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Help with setting my timing
http://classiccamaroclub.mfatw.com/viewtopic.php?f=3&t=3958		 Page 1 of 2
Author:  Yappy [Thu Jun 19, 2014 7:05 am ]
Post subject:  Help with setting my timing
I am after some help.

I want to set my timing as I had to change my pickup coil and I was wondering what I should set it at.
My Camaro is a 327 with a gen 2 HEI distributor, I have an Edelbrock 4 barrel with the standard intake manifold and the engine is fitted with performance headers.

One other thing I have noticed is when I disconnect the vacuum pipe on the distributor the engine revs drop loads, could I have week Vacuum advance weight springs.
It has been a while since I have set timing on a car and at idle I am sure vacuum advance should not kick in that much :crazy: , please correct me if I am wrong.

Any help would be great :thumbup:
Author:  3rdGenmalc [Thu Jun 19, 2014 8:31 am ]
Post subject:  Re: Help with setting my timing
Not vacuum advance springs, vacuum and mechanical advance are separate.
The springs hold the weights back, if the springs were weak the weights would up the revs.

I disconnect my vacuum advance, plug the port on the carb, then lower the rpms to about 600.
I set my timing to about 18º.

Try this;
http://www.carcraft.com/techarticles/cc ... ed_basics/

and this;
http://www.superchevy.com/how-to/46178/
Author:  Yappy [Thu Jun 19, 2014 1:48 pm ]
Post subject:  Re: Help with setting my timing
Quote:
Not vacuum advance springs, vacuum and mechanical advance are separate.
The springs hold the weights back, if the springs were weak the weights would up the revs.
Thanks for the links, good reading :clap: :thumbup: :clap:
Looks like I will be making some timing tape tonight then

This is what is happening as soon as I put the vacuum hose back on the revs raise loads and I am feeling this is a bit to much.
I think new springs are the order of the day, good thing is a new weight kit with springs are cheap :thumbup:
Author:  sportsroof [Thu Jun 19, 2014 2:57 pm ]
Post subject:  Re: Help with setting my timing
If the idle speed changes when you connect the vac line, you are connecting it to the wrong port. There should be a brass port about halfway up the front metering block on a Holley, that is where it should go to. I suspect you are using the port at the carb base or intake manifold. HTH
Cheers, Martin
Author:  Yappy [Thu Jun 19, 2014 3:01 pm ]
Post subject:  Re: Help with setting my timing
Quote:
If the idle speed changes when you connect the vac line, you are connecting it to the wrong port. There should be a brass port about halfway up the front metering block on a Holley, that is where it should go to. I suspect you are using the port at the carb base or intake manifold. HTH
Cheers, Martin
You know I think you are right there :thumbup:
I will investigate that tonight
Everyday is a school day!!!!
Author:  3rdGenmalc [Thu Jun 19, 2014 4:02 pm ]
Post subject:  Re: Help with setting my timing
I have a Demon carb and connect my vacuum to the port below the throttle blades, that way the
the vacuum works only when the blades move.

The debate about where to connect is very furious, I´ve seen it on several websites.

Which Edelbrock 4 barrel do you have, 1405 ?

Here is the instruction sheet for 1403, 1404, 1405, 1406, 1407, 1409, 1410, 1411, 1412, 1413.
Check the carb front pic, it shows the vac ports for the distributor, left is above throttle blades right is below..

http://static.summitracing.com/global/i ... l-1405.pdf
Author:  Yappy [Thu Jun 19, 2014 5:31 pm ]
Post subject:  Re: Help with setting my timing
Yep the topic of were to plug in the vacuum hose is a widely discussed topic, but I asked here as this is Camaro specific and you lot of Camaro lovers will have the best experience for car specific
Author:  Yappy [Thu Jun 19, 2014 6:44 pm ]
Post subject:  Re: Help with setting my timing
Been out and working on the car and have tried the vacume pipe for the distributor on the passanger side port on the carb, that's the one above the throttle butterflys.
All I can say is it is a lot better when moving from neutral to a gear, before I had to have idle revs high as the revs dropped loads when pit in gear. I have yet to go for a drive as it started to rain so I will do that tomorrow.
Thanks for all the advice
Author:  Yappy [Fri Jun 20, 2014 3:45 pm ]
Post subject:  Re: Help with setting my timing
Update on the timing.

I have Advanced the timing to 14 deg and it runs great.
I have changed the vacuum hose to the one on the passenger side and the car is a lot better when shifting from neutral to a gear, and I think I know why this happens.
There has been a lot of discussions on-line about which vacuum port to use on the edelbrock carb, my recommendation is if you have a manual its fine to use the driver side port but if you have an auto I would use the passenger side one.

Reason behind this is the passenger side one does not have vacuum at idle and the drivers side does.
If you set the timing and idle with the vacuum disconnected as you should, then plug the vacuum pipe back on to the drivers side the revs will raise a lot because of the vacuum advance caused by a constant vacuum,and what I was doing was setting the idle again as it was around 1200rpm.
This is not a strong idle as its all reliant on vacuum produced, as soon as you place the car in gear (Auto only) the revs drop slightly and so does the vacuum making the revs drop even more thus leading to a lower idle then you really want when in gear and standing still.
If you use the passenger side vacuum port this will not happen because the idle is purely set on carb set up and not reliant on vacuum as the passenger side port has no vacuum at idle.

This is only my opinion but I find that my car is a lot more stable on idle going from neutral to gear.
Author:  Pa's F-bodies [Sat Jun 21, 2014 5:54 pm ]
Post subject:  Re: Help with setting my timing
You need to use the port without vacuum what ever the set up or you won't get full advance eg. vacuum and mechanical together.

Because if you set your static timing with the pipe on the vacuum side then the vacuum advance is already used so all you have left is the mechanical advance?

That's how I set them up anyway and I think that all standard car's are like this?
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