Electronic engine management for the Slant 4

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Electronic engine management for the Slant 4

Postby 1972nail » Fri Jun 23, 2017 9:41 pm

I've still not fitted electronic ignition to my Firenza because I'm still researching it. While looking at the various systems currently available I came across the Aldon Ignitor MR-LS2 system at £120 plus postage. A bit more expensive than the Accuspark /Powerspark systems but it can be fitted without removing the distributor never mind dismantling it like the Acc/ Pow systems.

The advantage of the Aldon is that points and condenser can be retro fitted easily if it fails.

Anyone any experience of the Aldon system?

http://www.aldonauto.co.uk/ignition/ign ... plications
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Re: Electronic ignition for the Slant 4

Postby lord13 » Sat Jun 24, 2017 6:59 am

no experience of the aldon system, but why not fit the complete bosch dizzy, coil and ignition module from a late model CF slant? It's a 'bolt-on' job and maintenance free to a point, extremely discreet and looks 'factory' (because it was) ...just an idea.
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Re: Electronic ignition for the Slant 4

Postby 1972nail » Sat Jun 24, 2017 10:57 am

I would if I could (a) find one and (b) afford one when I find it. The advance curve isn't correct for the high compression twin carb engine either so needs to be professionally altered - more cost....
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Re: Electronic ignition for the Slant 4

Postby lord13 » Sun Jun 25, 2017 6:28 am

ah ok...I've not really had any trouble with them, neither has a friend of mine that runs twin 45's on his beast. The advance curve cant be that out to be fair, but i didn't know they were that scarce TBH. I've had a quick look on the net and i was struggling to find one.
I'm sure my mate runs one with a cavalier ignition module, i'll ask him, I could be wrong.
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Re: Electronic ignition for the Slant 4

Postby 1972nail » Wed Mar 21, 2018 8:38 pm

An update on this, a bit late as I've been running electronic now since last August....

I did find and fit a full Bosch system from a CF van at a reasonable price.

The advance 'curve' is not ideal...I say curve, but in reality it is basically a straight line from 0 deg to the design maximum at about 3200 to 3500 rpm. The design maximum of a 8.5:1 2300 slant 4 is 36 deg plus 6 deg vacuum, totalling 42 degrees. A 9.25:1 2300 (HPF) is 32 degrees plus 6 degrees vacuum. The CF is 42 degrees and 6 degrees vacuum a grand total of 48 degrees...... A full 10 degrees more than a mildly tuned engine.

I didn't alter the advance curve of the Bosch and found that running it on the standard static setting of 9 deg BTDC it would pull OK to about 2500 rpm but start to loose power and stop revving at about 4800 rpm. Pulling the static timing back to 3 - 4 degrees BTDC cured the top end drop off and it revved far better than it ever did on the Delco 300. It pulled just as well as it did before from 1000 rpm to 2000 rpm but was a lot smoother and more powerful from 2500 to 4500 rpm.

The only problem is that it has difficulty in ticking over smoothly and doesn't start just as easily because it doesn't have enough advance at cranking and tick over speed. :cry:

To cure the starting and lower rev range problems I intend to strip the distributor and see if I can restrict the mechanical advance to about 32 degrees which will allow about 9 to 10 degrees static advance and add a bit more advance in the mid range, which should in turn further aide torque. A fellow enthusiast with a Bosch distributor has bent the limiting tabs in a bit but I'm not sure if that is really how I want to proceed. Yes, the advance will be limited but at a lower rev range than i would like.

I've decided on 32 degrees instead of the 38 degrees of the standard engine because I intend to add a Blydenstien big valve head, a VF2 camshaft and a pair of 48 Dellortos which I just happen to have sitting in my garage :wink: . The DTV recommendation for the maximum mechanical advance on a tuned engine is 32 degrees.

So to conclude, the Bosch distributor from a CF is a good upgrade but you do need to sort out the advance by either getting it professionally altered or adding some sort of advance limiting on a DIY basis.
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Re: Electronic ignition for the Slant 4

Postby 1972nail » Wed Mar 21, 2018 9:56 pm

Yes, it is an option I am considering. I will be looking at Manta, Golf etc Bosch distributors with a view to see if parts from them can be made work. They rotate clockwise and the CF is anticlockwise.... needs a bit more detective work yet.
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Re: Electronic ignition for the Slant 4

Postby jpsmit » Thu Mar 22, 2018 12:58 am

I had my distributer re-curved by Advance Distributers in the USA http://advanceddistributors.com/wordpress1/

Haven't had the chance to use it yet but was not terribly expensive ($250ish USD) IIRC.

they also recurve it for current gas which is not as good as 60's/70's gas.
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Re: Electronic ignition for the Slant 4

Postby 1972nail » Thu Mar 22, 2018 6:02 pm

Yes, H&H Ignitions here in the UK (I think that's what they're called) want £150 to re-curve the Bosch unit, but I'll investigate what I can do on a DIY basis first.
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Re: Electronic engine management for the Slant 4

Postby 1972nail » Thu Apr 05, 2018 2:33 pm

I've changed slant on this .... excuse the pun.....and I'm thinking of programmable engine management as a whole complete with a future programmable EFI setup.

I want the engine bay to look as 'original' as possible but it won't be standard, something like a ''factory development style' rather than 'aftermarket'.

I will probably be using a single 48mm throttle body with an home made alloy plenum style manifold, adapted from an MGF, complete with MAP sensor, injectors, fuel rail, pressure regulator and various attached sensors, a modified AC Delco 300 distributor with a Hall effect sensor fitted, a Bosch '008' type (Intermotor 150000) ignition amp and matching Bosch coil.

Using a distributor rather than a modern Multi Coils setup will keep the 'original look' with a working distributor. This with a semi sequential injection configuration would be best suited as it won't need a 'high resolution trigger signal' from a crank and cam sensor configuration, however these might be added to fine tune it all.

The object of this build will be to do it on the cheap, do as much as I can myself, to keep the installation quite discrete and do something different from the norm. This route rules out the now quite common 'Jenvey' style individual throttle bodies.




All this will be managed using a DIY ECU. The Megasquirt system is the best known of these but the design is now quite old and kits are becoming expensive for what you get. It also won't work that well with the original distributor set up as far as I know.

I'm considering the Speeduino ECU which will run what I need plus provide wide band lambda data logging for fine tuning as standard.
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Re: Electronic engine management for the Slant 4

Postby 1972nail » Thu Apr 05, 2018 8:05 pm

The CF Bosch distributor can be used as as the trigger mechanism but it will need altered which would destroy it for any other application and reduce it's value considerably.

I stripped an old but good Delco distributor yesterday and to cut a long story short, it is very suitable for this application. To convert it to programmable ignition both the mechanical and vacuum advance systems need disabled and the relationship of the rotor arm to the 'points opening' cam needs altered.

The design of the Delco unit allows for about 110 degrees of base plate swing which will be more than enough to align everything for the new application.

I'm always on the scrounge for cheap parts for my projects and I found a bargain 7 pin ignition amp on eBay. This will be the main amplifier for my new system. It controls the dwell, (saves frying coils while setting it all up and one less thing to get wrong in the settings) has transient protection on all pins, it is designed to work with Hall effect systems, has a massive heat sink attached and all for a bargain price of £4.50. :lol:
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