Howdy,

Heres an easy one.....

Whats the correct ignition timing on a 74 Twin Carb 1800 with the engine code of AP. Mr Bentley doesnt seem to list the AP engine codes in the book. Is AP a recon engine code or an Aussie thing.

Im thinking it should be 10 degrees ATDC but the bus doesnt seem to like that. ) degrees seems to be fine but im sure thats not right.

Also is anyone using a dwell to tune properly is it worth the investement, cheapest ive found is Jaycar around $79

Cheers

Scotty

ap is 1800 my haynes manual says 7.5 degrees btdc
marcel

Marcels got it Scotty 7.5 degrees btdc. Most Aussie 1800's will be AP engine codes.
With so many engines having been re-built and modified over the years, it's best to go by what's on it for timing. I believe your's will have a single vacuum distributor and dual carbs (stock solex) and a manual, which will be as Marcel said. The timing is set with the vacuum line connected and the engine warm (so choke is off).
It's also worth reving the motor with the vacuum line connected and not connected to check both vacuum and mechanical advance work correctly.
As for the dwell meter, I got one which is handy, especially to see if dwell bounces around as you rev it (fault finding). I have found I can set it quite accurately with a feeler gauge though.
Don't forget the Bently is a US manual and they got a lot of options that were rare here such as a multitude of polution gear, FI was very common and dual vacuum advance distributors.
Cheers,
Andy

Done....

Both busses are now running bewdiful

Just a hint..
The vac advance should be disconnected to set the timing.
The dwell meter is best used without the engine running. You need to read the meter while cranking the motor on the starter motor.
Cheers