I have explored using Ford (Motorcraft) DG-508 COP units.
These are cheap and readily available. Quite small and light weight.
They have a 30 degree “boot” which works well on the V12. So far I have CAD
modelled it and worked out the fitment … but haven’t implemented anything
in the flesh.
BUT. I have throttle bodies (they may not fit with the normal inlet
manifold). All I require is a small spacer from one of the throttle body
bolts.
There are a lot of comments on the net about poor reliability of both the
boot and the coil plug. It appears that Ford did not specify Gold, Gold
Flash, Phosphor Bronze or in fact anything offering any kind of reliability.
The fix is to ‘goop’ the plug socket with gel and replace the boots with
aftermarket types when they fail. (Mean while the US is apparently full of
mis-firing V8 Crown Vic’s and Ford Explorers). It is also very difficult to
find the mating plug, which doesn’t seem to be anything standard. You can
get pigtails, but they are almost as expensive as the coil.
It does look like Jaguar used this coil on the S-Type V8, but I haven’t had
that confirmed. Nor have I heard whether they have had misfire problems
also.
Ideally, you would use a Beru/Bosch coil but you are generally talking big
bucks.
There are now also ‘pencil’ coils available which don’t have a ‘head’,
rather have the coil built around the tube. These don’t appear to need
fastening, just go on like a boot. I think a Porsche V8 has them and they
were surprisingly cheap, but I haven’t got any further with that.
Pro’s. Zero distributor. Zero Coil packs in the V. Zero HT leads snaked
around your injectors.
Potential for full sequential and individual cylinder advance/knock
control.
Con’s. Driving 12 of them. Only the really really expensive ECU’s will drive
twelve coils directly.
I see no reason you couldn’t parallel up two coils to drive 6 pairs (say),
but each coil will suck about 17Amps during charging and would normally
driven with a current limited output drive.
Cheers
Mark-----Original Message-----
As long as those COP units can
- physically be secured (the tend to have a heavy mass - the coil -
towards the top of the unit);
- driven electrically as required, I can see no reason why COP on
the V12 can not be implemented.
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