timing specs Chrysler 251

Hello,

Can anybody tell me some timing specs for my 251 flathead 6? I know the manual i have says the timing mark is 0. at idle. But i can't find any specs for setting the advance. Because of the vacuum canister on the distributor i think there must be. I'm not that great mecanic (yet) but i like to try it by myself.

 

Here's some basic specs that you might find helpful.

http://www.carnut.com/specs/gen/chry50.html

It looks like the initial timing is in fact 0 degrees, if I guessed right on the model year. In addition to that the mechanical advance should provide additional timing as RPMs increase and the vacuum advance should do the same depending on the amount of vacuum it sees. Are the mechanical and vacuum advance in working order?

I'd guess that the vacuum advance is connected to full manifold vacuum. If so, disconnect that vacuum hose temporarily when setting the initial timing and reconnect it afterwards. You could experiment with adding a couple more degrees of initial timing to improve driveability, as long as it doesn't cause pinging under a load or make it harder to crank over when starting.

 

Thanks... yes everything is in working order and the vacuum line is connected to the carburator.
Will try to set the time right today.

Thanks again.

 

I appaers to be on the second line l, as far as carnut goes. Forgot to tell it's a Chrysler Windsor from '51. But the manual says '0'. But do i need to hook it up on the first or 6th cylinder?

Danny

 

most timing is set with #1....pulling the plug out and stuffing a rag in the #1 hole - bumping the starter until you hear the rag pop out - it should be on the compression stroke and ready to fire - the line or 0 should be at the mark when the rag pops out....this is a old way to check timing - out on the road - if you think the timing gear had jumped....

 

Thanks!

 

Are you using a timing light or are you trying to time it by "eye"?

There might be more than one vacuum fitting on the carburetor. Generally, if the port is above the throttle blade it will be ported vacuum. If below the throttle blade it's usually full manifold vacuum. My best guess would to be to use full manifold vacuum.

 

The car was running great just a week ago. I think i messed it up myself.
After overhauling my carb (it backfired when taking off at the traffic light).
Result of the overhaul there were 4 checkballs in it instead of 2. An the needle wasn't in position anymore. Now it's picks up fine and it stays full with gasoline.
After putting it back i tried to fine tune the timing but forgotten to put the vac line back on.
Then tried to set it with higher rmp think there is it where it went wrong???

Now the car doesn't drive steady and holds back a little at constant speed.
At 30 and 40 mls. After 50 it's gone and it drive well.

Danny

 

I had a 230 flathead. I put a mini HEI from Langdon stovebolt...I set it at 0 degrees, then turned the dist advance ever so slight and drove the car. I reapeated this until I found a sweet spot....

It was tough to time, but the engine liked a little more then 0

 

At idle the initial timing is now about 3 marks after '0'?
But i can't rotat the distributor enough counterclockwise to get it back to '0' because of fasten bolt and vacuumline. This is strange cause the dist hasn't been out at all?
When i speed up the rpm it goes back to the '0' mark.

 

(If the engine backfired it may have blown the vacuum advance, what to do about this, I will discuss a little later in this post.)

(There is a small pipe plug in the head above #6 cylinder. If you take out this plug you can drop a screwdriver down on the top of the piston. This allows you to find top dead center. Turn the engine slowly by hand until the piston is at the top of its stroke. Another way of finding TDC to set the timing, and to verify that the timing mark is where it should be)

To set the timing idle the engine down to 400 or 500 (slow). Disconnect the vacuum to the distributor, plug the line if it affects the idle.

Set timing to 0. Connect timing light to #1. If you connect it to #6 it will work just as well because both fire at the same time on the crankshaft.

Check the centrifugal advance is working smoothly. Also check the vacuum advance. If the engine was backfiring there is a chance it blew the vacuum advance diaphragm. You can check the vacuum advance by putting a rubber hose on it and sucking, see if the advance plate moves (with the dist cap off).

When you get all done you can try it on the road. Find hill (If you can - I know not easy in the Netherlands lol). Take off from a slow roll in low range of high gear. Give it full throttle. If there is no ping from the engine, or just a slight trace of ping, you are ok. Too much ping back the timing off.

You should be able to give it 5 degrees or so of extra advance with no problems. Due to the higher octane of today's gas. This should give you a little more pep and mileage with no adverse effects. You may have to adjust the idle to get it back down to 400.

 

Did you notice that there are 2 bolts at the bottom of the distributor? One fastens it to the engine block, the other is for adjustment?

Check the timing marks by the piston, as detailed above. If the timing marks are right you can move all the plug wires over 1 space if you have to.

 

LOL! And now you get to fix it yourself!

Rusty's got you on the right track and I'm betting you'll get it all sorted out. You can barely feel or hear these motors running when you get them to idle down smoothly at 400 to 450 RPM.

Make sure that you do get the right number of check balls back in the right places in the carburetor. You might still have some issues with the accerator pump circuit if you don't.

 

The right number of checkballs are backbin the carb. I had a rebuilt kit for it....

I kept on adjusting the timing and it runs great again.
Had a 130 mile cruise last saturday with no problems didn't ran hot a single time.

Thanks for all the tips n tricks guys.

Danny