sound ..... )

beat

Sundodger · Post by **Sundodger** » Fri Oct 08, 2021 12:36 am

I'm looking at the pictures and thinking that if the Mongrel was left out in the rain for long enough the exhaust system would fill up and potentially hydraulically lock the cylinder

At best you could heat up enough water to make a brew

Post by **minetymenace** » Fri Oct 08, 2021 12:15 pm

SteveS, you been on the mushies again? Prefer the Vetter style, but it should sound nice with those things.....

baz · Post by **baz** » Fri Oct 15, 2021 2:37 pm

Very cool project

SteveS · Post by **SteveS** » Fri Dec 10, 2021 2:17 pm

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Thanks for the positive comments lads

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I've been trying to source a fuel tank and a seat unit for the bike. Wanted a flat track style seat so will probably go with this one:
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: Flat Track- Street Tracker Universal 384337735639

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Managed to get hold of a large tank which looks like it is past economic repair so i won't feel too bad when I cut it up to suit the frame. It will need a cut out at the front to miss the frame oil filler location but apart from that it should fit with a squeeze:
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: Tank 1

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: Tank 1 - base, well rotted

beat · Post by **beat** » Fri Dec 10, 2021 8:48 pm

Hmmmmm

this tank seams to need a cut to see inside what mouses are nesting in there...

good luck

SteveS · Post by **SteveS** » Mon Dec 13, 2021 9:02 am

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Hi Beat, no mice, but plenty of holes............
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I cut out the bottom of the tank as it was completely riddled with pin holes and paper thin in certain areas. I'll check the rest of the tank for other damage and then get it carefully blast cleaned inside and out. I then need some 1.0mm mild steel to form a new tunnel and base
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: Base removed from tank

beat · Post by **beat** » Mon Dec 13, 2021 7:32 pm

you ar on a good way

SteveS · Post by **SteveS** » Thu Dec 16, 2021 5:04 pm

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Made some good progress with knocking out a few dents and cutting the replacements sections to be welded in place
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: Ready for welding

beat · Post by **beat** » Thu Dec 16, 2021 7:44 pm

how was the uper part looking at the inside ?
any pics

beat

SteveS · Post by **SteveS** » Fri Dec 17, 2021 8:20 am

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Hi Beat
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The upper part of the tank was ok, although the filler cap neck was beyond repair so was replaced
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: Inside tank

beat · Post by **beat** » Fri Dec 17, 2021 8:59 pm

thanks !

SteveS · Post by **SteveS** » Fri Dec 24, 2021 8:35 am

The welding and pressure testing for leaks has been completed on the tank.

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Tank, seat unit and side panels are now in primer ready for colour finishing. Unfortunately my workshop is not heated so I will have to wait a few months for warmer weather before I carry out the spray finish. I plan to try to create the Candy Apple Red finish similar to that used by Basil with his project
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: Ready for painting

B44Claus · Post by **B44Claus** » Sun Dec 26, 2021 11:13 am

Well done Steve! How does it look on the bike? Surely you have tried it

Are you intending to fit the panels/covers to the sides of the tank?

Merry Christmas to all unit singles fans from Denmark

Claus

SteveS · Post by **SteveS** » Sun Dec 26, 2021 11:23 am

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Hi Claus
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Yes, tried them on the bike, seem to fit ok; however the tank is not sitting quite right so may have to modify the tank rubbers and also the fork stops as the forks get very close to the tank

. I didn't get any pics as the bike is in separate storage with no proper lighting. If I can justify the price to myself I will be fitting the proper BSA panels to the tank sides. If the price is too much I will have to think of something else(?)
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SteveS · Post by **SteveS** » Sat Feb 19, 2022 11:13 am

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I've got no further with the painting of the tank etc. because of the current low temperatures so I've turned my attention to the lighting. I know it's not to everyone's taste but I like the style of the Flat Track number board on the front. I may change my mind once it has been fully installed, not sure yet.......
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First step, cut apertures in the steel with a normal hole cutter, neater than cutting by hand
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: Apertures cut with holesaw

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Step two, bent the bracket to shape to fit between the fork yokes (triple trees) and mounted the lamps onto the bracket
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: Bracket bent to shape and lamps fixed in position

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Step 3, mounted the bracket onto the fork yokes
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: Lamp bracket mounted to forks

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Step 4, temporarily mount the housing
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: Mock up of lamp housing

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I'm thinking of putting a decal on the number board in the space left, but not sure what to choose?

Ian Hingley · Post by **Ian Hingley** » Sat Feb 19, 2022 12:19 pm

Well, keeping up the flat track theme:

Wouldn't be my choice of course...

Ian

SteveS · Post by **SteveS** » Sat Feb 19, 2022 4:03 pm

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Hi Ian
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Nice idea, I'll give it some thought
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: BSA 1 Decal; BSA '1' decal.png (72.2 KiB) Viewed 4483 times

Ian Hingley · Post by **Ian Hingley** » Sun Feb 20, 2022 10:07 pm

That's more like it!

Ian

Post by **minetymenace** » Mon Feb 21, 2022 8:14 pm

Before you go printing that thing, please note that the Union Flag is the wrong way up! Which means you are in distress, well that's as maybe, but being British and all that (or representing a British motorcycle), probably best get it right.

See here.

GlenAnderson · Post by **GlenAnderson** » Mon Feb 21, 2022 11:48 pm

Nice to see the work on the tank.

My T25SS is missing its tank and I’ve had my eyes peeled for one for the last few months without any luck. I’m considering getting a T120 tank and modifying it to fit, as I prefer the more curvaceous/traditional shape. It’s helpful to see what other people do.

SteveS · Post by **SteveS** » Wed Feb 23, 2022 9:43 am

Thanks for the comments everyone.

Gerry, I thought something looked strange about that Union Jack decal, well spotted with it being upside down

I will drop a note to the supplier - Zen Graphics

SteveS · Post by **SteveS** » Wed Mar 23, 2022 2:47 pm

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: OS

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: NS

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beat · Post by **beat** » Wed Mar 23, 2022 8:49 pm

the ugliest engine in a very nice framework

GlenAnderson · Post by **GlenAnderson** » Wed Mar 23, 2022 9:41 pm

Really coming together nicely. So many custom machines look out of proportion, but this is spot on.

I’m mulling over the potential for a T100C engine in mine…

B44Claus · Post by **B44Claus** » Fri Mar 25, 2022 8:32 pm

Hi Steve,

The

bike looks great! Good you skipped the alp horn exhausts

the new high level header pipes are way better and suits the handsome A65 power plant well

Regards,
Claus

SteveS · Post by **SteveS** » Wed May 11, 2022 7:04 am

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With the arrival of some warm and dry weather I have made a start at the spray finishing of the tank, side panels and seat unit. As mentioned previously I decided to go for the Candy Apple Red paint scheme consisting of a metallic base coat followed by translucent colouring coats which are built up in layers until you achieve the shade you are after. For ease all paint products were supplied in rattle cans, sourced on-line.

After cutting back the primer with 800 wet n dry I applied the Coarse Silver Base Coat which gives the paint its sparkle. The 400ml can just gave me enough for 3 coats on the 4 parts to be finished. Each coat was allowed to 'mat' off before applying the next.
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: Coarse Silver base Coat

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I left the base coat to harden off for a couple of hours and then proceeded with the Candy Apple Red. I ended up applying 6 coats at 15 minute intervals; this allowed each coat to 'mat' off before applying the next coat. The 3no. 400ml cans were just enough to complete the 6 coats. I was aiming for the darker colour used on the BSA MK2 R3 as opposed to the lighter colour (fewer coats) used on the B50 etc.
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: Candy Apple Red, 1 to 6 coats

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The Candy Apple red paint was left to harden off for about 3 hours. During that time I prepared the transfers I wanted to use on the seat unit and side panels. The '3 guns' is a waterslide decal, almost 8" (200mm) long, used on the old BSA Sidecars. The side panel vinyl transfer was made up from a Lightning 650 transfer (with 'Lightning' cut off) and some lettering I had made up in 'Impact' font which is close to what was used on the B50/B25 to spell out 'Victor'. The transfers / decals were then applied to the parts.
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: Decals in position

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The above picture indicates how tricky it is to rely on photographic evidence to colour match

All 3 parts are identical in colour and shade, photographed at the same time, yet two parts look red the other purple.

The sprayed parts were then left overnight ready for the lacquer to be applied in the morning. I used a 2 part lacquer, starting with a couple of mist coats at 30 minute intervals over the transfers to try and stabilise them, followed by a heavier coat. Looking at the finish I may have to apply another couple of coats of lacquer as I missed a few spots which is down to my deteriorating eyesight and inadequate lighting.

but overall the result is ok

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: Finished (?) tank

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GlenAnderson · Post by **GlenAnderson** » Thu May 12, 2022 2:43 pm

Lovely colour.

People get very sniffy/dismissive about rattle-cans, but in my personal experience, if you put the prep in, the results can be just as good as spraying with a gun, without the waste. Particularly for small bits.

beat · Post by **beat** » Thu May 12, 2022 8:41 pm

SteveS wrote: ↑Wed May 11, 2022 7:04 am but overall the result is ok

SteveS · Post by **SteveS** » Sat May 28, 2022 10:08 am

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Managed to get hold of the side panels etc. for the tank. Took a lot of fettling to get them to fit, the joys of pattern parts I guess

Also found a dent in the tank that I'd not noticed before which pi**ed me off no end

. Painted parts now test fitted

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: O/S

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: N/S

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I'm having second thoughts about the headlight

and may opt for a more conventional type? Also working on a heatshield for the exhaust on the left side. I could fit the A65 Firebird 'toast rack' (pics provided by B44Claus earlier in this thread) which I'm not a fan of or I may go something more reminiscent of the shield used on the B50/B25 lozenge silencer?
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: B50 heatshield

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Loads of detail work still to do but at least some progress is being made

Ian Hingley · Post by **Ian Hingley** » Sat May 28, 2022 1:46 pm

SteveS wrote: ↑Sat May 28, 2022 10:08 am I'm having second thoughts about the headlight and may opt for a more conventional type? Also working on a heatshield for the exhaust on the left side. I could fit the A65 Firebird 'toast rack' (pics provided by B44Claus earlier in this thread) which I'm not a fan of or I may go something more reminiscent of the shield used on the B50/B25 lozenge silencer?

I reckon something lozenge based would be a great idea

Ian

GlenAnderson · Post by **GlenAnderson** » Sun May 29, 2022 9:08 am

Really looking smart.

I think I’d go for a conventional round headlight too; but it’s your bike.

B44Claus · Post by **B44Claus** » Mon May 30, 2022 11:05 am

Hi Steve,

I like your idea of a heat shield inspired by the B50's.

How about an exhaust heat shield that resemble something like this:

I know it's a 2 into 1 but it might give you an idea of what it could look like.

I tend to agree with Glen on the headlight, - but I'm a traditionalist.

Keep up the good work

Regards,
Claus

SteveS · Post by **SteveS** » Mon May 30, 2022 4:57 pm

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Hi Claus
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I've had a first go at making the heatshield in aluminium. It's a fairly complex shape as it tapers along its length as well as bending twice in the opposing plane. I think I need to hit it a few more with a BFH times until I am happy with the shape, I will then have another attempt at marking out the holes, or I could use a ready made alternative?
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: 1st attempt in aluminium

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: Emmentaler Cheese