Sign in to follow this  
fred

Hard Cold Starting Chrysler Flat Head 6

Recommended Posts

Hi all, just wondering if any of you experience hard cold starts with your flathead 6 engines.

I have a 47 Chrysler, L head 6, all ignition is newer, ie points, rotor cap wires, coil, battery cables are new, but are only 1 gauge not 00.

Fuel system, rebuilt carb, reliable fuel pump, new lines new gas tank.

After a day or more, my engine takes a lot to get her fired up, the electric shoke is working as it should,once the engine fires up, it needs to clear itself like it is slightly flooded.

Once the engine has been run for a short time, it starts first touch of the starter button 90 % of the time.

Soemtimes in hot weather, and afetr a good run, the engine will crank over slowly, and sometime I have to floor the gas pedal to clear the carb.

Now I have been trying to correct all of this, so far I have failed, as it almost always takes a number cranks and tries to get here to fire up after a day or more of not being run.

I tried the priming the carb method, gas just poured out the carb body, so it has gas, not sure what else to do.

The coil was new but had sat on the parts shelf for many years before I got it.

My engine is not rebuilt but runs very smooth, and once running runs great, good oil pressure decent consistent compression average of 105.

So any of you guys have any ideas/suggestions on this one..............Thanx Fred

Share this post


Link to post
Share on other sites

Looks like you have most everything covered. Just a couple of suggestions. I see you have new points but make sure that small wire going from the out side of the distributer to the points is in excellent shape and super clean. I tend to get a bunch of disagreement on this one but if you rebuilt your carb I would consider getting it professionally rebuilt. These carbs need to be cleaned rebuilt by some one who can set this thing up to very close tolerances in order to give top performance. Just putting some new parts in the carb very seldom

works. Again this is just me but you may try advancing or retarding your distributor, because old engines can have lots of wear on things like timing gears and chains even though you may be right on according to spec. The engine itself may be asking for a plus or minus reading... This procedure can take a bit of trial and error with engine hot and cold. Finally if you even think you gas may be three months or older consider dumping it. Always use sta-bil if you don't use that gas up on a regular basis. Sounds like you may have made your own battery cables you need to make sure the connections are soldered very good you should be able to pull on them with pliers. Use only the best connectors, no screw assemblies on these 6 volt systems.

good luck!!!

Share this post


Link to post
Share on other sites

I have read in the past that this new gas if it sit for a while it will evaporate once you do get it started it will start the rest of the day is that correct.

Share this post


Link to post
Share on other sites

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 365</div><div class="ubbcode-body">Looks like you have most everything covered. Just a couple of suggestions. I see you have new points but make sure that small wire going from the out side of the distributer to the points is in excellent shape and super clean. I tend to get a bunch of disagreement on this one but if you rebuilt your carb I would consider getting it professionally rebuilt. These carbs need to be cleaned rebuilt by some one who can set this thing up to very close tolerances in order to give top performance. Just putting some new parts in the carb very seldom

works. Again this is just me but you may try advancing or retarding your distributor, because old engines can have lots of wear on things like timing gears and chains even though you may be right on according to spec. The engine itself may be asking for a plus or minus reading... This procedure can take a bit of trial and error with engine hot and cold. Finally if you even think you gas may be three months or older consider dumping it. Always use sta-bil if you don't use that gas up on a regular basis. Sounds like you may have made your own battery cables you need to make sure the connections are soldered very good you should be able to pull on them with pliers. Use only the best connectors, no screw assemblies on these 6 volt systems.

good luck!!! </div></div>

Hi and thanx for the reply, the battery cables are factory made, but are only 1 gauge, which should be plenty, but 2/0 would be optimal.

The carb was rebuilt in a shop, not just taken apart and kit thrown into it, but who knows, it's 60 YO carb, maybe there is still a problem with it.

I always seem to have lots of gas in the carb, unless it's been a couple of weeks without starting.

My problem is possibly spark, timing, points are pretty new and gapped again at .020, the little wire in the distributor is clean and in nice shape, the dizzy was cleaned, tested, and all new parts installed 2 years ago, the vacuum advance was tested and was deemed okay.

Tonight a friend is coming over with test equipment, this guy has woked on a lot of farm equipment with 6 volt systems and also knows the Mopar Flathead engine somewhat..........Fred

Share this post


Link to post
Share on other sites

Smell your oil and see if you have the oder of raw gas in it.

You could be leaking gas in the cylinders and washing away the luberication. I would take a hard look at the carburetor. Might be leaking by. Needle valve on your float might not be seating.

Year ago I had a friend that had "high torque fields" put into his starter on a hopped up chev. small block.

Find someone that rebuilds starters and ask him what he thinks. (or if I'm crasy).

My 2 cents.

Good luck. I used to have a MINT 50 Dodge 1/2 ton truck.

Was a Coke a Cola truck. The inside was yellow. It turned over slow when I pushed the starter but never failed to start. It would go when nothing else would.

Share this post


Link to post
Share on other sites

Installed a custom made set of 2/0 battery cables today, makes a big difference, engine turns over much quicker, and fired up easier.

Will still need to run some tests, and make sure all is well.

I did however discover my igniton coil is leaking oil where the high tension wire plugs in, so the coil will need replacing too. This coil was an NOS I had got a couple of years ago...........Fred

Share this post


Link to post
Share on other sites

Fred, It looks like a lot has been covered here. I've had two 39 and a 40 Chrysler over the last 35 years and I will say that I've never had any love for the electric chokes. I put hand chokes on all my cars. The '39 I had in Alaska would start when nothing else on the place would @ 40 below zero. That would be my addition. The electric chokes just don't close up tight enough......

Share this post


Link to post
Share on other sites

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 40packard</div><div class="ubbcode-body">Fred, It looks like a lot has been covered here. I've had two 39 and a 40 Chrysler over the last 35 years and I will say that I've never had any love for the electric chokes. I put hand chokes on all my cars. The '39 I had in Alaska would start when nothing else on the place would @ 40 below zero. That would be my addition. The electric chokes just don't close up tight enough...... </div></div>

I have often wondered if these chokes close tioght enough or not, it looks like mine is completely closed when cranking the engine, but maybe not tight enough.

Alaska, well this is Manitoba Canada region here,it was down to -26 here last night, with a windchill of -45

Share this post


Link to post
Share on other sites

Wind chill?

I had a guy tell me that he was afraid that his car was going to feeeze up because he was going to drive it and thus there would be wind, it was only 35 degrees.

That wind chill thing is something that the news guys made up and it only applies to human skin.

Fred, I know this is not what you were talking about...But that wind chill thing is one of my peves..There is no such thing, it is either cold or it is not.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this