Big Boys Heads

Swarm said:
Wow that looks awesome, your in Ohio do you know Todd in Salem
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Are you talking about the guy that is working on a flathead block design? If so, I've communicated with him, but never met him. I'd love to see an aluminum block flathead that supports 3.5" bores, with DART style sleeves and maybe available in both a 3 and 5 main version. ;)
 
FlatCad Chambers: I designed the chambers and pistons to mimic the Harley KR flathead race engine. As a purpose built race flathead, it is the most advanced of any flathead design that I know - and made up to about 1.5 HP per cubic inch on gas.

My neighbor built these engines and he was one of my mentors (like a second Dad to me). Anyway, I have KR cylinders, heads and cam designs . . . so I wanted to try some of this on our Bonneville engine. The engine made 650 HP on Alky.

Here is a photo of the chambers and piston:

Chamber_HandPolishedAndORinged.jpg

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The pistons were designed in CAD and then ordered with flat tops, I then hand formed the "ramp" on each one - it is aligned with the transfer area. This is necessary or the sharp edge of the pop-up piston will "burn" under high boost (we run 21 lbs). I had the piston tops ceramic coated - same with the chambers and valve tops.
 
Beautiful work Dale. I guess there are other flatheads beside Fords.

I have one question : "Ol' Ron" is a proponent of moving the spark plug into the transfer area, and for myself, I prefer Edmunds heads because the spark plug is moved into the transfer area enough, allowing the use of extended tip plugs. The "KR" chamber seems to refute this, with the spark plug directly over the exhaust(?) valve. Why would this be?
 
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The better news is that if a 'Winter Project' happened to find a way to get going, I already have rough SolidWorks models to work from (though they are quite preliminary).
 
tubman said:
Beautiful work Dale. I guess there are other flatheads beside Fords.

I have one question : "Ol' Ron" is a proponent of moving the spark plug into the transfer area, and for myself, I prefer Edmunds heads because the spark plug is moved into the transfer area enough, allowing the use of extended tip plugs. The "KR" chamber seems to refute this, with the spark plug directly over the exhaust(?) valve. Why would this be?
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It is actually over the intake valve. I've not had the luxury of talking to the original designer, though Jerry Branch was pretty much one of the gurus of taking the factory KR design and making additional improvements. My neighbor used to talk to Jerry about the various improvements he was making. While I've heard many "Ford Flathead" guys claim the KR has the plug in the wrong place, I decided that due to the amount of dyno and track work they did, they probably knew what they were doing.

I have a couple guesses:

1) The plug is cooled by the intake charge.

2) Given the design of the chamber, with the angled "shelf" area, my guess is they wanted the charge to fire above the valve (the "back" of the chamber) and then progress toward the angled shelf and piston. One of the reasons I think the shelf is angled (at a very specific angle), is that it uncovers the cylinder on that side . . . so the combustion is driven toward that side, down the cylinder, etc.. My guess is that it causes a "swirl" into the cylinder, which may increase the efficiency of combustion.

I only wish I had a dyno and unlimited time to try different chamber designs. Really, I would like a 1 cylinder Flathead Ford to screw with! LOL
 
I have a set of Grancor heads that had a very intersting chamber for a pop up piston. but the plug was in the stock location. I used these heads on the Bovell engine with a 3 3/4 stroke piston on a 4" crank. Unfortunately the dydo wouldn't pick up the load. I shipped the engine to Cal where the truck was, and flew out there. No Truck and a firm disagreement with the owner. Flew home with out it. Never saw it or the money again.
Bummer, At least I have a picture of the chamber, and it does resemble the Harley chambe.
the location of the plug has a lot to do with the flame front. The flathead has a very long flame front and placing the plug at the far end of the chamber allows the pressure in the chamber to denate the fuel charge. using the .050 piston to head clearance removes the vast majority of the AF over to the transfer ares with a high degree of turbulence, which will urn more of the Af mixture. The result is more power from less fuem.
At least that's the theory. Having the plug away from any valves allow the use of a power tip plug. Another plus. If this doesn't improve power, it will sure improve economy.
Gramps
 
B&S: You and your team are amazing. Those heads are beautiful.
A work of engineering art. It must be like magic when the CNC works its magic on a
big chunk of 6061. Do the heads have to be heat treated after machining?
 
19Fordy said:
B&S: You and your team are amazing. Those heads are beautiful.
A work of engineering art. It must be like magic when the CNC works its magic on a
big chunk of 6061. Do the heads have to be heat treated after machining?
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Come to think of it, I think we used pre-heat treated 7075 material.

I think the most painful part of the head project is that we did not have a mill big enough to put the block in and use the DRO to figure out the bore, water jacket and stud locations. I did all the deck surface, pan/girdle measurements, etc - using a 24" dial caliper! Now THAT took a long time . . .
 
flatrod said:
Yes I have a set of unused Big Boys, and my brother, Alaska Jim has Tony Baron heads. I bought mine from Paul years ago, I do remember talking to him when I got them, but don't remember much else.
I can compare the two if you like, I do know the Baron's are around 92cc, I don't think the Big Boys are that big chamber wise.

Thinking about it I think I do have some paper work somewhere, I'll look for it and report back.
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Why don’t you just call your brother and ask your questions ?
 
When desiging a racing style combustion chamber for a flathead. I think the wedge style is the best. having a flat surface at an angle and a piston with a corrising angle. This allow a very hi compression without restricting flow. Navorro made a set like this bacl in 2007??? JWL worked on this car someone else had this back in the 60's, but I cant remember who?? Altho the HD chamber is a good one, the ports are alsoverywell designed and aid in the power output. Today we have coputer programs that can help us eliminate questionable designs. Back in the 80;s I spent allot of time on a flow bench looking for the "oly Grail" of port and chamber design. In a flathead the port doesn't stop at the valve. The valve is actually in the intake port, which ends at the cylinder.
On another note, supercharging has shown us just how bad the ports really are. I build the block assy for Ron Horrell, a 294 ci engine for the street . however it had a magnason blower assy. On the dyno it produced 300ft/lbs of torque at 3000RPM and 235 HP at 4500 rpm ON 3/5 lbs of boost. The blower was liminated at 5lbs. The intake port was cleaned up with a 1.6 valve.

I like experimenting with these engines and I respect others that do the same and every year we learn more. Take care, be safe, and think Flatheads and you'll go to Heaven
Gramps
 
Just saw photos of these iron heads on FB, with chambers sort of like the KR chambers.
 

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