YIKES! Flathead Head Milled Backwards

Been talking to Bruce Lancaster about milling the top-side of a flathaed head to expose the cooling passages. Didn’t know whether anything was to be gained but might shed some light on the coolant flow.
A right passenger flathead head was selected to mill the top surface and expose the various cooling passages in the original casting. The head was an EAC of unknown origin and it is unknown if any milling had previously been done on the deck face of the head.
The head was positioned on a mill and a fly cutter was selected to remove the material. The milling was done, starting at the top of the head from the right end to the left end. Passes were made at an approximate depth cut of .050". Some sparks were observed during the fly cutting as hard materials were found in the casting near the temperature probe and heater line ports on the first pass. After two .050" passes of about a 2-1/2" width cut the cutting tool broke in the fly cutter. The fly cutter was then changed to a ¾" end mill. Passes were re-started with the end mill and preceded to the final cuts 4 hours later. The finished milled head was layed on white paper on a desk top and plugs as well as head bolts were inserted in the proper holes to show the cooling holes in the deck surface for the pictures. All white, open holes are cooling holes.
As the face of the head curves from the top to the bottom the passes were made in 5 "stepped" increments as can be seen by photo #1 end view of the finished head.


Photo #1 end view of the 5 "steps"



Photo #2 shows a surprise with a Number 3 that is a part of the original internal casting near the center of the finished head just left of the lower center head bolt.



Photo #3 the right end of the finished head




Photo #4 shows the center of the finished head



Photo #5 shows the left end of the finished head. Note the trapazoidal shaped passages at the extreme left end. This was an apparent change by Henry to allow more cooling to the back of the head/block in ’49 & up



Photo #6 shows the complete finished head



Photo #7 This area on the right end of the head appears to indicate a restrictive area where the casting includes the coil mounting holes.




Measurements were taken before any milling was done at the left end of the head. These measurements were from the deck surface of the head to the top left head bolt original machined surface and from the bottom left head bolt original machined surface. These measurements were repeated after the milling was finished.
Top head bolt surface to deck surface before milling 1.931"
Top head bolt surface to deck surface after milling 1.662"
Note! @ ~ 1.630" near the top side of the head the first sight of a water jacket opening was seen; this suggests that the thickness of the top casting above the water jacket is ~0.301".
Bottom head bolt surface to deck surface before milling 1.255"
Bottom head bolt surface to deck surface after milling 0.955"
A 5/16" hole was drilled from the deck side surface, at the center of each piston portion of each cylinder, in order to obtain the thickness over each piston. Again it is not known whether or not the head deck surface had been previously milled.

Cylinder #1 above piston thickness 0.258"
Cylinder #2 above piston thickness 0.318"
Cylinder #3 above piston thickness 0.352"
Cylinder #4 above piston thickness 0.364"
Note the .106 difference in thickness from the #1 cylinder to the #4 cylinder even though the milling was done with the head deck surface on the milling machine table and the top side thickness to the water jackets seemed to be uniform from end to end.

I will be dragging an 8BA out of the shed this week and blowing air thru the water pump discharge ports on the front of the block to see where the water feeds the heads.

 

Outstanding tech for flathead guys.

 

I'm never built a flathead but know that cooling is an ongoing issue. It seems that that flow rate is slow through the heads judging by the shape and passage configuration. It's like the water passages of an OHV V8. Are the heads the main contributing factor to high operating temperature of the flathead?

Ineresting to see this.

 

My flatty runs cool and it's blown to boot. I'm just trying to figure out whet may be a contributing factor to flathead overheating. There are many things that can cause overheating including rust, pump impellers, ignition timimg (one of the worst I think), radiator pluggage and on and on.

Guess I just have a curious nature.

It's for sure no Barrs stop leak will help that head now

 

that is a really great tech. i am always a curious little monkey when it comes to anything...dont stick your finger in the electrical socket, why....*zap*...oh?!

 

this is very interesting.i have a few nash 8cyl dizzys and was looking at building another set of duel plug heads.(i got one set now that were run on the salt by earl davidson)it looks like a plug hole could be cut out with a hole saw and welded in another set of heads.its nice to see the actual insides.great post ,thanks for sharing.

 

I have also always wondered about this, great to see it done! what I have also wondered was what are the finned heads like internally? do they have baffles to direct the water or are they just a copy of the original design?

thanks.

 

Great to see someone with the machinery and resources expose some of the mysteries in life. Excellent tech post. I wonder who the number 3 was put in there for...

Flatman

 

I thought about that. Could it be for the foundry so they didn't mix up the right and left head patterns? It is adjacent to cylinder #3.

 

Flatheads running hot is sort of a myth, like all Strombergs leak.

That being said, some do run hot and one of the main reasons is not doing proper block prep when you rebuild it. I have personally seen huge amounts of sand from the original sand casting inside the water passages in the blocks. When you hot tank the block, it doen't get out a lot of the sand and other debris inside. You really need to take a hi-pressure water nozzle and get as far in the water passages as you can to get everything out. The later blocks do not have as big a problem with this, but the early blocks had a lot of "sand shift" during the casting and it left it behind in the water passages.

My 2 cents....

Matt

 

Yikes?
What did you expect to find in there?

 

That's really cool. If I can ever get access to a mill, I'm going to do the same thing, but with an inline 6 head.

 

Blown49.....Hey, thanks a lot for the hard work, this is very good visual info to put in my files. Always wonderered you know......

31acoupe

 

Nice info.

 

Nice tech, keep em comin....

Rat

 

Been in lots of foundries - that 3 (notice it's reversed) is a core number. ?When the core room guys are building up the molds, they keep track of what pattern made the core. Remember, when the motor is built up, a series of sand 'cores' are put together to make mold. In the case of the head, there are two halves to the mold - compressed around a pattern of the exterior of the head. The internals are fabbed from a mixture of sand and clay; the core man places this funny looking sand/clay 'waffle' in the mold - the waffle IS the water jacket - rendered in solid form.

The patterns wear out - in the old days (of for low production parts), they made them outta wood. When they wore to the a specified point - they were tossed. That's what that number is for.

 

Now here's a crazy idea.
Given that you have the dimentions (and the locations of head studs and spark plugs) and an "inside view" of the cooling passages; what would happen if the water jackets were "cleaned up" and the results stored in a CNC mill??
Then duplicate the results in a slab of T6 aluminum. (would mean duplicating the block side - valve and piston clearence)

Then make a top cover (like a sandwitch) with the matching holes and LARGER water jackets.

 

I was just thinking this too which must mean it's a very bad idea.

 

Dave, it is not a crazy idea, Norman Frick does his heads that way.

 

My grandfather made the first set of (wood) patterns for the Dayton Stoddard Automible engine in 1913. Another reason it was an interesting experience for me.

 

Yes but that is no reason why he shouldn't finally get a new car.

 

SHHHhhhh... everyone will steal my idea...

 

This is interesting. I'm amazed to see so much restriction from the top of the head to the lower portion. Boy, Henry really opened up the inlet area of the rear area of the head. Didn't run into any trapped sand or other crap during the machining?
It would be interesting to see this on a good old aftermarket Edlebrock.
Thanks for sharing. This needs to go into techomatic!

 

Didn't see any trapped sand or other crap. If someone out there has a right side 8BA head from any aftermarket mfg. I'd do the same thing to compare. I would think any aluminum head would be thicker than the cast iron head because of the combustion temperatures and pressures. I have a set of Edmonds I bought in 1955 but I really want to keep them so milling one of them is out.

 

I have always wanted to see a flat head cylinder head extrude honed ($$$$$)

 

Cool idea to do this. Would be interesting to sandwich a thick piece of lexan on top and pump water thru it, and heat it up. See what happens. Excellent post.

 

So did Kong Jackson.

I don't think overheating has that much to do with the heads. Notice how there is concentration of the holes around the exhaust valves and ports. That is where I think heat would build, mostly inside the block. The big holes in back tend to cause more water to go full circuit from water pump, back of the block, then forward to the outlets. I've often wondered if you could keep a drag race engine cool enough using solid heads drilled for flow through the upper water ports around the valves. That would allow a person to design and carve his own combustion chamber without having to worry about a cooling chamber over the cylinders. The combustion chambers would get plenty toasty, but if you used a solid copper gasket, it seems to me that you could get rid of a lot of heat by conduction. Pipe dreams. Not at all suitable for the street.

 

Petejoe I've got some mixed emotions about the area for cooling. I'm certainly NOT an expert but consider the following:

1. The water pump(s) are a centrifugal type pump and as such have a certain amount of "slip" in the fluid. They will produce so much head and flow and then slip in the fluid.

2. Enlarging the heads cooling volume would increase the amount of water the pump would have to change a minute. That tells me the water would stay in the head (and block) longer and may not cool as well. Gotta keep in mind the cooling is done to the water in the radiator as I see it.

3. There was a thread on the MSN board last April by a guy that had a problem with his left head getting hotter than the right head and he felt the problem was with the gasket. I think the trapozoidal holes in the rear of the head (and block) are matched by the Victor Reintz gaskets but the Fel-Pro gaskets have a the bottom trapazoidal hole reduced to about a 1/4" od with a copper ring. When I called Fel-Pro about this hole reduced I was told by and older guy in their tech dept that the hole was reduced because of a recommendation from Ford or they (Fel-Pro) wouldn't have reduced it's size. He couldn't tell me when the change occurred date wise.

4. I ordered a right Fel-Pro head gasket today and will photo it and post.

Nothings ever easy is it?

 

Jim, all that you are saying is not that far fetched.My head porting buddy Larry used to work at a shop that did Prostock Ford motors.They used to mill out a channel to reach in and port? the internal water passages for better? heat control, then weld the head back together.