high conpression head ??

[[email protected]]

which head do you guys recommend , what brand , snyders, brattons ,bertz ?? pros and cons , thanks, steve

[Bruce of MN]

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.

[Synchro909]

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.

[Pete]

Winfield red.

[Gene F]

What incraments did the later Larry Brumfield offer?

[Pete]

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Originally Posted by Gene F

What incraments did the later Larry Brumfield offer?

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.

[updraught]

Originally Posted by Pete

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.

So was it like the Winfield Red?
Tod seems to be having problems getting foundry time for another run of Winfields.

[Joe K]

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

[jeepguy1948]

I strongly suggest that you contact Jim Brierley (on here) about his cylinder head

[Pete]

Originally Posted by updraught

So was it like the Winfield Red?.

Sort of but on a much smaller scale.

[Benson]

...

[updraught]

Originally Posted by Pete

Sort of but on a much smaller scale.

So the compression ratio was upped?

[nkaminar]

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.

[Pete]

Originally Posted by updraught

So the compression ratio was upped?

It was kept within reason for various fuels and engine sizes.

[ModelA29]

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

[nkaminar]

Nice. You will need pistons that have a lower top. Note that the intake side is relieved for easier intake air flow.

[Hitman]

Originally Posted by Pete

Winfield red.

This is the only real answer. Proven over and over, it's the flathead to beat.

[johnneilson]

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

[Pete]

Originally Posted by johnneilson

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.

...

[Hitman]

Originally Posted by nkaminar

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.

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.

[PC/SR]

I run a vintage Weiand head, 6.8 CR. On an engine dyno best HP at the flywheel was at 22 advance. The total advance for the A distributor is 40. Run the spark lever at about half way down on your total range. Every head and engine set up is different, but this should work for general usage. Mechanical or vacuum advance is going to take some work to modify depending on the type of distributor you have.

[Bruce of MN]

This is how I limit advance for my 6:1 head:

https://www.fordbarn.com/forum/showp...2&postcount=23

[nkaminar]

Hitman, That would depend on how you time your engine. If you use a timing light and degree wheel then your method is good, especially if you have a distributor with automatic timing. You also have to know what degree advance to set the timing at for your particular engine. If you use the method of finding the knee in the advance curve by experimentation, then timing your engine (with a high compression head) using the lever 3 notches down will work just fine. The setting of the distributor when retarded is not important. It is the timing where the engine is run that is the important part. In my case I retained the manual adjusted distributor advance and I adjust the timing depending on conditions. After 60 years driving Model A's, this is what I am used to.

[Boston Bruce]

Originally Posted by Pete

Winfield red.

winfield_17.jpg

[Hitman]

Originally Posted by nkaminar

Hitman, That would depend on how you time your engine. If you use a timing light and degree wheel then your method is good, especially if you have a distributor with automatic timing. You also have to know what degree advance to set the timing at for your particular engine. If you use the method of finding the knee in the advance curve by experimentation, then timing your engine (with a high compression head) using the lever 3 notches down will work just fine. The setting of the distributor when retarded is not important. It is the timing where the engine is run that is the important part. In my case I retained the manual adjusted distributor advance and I adjust the timing depending on conditions. After 60 years driving Model A's, this is what I am used to.

I get what you're saying, and if it works for people, that's great. I just wouldn't provide advice like that on the forums without huge caveats. Even between 28/29 and 30/31 styles, the steering column assembly can be different, the top portion with the groves is different, the levers are different, and even distributor bodies are different across the years. Throw in reproduction parts and it's anyone's guess. Add in other variables like head compression ratio, fuel used, worn parts, etc., and there's no one size fits all approach.

The best recommendation you can give would be time it by the manual and how current day manuals recommend. Start there and see how the car performs, find where the spark advance lever runs best in your application and tweak as you go. Monitor detonation, gas mileage, engine temps and other things to determine if you have it set properly.

[40 Deluxe]

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Originally Posted by Hitman

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.

Here it is: The best timing advice ever! It is amazing how well Model A engines tolerate ham-fisted mechanics using old seat-of-the-pants methods! However, higher compression and other mods limit the tolerance factor. Time to get scientific!

[Jyromefedx]

Are there any spec sheets that break down how the individual heads increase performance?

[Pete]

Originally Posted by Jyromefedx

Are there any spec sheets that break down how the individual heads increase performance?

Yes. I have seen a few in magazines or advertising. They are usually based on a stock a displacement engine but there have been a few based on various oversize engines.
Most people have only heard the old myth about boring a block just enough to clean it so there is plenty for the next rebuild. HOGWASH!!
How many of you have ever rebuilt the same engine 2, 3, 4 times??
If you bore to the limit as determined by ultrasound and
reduce that number by .030 you will have a block that can be rebored 2 more times and will produce enough more hp that you will be smiling all the way.
This is a far cheaper way to get the same results as a high compression head for a mild street engine.
If you want to add a head on top of this, then you are getting
into the realm of hot rodding and should be well aware of the other things involved in this modification.

[nkaminar]

The effect of different modifications can be seen here: https://www.modelaparts.net/dynoshee...ynosheets.html

[Gene F]

Originally Posted by nkaminar

The effect of different modifications can be seen here: https://www.modelaparts.net/dynoshee...ynosheets.html

This is some nice info. Thanks.

I always wondered how much adding the second Zenith carb impacted performance. (~10 HP). I spent a lot to get 13 extra HP. This would have been nice info to have when deciding what I wanted in an engine package.

[OldIronRookieDriver]

Question for all: Our Model B engine has a Winfield 6.5:1 Aluminum head... we're replacing the gasket now and have just noticed that there are small coolant channels that come up from the block and thru the gasket only to be blocked off at the head (ie. there is no hole that continues)... It appears in the pic above that the Brierly head above also does the same. There are 6 of these holes like this.... Wondering if anyone knows of the explanation, but it seems they reduce the circulation of the coolant thru the block in this design.

[ModelA29]

The one that got away. Early Winfield Super 7.0:1. Crowfoot combustion chamber. The early ones weren't marked "Super" and used the standard Model A size spark plug. I wavered on buying this one because I have a Brierley on order.

[nkaminar]

In my opinion, for what that is worth, that looks like a nice combustion chamber design. It looks like there would be no problem for the air/fuel to turn down into the cylinder during intake. But it looks like custom pistons would be needed because it appears that there are no pockets in the head.