10B Engine Loses Power When Hot

[Franklinguy]

Last year my 10B ran great.  This year it runs great at startup but loses power at low rpms after running for a while.  It will die at idle.  If the engine is shut off and allowed to cool, it runs great again, until it warms up.  When it loses power, it is still smooth.  No sputtering.  It seems to be firing equally on all cylinders.  It seems almost normal at high rpms.  Warmer weather is worse than cold weather.  This is temperature related.

 

The engine has a Stromberg OE-1 carburetor.  I disassembled and cleaned the carburetor.  Cleaning the carburetor made no difference.  A previous owner installed an electric fuel pump.  Thinking that the electric fuel pump puts out a lot more pressure than the original vacuum tank, I installed a fuel pressure regulator and set the pressure at 1 psi--no difference.  I ran it today and when it lost power, I shut it off and checked the carbureter float level--Normal.

 

I will appreciate help with this

 

Frank

[hook]

If compression is basically the same hot or cold, my vote is on trying a new/different coil and condenser.

Bill

[olympic]

I agree with hook. I had a similar problem with my 11B.  It was the coil. I relocated the coil inside the car and haven't had any problems since.

[Franklinguy]

Thank you both for the recommendation.  I was thinking carburetion.  A couple years ago, on another Franklin with a Stromberg OE carb, I had a stuck float that was causing flooding and it seemed just like what I was experiencing with my 10B.  I think I have eliminated flooding as a possibility.

 

I have known for a long time that it is better to have the coil on the inside of the firewall.  It sure gets hot under the hood of a Franklin.  High temperature tends to wreck coils of many turns of fine wire, like an ignition coil.  I am now relocating the coil inside the firewall. I am using a new coil.  It will take me a few days.  I will let you know the result when I am done.

 

I will also replace the condenser.  A previous owner installed a Chrevrolet distributor.  It should not be hard to get a replacement condenser, but I hope my friend at the local parts store can figure out which one.

 

Frank

[Scott in PA]

Frank, we relocated the coil on my 10B to the engine side of the firewall and it has been fine.  Warm, but no where near as hot as it was getting.  I went to Auto Zone and asked for a condenser for a '53 Chevy.  The Duralast part # is U1505.  Good luck, let us know!  

 

Scott Arnold

[hook]

Frank it's great to see others with the similar problem respond. But I appreciate your response and the pledge to let us know the outcome. Sometimes we are so happy that we got a problem fixed that we forget to tell the group exactly what

transpired with the fix.

Thanks

Bill

[Franklinguy]

I replaced the coil and the condenser.  The car runs a lot better than it did, cold or hot.  In my original posting, I said the car ran ok when cold.  Now it runs a lot better even when cold.  I drove it for about 1/2 hour when the air temperature was above 80 degrees and it did not lose power.  I stopped the road test because it started to rain.  Tomorrow, I will run it for about an hour, but I am pretty sure it is ok.

 

As Scott recommended, I went to the local parts store, in this case, O'Reilly, and asked for a condenser for a 1953 Chevy.  The man behind the counter came up with BWD pn G102A.  It is the same size and shape as the one that was in the distributer and it works just fine.  The old coil was mounted on the engine side of the firewall and I mounted the new one the same place. 

 

I thank everyone for the help.

 

Frank Pennypacker

[Povertycove]

I'll make one more suggestion, as I had a similar problem with an 11B. Change the spark plugs. Try something a little hotter.