Maximum mechanical timing on a new MSD 8362 distributor

[ggevaert]

Hi,

What is the maximum mechanical advance on an 8362 MSD distributor?
The sales brochure says 21 degrees but that does not match what I am seeing when I'm working through my timing.

I have a new MSD 8362 installed on an SBC with medium cam and I set initial timing at 18 degrees; it idles fine at 18 degrees (vacuum advance disconnected and plugged). I installed the medium springs (silver) that should be all-in at 3000.

I see 36 degrees at 3000 RPM, however, when I go to 4500 RPM I am seeing 45 degrees! 18 plus 21 only equals 39 so am I missing something?

Furthermore, I did an experiment, I removed the springs altogether as, in my mind, that means that all mechanical advance will be in right away. That then gave me a timing read of 55 (at 2000 rpm)! now I'm really confused. this means that the maximum mechanical advance of the MSD 8362 is 37 degrees? is that correct?

Another question then, if it ends up that the timing range is that large does MSD sell kits to limit the mechanical advance on a 8362 or do we need to manufacture something?

Thank You for any assistance you can provide.
Gary

[Gaz64]

Gary,

What timing light are you using?

[LARRY70GS]

On every MSD distributor I have seen, they include advance stop bushings. There are four of them, and they are color coded. To limit the mechanical advance to 18*, you must have the black bushing installed. Springs only change the rate of advance gain, not the amount.

http://www.msdignition.com/Products/...stributor.aspx

[msdtech1955]

thats a 8362 "STREET FIRE" a factory oem replacement distributor ( for -non race use)
that one does not have the adjustable bushings.

would have been better off with a 8365 pro-billet.( more adjustment and current/voltage output)
;

[LARRY70GS]

Originally Posted by msdtech1955

thats a 8362 "STREET FIRE" a factory oem replacement distributor ( for -non race use)
that one does not have the adjustable bushings.

would have been better off with a 8365 pro-billet.( more adjustment and current/voltage output)
;

Yes, I just looked at it, an HEI. According to the instructions,

MECHANICAL ADVANCE
The mechanical advance of the Street Fire HEI
distributor is tuned to provide 22° at 4,000 rpm.
Figure 4 Optional Centrifugal Advance Kit.
OPTIONAL ADVANCE KIT
If you would like to adjust the centrifugal advance of
your Street Fire HEI distributor, a Spring Kit is available
as PN 8428.

Does the above kit have different center plate and weights? That is the only way I have seen to change the amount of mechanical advance on a GM HEI type distributor.

[ggevaert]

Sorry for the delay in responding, was out of country for a while.

gaz64, I am using an OTC 3367. I am not using the dialback feature as I have a timing tape installed. I also have an older non-dialback unit that I also tried out and it shows the same readings.

My unit 8362 does not have a mechanical stop provision. I manufactured a screw that I am using to limit it to 36.
The difference in price between teh pro-billet one and mine is about $300 here so I went with the cheaper unit as the only difference seems to be the ability to install a stop advance more readily than in mine.

The 22 degrees at 4000 does not appear to be the maximum; when it says 'tuned' it seems to be with the springs and weights installed from the factory.

Gary