Sherman head

[big2bird]

I just horse traded for this head. What's the good, bad, or ugly about it?
What 14mm plug would you try first?
I have a low head on the car now, but would like a little more " thump."
I also have a Z head , but leaning this way.

[TXGOAT2]

Looks like a good design. I'd use NGK plugs.

[Craig Leach]

Hi Jeffry,
I have never heard anyone say anything bad about a Sherman head. Autolite #66 are my go-to 14mm plug. Not so much anymore but you used to
be able to get them at any auto parts store. The last time I picked some up they were on sale for under $2.00
Craig.

[T4Tom]

I had a Sherman Super Fire on the speedster my grandfather built. The performance was great and the car had excellent hill climbing power. The performance is miles ahead of the Waukesha Ricardo that is on the car now. Unfortunately, the speedster sat for a long time and the Sherman head was totally seized to the head bolts even though anti seize was used. I tried all the tricks to remove it, but ended up having to the saw the Sherman head off the block. Bummer!

I do not remember what plugs were used. I bought a Z head to replace the Waukesha but it's poorly made compared to the Sherman. The Z head gasket mating surfaces are machined such that a significant portion of the gasket is exposed into the combustion chamber.

You may need to run your spark a bit retarded to avoid knock given the higher compression.

Tom

[TXGOAT2]

I believe that most or all NGK plugs are plated to resist seizing in aluminum heads.

[BE_ZERO_BE]

I have used both Sherman and Z heads.
I would give a slight edge to the Sherman head on performance.
I had to use the hottest plugs I could find to keep them from fouling.

[big2bird]

I have used both Sherman and Z heads.
I would give a slight edge to the Sherman head on performance.
I had to use the hottest plugs I could find to keep them from fouling.

Thank you. That's good to know.

[Kevin Pharis]

I have ran 3 Sherman heads on my speedster prior to the Akron-Hed conversion. Castings are sturdy and never had any gasket problems with copper clad, solid copper, or the silicone composite options. Most common heads were marked “Super” or “Spit” Fire, but compression ratios vary. Expect 5:1 to 6:1 ratio for a Super, and 8:1 for a Spit. Rare versions had 2 and 3 spark plugs.

I saw a couple machining issues on my heads. Spark plug threads were not perpendicular to the counterbores in one head, causing leaking that led to over tightening and eventual thread failures. Another was machined at an angle to the combustion chambers, bout 4:1 ratio in front and 6:1 in rear. All issues were fixed and ran for a long time. Heads were swapped around due to continuous engine upgrades.

They run good! But listen for detonation, and run a water pump. More power = more heat, and thermo-syphon simply can’t keep up

[big2bird]

I'll know soon enough about it. Maynard will be all over it. He's done Motorcycle heads forever.

[big2bird]

Kevin. What spark plugs did you use? Just curious.

[Dan McEachern]

The recommendation from Jerry was to use Autolite AG32, AG42, or AG52 plugs starting with the AG42. These plugs are obsolete now but there are modern equivalents available.

[Kevin Pharis]

NGK BP5ES, BP6ES, BP7ES. Never could tell the difference in how it ran, but if I kept the choke closed for just a moment too long… they all fouled the same!