21 replies to this topic

[Haynes]

Engine is 1380, 296 cam, dcoe45 on 5" manifold, 3.7fd on sccr box, big valve head and 1.5 rockers. Car is road legal hill climber, currently using Aldon electronic ignition with modified dizzy.

As you'd expect car has plenty of go and pulls cleanly from 3000 rpm and you can nurse it along below that. I definitely do not want a milder cam or to de-rate it in anyway, love the way it goes on the open road, just thinking about the things that stop me using it a lot more.

Mainly l'd like to improve the starting and cold running. If it was a bit easier to start and a little happier in stop start traffic I would drive it more, making it easier to drive to work which is 15 - 20 miles of mostly country A roads, just that there's always a 10 min queue to suffer at home time.

What effect would mega jolt have on:
Starting?
Cold running?
Tick over?
Emissions?
Mid range torque and power?
Part throttle and road manners?

[neal]

Engine is 1380, 296 cam, dcoe45 on 5" manifold, 3.7fd on sccr box, big valve head and 1.5 rockers. Car is road legal hill climber, currently using Aldon electronic ignition with modified dizzy.

As you'd expect car has plenty of go and pulls cleanly from 3000 rpm and you can nurse it along below that. I definitely do not want a milder cam or to de-rate it in anyway, love the way it goes on the open road, just thinking about the things that stop me using it a lot more.

Mainly l'd like to improve the starting and cold running. If it was a bit easier to start and a little happier in stop start traffic I would drive it more, making it easier to drive to work which is 15 - 20 miles of mostly country A roads, just that there's always a 10 min queue to suffer at home time.



What effect would mega jolt have on:
Starting?
Cold running?
Tick over?
Emissions?
Mid range torque and power?
Part throttle and road manners?

I've got a good feeling that you have answered your own question and you have the flexibility of different curves for different driving styles.

https://www.autospor...should-fit-one/

Edited by neal, 02 November 2016 - 07:12 AM.

[nicklouse]

I fitted a Polestar mapped ignition system to the metro and it made it much more tractable around the paddock.

But even so you should not be having cold start issues with that set up

Consider this any part throttle running will need a throttle body pot fitting (no idea what imputs the mega jolt has) and exhaust gas analysis is useful.

[klivins]

I don't think megajolt would improve cold start, but for sure it is easier to play around with it and find a curve best suited for you. You can make 2 files even, one for day use, other for hill climb. Iirc, with litle effort it is possible to make the two curves changeable with a toggle switch.

[Carlos W]

If your starting issues are caused by too much or too little advance then Megajolt will definitely help.

[Dusky]

How are you doing your cold starts?
The cold start mechanism is, like any part of the Weber carb, something that you need to fine tune.

Megajolt on that setup will make it a lot easier to tame on the low revs. But ,ofcourse, it will never be ideal with that cam.

[neal]

Consider all the mechanical links from the moment the crankshaft turns to the rotor arm turning, if there is the slightest bit of play will this not affect your timing?

 

I'm considering spark scatter on a cold engine with a standard ignition format. Surely a mega jolt should help to reduce an amplified cold running issue?

Edited by neal, 02 November 2016 - 07:25 AM.

[nicklouse]

Consider all the mechanical links from the moment the crankshaft turns to the rotor arm turning, if there is the slightest bit of play will this not affect your timing?

 

I'm considering spark scatter on a cold engine with a standard ignition format. Surely a mega jolt should help to reduce an amplified cold running issue?

it should start fine on Points if set correctly, never had issues before MegaJolt or any other mapped system.

 

just makes it tamer at low revs as you can set it accordingly.

 

I still run mechanical advance on mine with no real issues except for going slowly.

[Orange-Phantom]

Another alternative than the Mega Jolt to give you mappable ignition would be the Aldon Amethyst (TPS version).

 

http://www.aldonamethyst.co.uk/

 

http://www.aldonauto.../aldon-amethyst

 

Just throwing it out there as another option for you.

[mini13]

I would personally go for a trigger wheel like the megajolt unit over somthing that works from a dizzy as the  accuracy will be much better.

[Mini Manannán]

Megasquirt dues the same job as Megajolt but will let you run fuel injection, that'd get you tidy.

[mini13]

Injection on the A series can be tricky, especially on a cammy engine like this, read up on charge robbing before going that route.

[59 Speed]

If you're not into getting it fuel injected straight away you can get the mega squirt system and get it to just run the ignition side of things for now, then add injection later. That's what I'm doing (well, planning on doing ;)

With reference to charge robbing if you get a certain mega squirt (v3 I think, maybe even v2?) you can program it to cope with the siamese ports.

Edited by Smackfiend, 02 November 2016 - 05:56 PM.

[Orange-Phantom]

Yes a crank sensor is the most accurate way of measuring crank position, but fitting involves a great deal of work (engine out?) and extra cost.

 

Anybody who has set up static timing knows that, when the crankshaft is turned, there is some play before the distributor shaft starts to move.  Aldon's tests with fixed advance and a strobe light suggest that play is generally very small once the slack has been taken up, usually less than a degree.

 

Aldon state that it is theoretically possible to make Amethyst trigger from almost any type of distributor or crankshaft position sensor if you wanted to go down that road.

 

Furthermore if the chain cam drive is good enough to open and close my valves at the end of the day....

 

Anyways there's a few options on this thread for Haynes to ponder.  Always good to have choices at the end of the day!

[matty...]

With all the parts available now, it's a job you can do over a weekend, engine can stay in the car and together. The "hardest" part is swapping the crank puller over, to one with teeth, which isn't that bad to do really.

Mapable ignition makes huge amount of difference, the engine idles smoother and flats spots in the torque can be overcome with some mapping and setting up. Well worth the money in my opinion.

I fitted it to a dyno at my old work, to run Vintage Bugatti engines on, as the magnetos would give too much interference for lambdas to work. They gained power also running on Mega Jolt.