I just finished rebuilding my eng. I put an edelbrock carb 600cfm #1401, edelbrock intake, have a XE256 comp cam in it, dynomax headers, I also have the pertronixs ignition kit under my stock distributor with a recurve kit (medium springs used) and the pertronix 40,000 volt coil, my heads are the original 194 camel humps pocket ported and polished.
Im having problems setting my carb and timming to get good performance. The timming is set at 10 BTC and my carb is set at 1 1/2 turns out on both. The shop told me they think its my distributor because the advance when at 2500 rpms only advances to 28 and should be around 35-40. I went and bought a recurve kit and used the silver (Medium springs to see if that would help.
It seems to be running better but on exceleration it just doesnt seem like it has enough smooth power when I step on the pedal.
(Poor engine performance).
Does my timming need to be advanced farther? It is set at 10 BTC now, the book say 4BTC, but I dont have it stock anymore.
Any help is much appreciated.

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Mike
68 RS Convertible
http://www.camaro.lookscool.com

I wish Ignitionman were here to answer this one.
Do a search on past messages here and in the Engine and Drivetrain areas. There are some great past answers to the advance question.

You need to get the distirbutor to advance to around 36 degrees total advance somewhere just above 2500rpm.
When you get the distributor to do that, then work with the springs to get as much adavance as the engine will take without pinging.

Take a good look at the advance weights in the distributor and see if they are contacting the cap and stopping the advance too soon.
Normally there is a slot in the breaker cam piece that is contacted by a pin on the bottom of the dist shaft. This is supposed to limit the total advance, not the weights.

Some times people swap the weights and they don't fit right or are the wrong shape and the advance gets limited by the weights. Otherwise it's probably the slot that needs lengthing or the pin has a bushing on it that can be modified.
You really need a distributor machine to do it.
I think you need around 10 to 14 degrees advance at idle. 4 is too low.

Do the search on advance and read up on it.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Does any one here Know how to ge a hold of Igintion Man? He is great on stuff like this, & his tips have always helped me a lot

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johnny

[This message has been edited by johnnyr (edited 11-18-2000).]

I advanced my ignition to 14 btc and seems to run a heck of allot better. No pinging when I excelerate.
Can I keep advancing tell I get pings and then just back it off a bit tell it stops?


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Mike
68 RS Convertible
http://www.camaro.lookscool.com

Make a mark on your harmonic balancer at 36 degrees. Use that mark to set your total timing somewhere between 36 and 40 total. 327's seem to like around 38 to 40 total timing. This will be your best bet for performance. Remember, detonation can be occuring even though you don't hear it, so don't get too carried away. Sounds like you're headed in the right direction already. Keep us informed on how it's running and the changes you make.

I dont know if all of them have it, or I was just fortunate. But after I got the total timing I wanted. I stuck a allen wrench in the vacumn advance hole and twisted it until my intial timing was at 10 degrees.

Just a thought, but you must first disconnect the vacuum advance hose and plug it before setting initial timing. Then try 10 degrees initial advance at 600rpm. This is a bit of a dance as turning the distributor to get this number will change the idle so you might need a second set of hands on the idle screw. Total advance should only be about 32 with it all in by 2800.

If you set initial with the vacuum connected, you'll be way, way off.

I was reading the post on timing and I have a question, on my stock 69 z with 302 the timing also says to set a 4 degrees. aat that setting the motor is not very responsive at lower rpms. Now I have it set around 8 degrees with the vacumn advance disconected, I run a 50-50 mix of sunoco 110 and 96 unleaded to prevent detonation. Why is the factory timing on early engines set so close to tdc if they run so badly at that setting?

Well I marked my harmonic balancer bumping the engine and using the timing mark and etched marks at 10 btc, 20 and 30. Just like doing a dial back but on the balancer.
Check my total advance with the GM curve kit-weights and springs. Total advance was 28 deg. So I changed back to my original curve weights and used the springs in the kit. They came with gold-heavy, silver-medium, and black light.
The silver brought the total to 30 with an initial timing of 12.
The black brought the total to 33 with initail timing of 12.
So I will stick with the black springs and retain my original curve weights. I beleive if i advance my timing to 14 initial this should increase my total too. Thats next.

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Mike
68 RS Convertible
http://www.camaro.lookscool.com