Matchless Engine

[jon v8]

Ten to eight ?

No,the year... I think I'm a victim of being born too late,apart from the internet and modern medicine there is little I like about the 21st century.

[aawil]

i have been using lucas sr1 mags on all of my competition bikes mostly panthers all start 1st kick hot or cold, matchless used them as std before 1965 so problem solved. will.

[rusty ken]

Hi Folks,

Thanks for your comments on the engine idea.

I had no plans to build a short stroke engine, despite the positive comments from Don Morley. But I am interested in an early bottom end, with the lighter road flywheels, paired into an alfin barrel with an alloy head. The only remaining issues are which rod to use; the long early rod or the shorter later rod, and what bore to use.

Seems that the easiest answer is to use the long rod with a BSA piston? So its good to hear that in principal it works ok.

For sparks I`m using a refurbished lucas wader, but am seriously considering a new digital BTH, even if they are a bit pricey.

[laird387]

Hi rusty ken,

An interesting glimpse into history for you! Known as the 'Maestro' of Plonk, the legendary Competition Manager of AJS/Matchless, Hugh Viney, ALWAYS used a BTH magneto on his machines, even when the production competition models were being fitted as standard with the Lucas 'so called' wading magnetos, why?

The simple answer is that the BTH magnetos, produced in Rugby, had almost 50% more secondary windings on the rotating armature than any of the Lucas models. Electronically that means a greater voltage generated, rev for rev, than the models from Lucas (Advertising slogan, remember, "The Prince of Darkness") - the greater the voltage generated the better the spark at low speed.

Sadly I don't know anything about the digital BTH - but I would doubt very much that it will be a lower performance specification than their mechanical units??????

Just a thought - more details coming in ORRe shortly including an illustrated guide as to how to strip and service a magneto to achieve a better spark........

Deryk Wylde

[bb32a]

Hi rusty ken,

An interesting glimpse into history for you! Known as the 'Maestro' of Plonk, the legendary Competition Manager of AJS/Matchless, Hugh Viney, ALWAYS used a BTH magneto on his machines, even when the production competition models were being fitted as standard with the Lucas 'so called' wading magnetos, why?

The simple answer is that the BTH magnetos, produced in Rugby, had almost 50% more secondary windings on the rotating armature than any of the Lucas models. Electronically that means a greater voltage generated, rev for rev, than the models from Lucas (Advertising slogan, remember, "The Prince of Darkness") - the greater the voltage generated the better the spark at low speed.

Sadly I don't know anything about the digital BTH - but I would doubt very much that it will be a lower performance specification than their mechanical units??????

Just a thought - more details coming in ORRe shortly including an illustrated guide as to how to strip and service a magneto to achieve a better spark........

Deryk Wylde

Been using a BTH mag on my BB32A since 82.Rebuilt twice ,once in the 90s after drowning in the Irfon Crossing(remember Deryk ?)Front wheel didn't see a rock... Bent the rod also. Both mag and rod lasted the year out with regular drying out and a bit of smoke. Rebuilt again in 2014 due to I believe lack of use and stored in a damp garage. My first experience of BTH was in 67 when I started my apprenticeship/fitting working on 10 and 30 MW BTH steam turbines. Finished fitting on turbines in 93 on 500 MW units.(Not BTH)

[stickinthemud]

I had no plans to build a short stroke engine, despite the positive comments from Don Morley. But I am interested in an early bottom end, with the lighter road flywheels, paired into an alfin barrel with an alloy head. The only remaining issues are which rod to use; the long early rod or the shorter later rod, and what bore to use.

I use a WD '1941' engine in my rigid Matchless and fitted an Alfin barrel and alloy head. If my memory serves me right you need to fit the shorter (7") conrod instead of the earlier (7 1/2") longer variety and the older high gudgeon pin piston.

Also the earlier flywheels had the single start oil pump worm gear drive and a good upgrade would be to fit the twin start drive and matching oil pump plunger but watch out for the different diameter guide pin.

Oh and if you are using the mag behind the cylinder, you will have to move the carb back as it will foul the mag. You will then have to move the oil tank to the left as there is no room for the original or a central oil tank with the original style rigid frame.

I also have a later engine that has been bored out take a BSA A65 low compression piston to give 410cc. This requires the barrel to be shortened by around 3mm and the head shaped to avoid it being caught by the piston.

As for power characteristics, the WD 350 has good low down power and the lighter flywheels means that the front end can be lifted easily and deceleration for hill tops and sharp corners is quicker than the later flywheels. The 410 certainly has the power needed to lift the front wheel up rock steps (something I found lacking with it as a 350) and plenty of grunt for the big hills but the heavier flywheels can run on and catch you out.

Good luck - Hope this helps.

[laird387]

Hi stickinthemud,

When you say the heavier flywheel power can 'run on and catch you out', the Maestro Hugh Viney always used the ignition retard precisely to stop that happening. He had the longer advance/retard lever set so that the ball end sat in the 'V' of his left thumb/forefinger and you would see him using his right hand twisting the throttle and his left hand 'twisting' the advance/retard. You need to fit a stronger spring on the magneto end of the cable to be sure it springs easily to retard.....

I tried it and found it made a world of difference, it made riding so much more controllable. Later I learned to use a similar method for those 'looping' sections with a steep drop to a tight turn then a sharp climb back up the bank, drop over the crest with the motor retarded and the power 'lazy' then tweak it back to normal advance as you turn at the bottom ready for the swoop up the bank - especially on those ultra frosty mornings at Post Hill on the sections along the river, where the sun didn't get to the bottom of the sections 'til late in the day, so the frost down there just glazed to solid ice........

Happy days.

Edited November 25, 2014 by laird387

[aawil]

what a great looking PROPER pre 65 trialer, all thats missing is the chair . i agree with deryk about the long lever i adjust the advance on my panther outfit with its lucas sr1 modifyed to manual use and vary it in the sections, the same on my road outfit and my special hillclinb panther solo , all fitted with the good old lucas sr1 magnetos which start first kick hot or cold , who needs modern electronics. will.

[jon v8]

That picture reminds me of the old ex WD G3 on girders I used to ride on the road,excellent bike,wish I still had it - despite having 4 chains to look after.

I find no need to alter advance at all when riding in sections,I might retard it a bit in a tight twisty section,other than that its basically on full advance.It grips so well on the IRC rear tyre its actually pulling the knobs off.It will find any grip that there is, often much better than springers or moderns.Its only big rocks or steps that muck it up.All I need to do is look where I'm going and concentrate on how much throttle to apply.

Flywheels taking it on is no problem either,just whip the clutch in - which you have to do now as so many trials are biased towards the 2014 James/FB/Cub riders.Some turns you are forced to clutch around...

[jon v8]

This is the engine in my Ajay, its a real mishmash of parts,even the crankcases were not a pair.The crank is a 1955 road version which I had balanced to 62%.Barrel is an Alfin which has been messed around with,stud centres altered etc.Head is bog standard as far as I know,but not its age.The piston is an Aussie JP one which has had material removed from inside the crown to reduce weight and the pin bored for the same reason.The piston was also coated in a modern high tech low friction material which works very well.

Its running a 626 Amal MK1,one of the premium range.I've just replaced the Lucas racing mag with a new BTH electronic one as an experiment.After a lot of fiddling around to get the timing right it is really proving how good it is in terms of a strong and accurate spark.The engine has never run so well...

Its not cheap or easy to build a proper bike engine,and you get told a lot of rubbish along the way,spend the time and the money - be prepared to experiment and you end up with a lovely bit of kit.So satisfying to ride,and listen to.

Hi Folks,

Thanks for your comments on the engine idea.

I had no plans to build a short stroke engine, despite the positive comments from Don Morley. But I am interested in an early bottom end, with the lighter road flywheels, paired into an alfin barrel with an alloy head. The only remaining issues are which rod to use; the long early rod or the shorter later rod, and what bore to use.

Seems that the easiest answer is to use the long rod with a BSA piston? So its good to hear that in principal it works ok.

For sparks I`m using a refurbished lucas wader, but am seriously considering a new digital BTH, even if they are a bit pricey.