high conpression head ??

I like my 6:1 Snyder’s head, but now that the Burtz head is available, I’d strongly consider it. Be aware that you will want to limit your spark advance.
 
All I would add to Bruce's comment is that the Burtz head fits the block better than the other cast iron aftermarket heads and at (I think) 6.5:1, they give a bit more punch.
Agree 110% with the advice to limit the spark advance. I run a 6:1 head on one of my cars and I have the advance of the automatic advance distributor limited to 22°. Many people say the bottom end won't handle a higher compression ratio. I've had a high comp head on one of my cars for about 11 years now and after 70,000 miles (about 50,000 done towing a camper at 50 mph), it is still going. Any problems created by the fitting of a high comp head will be due to the timing being too advanced, not the compression.
I tried limiting the advance by making a stop which I screwed tot he side of the distributor. It had a screw to stop the advance on an original dizzy like we see on he throttle stop. I found that the engine was so sensitive to the high compression (6:1) that I had to manually adjust the timing as the engine revs rose. When the time came to change up a gear, I had to retard it again, then advance again as the revs rose again. It didn't take long for me to run out of hands and patience so I had a distributor made that uses mechanical and vacuum advance.
In short, go for it but be careful about your ignition timing.
 
Gene F said:
What incraments did the later Larry Brumfield offer?
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I can't answer your question but I DO know that if he had lived, the new design that he was going to re-start up with would have put all the rest out of business if performance was the goal.
 
Pete said:
I can't answer your question but I DO know that if he had lived, the new design that he was going to re-start up with would have put all the rest out of business if performance was the goal.
Click to expand...
So was it like the Winfield Red?
Tod seems to be having problems getting foundry time for another run of Winfields.
 
Vince Falter (Fordgarage.com) says that the manual adjust "span range" of the Model A distributor timing is about twice what is needed.

If you have to go much above horizontal on the handle, you're probably too advanced - or your initial timing on the Model A engine is off.

Also, the "built in timing" of the Model B engine centrifugal distributor is about half the span of the Model A manual timing span.

I can see that one might narrow the optimal timing band even more with elevated compression. The engine will be more "sensitive" to an off setting.

Joe K
 
Regarding timing with high compression head: I set my distributor with the lever 3 notches down. I drive with the lever about horizontal. This has another advantage in that you can idle the engine way down by moving the lever all the way up.

Regarding high compression head design: The area where the air/fuel charge moves down into the cylinder has to be carefully designed. The roof has to be raised and a large radius provided. if this is done the compression ratio can be raised beyond 6.5 to 1. The custom V8 heads, shown below, illustrate the idea.
 

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The Brierley head is 7.0:1. Lots of hours developing the combustion chamber. You also need longer studs to run it.
 

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Nice. You will need pistons that have a lower top. Note that the intake side is relieved for easier intake air flow.
 
Yes
There is a balance point between C/R and airflow
This has been demonstrated on flow bench testing
All moderate c/r heads will probably perform well within reason
Spark plug placement is another topic that really makes a difference
 
johnneilson said:
Yes
There is a balance point between C/R and airflow
This has been demonstrated on flow bench testing.

> Dyno testing has also proven that the flow bench results do not always show
best on the dyno. Briggs & Stratton found that early on.
Remember, we are talking flatheads ONLY here.

All moderate c/r heads will probably perform well within reason.

> At least they make the wheels go around.

Spark plug placement is another topic that really makes a difference.

> For sure. Some have it right. Some don't. It has mainly to do with initial
flame front QUALITY and speed to full charge burn.
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...
 
nkaminar said:
Regarding timing with high compression head: I set my distributor with the lever 3 notches down. I drive with the lever about horizontal. This has another advantage in that you can idle the engine way down by moving the lever all the way up.
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Never time a car to this. Your three notches are different than mine, your horizontal level is different than mine. Even 28-29 vs 30-31 columns are different as well as their notches. Since the cam and rotor are adjustable, there’s no way to standardize the timing by notches, position, feel or other things.

Always time the car with a light, ideally setting the timing for total advance. Depending on factors, should be 26-32 degrees. I aim for 28-30 deg at 2500 rpm for a mild street engine.

This assumes, dwell, shaft bushings, and other factors are properly set.
 
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