21 replies to this topic

[neal]

HAYNES,

 

You said, quote - 'Mainly l'd like to improve the starting and cold running'

 

And asked:

 

What effect would mega jolt have on:

Starting?
Cold running?
Tick over?
Emissions?
Mid range torque and power?
Part throttle and road manners?

 

 

You stated, quote: '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'

 

 

I think that you have quite a high state of tune engine and would imagine slightly lumpy tickover when warm let alone when cold, also does it have a lightened flywheel?

 

 

Check these links out on spark burn time and ignition systems and consider how long the spark lasts and how crucial is needs to be at the right time including your engine spec, how your engine runs below 3000rpm, then finally consider you engine spec for starting and cold running.

 

http://www.crypton.c.../burn time.html

 

http://www.w8ji.com/...ion_systems.htm

 

 

An electronic ignition such as a Mega Jolt incorporates a  trigger wheel and inductive pick up sensor, this gets rid of any mechanical interface causing ignition delays.

 

 

A timing chain that is only a tiny bit worn will cause the spark to be a tiny little bit too late, also if an engine hunts slightly (engine spec/camshaft profile?) the chain will flutter causing additional problems when delivering the spark at the right time.

 

 

In short,

 

Will a Mega Jolt system have a positive impact?.........YES, but you have to remember your engine spec and where in the rev range does it run at it's best, 3000rpm+.... it's not at tickover at won't be amazing when the engine is not up to operating temperature.

 

So, the mega jolt (or similar electronic system) will deliver a more precise and consistent spark all the way through the rev range in comparison to any mechanical delivery.

 

The timing curve can be manipulated more accurately than any mechanical ignition system.

 

But it won't completely iron out everything that you want, but it will be better.

 

All you need to consider is whether if the benefits of a Mega Jolt (or similar) outweigh the cost for a 'Road Legal Hill Climber' that pulls cleanly from 3000 rpm and you can nurse it along below that.

[mini13]

one thing I will say is mega squirt is nice even if you are not injecting as you can use it for logging stuff, the usual culprits being

 

water temp, lambda, TPS, rpm & MAP although the last two or three are a given...

 

others can be added in, like oil temp, speed (from a phone). also you can use a phone/ tablet as a dashboard/ logger

 

http://www.tunerstud...hadowdashmsmenu

 

http://www.tunerstud.../shadowloggerms

[tiger99]

In this day and age does it make sense to keep the old ignition system? I don't think so except in rare early models where originality is important. And even then, as long as you don't drill unnecessary holes, it's fitment is reversible.

Nowadays we can banish technology from about 1910 and enjoy far more consistent engine operation and better fuel consumption with no significant downside. And no faffing about with distributor weights and springs to get the advance maybe somewhere near correct at a couple of specific speeds only. Surely a no-brainer?

The carb(s) should ideally be gone too, but as well said above, that decision is not so simple on a siamesed ported engine. A 7 or 8 port head is the answer but we are then talking very serious money....

[Haynes]

Thanks for all replies and useful information.

 

Reference my cold start issue, I think the issue is that it is slow to crank over.  It has never not started, but you turn the key and it just doesnt spin into life.  Ive just always accepted this assuming its normal for a highly strung high compression engine and that the static timing might not be right, having been sacrificed for the top end.  Now i'm thinking this can be improved.

 

I'm just looking for a bit of fine tuning.  The engine has all the power I need, I want to make smaller gains and improvements, eg things like better suspension set up.  The ignition curve is something that ive never been convinced about it.  So at least with Megajolt or similar + a good rolling road session, at least i could get the curve spot on.

 

Yes ultralite flyweel and no vacuum advance.  

[nicklouse]

sounds like the whole car needs looking at.

 

duff battery? poor wiring? earths.

 

no need to sacrifice starting for top end you just get the dizzy set up correctly. 

 

so first go through the wires for the starting circuit check for voltage drop at every connection as that will help show any poor terminations/connections.

 

then work out what advance your dizzy is actually giving.

 

it might be a very simple fix.

[tiger99]

There is no absolutely definite indication of problems in the starting circuit, although there could be. A high compression engine on a standard starter motor may be the only thing that is not good. Perhaps a modern high torque permanent magnet starter motor would solve the problems? They happen to need less current too. An upgrade that makes sense in many, but not all cases.

[mikal]

I have a standard Lucas starter motor (replaced the brushes few years ago) on my 11:1 compression 1293 and it spins the engine over no problems. Give the weber a couple of pumps and the engine fires up straight away....