A 1978 18V847 should have a 41610 distributor, and it is this that
determines the factory settings to use. The strobe setting should be 10
degrees @ 1000 rpm. There is not a Static figure given in the sources I
have, but for the pre-1976 engine with the same distributor it was 7
degrees, so that should be OK to get it running.
You might like to check the centrifugal and vacuum advance while you are at
it, you can find the information on by web site below. Select 'Spanners'
and 'Curves' for the figures, an adjustable timing light is extremely useful
here.
If you have a UK spec car with the vacuum take-off from the rear carb you
can run the engine at 1500 rpm or so and connect and disconnect the vacuum
pipe while watching the timing to see how much it changes. Alternatively
you can suck on the carb end of the pipe, but watch out for petrol.
You need to be careful with using a vacuum gauge on a UK spec car as you can
get it over advanced and it will pink at light throttle on a slight incline.
This seems to happen on my B (albeit with a non-standard distributor at the
moment), although I used that method many years ago on an A-series engine
without pinking. In that case I advanced it until the needle started to
flick, retarded it till the needle was steady, then retarded it a further
3/4" Hg.
PaulH.
MG Cars Webring MG Site of the Month - September '99
http://freespace.virgin.net/paul.hunt1/
(or if that URL doesn't work try )
(http://194.168.54.52/paul.hunt1)
----Original Message-----
From: Martin C. Jones <M.C.Jones@staffs.ac.uk>
To: mgs@autox.team.net <mgs@autox.team.net>
Date: 16 September 1999 12:16
Subject: MGB Timing
>I want to set the ignition timing dynamically on my 1978
>BGT but I've read conflicting information in a few of the
>books(the degrees BTDC vary widely)
>
>My engine number is 18V847H
>
>It has also had its heads converted to unleaded.
>
>Thanks
>
>Martin
>
>
>
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