Amazon: Accuspark ignition

[swedishandgerman]

The 026 is a good distributor with a very nice advance curve. But the points kit is quite complicated compared to a later distributor. Once set up properly though, that engine should run well

I forget. Do you have a vacuum take off on your carb? Were you able to connect your vacuum advance?

[redcar]

cheers, it has a vacuum alright, but i've no take off connected.. afaik the vacuum is to retard at idle.
i need to tap a connection into the manifold, so that's job i'm putting on the long finger for now, as it goes fine as it is. idling is a bit high, but once on the move, there's no real difference.

[woodman]

A module like this transformed my Triumph 1500 a few years ago, but on the Amazon has made virtually no difference compared to the points.

As far as I can tell the main reason is that on the Triumph there was free play in the dizzy shaft so it could wiggle sideways during running, and this would vastly affect points gap - whereas with the optical gate module fastened securely to the shaft, the module wobbles in sync with the dizzy and doesn't alter the spark. If there's minimal play in the shaft, as is the case on my Amazon, then the module is giving much less benefit over points.

One issue with the Accuspark kits is they have a very precise minimum voltage below which they won't operate at all. So they're less forgiving of a weak battery, earth problem etc and need the auxiliary bypass modification to the wiring that Ron Kwas has written knowledgeable about.

Originally Posted by swedishandgerman

I can't recall what type of distributor you have in your car, but I think you kept your B18A distributor in there when you upgraded your cam and converted to twin SU's, right? If that's the case, you have a 2-piece points set, so you might need to think about that when ordering

This is a fact.... These kits cannot provide a better spark, better mpg, better running etc compared to a standard set of points and condenser provided they're set up properly. It just can't happen. If the points gap is correct, then the angle of dwell is correct, so the maximum 'time' that the current goes to earth is achieved AND the maximum time that the current goes to the coil to give a great big voltage crack at the plugs. You can't improve that with one of these kits

HOWEVER, I would hazard a guess that 75% of our cars with standard points ignition systems aren't running spot on! Points surfaces degrade quickly, the little plastic arm that rides on the distributor shaft wears out at a fast rate and leading to condensers deteriorating and so on. So even if you've set up the thing properly, within a short mileage, they're out again

Another advantage of this kit is eliminating points bounce at high rpm. But we're talking about HIGH rpm before that happens

So once one of these kits has been fitted, you can be rest assured that it won't go out of tune again and you can consider that it is producing a fatter spark, better MPG and better running etc than one of those 75% that aren't in tune!

[swedishandgerman]

That's a vacuum advance unit on the 026 distributor, Mr Redcar

You need to think carefully about where you'd need to tap a connection on the manifold or carb in order to get the correct amount of vacuum to operate that particular vacuum unit

Basically, the vacuum retard unit requires a large whack of vacuum to operate it, like the great big vacuum that occurs in the manifold when going down hill or between gear changes. The point of the retard is to burn the unburnt gases when you come off the throttle quickly (gear changes etc) - that's also why modern petrols continue to rev when you come off the throttle

In effect, the vacuum tap is so positioned on a vac retard unit so that the great big whack of vacuum is achieved

If you try to combine that with a normal vac advance unit, in theory, you could be get too much vacuum to operate the unit. This could result in getting too much advance too early

To be honest, the mechanical advance curve is so nice on that distributor that I would leave it alone. Additionally, the tiny, tiny amount of advance the vac unit on an 026 is such that you are unlikely to notice ANY difference in performance - the twins shove a nice amount of gas down the holes when you plant the throttles! However, you might notice a very,very slight improvement in fuel consumption as a little bit more advance when you plant the throttle would make it burn a bit more efficiently

The 026 gives a nice small amount of advance at low rpm so in theory it should make it idle nicely and perform well at low rpm. The distributors specific to twin carb engines have more advance at low rpm, so provide better fuell efficiency. At high rpm (above about 2,750 rpm) there's no difference

If I was you, I would get the points set up absolutely properly first - if you can get access to a dwell angle meter, set it at 59 - 65 degs. Then (and only then) set you timing at about 34 degs at approx 2,750 rpm and incrementally keep tweaking it untill there's no pinking

Why's your idle high? Do you have some kind of cam trickery in there? If it's nothing too out of the ordinary, you should get a good steady idle at about 975rpm

[redcar]

Oops S&G, so know you know how much i really know about ignition... :blush:

the mechanic who did the engine work originally (d-cam, twin carb, etc, etc) advised me to use the dizzy as is, as the gain from plumbing in the vacuum was not really worth it.

wrt the high idle, it's always been a little high, say around 1000 rpm since the work was done. i assumed it was because the vacuum advance had been removed and idle was affected.

I've ordered a set of new points, condenser, etc to fiddle about this weekend, so i'll see if it makes a difference to the power delivery at all.

ps. i dont think there's many dwell meters around dublin anymore.. but i might take the car down to the original mechanic again, once everything is set up and get him to tweak it a bit. he is pretty good around these type of engines.

for setting up the timing/gaps, etc, i'm reverting back to your distributor write up for now..

[woolfie1948]

I bought my dwell meter on ebay for about £5 and would really recommend you try to get one.
Before I got it I thought I knew how to gap points!

[Tail]

I bought a draper multimeter and the instruction book tells you how to test the dwell, just looked and £13 on Amazon.

[redcar]

fair enough.. £13 isnt a fortune. i'll pick one up off amazon.

for the less experienced, like myself, here is a pretty good guide for tuning up the engine.. http://www.secondchancegarage.com/public/670.cfm

[swedishandgerman]

Originally Posted by woolfie1948

I bought my dwell meter on ebay for about £5 and would really recommend you try to get one.
Before I got it I thought I knew how to gap points!

The same here! It's surprising how out the dwell angle is when it feels spot on with the old feeler gauge

The other beauty of having a dwell angle meter is that you can set the points gap at the wide end of the range given in the manual. Then after a few hundred miles have been covered, you can simply connect it up again and check that it's still within the range. Once it's gone to the low end, re-adjust. Simple!

I strongly recomend a Gunson Automotive Multimeter. The latest version also includes a rev counter. It was extremely cheap on ebay and is worth every penny

I was lucky on ebay - this guy was selling a job lot of those Gunson Multimeters and mine was cheap. At the same time, I was looking for a good strobe light with an adjustable advance and I wanted a Gunson Superstrobe. They're expensive even second hand. However, I accidentally typed "Superstorbe" only to find that some poor sod had done the same when listing one for sale, so I got it for a few £'s. Deep down, I felt sorry for the seller's mistake. That was untill I got the thing and used it....

Now I can do dwell, do carb things my rev counter, check out advance at different engine speeds etc, so I'm a happy geek

[swedishandgerman]

BTW, I'd be quite happy with idle at 1,000rpm, Redcar. Perhaps a tiny bit fast, but I'd prefer it that way than the other

I don't like the suggested idle speeds given in the manuals for these cars for a number of reasons

Firstly, the old amp light glows

Secondly, with old fashioned steering, I like to be able to lift the clutch with a good idle speed to get the old bus moving to make manouvering a bit easier

With a low idle, you get to feel any splutters and caughing particularly with a D-cam I'd set it high

Also, there's a weird thing I've experienced with twin SU's and I've read on here that the needle valves stick resulting in petrol spilling out the sides with too low an idle

Mine's a simple old A-cam with a Stromberg and that one's set up at 950rpm