your own ignition

Here you can talk about all kind of TECH for the B50 B44 B25 And Other BSA unit Singles

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stew79
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your own ignition

Post by stew79 »

hi all, if my messing around with standard shop bought components, to fix my own bikes, (H*nda, S*zuki, Y*maha, ccm) could help some one else here. i will share any useful information i may have. but if you do something i advise, and accidentally get electrocuted or some thing, you must understand any video film of this must be shared with all on this site.
stew.
ps i am not trying to steal or make profit from any one else,s systems. as i am aware there are over 20 different companies selling copies of just about every ignition system ever made, from hitachi to ford, nippon denso to made in china pit bikes. if you use any advise here for your own profit, thats up to you.
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Re: your own ignition

Post by hwan »

Is this where we publish all our various homemade ignition systems, then ?
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Re: your own ignition

Post by Andy Chaos »

Or you could just fit interspan
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Re: your own ignition

Post by HPbyStan »

Image
This from the B25 that I did away with the whole right side so had to make an ignition on the left side. Automotive trigger, home made reluctor, H o n d a Ascot 500 twin igniter box with the advance curve built in, Dyna dual lead coil, constant loss non charging system.
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Re: your own ignition

Post by beat »

hi stan

what a non matching engine Nr. on this carnival bike !

once more it seams you have not been a good stock BSA boy <021

;-)
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Re: your own ignition

Post by beat »

hi stew,

BTW, we DO share ALL our secrets together here in the B50 .org community :!:

and if one could make some money out of what ever, - it could NOT been big monay anyway and others can profit one day two from this effort maybe.

so, - lets sharing and be not disappointed if some hars words are coming along, we are just bikers.... :oops:

:lol:
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Re: your own ignition

Post by lathejack »

Oh bloody hell! I've just bought another Pazon kit, have I just wasted my money?
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Re: your own ignition

Post by stew79 »

hi hpbystan, thats a great looking bike, with lots of modifications to it. its nice to see a good old vm mikuni taking charge of the mixing as well. 32mm ? had several of them over the years on jap 250s , a good carb. what sort of power dose it make ? do you use a two stroke type plug in it ? i have tried putting the complete ig system from one bike to another several times with not much luck ! the mechanical part is straight forward, but then you can be stuck with the spark (perhaps a very good one) in the wrong place at the wrong time as well with no easy way of adjusting it ! (if its degrees and rpm are pre-set in a box on a chip) at least with mechanical ad / ret you can alter the caricaturists to suit your needs (like on the earlier version of the 500 H*nda system you are using)
very nice, stew
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Re: your own ignition

Post by stew79 »

hi lathejack, im sure the system you have bought is fine, you must understand that i am just a fussy engineer who is always looking for "better". i blame that on a stressful carer in toolmaking (all types of machinery, design through to finished press tools or products etc)
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Re: your own ignition

Post by HPbyStan »

Image
34mm Mikuni, 14mm NGK in standard position, 10mm NGK added
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Re: your own ignition

Post by BSA_WM20 »

Now I am curious.
Why the different plugs ?
I appreciate the need for different sized plugs but why the different makes ? ( If it isn't a trade secret.)
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Re: your own ignition

Post by stew79 »

hi hpbystan, i meant to ask about the need for 2 plugs but suspect it could cause an argument........ no i will be brave "why 2 plugs?" on a two valve head with a cylinder over 5" or so i can see, but on a fairly small head ? "butler and smith" used 2 plugs in the heads of there incredible 1000cc flat twin beamer race bike in the 70s, but it wasnt for any extra performance gain, just to even up the thermal expansion problems that one plug hole caused in the head. (bigger valves and seats meant that when hot the head distorted unevenly and the valve seat kept falling out. with 2 evenly spaced plug holes the fit between seats and head can be controlled better and the bike went on to beat every thing else out there !) even the old S*zuki sp play bike has 1 of center plug (2 valve engine from the 70s) it has been tuned up a bit and goes really well, 3 weeks ago it had some drag races on an old air field with an xr500. the sp kept on out dragging the xr and got it on top en as well!. its got a D8EVX plug in it (two stroke style, but becoming more popular in turbo charged and performance cars)
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Re: your own ignition

Post by ghislain »

The two plugs are NGK, or am I wrong reading ???

And Stan, I enjoy the way you changed valve springs for elastic braces !! Much more lighter , hé !!! :thumb
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Re: your own ignition

Post by hwan »

If a twin plug head shows an improved torque curve on a relative square (or even long stroke) engine - it usually down to porting or crap combustion chamber shape (including piston).

The B25 responds surprisingly well to a second plug, despite a small bore and under square bore;stroke ration - despite a relatively good piston shape.
Almost certainly due to lack of swirl and/or the poor standard plug position - in fact the center plug alone, allows a much flatter ignition curve than the std plug - according to my drives around the paddock.

I have a nicely welded b25 head, with significant squish pads which i want to try on something at some point - unfortunately someone has been at the already big Inlet port - may be something i try filling with epoxy once current B25 project is finished, running and dyno'd.
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Re: your own ignition

Post by hwan »

As far as any mods go - particularly ignition - the simpler the better.
HPstan's use of a standard automotive reluctor and a jap ignition box is a case in point.

And who the f**k came out with the 'equalize temperature across the cylinder' tosh - if he couldn't keep valve inserts in the head, then there's something else wrong (ok, i know that even Norton comp department resorted to grub screws to keep bronze seats in their magnesium heads!)

The BMW i raced - needed the twin plugs simply because of the combustion distance across a +96mm piston!
Once it was twin plugged i could reduce ignition advance MASSIVELY and also needed no advance curve as such - allowing the use of an old TZ750 femsa ignition system.
The beryllium valve seats (courtesy Williams F1) fitted by myself using the wife's RayBurn, offset valve guides and oversize valves stayed in place.

Even the 750 BMW went better.
Even my F650 has twin plugs ... though more likely for emission purposes.

For the record - i dont like twin plugs as it increases the change of the head cracking - but when needs must .... you do.
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Re: your own ignition

Post by stew79 »

hi hwan, i have only ever had 3 bikes on the dyno, but can see that it gives you lots of detail about spread, as well as peek power. in the next 2 weeks or so the sp is going on one just to see what can do. its been set up by ear and feel as best as possible,(like all my bikes) so it wont be adjusted on the roller at all (that cost more money !) perhaps there is something in this 2 plug thing ? or is it two week sparks better than one week spark ? could one really good spark be better than two average sparks ?
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Re: your own ignition

Post by HPbyStan »

The igniter box from the VT500 H o n d a is used on a very good combustion chamber so doesn't need a wide curve. 2 spark plugs cuts the flame travel in half on the BSA and helps to make the spark requirement about the same imo. One reason I chose as many OEM components as I could is OEM doesn't seem to have the huge electrical draw that most after market stuff does and one doesn't have the problem of the battery getting drawn down with a constant loss system causing the ignition to go nuts and shooting the timing ahead and wrecking the engine. Once I got the bugs out of the B50, the only mechanical failures I ever had with it were when trying after market electronic ignitions. I still build them with 305 H o n d a Super Hawk points, BMW condenser, and a Dyna electronic booster to take the work load off the points. Is this the "only" way to do this? Heck no, it's just the way I do it.
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Re: your own ignition

Post by stew79 »

hi hpbystan, i thought you said the bike in the pictures was a b25 ? is it a b50 ? (34mm carb on a 250 sounded a bit over the top !) as for 500 ascot ? i thought you ment the ascot single ? (ft thing based on a very tuned down xr 500 single, small cv carb for pottering about on) but over there its a twin ? totally agree that if you are haply with what ever gives you your sparks, then why waist time or money on something else.
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Re: your own ignition

Post by HPbyStan »

The bike in pics is a B25 with a 34 Mikuni.
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Re: your own ignition

Post by lathejack »

Stan

I like the neat little hydraulic unit for operating the clutch.

I don't know if it is an illusion caused by the photo, but the pushrod cover and the top of the rockerbox seem to be sloping downwards compared to the rest of the motor. Or is it the result of some major modification?
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Re: your own ignition

Post by hwan »

One damn good spark from one is all you need in a well designed combustion chamber.

In the b25 and B44/50 the porting and chamber is primitive - hence twin plugs and multi-spark to get the burn completely finished, in as short time as poss.

Ignition advance (or lack of) is always a good indicator you are doing something right.
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Re: your own ignition

Post by gunnag »

I believe the sloping rockerbox is a result of Stans high port mod where he has completly redesigned the inlet manifold and raised the inlet valve seat.

Im sure Stan will add further details in due course.
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Re: your own ignition

Post by HPbyStan »

Turned out a 3/8" thick aluminum donut on the lathe. Pressed it onto a valve guide. Pressed the guide into the head. Welded the donut to the head. Milled the roof of the port right out of the head. Ported right up through where the bottom coils of the valve spring used to be. Now there is room to get in and weld up the too low floor of the port. Now have to make the rest of the port from rod. The inlet valve needs to be made 3/8" longer to make room for the spring package. Now the rockerbox won't fit so I cut that in to and cut out a 3/8" spacer for the back half and weld the whole mess back together. Now as the valve got longer at an angle and the back 1/2 of the rockerbox got spaced straight up, the inlet rocker can't reach the valve any more. Since the rocker ratio is just plain wrong anyway I have to make one out of two and weld them together with "Super Missile" Rod. I was kinda surprised that pushrod inspection cover still bolted back on at the angle with no mods but it fit a treat.
Image Click on the pic to get to Photobucket and then use the arrows to see all kinds of foolishness. I had all the photos in order at one time but Photobucket scattered them all over so if you don't loose interest too quickly you can at some point see all of them.
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Re: your own ignition

Post by hwan »

Nice work Stan -
Did similar on a BMW flat twin - much much easier, you can actually bore and press fit a stub - achieved something like 15-20 deg of 'downdraft' relative to the head-face (more relative to valve).
Made a MASSIVE difference to my BMW outfit, biggest improvement of any mod - nearly lost AndyChaos off the s/car, first time out after this mod.

Like most older m/c's the fuel tank limits the height of the inlet port - my Westlake/NRE/Triumph was particularly bad and i would expect the 4V CCM to be just as bad, particularly with almost vertical valve angles, further reducing 'down-draft'.

Adds to the fun.
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Re: your own ignition

Post by stew79 »

hi hpbystan, i was advised to start this new topic "your own ignition" by minetymenace for possible solutions to members ignition needs. however the side track of different ways to tune up these lovely old engines, is just as interesting anyway. with that in mind i took some pics of a standard spare old 2 valve head and piston from a S*zuki 370 to see what members have to say about how it compares to bsa stuff. (it was probably copied from england anyway !) the valves are 42mm in 35mm ex, wide angle, bore 85.5mm (0.5mm os) the camber is 21mm deep, inlet port 34mm, ex port 30mm and the height of the dome on the piston is 7mm. there is a squish band of 1.5mm thick by 3mm wide round the out side. the std comp ratio is 9.2 /1 (stroke 65.2mm ) valve lift is about 9.5mm (both same) cam timing mild ? ignition advance is 35deg but it dosnt get there till nearly 5000 rpm (spends most of its time at only 25 deg ? std with points etc) carb is quite small and generally runs week. this was the starting point for the play bike scrambler i made for the kids to play on as they grew up.(i was given lots of sp engine parts so thats why has this engine) i have ridden many of these in standard form even the 400 cc version with cdi ignition, they are all nice dull reliable bikes.(the cdi version wont advance quick enough and dosent go far enough and cant be altered) i think the biggest improvement i made in performance was the home made ignition. (cdi) this meant that the bigger carb (36mm vm mik) can be jetted quite rich,(with all them lovely modified 2 stroke parts !) with ig timing of 0 deg kick over to 40 deg btdc at 3000 rpm staying there till it goes bang !(not yet figured out a rev limiter) 1mm skimmed of the head, 0.5mm of the barrel, copied the outer angle of the piston crown to the head to make the squish band 8mm wide by 0.75mm thick, lots of porting, lighter crank and flywheel. on super unleaded it goes brilliantly.
stew.
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Re: your own ignition

Post by stew79 »

some pics of sp
Attachments
head 006.jpg
head 005.jpg
head 004.jpg
head 003.jpg
head 002.jpg
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Re: your own ignition

Post by HPbyStan »

I bought a SP370 new. My biggest memory of the thing was the large amount of slop in the drive train. Not sure if it was all in the rear hub rubbers or if the transmission gears had extra wide slots in them or both. Liked the bike except for that. One almost never hears me complain about an engine having a too LONG con-rod but the DR370 had one. My thought was it was going to be a 500cc engine but got the stroke cut at the last moment for whatever reason and that resulted in the unusual rod ratio for a Japanese engine and a bit of an odd displacement.
Last edited by HPbyStan on Tue Mar 01, 2016 8:27 pm, edited 1 time in total.
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Re: your own ignition

Post by hwan »

yep, had one in Abu Dhabi - traded it for a XL250 H*nda which had a bit more power and better suspension - then bought a monoshock Xr500 - much better bike - - but a complete twat when hot ....... not good in the middle of a desert when you've crashed off the top of a sand dune ........

All suffered from being heavy and over complicated - ok as they were new, but even then i could see problems down the line ... like no greasing nipples on the XR, etc.

The joy of these old bsa's is their relative simplicity.
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Re: your own ignition

Post by beat »

Sorry when I got back to the Topic, but:
HPbyStan wrote: I still build them with 305 H o n d a Super Hawk points, BMW condenser, and a Dyna electronic booster to take the work load off the points.
this is real BALM FOR THE SOUL :!:

<038 <038 <038

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Re: your own ignition

Post by HPbyStan »

For beat.
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Re: your own ignition

Post by beat »

it looks smal and fine, isn't it ?

:!: :!: :!: :thumb
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Re: your own ignition

Post by stew79 »

briefly back to some ignition stuff terminology.
types mdi (old fashion stuff)
cdi (can be better than mdi) (preferred)
power supply direct (preferred but can have minimum speed for spark issues. with "et" advance can loose best magnetic power from alternator)
indirect (works from very slow speed, not for speeds above 10000rpm)
total loss (works from slow speed, heavier, time limited)
timing fixed (very small cc,s only)
mechanical ad / ret (simple, easily adjusted, reliable)
basic electronic ad / ret (preferred, harder to adjust)
digital (over the top ? far too complicated for an old bike !, usually linked to fuel injection, emissions fiddling, car world etc)
trigger points (can be very good, simple)
magnetic (preferred)
optical (never used ?)
any combination of the above will work fine but they all have limits, problems, + and -,s etc. its up to you what you want to achieve.
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Re: your own ignition

Post by beat »

lot of different stuff around, - isn't it ? :lol:

make your choose and stick on it...

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Re: your own ignition

Post by stew79 »

hi beat, how dose the S*zuki head compare to a b50 one ? or the piston ? (i have never seen a b50 in bits) the 2 valve S*zuki is going on the dyno tomorrow morning. (stuck an old road tyre on the back today as the knobbly is a bit too coarse) do you still want a diagram of the little oscillator thing from the web ? i counted the bits that make up the simple cdi thats on the suzuik (very reliable and small) 1 cap, 1uf 630 vdc, 1 thyristor, ts820, 2 resistors 150 / 2k7 ohm, 1 diode 1a 1000v, 5 diodes 5a 1000v. thats it ! sparks from 130 rpm to 12000 rpm (on test rig, as the bike would go bang!) this is a direct system as the S*zuki alternator (with home wound single small coil 300 ohm) is big and wide enough to supply the power at slow speed. the bsa one cant do that at slow speed no mater how you re wind the coils.
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Re: your own ignition

Post by beat »

stew79 wrote:do you still want a diagram of the little oscillator thing from the web ?
yeas pleasy, if it is not too much to get it here.
stew79 wrote: how dose the S*zuki head compare to a b50 one ? or the piston ?
chamber and piston top are different - but I am not expert on this things, guess Stan ore Mark ore others knowing much more....

beat :roll:
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Re: your own ignition

Post by stew79 »

hi beat, here are some pics of how i prototype circuits, wood and superglue to keep things still.the secondary coil can have 500 turns or more if you want higher voltage, but 270 t will give you 1000 volts dc from 1.5 volts in. if you start with a small battery or run it through a 6 v bulb or something, if the winds go the wrong way or something else is wrong it wount damage any thing. when its right it will buzz. any size or type of transformer will do but the turns on the power side may need altering . the tvs values can de added together if you need a certain regulated voltage, (its always best to have more power and volts to start with so the bc 338 can keep it in cheque, or leave it out completely if you want)
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Re: your own ignition

Post by stew79 »

pics
Attachments
i 010.jpg
i 009.jpg
i 008.jpg
i 007.jpg
i 006.jpg
i 005.jpg
i 004.jpg
i 003.jpg
i 002.jpg
i 001.jpg
d.jpg
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Re: your own ignition

Post by stew79 »

disappointing run on the dyno with old 2 valve S*zuki. old hard skinny back tire kept spinning up, interference from cdi kept jamming rev counter and computer ? got one rev reading of over 9000 rpm, but max power was at 8000. carb mix was a bit rich (i like that as rich is cooler than weak) done a run with roller speed instead of revs and nearly topped a tone. (with mx gearing ?) max power just over 32, (with some slip, conldnt sit back any further on seat) curve was nice and flat. i suppose not bad for std cam, piston, valves, springs, etc and 390odd cc,s
stew
ps on the little sketch of the diagram for the oscillator, the earth from the power in ( - near the bottom) should go to the earth at the top from the bridge rectifier, not the ac from the secondary. (too tiered)
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Re: your own ignition

Post by beat »

hi stew,

thanks for pics and roadmap.

myself, after spending lot of time ( and money with NE 555), I came to the bug called LM 2587 T 12 , it switches 5 Amps and runs away on 5 legs only.
( TO 220 housing abouth, not so complicated )
d'id you know him ?

as my source is a ( hopefully ) stable 12 Volt battery and the Sparx generator of the B50, there is enough power in backyard for this cdi.

about details I posting it in the " it sparks by cdi "

beat :roll:
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Re: your own ignition

Post by stew79 »

hi beat i have just looked back at "it sparks by cdi" i thought you said you were starting a new topic ? it been going for a while. (i didnt no) anyway if you are using a 12 volt battery that makes every thing so much easier to do. there is a similar circuit i have that regulates its self,(similar to the first one) and is very reliable. (needs 6 volt min to work) it only has one extra resistor and is very efficient. it can have a tip36a or MJL 21193 trans, and any size transformer to give you 500 volts dc or what ever you need. it charges the cap up to the set voltage then shuts down to save power, when more sparks are needed quicker ,it automatically draws more power to keep up. this is good for 10000rpm (5000 sparks per min with 1uf cap) as for length of spark time that is totally to do with the coil design. certain cleaver old people wouldnt have spent lots of effort making there own very good coils, if they could have bought a good coil in the first place. there is a lesson there.
stew
ps i havent seen the 5 legged component before, what frequency dose it switch at ? how sharp is the switch ? how could you regulate it ?
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