Timing mark

[FMSPEED49]

Everyone seems to set the timing different, i do the old rotate till it stumbles, and then reverse and set her in the middle. seems to be right about dead center 0.

So where are you guys ending up at?

BTW, 230 , bone stock.

[greg g]

I am runnig 6 BTDC on my 56 230 With dual carbs milled head and decked block.

[Normspeed]

I set mine at 4 btdc at idle with a timing light.

[FMSPEED49]

I'm thinking i may be too far advanced.

[FMSPEED49]

But it sure runs good, lmao

[Normspeed]

I plan to start sneaking it up a degree or twoat a time, just to see how it affects performance and running temp. Mine runs great and very cool but there's always room to tinker.

[greg g]

About 3 weeks ago, I posted a portion of an article regarding spark Knock and detonation.

Could be a good time to be a little retarded......

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=4153&highlight=detonation

[Powerhouse]

I have my 53 engine set at 10 BTDC. I had it at factory TDC and it was no good. I asked my Mopar mechanic, who really knows his stuff...he said to set it at 10 BTDC and set my point gap at .16

Know it idles smooth but is sluggish on the road...I don't get the high speeds I use to.

[grey beard]

Interesting discussion here. By the bye, just in case anyone wonders, if you continue to advance the timing on a MoPar flathead six beyond a certain point, you will notice two things. First, (and this depends on engine condition and the actual compression ratio of your engine) is pre-ignition on acceleration. The secod is that it will actually crank harder, what with advanced ignition timing blowing the piston down before the compression stroke is fully accomplished. Cranks just like the battery is low - hesitates over each top dead center.

Just for grins, I set my own timing with a light and checked it both with and without the vacuum line connected to the carb. As I suspected, the vacuum source is ported, and therefore vacuum is nonexistant with the throttle plates at idle position. This means the vacuum advance line can stay connected for timing light checks.

If any of you do bother to set your timing with a light, please remember to be sure your idle speed is nice and low. Otherwise those centrifugal weights can begin to advance and give you a false reading on your timing mark. I back my idle down till I can hear the valve tappets - these things will idle aroud 250 rpm if they're really tuned nicely - just barely ticking over.

That said, I run my timing at 10 degrees BTDC. It's sweet to listen to. JMHO:)

[Powerhouse]

After I set the timing to 10 BTDC...I notice a harder start...and it does sound as if the battery is dieing...maybe I should back the timing down to less than 10 BTDC...like 5 or so? Will that give me the stronger speedier feel I used to have? I wonder. Or maybe I should up the idle a bit.

I've been setting the timing with the vacuum advance connected the whole time...I didn't know you were supposed to disconnect it...I'm new at this stuff. I never had any actual schooling on it...just listened to what the guys in my club tell me. My dad never worked on cars...so I didn't get any helpers from him. I actually just heard that there are two adjustments to make while setting timing...the side nut and the screw in the plate....I just thought the screw in plate was to lock it in place....I would just loosen everything..set the timing and then tighten it up.

My wipers don't really work so great either...never did...I rebuilt them and there really solid now...but they hardly move the arms...I think the arms are the wrong kind...maybe to much pressure from the springs??? I don't know...I'd rather use rain-x instead.

[Tony_Urwin]

Here's an interesting post on flathead timing from over on the DeSoto forum...

http://www.duricy.com/~desoto/despatch/despatch.pl?read=17281

[martybose]

Here's an interesting post on flathead timing from over on the DeSoto forum...

http://www.duricy.com/~desoto/despatch/despatch.pl?read=17281

Unfortunately, your link requires an authenticated login and password .....

Marty

[Manuel in Oz]

I can't open the link either.

Could somebody bring the flathead timing post over for us?

Thanks

Manuel in Oz

[Tony_Urwin]

the website is www.desotoland.com

the forum link on that website is "the despatch"

it's a great forum, lot's of flathead discussion.

got t desotoland, register, and then try the link

[Tony_Urwin]

I copied the text from that link, but like I said, the forum there is worth a look. and NOW FOR YOUR VIEWING PLEASURE.....DESOTOLAND!

What follows is a tragic story. For those of you who may think I brag a little about how much I drive my car, this takes me down a peg.

I pulled my distributor last winter to check the points because I hadn't made a note of the last time I changed them. They were perfect, and I put the distributor back in and timed the ignition. All was right with the world.

I took a trip to Santa Cruz in February, and I noticed the engine pinged hard at low elevations where there's a lot more oxygen in the air. As soon as I rose to higher elevations -- say, above 1,500 or 2,000 feet -- it quieted down and was fine. I figured the timing had slipped a little after I put the distributor back in. I also thought that, because it's only pinging at low elevations, the timing must have only been off by a little bit because, if it were way off, it would ping all the time no matter the elevation.

My mother died in March under especially tragic circumstances, and being that the car wasn't pinging around town at high elevation, I wasn't even thinking about it. I then took off for a trip to Phoenix, and the car pinged hard climbing out of all those low valleys in the eastern Mojave Desert on California Highway 62, and when I crossed the Colorado River at Parker, Arizona, it really pinged until I had driven far enough to get up to a better elevation.

I knew this was hard on the engine, but I still thought that it must only be off by a little, otherwise, it would ping at the higher elevations.

Phoenix is very flat, and it was fine around the city, but when I headed for Kingman on US 93, it pinged for miles and miles until I was high enough that it stopped.

After all this, I also took it down to Los Angeles a couple of times having forgotten about the pinging at home in my usual elevation but was rudely reminded climbing on the way home.

Last Sunday, I pulled the oil pan to change the leaky rear main seal, and as long as I was in there, I had decided to change the rod bearings just as a preventative measure because my engine had overheated badly three times in the last five years during mishaps like the time my radiator cracked open in nothern California at 4 PM on the Friday before Memorial Day Weekend in 2003! I figured the bearings were probably pretty worn from the crankshaft expanding during these incidents, but I wasn't prepared for what I found.

The top halves of all six rod beatings were shattered! That is to say, the soft coating was shattered and blasted off of them.

All that pinging must have been smacking the piston downward while it was still coming upward. The gases in the combustion chamber were also reaching their highest pressure when the crank journal was straight up instead of having just passed its arc and on the way down. I also get the feeling that the extra oxygen at low elevations just made the advanced timing audible and that, in fact, it was badly advanced all the time, but I could only hear it when there was enough oxygen to make the sound.

As you all know, it's not like me to let a symptom go like that, but I'm trying to not beat myself up over it considering the circumstances with my mother and selling my house and the fact that I was fooled by its silence at elevations above 2,000 feet where this car spends all its time.

When I finally checked the timing a few weeks ago, it was six or eight degrees advanced at idle -- a sure sign that the distributor slipped because I sure didn't put it there.

Needless to say, I did the rear main seal, but my mind was far more occupied with and interested in the rod bearings. The crank looks great! The crank journals look like they just came out of a machine shop. I used Plasti-Gauge on all the new bearings, and they checked out perfect, so I know it didn't hurt the crank. I pulled a couple of main bearing caps, and the mains look great, too, and for that, I thank the full-flow oil filter.

I also think today's gasoline might have played a part in this. I'm not an expert, but I've heard the old-fashioned gasoline burned more slowly and pushed the piston all the way to the end of its stroke, while todays gas goes off with a quick, violent bang, and the piston more or less coasts all the way down from the shock. I realize this is happening in about 1/20 of a second at highway speed, but you get the idea. This could mean the effects of advanced timing are worse nowadays because the burning happens more quickly and the maximum pressure is reached in a more violent fashion, meaning the still-upward-moving piston is smacked harder than it would have been with the gas of yesteryear. I'm not as sure of this, but it's a thought. Maybe one of you knows more about gasoline than I do.

So, CHECK YOUR TIMING! ! !

Here's a bad image of one of my upper rod bearing caps. I just set the cap on my scanner so it's not the best quality, but you'll see the damage clearly enough. I went all over the internet looking for images of bearing damage. I finally landed on the Lycoming Diesel web site and looked at all their images of "bearing failures." What they call a "bearing failure" from pre-ignition is a fraction of what I found in my engine. My bearings were WAY beyond what Lycoming calls a "bearing failure."

JON

[Tony_Urwin]

P.S. If you want to see the image of his bearing, you'll just have to register at DeSotoland

[Don Jordan]

It is with great interest that I am reading this timing thread but I do have some questions.

1. My tack and dwell won't work with positive ground. So I don't know how to tell the idle other than ball park the sound.

2. Does anyone make 6V timing lights?

3. I have a mark on the pully about 1/2" wide - it was painted on there when I bought the car - I am so embarrassed to ask this but is BTDC with the mark on the drivers side?

4. I think my distributor is upside down. (now you really think I'm an idiot) the vacuum advance is about 11 o'clock and the wire from the coil is completely underneath.

The reason I am so interested in all this is I CAN'T GET THE CAR TO START!!!

If I spray starting fluid it will start and it runs fine - other wise it won't start.

New battery, rebuilt starter, generator, new volt regulator, new wires. It won't turn over as fast as I think it should to start. I don't know what else would hold back the cranking speed - of course now I understand it might be timing.

Once it is running it purrs. I drove it 200 miles the other day - no problems other than starting. Same hot or cold.

Thanks

[Jim Yergin]

Don,

It is my understanding that with a 6 volt system the size of the battery cables is very importnant to get the proper cranking speed. In your list of things done to correct the problem I did not see battery cables. Do you have the correct size?

Jim Yergin

[Don Coatney]

4. I think my distributor is upside down. The vacuum advance is about 11 o'clock and the wire from the coil is completely underneath.

Your distributor is not in upside down. Or your and my distributors are both installed upside down. But as long as they work who cares?

Follow the good advice given by Jim Yergin on battery cable sizing.

[DonaldSmith]

It doesn't really matter. What matters is where the rotor is pointing in relation to the plug wires.

Usually plug wire No. 1 is at 7:00, and the rotor of of course points to 7:00 when the No. 1 piston is at or near top dead center (TDC) at the end of its compression stroke and beginning of its power stroke. (Read squeeze, bam.)

The rotor goes around once for every two engine revolutions. The trick is verifying that the piston is TDC after the compression stroke. With a thumb over the plug hole, you will feel the compression as the piston rises. If you're 180 degrees off, no compression. Pistons 1 and 6, and other pairs, are at TDC at the same time, but only one is at the end of its compression stroke.

My rotor is 180 degrees off, but so are the wires, with No. 1 where 6 should be, and so forth. It works. I'll leave it for now.

If your rotor is 180 degrees off, you can pull the distributor up an inch or so, rotate the shaft 180 degrees, and lower the distributor to seat the end of the shaft in the slot.

[Don Jordan]

Don - thanks for the pix. My dist. is just like yours but different from what my Chilton's book shows. Again I guess if it ain't broke...

2 questions - I notice 3 tubes off your vacuum advance - what's that?

and your oil tube is straight down - mine has a dog leg in it. Just curious.

I bought my battery cables from an auto parts store - I didn't even know they had different sizes - what size do I need?

Thanks again

[Don Jordan]

I gotta tell you it sure looks easier to get to the distrib. when the engine is out. The wire from the coil was so hard for me to get to I finally just took the dist. out.

[greg g]

Battery cables, and cabel going from the solenoid to the starter should be a minimum of 2 gauge cable. Thsi would be nearly as thick as your little finger. Six volt systems, especially heavy draw items like the starter depend on current flow to get the job done. Anything that introduces more resistance in the circuit, loose connections, poor grounds, corrosion, and or thin 12V style wires, will make the circuit less effective, and make the accessory work less effectively.

http://www.dave-cushman.net/elect/gif/gaugeplate.gif

[Don Coatney]

Don - thanks for the pix. My dist. is just like yours but different from what my Chilton's book shows. Again I guess if it ain't broke...

2 questions - I notice 3 tubes off your vacuum advance - what's that?

and your oil tube is straight down - mine has a dog leg in it. Just curious.

I bought my battery cables from an auto parts store - I didn't even know they had different sizes - what size do I need?

Thanks again

Don;

My engine is from a 1953 Desoto. They must have replaced the dog leg with a straight pipe for some reason. There are not 3 tubes connected to my vacuum advance. I had a loop in the tube to allow for movement when I set the timing. I have sence eliminated the loop and replaced it with a short section of rubber tubing.