Guy Croft 2L Video

[So Cal Mark]

since the question of spark plugs came up in another thread, read Croft's text to get his thoughts about plugs;


http://www.youtube.com/watch?v=pPq694wA ... Ijl0f70pTl

[guycroft]

and a 'plug' for your Computronix ignition Mark which is really a piece of work.

I buy them from Mark and have the calibration set by a couple of guys in the UK (H&H Ignition Solutions) and they said to me, 'we just cannot figure out how they fitted such a powerful system into such a small space, never seen anything like it, the spark is like a bolt of lightning!'

GC

[mdrburchette]

That's a big feather in your cap, Mark! Way to go.

[boogiedude]

and a 'plug' for your Computronix ignition Mark which is really a piece of work.

I buy them from Mark and have the calibration set by a couple of guys in the UK (H&H Ignition Solutions) and they said to me, 'we just cannot figure out how they fitted such a powerful system into such a small space, never seen anything like it, the spark is like a bolt of lightning!'

GC

Why do they need to be calibrated, and what exactly are you having done to calibrate them? Recurve? Doesn't that make them somewhat useless if they need to be adjusted for our engines after purchase?

[maytag]

Boogie, do you think that the curve that is right for your motor its also going to be correct for mine?

I mean, you do understand that the optimal curve for your motor is derived from many factors, including cam, carb, spark plug, altitude, and yes, even gear ratio and the way you drive, right?

[spiderrey]

Thats just his way of gettin his cheap shot in. Ignore it.

[maytag]

Thats just his way of gettin his cheap shot in. Ignore it.

Oh... I see. What's the old saying about "better to keep your mouth shut and be thought a fool.... Than to open it and remove all doubt"....

[So Cal Mark]

Guy is building race motors and has the curve changed slightly to suit his particular application.

[boogiedude]

What's with the hostility? It was a simple, legitimate question. I am a huge supporter of marks products. I've purchased two sets of his badges, his front spoiler, his radiator and cooling fan, his turn signal kit, and I have his header and full exhaust system. There was no cheap shot intended.

Boogie, do you think that the curve that is right for your motor its also going to be correct for mine?

I mean, you do understand that the optimal curve for your motor is derived from many factors, including cam, carb, spark plug, altitude, and yes, even gear ratio and the way you drive, right?

From what I've read, and based on my basic(but growing) understanding, while distributor curves should ideally be set up for each individual motor and dialed in with the driver, they should still fall in a ball park curve and advance limit.

I happened across a post on guy crofts website regarding these units, and they do sound amazing, but from what I read over there, the units need to have their total advance increased somewhat significantly to match even the stock distributor curves. The unit maxes out at 20 degrees total advance out of the box, while our stock units went up to 30ish IIRC. And guy croft recommends 34-36 degrees total advance for all TC motors, not just his highly tuned race motors.

I'm offering a complete distributorless igntion system for Fiat TC or X1/9s. The kit consists of a billet trigger unit that mounts in the block location rather than cylinder head; a coil pack, spark plug wires and harness. All electronics are contained in the trigger unit. The system produces 60,000 volts up to 12,000 rpm. Advance is obtained with weights and can be adjusted, but comes from the factory with 20 degrees of advance. The trigger unit was developed for off-road racing and is sealed from dust or water. The kit is very easy to install and comes with installation instructions.
The kit for either engine is $550US. Priority shipping in the US is $20, international shipping is $52, Units can be ordered directly from my website at http://www.allisonsautomotive.com

http://www.youtube.com/watch?v=x-dDV0Akhcc

I just bought one of these for a STIII 2 liter 8v and I can say it is a 1st class setup!

For TCs I recommend recalibration of the advance curve to give 34-36 deg total but for the 128/X19 1300//1500 types SOHC it is right 'out of the box' (28 deg total). I had mine adjusted (quickly & at remarkably low cost) by H&H Ignition (who have a link on this site). H&H remarked (and they really are experts) 'never seen a spark like it..!'

Similarly it could be used on a 16v conversion and they need less advance than even the SOHC so recal is a must.

I don't have a problem with recalibration at all - just for the record. I happen to think it is marvellous to have such a nice unit available at all.

G

Once again, I'm no expert, but just trying to gather facts from those who are in-the-know, and make an informed decision.

[So Cal Mark]

even though the mfg says the unit has 20 degrees of advance, in reality it's about 22. We recommend setting initial timing at 12btdc. If you want to change the curve, or set it for more advance, it's easily done by changing the springs on the advance unit.

[guycroft]

I don't want any problems caused to Mark Allison because we here happen to recurve the distributors, OK?

If Mark finds them OK as supplied that is fine by me.

GC

[coise]

What do you guys think of this one?
123 ignition installation manual:
http://www.123ignition.nl/pdf/123FIAT124.pdf

I like the selectable curves up to 36 degrees.

[Daniel]

Marks is a complete replacement not a module ad on so its not a fair comparison

[coise]

Ooops sorry, I wasn´t trying to put Mark´s Computronix unit down at all.
I was just wondering what is more important for a mild modyfied engine (and if you want to rev it above 5500 RPM from time to time) , is it the curve or the quality of the spark?
Thanks

[So Cal Mark]

by the time your engine gets to 5500, the curve will have been at max for some time and spark intensity is crucial