Hitchcocks Forum

Hi there, I am overhauling my 500 std engine, and would like to know what is involved in converting the cylinder head to a twin plug arrangement.
Is there more to it than just fitting a plug in place of the valve lifter. I have to fit a new coil, so await the outcome of your responses.
Thanks to everybody.

Hi there ,
may I correct myself, it should read decompressor instead of valve lifter.
cheers.

Mr H has a twin lead coil but why would you want two sparks on a standard engine? I suppose if one plug packed up you could continue with the other one but you would probably never know as the engine isn't going to perform any better with two.

As Pete says,not really worth it on a standard engine, you probably get just as much improvement using electronic ignition and Iridium plugs. A tuned engine is a different story!
REgards, Mark

Joppalad. I have done this and it has proved (on my 1996 tuned 500 Classic) to be very successful. And I have retained the use of the decompressor. Look down a few weeks below and you'll see what I mean - and all from direct help from this excellent site. You'd have to take the head to a machinist to make a block to screw into a ne threaded hole in the finned area at centre of the head, drill a 2mm hole from centre of combustion chamber vertically through head so that the decompressor can be seated there. Yes there is enough space anmd it works perfectly.
Cheers
ChrisD

Thank you,thank you,thank you, CrissD,
You actually answered the question I asked.
My thinking is to fit a valve lifter (Mr H ) in place of the decompressor and have a bit more reliability.

Cheers

joppalad