No vacuum advance on my dist, trying to set the timing Options

[terrymason]

I'm trying to time my 1.8 with carbs, and am having a rough time. I'm not sure if I am suppose to have a vacuum advance or not on my dist. Anyone know if the dist on my car is stock, or if it's an "upgrade". If it's an upgrade, is it any good?

I ordered a new condenser for it, and the one I ordered didn't seem to be right (original had a separate bracket that held the plug in - replacement had the bracket attached to the condenser). I believe that I had to mount the condenser upside down for it to fit properly (as it was originally). If the condenser was mounted in what seemed to be the proper position, the dist would not fit back into the engine properly.

(IMG:http://img106.imageshack.us/img106/5383/picture2007012as1.th.jpg)

[Kargeek]

Terry,

You have an aftermarket bosch "009" distributor. Some say not a good version to use on the type IV others use the 050. There are differences in the total amount of advance and advance curve between the two. However, you can get your engine to run OK...as a starting point try timing the engine with a total advance of 30-32 degrees at 3,000 RPM. "power timing" this way gets the distribuotr advance in all the way in. You'll need an adjustable timing light using the TDC mark on the cooling fan. Dial the timing light to 32 degrees run the engine at 3000 RPM and set the distributor on the TDC mark.

Always be sure to have your timing correct prior to adjusting your carburetors.

I'm sure others will have a comment on this...

DH

[So.Cal.914]

Yes your car came with a V advance, what you have looks like a Bosch 009.

Is it any good, IMHO, in a word, NO. But your car will run.

[terrymason]

You'll need an adjustable timing light using the TDC mark on the cooling fan. Dial the timing light to 32 degrees run the engine at 3000 RPM and set the distributor on the TDC mark.

Kargeek,
Thank you very much for that explanation! I've been going back and forth from different sources, trying to figure out exactly how to time my engine (I don't think I really understood what was meant by "advance"). I'll give that a try tomorrow.

Thanks again! (IMG:style_emoticons/default/clap56.gif) (IMG:style_emoticons/default/clap56.gif) (IMG:style_emoticons/default/clap56.gif)

[Kargeek]

Terry,

You have two basic types of engine timing advance- static and dynamic. Let's say your number one cylinder piston is set at top dead center on the compression cycle- the piston is at the top and both intake and exhaust valves are closed. If your ignition timing was to fire the spark plug you would have 0- spark timing.

If let's say, the spark plug was to fire 5 degrees of engine crankshaft rotation before top dead center, you have 5 degrees of advanced timing.

If you had your distributor timing set to fire 5 degrees- after top dead center- your timing is retarded 5 degrees. Engines like to operate with spark timing advanced...

Engine distributors have a mechanical advance system that is operated by a set of centrifugal weights- as engine and distributor RPM's increase, these weights move the distributor's contact points and "advance" the engine timing. Different distributor designs and their centrifugal weights have an "advance curve"- a rate of advance and total amount of advance depending on the engine RPM's.

Now, with vacuum advance- this is a vacuum diaphragm linked to a shaft connected to the distributor contact points mounting plate. A vacuum line connected from the engine manifold or carburetor provides the necessary vacuum signal so under part engine load and idle, high vacuum "advances" engine timing.

So, static, dynamic and vacuum advance engine timing is to provide a variable amount of ignition spark timing to suit various load and speed conditions of your engine.

So, what I'm helping you to do is to get to a starting point- timing your engine at a high RPM will max out your distributor's mechanical advance and leave you at idle with around 5 degrees of static advance.

Here's an article from air cooled net- some good basic reading on distributors:

Air Cooled Net

I am sure their are other engine experts here are can shed some additional light on this subject.

And remember, do not mess with your carburetors until you have your engine timing correct.

Good luck!

DH

[rhodyguy]

trying to sustain 3200rpm and setting the timing you will need a third hand. unless...turn the IDLE SPEED adj screw on the dr side carb in until you achieve the desired rpm. DON'T touch the pass side screw, as the linkage and pass side carb will follow suit and the pass idle speed screw will (should ) be off of its stop. if you have adj the valves, the dwell is correct, the timing is correct, now would be a good time to check (while the idle is high) the flow of the carbs with your Unisyn/syncronizer tool using the forward venturi of each carb.

k