aluminum head

Harry: A high compression head is not going to harm babbitt, increase oil comsumption or do anything else detrimental the an A engine in ordinary use if the engine is in good condition. The limiting factor of an A is RPM which conventional wisdom has at around 4K when the rods cannot get enough oil. I have never seen any tests or other scientific confirmation of this, but neither have I tried to press an engine to failure. 4K (with babbitt) has not been a problem for me on hill climbs with a stock oil system with filter and opened up passages and pressure center main. However, friends that do high performance runs at Bonneville and El Mirage use pressure oil for their higher RPMs in the 5K plus range.
Basically, if you are not into heavy duty racing, don't worry about it. The A engine can handle it. Use an HC head, more carbs, good cam, whatever you like. Trust me you will recognize when you decide to get into high performance. It is a disease that affects your wallet and makes it shrink. Then you start lying to your wife. Get Brierely's book for the range of performance options available.
 
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I would like to mention here that Mr. Brierley has a new head design that looks very promising. The casting is top quality and the chamber design should be efficient.

J
 
I think the only option back then was babbitt.

If you look at many examples of babbitt journals, the surface area is nuch larger than modern pressure fed bearing designs.

The Model A is a good example of this.

Both work very well if the application is proper for the design.

John
 
Let me add at this point that I have run many model a engines with high compression heads (flatheads and overheads) over the past 50 plus years. The car I am working on now has had a 7:1 Winfield for 11 years. I have no worry about high compression. I asked about a 6:1 or less compression ratio as I was curious to see if it might reduce oil consumption in my weakening engine.
 
You could use 2 head gaskets to lower the compression, easy and quick to do but I also don't think it will make a difference in oil consumption.
 
You are probably right but what got me started on this train of thought was when I raised the compression on an a B engine years ago from about 5:1 to 7.5:1 it started burning oil. So recently thinking back on that I thought I would like to see if the opposite might hold true. Just curious.
 
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