One for 45 Brit

Found by Limey Dave; Norton frame, AJS/Matchless top end, 45 bottom end.





I remember this bike (or its twin) being featured in a copy of the 45 Club's magazine. Unfortunately the print quality was very poor, but I'll try and find it nonetheless.

Looks well put together but I think I'd be inclined to be a bit more imaginative with the exhausts!

[Pa]

Shouldn't be able to get burnt on those exhaust though. Pa

Anyone got details on the barrell to crankcase fit? I.e stud positioning, crankcase mouth opening? I've always wanted to try this after hearing that it can be done.

I'll try and dig that mag out, if necessary I'll transcribe the relevant info as it isn't clear enough to scan.

here's some pics I have collected over the years; the first one shows the cylinder mount detail if you look closely, seems to be a crude arrangement of keys gripping the cylinder base rim. I would guess that the cases are fly-cut so that the Matchless barrel spigots sit within the top of the cases





this one is a variation on the original theme;



this one, I think, is the original bike as shown in the magazine;



and this is a variant with the flathead enmgine in a Norton frame



they were never popular because the Norton frames were in too much demand for Tritons and TriBSAs!

I also remember a sprinter with a Matchless top end in the early 70s but can't find any pictures of it... I have seen at times, references to similar bikes using Ariel top ends. I have heard rumours that they are unreliable, being overstressed and lacking lubrication ( ie having the same sort of problems as Magnum units ).. I don't know how the top end lubrication supply would work, for one thing, maybe off the chain lubricator and back down the pushrod tubes?

this one I have no idea about except that it appears to be an Indian Scout engine fitted with BMW top ends, so it is presumably a 500cc or 600cc unit, fitted into an Indian vertical-twin chassis

of course you could do THIS.. JAP engine in Manx frame, I remember seeing this at Duxford although this actual photo is credited at Podington ( rather than Santa Pod, so that dates it as sometime in the mid-60s )



I would guess that this would be a 1260cc version, probably running on methanol, most big JAPs did.. note the twin points conversion in place of the two magnetos, parts for this are probably from a Royal Enfield? Traditional 'period' 4.00 x 18" Avon Racemaster slick there.... real Alf Hagon stuff... I would guess that the carbs are Amal RNs ( that word again ).. a special 'dope' carb similar to the TT but with the needle in a side chamber to give maximum unrestricted airflow.

Yes i knew there would be a catch concerning the barrel lstud arrangment. Keep these pics coming please.Parts for 350 matchies are common here because everyone converts them to 500's

I don't see why the retaining keys idea wouldn't work, it's just that it would introduce a weak point by stressing the engine at a point where it isn't designed to be stressed. I've seen racing Rudge engines split at this point, cracked through above the barrel flange, and that's an engine which is designed that way.

My feeling would be that you would be best advised to weld up the original bolt holes, weld on a new bolt flange and drill and tap for a bolt circle to match the AMC ones.

at this stage, I would say you were heading for lubrication problems and reading all Dr Dick's posts about fitting Sportster oil pumps.... for what you can get an ironhead Sporty for, I don't see why you want to do all this work. There's nothing technically dificult about cutting the gearbox off a Sporty, after all, it's just a lot of work for no good reason unless you have a Sporty with broken cases to start with

I have an idea that cut-off Sportster has a thread of its own, somewhere. The point I was making is that you can do an engine like that, if that's what you want, cheaper and easier than an ohv 45, and the result will go better and be more reliable.

I'd tend to feel that preserving a historic conversion is good, especially if ( as is lilkely to be the case ) it isnt feasible to restore it to stock anyway; but building a special of that sort at this stage, is mutilation of historic parts for no good reason

I can't see in the cutoff sporty motor where the rear engine plates would bolt up to.I would only attempt something like this with mangled gearbox cases though.

I have an idea that cut-off Sportster has a thread of its own, somewhere. The point I was making is that you can do an engine like that, if that's what you want, cheaper and easier than an ohv 45, and the result will go better and be more reliable.

I'd tend to feel that preserving a historic conversion is good, especially if ( as is lilkely to be the case ) it isnt feasible to restore it to stock anyway; but building a special of that sort at this stage, is mutilation of historic parts for no good reason

I'd agree with all that; given that the Ironhead's acknowledged weakness has always been its transmission this might even be classed as improving on the original!

Agree with Nick's comments about the rear motor mount. I notice that the two examples shown by Patrick don't seem to address this problem.

Regarding top end oiling with Matchy bits one would just run a" T" join in the return line to divert a certain amount to the rocker inlet unions, experimenting with different sized restrictors.Some BSA and Nortons use this system.

so they do... but what about the return flow?

Kev: I notice that the two examples shown by Patrick don't seem to address this problem

It's taken care of. The back of cut down engine is machined for plates, same spacing/alignement as the front ones. Idea is to fit that in a rigid MSS or KSS velo frame if I can find one before I depart these shores!!!

45 Brit: I'd tend to feel that preserving a historic conversion is good, especially if ( as is lilkely to be the case ) it isnt feasible to restore it to stock anyway; but building a special of that sort at this stage, is mutilation of historic parts for no good reason

Well, it's an AMF 71 Sporty, they bashed them by the 10s of 1000s by that era, can't be that rare, so no sacrilege in me eyes!!! Stuff I've done on my KHK is probably worse from an "historic" point of view!!!

Patrick

Kev: I notice that the two examples shown by Patrick don't seem to address this problem

It's taken care of. The back of cut down engine is machined for plates, same spacing/alignement as the front ones. Idea is to fit that in a rigid MSS or KSS velo frame if I can find one before I depart these shores!!!

Velo people are funny old souls, don't let them get the idea that's what it's for. You will probably be tied to a post and flogged with pipestems, beards and Barbour jackets, then locked in a cage held shut with a Velo clutch which you have to get set up to open the door Joking apart, from my experience of 45 engines in British frames I would say you would need a BSA A10 or Ariel frame to have room for the motor, it's the dynamo on the front which causes the problems. The 45-engined A10 chops you occasionally see, usually have 3" or so let into the frame for this reason.

45 Brit: I'd tend to feel that preserving a historic conversion is good, especially if ( as is lilkely to be the case ) it isnt feasible to restore it to stock anyway; but building a special of that sort at this stage, is mutilation of historic parts for no good reason

Well, it's an AMF 71 Sporty, they bashed them by the 10s of 1000s by that era, can't be that rare, so no sacrilege in me eyes!!! Stuff I've done on my KHK is probably worse from an "historic" point of view!!!

Patrick

well, so they did, but how many A10s did BSA make?

45 Brit: then locked in a cage held shut with a Velo clutch which you have to get set up to open the door

No probs then, I have some past experience of Velo Clutch and Holy Pin, plus Titch Allen's book to help me see the light!!! By the way, my specials are usually without lights so gene won't be in the way... And if engine's too tall, I can always fit -SHOCK HORROR- shorter Evo rods!!!

To me, next best thing to H-Ds are Velos, so I won't even entertain talking about BSA A10s or using any of their bits... What a thing of beauty, rigid MSS/KSS/KTT frame...

Patrick

Look at picture no 3 and 5 from top. Notice how the pushrod-angles are different. The top end seem to be rotated to align the angles on one of them.

I suspect that the red one has the front head rotated slightly to make the port angles work, it has 90 bends on both inlets and carbs both sides, which the Norton framed one doesn't.

Patrick - I suppose if you have a mag ignition and no generator, it makes life easier that way. A 45 will go into a BSA M20 frame apart from the generator, I know someone who is trying to solve this particular headache at present. How you would get the transmission lines to work, I can't say, presumably by using a Burman or Albion box?

Hi 45 Brit,

No, the Sportster left crank bearing centre to crank centre distance is only 3.5" and the whole engine is offset to the left in the std frame by about an inch.

If centered in a Velo frame, it shouldn't be far from aligning to the Velo box inboard clutch...

Patrick