Spaceboy wrote:
they are not suitable for an a-series and must be treated accordingly with the correct modifications and precautions to ensure you do not damage your engine.
OK, time for me to pipe in here, and I'll do it in point form (cuz I'm at work
• Ignition is the single biggest black box subject in the auto industry and as such carries a huge amount of ignorance particularly amongst the amateur enthusiasts.
• Phrases like “the Lucas pulled harder” and “I put a Pulsar in and it blew my engine” speak to that level of ignorance.
• In my experience the least understood component gets the blame for any calamity that occurs after that component is changed, whether it is setup correctly or not.
• There is an inexplicable notion that a distributor somehow makes power. It cannot. You can spin the little thing to 19,000 RPM and it still would not make one Shetland pony more power at the wheels: distributors help the engine make all the power it is capable of, no more. If it’s not specified correctly, not installed correctly or worn out, then it can only restrict the engine from making all the power it is capable of.
• The engine does not know what distributor it is being serviced by. Comparing apples to apples, a Lucas, Hitachi, Bosch or for that matter 123 or ECU controlled ignition WITH EXACTLY THE SAME CURVE will let the engine produce exactly the same power. Hell, it won’t know if the sparks are being generated by virgin fairies riding vandergraph generating exercycles! The big difference is if you can buy parts to get the distributor in perfect working order and change the curve to suit.
• Changing a mechanical curve means having replacement parts: there are 5 degrees of freedom when changing an advance curve: primary and secondary spring rate, primary spring preload, secondary spring cut-in and total advance. In order to change the rate of advance one has to change the springs themselves, so if you are having a distributor recurved you had better ask where the technician is getting his springs, or if he is winding them himself. No spring change, no rate change. It’s as simple as that. Lucas parts are NLA, and AFAIK Nissan (Hitachi) do not sell springs for 20 year old cars.
• In addition to the 5 degrees of freedom in the mechanical curve, there’s an additional variable: static advance. Static advance plus 2x the mechanical advance determines the total advance. If you set up your distributor completely wrong there’s a good chance of 1)overheating, 2)blowing a hole in the head gasket or 3)punching a hole in a piston. Following the 30 year old instructions for a Lucas distributor setup while installing a 123 is a sure bet to score one of these problems (see the first points, above
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• When I did the article on using a Hitachi (AKA Pulsar) distributor in A and B series engines (you’re welcome) I put the HUGE caveat on it that the curve should not be used without modification to suit the application. Very few people follow this advice. If you just plunk it in and it doesn’t work, that does not mean that it’s a bad mod, you just executed it badly.
