Flathead Timing/Tuning Question

So I got me a timing light with an advance adjustment and a vacuum gage. The flatty in my coupe is a '53 Ford with a Mallory dual-point with the Uni-Lite electronic module fitted and 3x97s.

Here's the stinky - I adjusted the timing using the vacuum gage and got it to pull 16-inHg at a smooth 700-rpm idle. Then I used the timing light to check the setting - it's 16-deg advanced (!). If I rev it from here, the advance usually tops out at 25-deg or so, so I know the advance is working (one thing I was worried about since it runs hot at higher revs). Since the 16-deg advance at 700-rpm didn't seem right, I retarded the dizzy as far as it would go - stops at 6-deg advanced and will idle (rough), but only pulls 11-inHg of vacuum.

What would you do next?

 

Unless the engine is a bit worn or has a cam then 16 is a bit low. The first thing I would check externally is for vacuum leaks. What happens to the vacuum up thru about 3K?
I can usually pull 18 on a tight stocker.

A stock 8BA wants about 2 deg initial and 12 total at 2500 rpm.

Im thinking that your settings come out that way to compensate for carb problems.

 

Thanks - a total rebuild of the 97s is on the short list of things to do as soon as get back from vacating next week. The vacuum pulls real good up to 3000 rpms or so, but I never got more than 16-inHg at idle.

So... the big question in my mind is whether I should set the timing for the highest vacuum setting (which would be 16-deg advanced at idle!), or should I set the timing at the 2 to 5-deg advance at idle and work any issues from there as carb/fuel/vacuum problems.

I guess what I'm looking for is insight into which variables I should eliminate first. Anyone else?

On a side note, I just took the coupe out to So-Cal for the regular Thursday night meet - stopped to get gas, and now the T10 is stuck in 3rd - AARRGGGHH! Long, slow drive back home...

 

I agree with what 286merc said about the high timing masking something else. I don't know how common it is on flatty's but sometimes the timing marks can be off too, especially if the crank pully has a rubber mounted ring.

I had similar results with my 300-6, idled great at about 16 degrees initial with about 16 inches vacuum, barely idled at 6 degrees initial with about 6 inches vacuum. I knew mine had a vacuum leak and the rings were toast with tons of carbon built up behind them. Fixed both but have been to lazy to tune it like a man.

What's the overall condition of the engine?

Chris

 

I prolly need to do a compression check to determine the condition of the rest of the motor, but you guys are making me think I need to jump on those carbs pretty quick. I intended to pull the heads and scrape the water passages, etc... while I have the radiator gone thru. I'll use that time to double-check the timing mark and replace the intake gasket, too.

Based on what you guys have said, sounds like I should get the timing set first, then work on tuning from there - that's the direction I was looking for.

Thanks.