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idle speed & timing
REDKG - December 23rd, 2015 at 06:58 AM

For a 1200cc engine what is the correct static timing and idle rpm?One handbook states 10 dgrees btdc and 550 rpm.
(later engines use 7.5 dgrees and 850 rpm)

Bizarre - December 23rd, 2015 at 01:22 PM

What distributor do you have?

550 rpm does not sound right


7.5 deg and 850 rpm sounds right for a vac distributor

if 009 it should be set to 30 - 32 deg max

REDKG - December 23rd, 2015 at 07:47 PM

I have an original 1960 karman ghia handbook and a '61 beetle book and they both say set rpm at 550 then adjust mixture . That is for a 28pict and 30-1 carby . Both using a vaccuum only distributor. Also has two notches on the pulley and states set to 10 degrees btc static.

As you
stated i have always used 850 rpm and 7.5 static with a 30-32 final on 1500-1600 engines.
then again the early motors had a variety of valve clearances, most people now use .006.

psimitar - December 23rd, 2015 at 11:18 PM

IIRC the 10 degrees relates to the dual vacuum dizzy fitted to some auto's and yank emission control engines.

If you only have a single outlet vac can on the dizzy then 7.5 @ 850RPM is the way to go. YOu can also static time a 009 to this for starting and then time to 30-32 deg at over 2500rpm, 3000 is best to ensure some of the cheaper dizzys don't over advance things as there curve can be larger than expected.

AA003 - December 24th, 2015 at 09:35 AM

Quote:
Originally posted by psimitar
IIRC the 10 degrees relates to the dual vacuum dizzy fitted to some auto's and yank emission control engines.


Australia had them also around '71-'72.

I think that they were set at 5 deg ATDC.

REDKG - December 24th, 2015 at 12:43 PM

timing @ 10 degrees. rpm 550

REDKG - December 24th, 2015 at 12:49 PM

rpm 550.

psimitar - December 24th, 2015 at 03:55 PM

Quote:
Originally posted by REDKG
rpm 550.


What manual is that from? Both my Haynes, Gregory and VW Service Manual say 7.5 BTDC for the majority of engines and 850rpm. there was only a small number that used 10 BTDC.

AA003 - December 24th, 2015 at 06:00 PM

Was 10 BTDC for the 1960s vacuum only distributors? The big flat ones.

REDKG - December 26th, 2015 at 07:24 AM

Correct, was the big distributor. this information came from the glovebox handbook printed in august 1960. The workshop manual from Delius,Klasing & co printed in berlin in 1965 also refers to idle at 550rpm and timing at 10 digress but mentions to set timing at 7.5 if "pinking" occurs from low octane fuel.

The 1965 glovebox book for the 1300, still refers to 550rpm but timing at 7.5 degrees.

My experience (1200cc 40hp) is it runs fine at 10 degrees but isn't smooth at 550rpm, much nicer at 850rpm

ACE76 - December 26th, 2015 at 02:39 PM

An early Australian S.P. manual dated 1/1959 clearly says 7.5 deg BTDC and approx. 500-550rpm for all 1200's from Jan 1954, up to 1959. It says the dist. is mech AND vac. advance.
This is for what we call the "36hp" 1200 (though there were two different C.R's during that time).

If you have a later 40hp 1200 it may be different. Is that what you have?

REDKG - December 26th, 2015 at 04:50 PM

first of the 40hp ( september 1960). they had a vacuum only distributor with a large body with the condensor inside.