Cyliinder Heads on the Twelve

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Just curious, as I was discussing Packard Twelves with a friend.

On Packards, the cylinder heads were typically aluminum but due to electrolytic interactions, the heads corroded and can literally fall apart with age. If you have a Packard Twelve, you either need new cylinder heads or will, unless you want garage art.

Does the Pierce Arrow Twelve have such concerns?

For that matter, is there a weak area in the Pierce Twelve at all?

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Fear not! Cast iron heads were used exclusively through 1935, with any 462 heads being interchangeable.

If a 1936-38 still has original aluminum heads with problems there are some new reproduction heads still around the P-A community. Many if not most later cars have been changed to cast iron.

The only issues found in our 1933 were due to poor maintenance by previous owners and easy to address once diagnosed. These are tough engines and compared to Packard 12’s are easy to work on if issues do arise.

Despite being a Packard Club member for 3 decades I would never buy a later Packard 12. Fortunately I got into Pierce-Arrows and the Society before I made such a mistake!

Dave Stevens

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Does the Twelve suffer from vapor lock or other carburation and fuel problems on hot days?

What sort of fuel economy does it get? Like 6 mpg?

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Pierce Arrow cars of any vintage don’t have any issues, if properly restored and sorted for driving. I have driven my 1936 twelve about twenty thousand miles since the restoration was finished in 1995. It burns LOTS of gas, especially when going down the highway at high speeds………over 60mph. Around town and back roads…….I get 8mpg. About the same as towing it with my GMC dually diesel. If you gotta worry about the gas bill, you don’t want any Pierce. I do run an electric fuel pump at all times on my 12’s, as todays modern fuel will boil at 117 degrees, and the under hoot temperature far exceeds that, so on shutdown the carbs boil themselves dry. Thus is lots of cranking to fill them with the mechanicial pump, or purge the system with an electric before starting. While I’m a purist it just isn’t worth not running an electric today.

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Scott,

Adding to Ed’s comments, John Cislak sells a fittings kit to install a larger diameter fuel line (approx. 1/16″ larger). This combined with an electric fuel pump has prevented any alcohol gas / vapor lock issues for us on hot days. We also have the original aluminum head on our ’36 Eight which was just recently removed to replace a head gasket; there were no issues either removing or re-installing the head. Stu”

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Stu……I try and not do sales pitches here……even though I am not longer working with John on a daily basis. I sold him all my spare parts about three years ago, so now I just help him out at Hershey. I have the oversize line on all my cars, and they never have vapor lock issues. It’s amazing how going up one size on the line virtually eliminated all the problems. My best, Ed

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Scott,

John Cislak has made larger carburetor jets for Stromberg EE3’s (and others), we have these on our ’36 and they help prevent vapor locking from alcohol gas. Stu

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Scott, you might want to contact Lynn Kissel regarding vapor lock on 12’s. He has a beautifully restored ’33 (he took first in class at Rohnert Park) that has had problems with vapor lock. He installed thermocouples and tracked what temperatures and conditions will bring the onset of vapor lock (I wonder if he got any deductions for his thermocouple leads?). He also installed a clever fuel vapor return system to alleviate the problem. In my articles I mentioned that I didn’t think a fuel recirculation/return system would likely benefit vapor lock partly because the recirculating fuel would heat the fuel in the tank. Lynn’s system is designed to separate the vapor at the carburetor and return only vapor to the tank. That could mitigate much of the heat gain problem.

Jim

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Here are a few things I’ve done to my ’34 1240A Conv. Coupe. We wrapped the exhaust manifolds and header pipes with racing tape that is normally used to keep heat in the manifolds in racing. We also used a ceramic sheet material to wrap around the carb float chambers. AND we wrapped the fuel line crossover pipe with the same ceramic material.

All of this made a significant improvement in the tendency to vapor lock.

Bill

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