I know most of you will probably disagree with my setup but, it has been working for me for quite a while. I have initial timing set at 14 deg. idling at 900 in park. The mechanical advance is completely locked out. If I use the mech. advance, it wants to come in at 800 rpm, which completely f*ks with my idle. I have used stock weights and springs, and aftermarket setups in as many variations as possible and still cant delay the mech. advance. I want it to come in around 1400 rpm. Does anyone out there have any suggestions on how to delay the mech. advance that far?

 

the mechanical advance shouldn't come in that quick, and you say you've tried heavier weights and springs? try another distributor and see what happens.

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ICON Motorsports

1st & 3rd
MM Black Diamond 538 F&AM

 

Weights (and the center cam) limit how much advance to give. Most are around 22 degrees but you can change it by swapping the weights and center cam.

The springs limit how quick the advance comes in. Light springs allow the weights to advance at lower rpms. Heavy springs hold the weights back until higher rpms.

Vacuum advance is usually about 10 degrees and is used in part throttle operation.

You have 14 degrees initial. If the mechanical gives 22 then your total advance is 36. The springs should hold back the weights from going to full advance until about 3000 rpm. Unless you have some heavy springs, the weights will start to move at about 1200 rpm but you want to be at full advance before 3000 rpm. Stock springs will hold the weights back from full advance until around 4300 rpm or so.

If you can't figure it out with a timing light I'd suggest taking the distributor to someone with a recurve machine. It's worth the money to get it set up properly.

Locked out advance means that there is no mechanical or vacuum advance at all. My distributor is locked out and set at 38 degrees. I use an ignition retard to start the engine. A race engine doesn't need any ignition advance since it's either running at idle or WOT with limited part throttle operation driving through the pits and down the return road.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

[This message has been edited by Stephen 87 IROC (edited April 29, 2001).]