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Hi Allan,
From "67 Lightning. Have original coils" in the original post, I assumed the o.p. was talking about MA12 coils; I've never known red or blue "Lucas Power" coils in this size, only the smaller '70-on size?

Condensers are wired in parallel with points. Not sure how multiplying their number in parallel with a given set of points is supposed to "improve starting and top end performance" but I'm open to being educated.

The 4CA had the condensers mounted on the plate, where engine heat knackered them in short order. Aiui, specifically with the 4CA, the second condensers - mounted outside the engine - were so an owner wouldn't experience any performance degradation when a condenser on the 4CA plate failed? Once the 4CA was superseded by the 6CA, there was again only one condenser per set of points.

For coil charging, John Carpenter (Mistral Engineering) had a test rig including battery, tachometer, HT lead, plug, etc. Any time I took Lucas coils to be tested, the tachometer would be indicating around 20,000 rpm before the sparks became intermittent. I appreciate sparking in the open air can't be equated directly to sparking in a compressed air-fuel mixture; however, a coil'd have to be significantly-degraded before 20 Krpm in the open air didn't translate to reliable sparking at max. rpm on any of these old heaps?

Hth.

Regards,

Ok guys...looks like the nylon bike covers is a bad idea....going to raid the wife's bedding cupboard....for some sheets....just had it in my mind they will absorb moisture from the atmosphere...so maybe they wont.

I use GT85 as a corrosion spray...got 4 big tins so I will carry on with that....

Thanks for the tips and advise.

Nick.

Having seen quite a few barrels over the years the issue of the cylinder liners dropping below the gasket face is not uncommon. It would seem that after a period of being run (and this could be over a substantial period) the liners which started life being proud of the gasket face by 2-3 thou drop below the gasket face with attendant problems occuring as a result. The established method of correcting this is to have the cylinder face ground to restore an even surface, this being done on a surface grinder. Since the barrel to bolted to the surface grinder on its crankcase face the top face when ground is parallel with that.
I've watched this operation being performed with very small increments being removed, its amazing how far out the barrel can be both front to back and left to right, I'd definitely recommend considering having this done if you have a barrel off for any reason and suspect that it may not be flat accross the gasket face.

I have this headlight. $60 free shipping US only.

I have 2 complete (now) '76 on clusters waiting to go into pre-unit shells that cost me complete £706, roughly $480 each. These were bought piecemeal on fleabay with new parts to bring them up to scratch, and include all of the selector parts etc, only bearings to get, so the stuff is around if you know what you're looking for. I've done at least 8 boxes, some using the slighly earlier cluster. $1300 is buying everything new top dollar from a Harris dealer.
Mick.

Last time I put my motor together I measured cam duration and open close points. From my workshop notes. measured with 0.015" clearance
IO 51 BTDC IC 68 ABDC duration 299

Ex O 78 BBDC Ex C 37 ATDC duration 295
I took these readings with a clock gauge at the ends of the push rods, not rockers, figures are means from 3 values, I took the open points after 15 thou of needle movement, and worked back from closed by 15 thou for the closed values.



Didnt measure lift. I have a 3 key way cam gear , this position was closest to stock timing, the cam is not original , was a replacement from SRM years ago.

In case you got the cams arsey facey , Inlets cams are on the outside of the shaft , exhaust in the middle.

I saw this on facebook. Not sure how to put the actual video on here but follow the link.


https://www.facebook.com/1210047051/videos/10218944347778915/

John

Thanks for the replies, plenty to consider. Think I'll go with Colsibro as it's nice to machine. I like the idea of line reaming so may see if I can make something from silver steel to go through the crank case bearings and ream to final size. Keep me busy for a while!

I'm sorry Reverb but you have got me on that one. I'm sat here reading a PPG training manual just in case I was pointing Alan in the wrong direction. It quite clearly states that polyester primer should be applied over an epoxy primer and never over bare steel.

I'll leave it at that and I hope we can agree to disagree.

Hi Nick,
Brilliant idea!

However, the first major reality check is it would require HMG to have a collective universal revolutionary attack of common sense ...

Second major reality check is, at a time when the numbers of unemployed are shooting up, making all those tax accountants and civil servants redundant would be bad publicity.

Regards,

Bulk remail has been going on for decades
The first freight company I contracted to around 1980 used to shift several tons of remail daily from all over the world.
Latter on I helped a customer set up a magazine remailing service , same story mags got airfreighted to him & he addressed then presorted sorted & I delivered them to the mail sorting house at St Lennards .
Eventually he got greedy and strted to send them to newsagents usually a month or two before Gordon & Gotches sea freight magazines arrived.
So G & G ended up sueing him , won the case hands down and the whole set up closed down.

I do feel for you, MM I like to keep hard copy & like to have complete sets

You mean like most of the BSA racers I've seen?
Maybe they liked marking their territory with the small oil spot on the pavement under the primary?
Maybe cause they all went to Umberslade and took a long nap until someone woke them up to tell them the company was out of business.

"BSA guy and a Harley mechanic," there's your trouble. The only time I sent my head to a Harley guy it came back shaved. The valves barely kissed the pistons after that. Didn't bend pushrods, but the head would not stay torqued.
I didn't even know that Sparx made a triple ignition, though they do make 4V coils. Those ignitions aren't too bad, but the connections at the pickup plate are ludicrous. Solder the wires to the plate under those tiny nuts. Or just dab some paint on the nuts after tightening, they tend to vibrate loose.
Good luck with it. Find a good machine shop.
FWIW: None of these old crates will ever be worth what we have in them
until long after we're dead, if then.

My initial thoughts are ignition switch as well. Can you bypass it and go for a ride? See if it still occurs.

reverb,
Modern forged pistons made with high silicon content alloys weigh less and fit tighter than the forged slugs of yore. I can look up some numbers if you want but just off the top of my head my 77.5 mm 9-1 cr zero deck tight quench forged pistons weigh 264 grams, the same as stock T140 76mm 8.5-1 cast pistons. My forged MAP 7.5-1 cr 76mm for a Routts kit weigh 231 grams per piston. The smaller diameter T120 piston pins are also lighter than the 3/4" T140 but of course are only used in long rod engines. My pistons are for long rod engines but with T140 crowns for use with 10 bolt heads and all the weights are without pins or rings.
Even MAP 79.5mm forged pistons are about 270 grams,,,all these pistons are fully CNC machined underneath except for the 79,5mm which aren't finished to the same degree yet, so weight shouldn't be a problem for you, if your supplier follows similar design considerations. Mark.R.

Hi,

I think that would be a great candidate for restoration. It looks very complete and original. I’d almost guarantee that you’d be unique at any show etc! BTW it’s in Northern California.

Ian
SoCa

It's really easy if you just take a few minutes to try and figure it out.

Triumph T20 Engine Cases

I knew there was going to be some select fitting of gears to set the backlash, just wasn’t expecting the breather pinion to be included. Won’t even slide in.

4F90735B-8915-4DA0-B0BA-290C45202CE1 by First Last, on Flickr

69E5B041-6E91-4A2E-8868-6C3935920DB9 by First Last, on Flickr

The one from Coventry looks the same from the top, but the base is black and has the attachment for the tool tray. Fabric has slightly less texture to it. Finish is just as nice as that one, but also just as ugly.

It’s certainly not critical that it works or even makes sense for that matter.. as long as it doesn’t bother the brew and I don’t see how it could as long as I don’t screw up the polarity.

This was one I built and sold...

Pub car park entertainment.

were the people who abandon their carts in the middle of the parking lot doing it to provide jobs for the unfortunate, i would heartily agree with you, richard.

but in fact, i doubt whether they have a thought in their heads about it, as indicated by the many conversations that the "cart narcs" have published on youtube.

i've watched wayward shopping carts traverse my local lots at 20 to 25 mph under high winds, smashing their way into whatever was in front of them across the property. wouldn't happen if they were corralled in the return racks.

but it's not a subject i have any investment in. i always return my carts to the central pickup point, flush public toilets, drop my trash in receptacles, and in general try not to be a public burden in both small and larger matters. people that think otherwise-- for reasons other than the one you point out-- are not the sorts of people i choose to expend any thoughts about.

not to worry either way.

1970 Floyd Clymer Indian Enfield 750

Not any more!

John