'75 Sceptre electronic ignition

[colc]

Any one out there fitted electronic ignition to ye olde 1725cc, and what do you recommend?

[sceptre511]

I used a Luminition system, great,no more messing around with points ever again !!

[colc]

whilst on the subject anyone else have any tuning tips? Holbay heads being slightly rarer than rockung horse poo, any other ideas [already have twin Strombergs, I was wondering about extractor manifolds /exhausts/cams]

[sceptre511]

Electronic ignition is a good start,A good quality coil is a must to get a good fat spark,having a more powerfull coil means you can open up the plug gaps 5/8 thou.as these cylinder heads are such old designs and not as efficent as modern ones the ignition needs to be as good as can be to get the best chance of burning all the air/fuel mix.

A good design cam is much better than the old 1970s one on the old holbay engine,the old holbay head had smaller intake ports than the standard head,this sounds odd but it was to keep up gas speed at lower revs ,with the old design of cam.if i was building a tuned rootes engine now i would probably use a standard head,gas flowed ,and a good modern cam.

The flywheels are heavy and can be lightened a fair bit ,but must be balenced afterwards.

I built a tuned Holbay engine years ago ,found the twin webbers made only a few bhp more than the twin strombergs,then found a 1989 Astra SRi made the same power,runs on unleaded and is an easy swap,and went that way insead.

Strombergs can be modified to flow more air quite easily for nothing more than time and some trumpets on the ends and some deep K+N filters will work very well.

The head can be skimmed a small amount to raise the compresion ratio,which will help torque.

of corse going fast is only down to how much time and money you spend !!!

p.s if you want any more tuning info let me know.

[scoot]

Hey there Sceptre511.....I've "pm'd" you.

[Roomsy]

Where can I get hold of one of these decent coils and the Lumenition ignition to go with it? I've got a '72 rapier but I assume it's all the same for the 1725?

[sceptre511]

Give merlin motorsport a call on 01249 782101 electronic ign kits from 80.00 to 200 pounds ,expensive but well worth it.you just need to tell them what distributor you have (stamped in to the side of the body ).
if you can fit a set of platinum tipped plugs and that'll be another thing that won't have to be replaced for years.