i am trying to wright a base map for my pinto i know it wont be spot on and only a rolling road will sort it out spot on.
anyway my question is if the total advance for my pinto is 36 degrees at 3600rpm and the vac advance is 15 degrees max what happens with a standard
distibutor when you are at 3600 rpm and you take your foot off the throttle
does the vac advance take the timing to 51 degrees ie 36 + 15
or is the timing limited to 36 degrees no matter what
thanks dave
I.I.R.C. the vacuum decreases with load , so at full throttle and max revs there would be no or little vacuum advance , so max advance would be 36 degrees . may need more advance at lower load/ revs? could be wrong though, but hope this helps
It is an irrelevant question as the engine is doing no work at this point. Leave the advance at 36.
quote:But what about just before you fully close the throttle? Especially a cruising speeds (eg motorway) when you're travelling at a set rpm with very little throttle open. Lots of advance here should improve fuel consumption.
Originally posted by gazza285
It is an irrelevant question as the engine is doing no work at this point. Leave the advance at 36.
vacuum advance advances the timing in proportion to the amount of vacuum in the manifold. i.e. at full open throttle it advances the timing, no?
Vey little vacuum at full throttle as the chokes are wide open.
Lots of advance at motorway cruising speed will melt the pistons. Set your maps on a rolling road or dyno, it is the only reliable way.
quote:Hmm, pre-detenation I'm guessing? Surely if you listen out for pinking and retard it until it stops you should be ok?
Originally posted by gazza285
Lots of advance at motorway cruising speed will melt the pistons. Set your maps on a rolling road or dyno, it is the only reliable way.
hello matt i have found nottingham uni does engine testing for ford i help out with some industrial stuff nothing to do with cars
anyway one of the guys there needs my help
so one favour for another he he
i will try and get to see him soon and ask about the vac advance at part throttle
i asked last week but the main man wasent in
i still think the best thing is a rolling road
but we should be able to get somwhere near
cheers dave
You may be a little overcarbed using 45s with a standard cam. Whatever you do running Webers is a dear job, my old Mk1 Escort ran a 1600 X-flow on 45s, sounded lovely between petrol stations, but cost me £90 to get to Stranraer and back (480miles) six years ago.
quote:Funny you should mention that, as I've just taken delivery of a Kent FR32 fast road cam
Originally posted by gazza285
You may be a little overcarbed using 45s with a standard cam. Whatever you do running Webers is a dear job, my old Mk1 Escort ran a 1600 X-flow on 45s, sounded lovely between petrol stations, but cost me £90 to get to Stranraer and back (480miles) six years ago.
Once installed, I plan to take the whole lot down to a rolling road and get him
to tweek the ECU too. Hopefully I'll end up with something faster and a little lighter on the wallet! 
I have set up the ignition timing on a hotrod oval race car with a very peaky cam. The vac advance was not connected as the engine runs at peak (up to 8000) revs for most of the race. The engine suppliers advice is that full mechanical advance happens at around 5000 revs and ignition timing should be set at 32 degrees. Hope this helps and good luck.
Sorry should have said it was a 2ltr pinto .
hello matt i have sent you a map in excel
its 10 x 10
see what you think
dave