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Timing questions

Posted By: GTXMEX

Timing questions - 09/14/14 01:09 AM

Have a 440 with MSD 6AL and Pro Billet mechanical advance distributor. Couple of pathetically dumb questions.

1) Looking down at top of distributor, do I turn distributor clockwise or counter clockwise to reduce timing?

2) Reviewing the attached picture of my engine, how would I know where top dead center is to set the timing?

3) What is the cheapest timing light I should get to check and set timing accurately? I hear the MSD box can cause issues setting timing with some timing lights.

Thanks for any help in advance.

Thumper, you up for making a little money and doing a house call?

Attached picture 8269410-timingmarkersmall.jpg
Posted By: v8punch

Re: Timing questions - 09/14/14 01:49 AM

Distribuitor rotates counterclock, if you need to retard timing, tourn it counterclock.
Don't take the cheapiest timing light, spent your money in a good one.
On summit you can find a great timing for about $139.
http://www.summitracing.com/int/parts/ino-5568/overview/

http://www.mopar1.us/engine2.html
Posted By: GTXMEX

Re: Timing questions - 09/14/14 01:53 AM

Thanks V8 punch. And your confident this light works with MSD 6 AL box?
Posted By: v8punch

Re: Timing questions - 09/14/14 02:01 AM

I have one and works perfect with msd.
Posted By: GTXMEX

Re: Timing questions - 09/14/14 03:04 AM

So I just tried my dad's ooooooldddd school Penske non-induction light and it seemed to work fine. I had 24 degrees of inital timing and something like 38 - 40 total. Per the included pixture, my timing marks stop at 30 and total timing went significantly past even the end of the timing tab. I seem to have no spark knock. The engine does smell like it's running slightly rich. Started on first turn of the switch this time easy. It was 100 plus here today when I was running it. With 165 thermostat it got to 185.

Do I leave it as is? DoI try adjusting the carbs to be leaner? Do I add or remove timing? Car has Crane cam 302 that's advanced for what it's worth.

Maybe it's just a very hot day so after driving and trying to start it would start hard and temp just would run a lot higher?
Posted By: ahy

Re: Timing questions - 09/14/14 03:40 AM

In general, with a "warm" cam shoot for around 20 degrees initial and 34 or maybe 36 total mechanical advance. Based on what you are seeing with the light, suggest you back off timing around 4 degrees.

One thing that is important to check is the timing marks. They can be off quite a bit. With an assembled engine checking with the "positive stop" method is best. The positive stop screws into #1 spark plug hole. It has an adjustable stop bolt that extends into the chamber and is adjusted to hit the piston top. You adjust the bolt so it hits near TDC. Roll the engine one way until it hits and mark the damper. Roll the engine around the other way until it hits again and mark the damper. Half way in between the marks is true TDC.

My timing marks were off nearly 10 degrees. This step is really important.

As far as mixture, a higher overlap cam will typically smell rich at idle. Its passing some un-burned mixture through the chamber. To some extent its not avoidable though correct advance and idle adjustment can help. More important is the mixture under load. One way to check is to run it down the road and run it a bit hard. Then shut it down with minimum idling and pull the plugs and read them (or post pics). Another way to check is to install a wideband AF meter and monitor AF under varying conditions.
Posted By: GTXMEX

Re: Timing questions - 09/14/14 05:00 AM

GREAT feedback!! Thanks. Any chance you can give be a link to a positive stop tool?
Posted By: Cab_Burge

Re: Timing questions - 09/14/14 05:52 AM

I use the race MSD7AL boxes on most of my race and street cars, I bought the cheapo(under $50.00 at Summit ) Flaming River battery powered timing light to use on them As far as a piston stop you can make one out of a old spark plug, knock the center porcelyn and main conductor out of it with a punch, remove the ground strap and insert a bolt(weld in place if yuo want or use alltherad with two nuts to hold in place) to act as the piston stop You cane buy them at most tool places also, I bought mine from Cheif Aircraft supply in Grants Pass, Oregon years ago when I owned and flew my airplane Make sure you get one for both 14 and 18 MM for airplane and car use AKA you need the 14MM stop
Posted By: RobX4406

Re: Timing questions - 09/14/14 06:10 AM

I hope you aren't using those dabs of paint as indicators. Those are ATDC.

If your car starts real quick with a key flick when hot, you are in a good place for initial timing.
Posted By: buildanother

Re: Timing questions - 09/14/14 06:52 AM

Uh, those marks are before top dead...
Posted By: RobX4406

Re: Timing questions - 09/14/14 07:16 AM

Quote:

Uh, those marks are before top dead...




Those sure look like a pass side view and timing mark. Reverse rotation engine?

Pic upside down?
Posted By: buildanother

Re: Timing questions - 09/14/14 07:23 AM

No, the pic is fine. btdc is the way them numbers are lined up.
Posted By: RobX4406

Re: Timing questions - 09/14/14 07:32 AM

Quote:

No, the pic is fine. btdc is the way them numbers are lined up.




Pointer on pass side, correct?

Which way does an engine rotate. Looking at front, Clockwise Correct?

Now think about it for a minute. Which mark arrives at the pointer FIRST?
Posted By: buildanother

Re: Timing questions - 09/14/14 07:49 AM

Alright, the timing light is used to locate a moving target(the groove on balancer), so the fixed tab shows the approx degrees of advance in this case. How's that.
Posted By: RobX4406

Re: Timing questions - 09/14/14 08:00 AM

The paint tabs are AFTER top dead center. Or I've been marking balancers wrong for 40+ years.

Isn't that what you decided to point out as incorrect?

I'll say it YOU ARE WRONG about them being BTDC.

Carry on.
Posted By: buildanother

Re: Timing questions - 09/15/14 12:51 AM

Got it Rob. You WOULD be correct if the numbers were on the balancer. They are on the FIXED tab.
Posted By: ahy

Re: Timing questions - 09/15/14 03:09 AM

Here's a link to a positive stop (AKA top dead center) tool.

http://chucker54.stores.yahoo.net/moptdcintool2.html
Posted By: Hemi ragtop

Re: Timing questions - 09/15/14 03:23 AM

First rule, NEVER trust a dampner and timing cover! I have seen up to 28 degrees out! Make a piston stop from an old spark plug. find TRUE TDC. Mark it, THEN check your timing! PS a big block rotates COUNTER CLOCKWISE. So rotate COUNTER CLOCKWISE to REDUCE timing.
Posted By: GTXMEX

Re: Timing questions - 09/15/14 03:42 AM

Thank you!
Posted By: elmor353

Re: Timing questions - 09/15/14 09:21 PM

The marks are definitely BTDC or I've been marking them wrong for 50 years.
Posted By: RobX4406

Re: Timing questions - 09/15/14 09:24 PM

Quote:

Got it Rob. You WOULD be correct if the numbers were on the balancer. They are on the FIXED tab.




Oh crap. On my screen it looks like the marks are on one of those chromish balancer. Need a better screen or better eyes. Sorry about that. I apologize.
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