adjusting timing 101 advice please!
 

Okay guys,
If some one tells you that they set up the timing on your car to " 30 degrees at 3,000 rpm" what do they mean and how did they do it?
They informed me that the only adjustment for timing was by rotating the distributor, so how do you know when 'whatever ' is at 30 degrees.
Can anyone translate this into something this technically challenged man can undertsand.
Thanks
Benhttp://forums.pelicanparts.com/uploa...1074892931.jpg

First of all you'll need a timing light. What you do is attach the timing light to the car per it's instructions. Then you aim the light at the crank pulley. at 1K rpms you should notice that a little tick mark shows up near the tick mark on the fan housing. As you rev the engine the tick mark should move (the distributor is advancing) there is a second tick mark at 30 degrees and you should turn your distributor so that @ 3000 rpms that 30 degree tick mark should line up with the fan housing tick mark. Sorry unless you do it it can be hard to explain.

You use a timing light, and then rev the engine to 3000 rpm. The mark on the bottom of the fan housing should line up with the mark on the front pulley that is 30 degrees in front of the Z1 mark.


But that seems like too much advance for twin-plug. Twin-plug engines don't require as much advance, since it takes half the time to ignite the entire mixture as single plug, necessitating less advance. Usually you can retard the timing from the stock spec by 10 degrees when using twin-plug, but that depends on the specs of the motor.

That makes sense, although the car is not with me at the moment.
Seems simple?
I will borrow or buy a timing light when next with the car and try it!

Thanks Tim
Rgds Ben

This may be too obvios(or maybe not). The pulley timing marks mentioned above are only good when the timing light is connected to cyl #1

Tyson, the car was a stock 2.7 . But then the garage for the PO had 10:1 cosworth pistons and a custom crane cam. The twin plugs are fired from a 964 twin distributor system, More specs I dont have, which makes life hard when getting/applying advice.
I guess with all of the custom stuff in the engine, I will not get definative answers like timing settings, I guess it is just a case of 'suck it and see!'.


- Bill nothing is to obvious to me!
thanks for chirping in, I appreciate it!

101 Projects goes over this in detail...

-Wayne

I always like to put a mark on both the Fan Housing and pully for ease of seeing. I use a sharpie or a permanant marker

Maybe Steve Weiner will chime in, but I believe he said you should set twin plug timing so full advance is 24°.

Tom

oops, sorry Wayne
guess I have not got to that section in the book yet, figured that maybe this engine was that different that maybe it was'nt the same as regular engines.

Yep, sounds right to me.

when you're doing this for the first time it helps to have a helper sitting in the left seat and doing the RPM thing. Standing a foot from the fan with a timing light in one hand and revving the motor to 3K can be daunting to the uninitiated. Also get a good 13mm crowsfoot or dist wrench. Don't stick your paws in there with a regular wrench wilst the motor is running.

Oh yeah, don't do this while wearing a tie!!! ;)