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No Power


Guest rickbrown

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Guest rickbrown

1947 V12. First time out, found the car had little power, lots of trouble pulling hill. Compression test revealed blown head gasket left bank inside cylinders. No water jacket there so no problem with leakage. Put new gasket on and torqued properly, recheked and compression is now acceptable -- but now it has even less power, cannot even start out on a hill. Car starts and idles fine, revs fine, but no power.

Checked spark by pulling one wire on either side and holding out from plug -- have nice blue spark jumping to plug. Checked fuel by pulling line from carb, cranking engine, and the fuel pump seems to be pushing plenty of gas.

So, I have a car that starts fine, idles fine, revs fine, has spark and gas, but absolutely no power. Starting out on even a small hill is impossible -- I leave out the clutch and eventually the car dies as revs equal the zero MPH of the rear wheels.

I am now going to drain the gas tank and fill with fresh gas. Someone also mentioned possible collapsed muffler, but seems to be plenty of exhaust exiting the tailpipe.

I'm stuck -- would really appreciate any suggestions. Thanks in advance.

Rick Brown

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It sure sounds like you are losing one bank of cylinders. These 12's will start up and run on 6 cylinders but have little power. Be sure you have good spark to both banks. A check of the spark plugs would show if the ignition is up to snuff. I had a similar problem and it turned out that one set of points would stick open. Another remote possibility is that one side of the carburetor is stopped up. There are only 2 small equalizing passages between the left and right runners in the intake manifold so anything above idle could starve one bank.

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Sounds like 6 of 12 cylinders to me also. Remember, each set of points fires cylinders on both banks, so you many have pulled two plug wires from the same set of points. You can measure the voltage at the points, just look out for the fan. Should be 3-4 volts on each set when engine is running. You may need to remove distributor to check points. If points are fine, check coil, and make sure brushes are touching.

Abe

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Guest rickbrown

Thanks for the input. Basic concept of running on 6 cylinders must be right when you think about it. Spark is good on all 12, so I went on to gas. Began my eliminating a fuel pressure regulator and bypassing the accessory electric pump. Car now has enough power to go. Still not perfect, but will drain stale gas and go from there.

Car people are the best, and I thank you guys for the help.

Rick Brown

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Peecher, Rick and I have the same no power problem. I still have not ruled out the points problem yet. My engine runs and sounds relatively smooth but the carburetor needs priming to start when cold and the fuel bowl does not drain dry when it sits. The accelerator pump squirts fuel but it still needs priming. The plugs on one bank look sooty compared to the other bank. Could you explain further or how to check the clogged carburetor passages you mentioned?

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Sounds like you're losing spark on one bank. The first thing to check is the condenser for that bank. Another possibility is that the power valve in the carburetor is leaking causing a way-rich mixture. This would also be the cause for having to prime it as the fuel in the carburetor will leak out as the car sits.

I would check the spark first and if it's ok, take a look at the carburetor. Any dampness ( gas) on the throttle base or in the cavity under the power valve is a sure sign of a leaking power valve. It doesn't take much fowling of the plug before they mis fire so besure to clean them.

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Thanks Peecher, My coil is fresh from Jake, with new condensers and I am taking it for granted. Luckily, this car came with a collection parts from the previous owner/mechanic that owned it since '54. I have extra distributors, coils, carbs, engine, trans, you name it.

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