(15-10-2018, 06:18 AM)LTony Press Wrote:

(15-10-2018, 05:55 AM)Ian Williams Wrote: I have been doing exhaustive inspection and testing of one of these new Accuspark units, full details of the build quality, or lack of it, and performance under measured conditions soon. I would be interested to hear how others have been getting on over a period of extended use too, actual measurements rather than just subjective, "it sounded and felt better" and against what have you measured the new unit please.

Ian,

I would be interested in your report- our Spares manager seems to want to get some of these Accuspark things- I am not convinced.

Tony.

(15-10-2018, 11:12 AM)Ruairidh Dunford Wrote: Tony,

I have no desire to get caught in the crossfire (again) between the supplier of these units and an ex customer but I can share my experiences of the units with ‘you’.

I was incredibly sceptical of the technology when it came to market but believe that to know something properly you must use it in the way it was intended and then make up your own mind, so I put one on my car.  The DK4a it replaced was well maintained and gave good service, despite this the new unit gave instant and noticeable power gains, tickover was remarkably slow and the engine ran smoother.

Since then the unit has performed well.  

There have been a couple of issues with the solid state trigger unit failing on some units but, if this does happen, it appears to do so very quickly and, in my experience over the time the new unit has been available, the failure has matched that of convential points, condensers and rotor arms available today.  I have also discovered that the new units will fry themselves if the wires are not secured very tightly and if the coil offers less protection than 1.5 Ω.  There was speculation that copper cored HT leads caused problems but I have not found this to be the case amongst those I have been closely involved with.

If I were your spares manager I would ask for a small sample to try out and then you can make your own mind up - like I did.

(15-10-2018, 12:11 PM)peter burton Wrote: Now, I'm not getting into the if, buts etc. of these electronic distributors but surely the ultimate must be with the lucky chrome rad Seven owners who have manual advance/retard levers on their steering columns. First remove and alter the advance/retard locking ring from the the old (static) dizzy and modify it to fit the new electronic thingy. Even I managed it so it is no way difficult. Retime as per normal and once running lock up the arm to dizzy at the halfway point on the lever. Go for a good run and find the ultimate timing point whilst driving, inside, dry comfy etc.
Oh so easy, only thing is to make a mark before forgetting where you thought you left it as most engines seem to start well retarded when cold.
All the best,
Peter.

(17-10-2018, 02:47 PM)Martin Baker Wrote: I'd like to add my experiences. I  have had an Accutronics baseplate on my Pearl for about 5 years, which has been super (standard ignition cables). I thought I would try the new complete distributors to overcome the various wear issues of an 80 year old dsitributor.
I found it nigh on impossible to get the timing right, which I put down to the two advance springs being identical and weak. I therefore reverted to the original distributor with correct springs etc and hey presto timing was again settable and the car performed well.
Bear in mind my engine is somewhat tuned; shaved high compression head, large valve ported block, Paul Bonewell cam and followers with a Nippy manifold and downdraft Zenith. This may make it even more sensitive to timing. I might try some new Lucas springs in the Accutronics distributor and see what happens. BTW Apparentlly the Distributor Doctor is working on his own replacement distributor which may well be better but probably more expensive.

(19-10-2018, 05:48 AM)uIan Williams Wrote: As promised the first instalment of my detailed feed back on these Accuspark distributors. The unit under examination is new and the first thing I noticed was the large amount of side play in the spindle, so before installing it on a car for testing I decided to dismantle the unit, take measurements and compare them with genuine Lucas components.
So first up side play in the spindle bearings was 14 thou, even some fairly clapped out DK4's in my parts shed have trouble matching this achievement in authenticity! The reason for this was revealed once it was apart, the bearings are roughly machined from steel and pressed into the aluminium body, the top one being 1/2" to low in the body leaving the top of the spindle poorly supported.- see pictures comparing with a bronze bushed original. 
Once dismantled it was apparent none of the components were hardened, in fairness the Lucas distributors have not got all of the important wear surfaces hardened either, but some items like the cam are. There were no lubrication scrolls or oil drillings other than the bit of bent tube attached to the side of the body. Once the smear of grease has been exhausted it will be almost opposable to re lubricate unless dismantled. I guess virtually nobody ever did, and very few now actually lubricate their distributors anyway. Next I measured slop in the advance mechanism, for reference all the pins on the Lucas Distributors were 3/16" or 187 thou, I have a number of New Old Stock spares to compare with. On our Accuspark they varied quite a bit from 181 thou on the cam pins, 182 thou on the base plate, and 185 thou on the steel advance weights - the original weights were lead with steel pins. Side play in the toggles which fir over the pins measured 8 thou and were quite sloppy on the pins, new Lucas parts are a snug fit and clapped ones are often worse the Accuspark, wear in this area, the toggles and pins particularly is why many advance mec's don't work properly. The accuspark springs were both the same weight and much lighter than the originals, this would create a different advance curve and partly explains why some people have difficulty timing the units accurately. Lucas units use a two stage advance, a light spring controls initial advance and a strong spring takes over as speed increases, the end of the strong spring should be loose over the pin fully retarded and is shaped to accommodate this- see picture
Side play between spindle and advance cam was measured at 4 thou, a new Lucas has negligible play in this area, The Accuspark base plate has 10 degrees of advance giving 20 degrees engine advance, any owner fitting one should take this into account. In summary I found excessive play in every component and many of the bearing surfaces were roughly finished, as a result I would anticipate quite rapid wear.

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Pictures below, Accspark is on the left Lucas the right

(20-10-2018, 07:12 AM)Ian Williams Wrote: Tony the spindle is mild steel and unhardened with no oil scroll, I did not remove a bush as I wished to run the unit as it was delivered, therefore I can not be certain if cast iron or steel however they appear to be the latter and the surface finish of the bore is rather poor. It would be educational to strip one of these after 5000 miles and see how it is bearing up.