View Full Version : will i see a difference in performance

05-08-2006, 08:52 AM
Hey Guys,
Question for anyone. I have a MSD 85551 dist with a 6al and msd coil. My car is as follows:
68 Cam
3.55 gears
turbo 350
357 chevy w/
10.2-1 comp
comp cams 280hr
victor jr intake
holley 750 vac secondary
1 5/8 headers
1.5 ratio rocker arms
trick flow heads with 202 and 160 valves.
160* therm
pretty sure my plugs are gapped at .045
Also to not i took out the dist over the weekend and noticed as many have said the dist was dirty inside. Needed to clean the green corrosion and junk. Hoping this helps perf too.
Couple things. I never cared or new about timing till i found out i may have hidden power. The springs that dictact the timing curnve are the msd factory set ones and are the strongest. Full advance doenst make its way it till 4800 or so. So given what my engine is and has what is a good initial timing? and what should total timing be? Also when should total advance be realized by...2500, 3000, ect? Also should i feel a noticable difference?
Thanks guys.

06-19-2006, 06:40 PM
Start safe and work from there. Pistons with holes in them don't make for fun motoring :)

Start with 8-10* initial and try to get about 32-34* advance in full by 3200 RPM and then experiment from there.

Every engine is different and the difference you COULD feel might be quite significant.

Your Distributor as it comes from MSD is going to give you about 21* Centrifugal (Mechanical) advance @ about 4,000 RPM with the factory installed BLUE springs and BLUE Advance Stop Bushing.

If you switch to a Silver (light) & Blue (light) spring it should come in about where you'd want to start your tuning.
Now switch the stock BLUE advance stop bushing with the supplied SILVER advance stop busing and you will be adding about 25* of mechanical advance.

This information and the instructions on how to do this came with your distributor and are available online. Here is a link to your instructions : http://msdignition.com/pdf/85551_frm22016.pdf

Usually if you are using a vacuum secondary carb you'll want to also use a vacuum advance distributor. That's the best combination for part throttle fuel mileage.

Good luck with your project!

06-19-2006, 06:47 PM
Post back with your results!

06-19-2006, 06:58 PM
Hey Chad,
I had taken the dist out to clean the corrosion( the little there was) and had put it back. I had the blue buhing like u stated but left that and it also had the heaviest silver springs from the factory. I replaced them with a light silver and blue and brougth the advance to be in full at about 2300-2500. I set timing at 14 initian and with the 22 mechanical i have a total of 36. Took the car for a drive and not the hugest difference i thought it might be but a difference. Seemed to pull better. I also replace the 4 barrel spring with a little lighter one so the 4 barrles would open sooner and again a bit of a better difference. Now i am able to let the car idle in gear and get on it the tires blaze for a decent amonut longer. I know, i know, no traction is bad but it gives me the idea that it is puuting more power to the wheels. Thnaks for the help Chad. Always looking for a helping hand.