Ideal Flathead combustion chamber shape

[Hemi Joel]

My ideas on this subject will be a bit different. I like the idea of FT pistons, with a enhanced, transfer area. Flow bench the transfer area to see what flows the best.

What I learned about fluid dynamics, say that the pressure will be equal, within any given space and that pressure will exerted by the square inch area, regardless of shape.

Flame travel is very different from pressure and I agree with moving the spark plug. I would put it on the edge of the transfer, angled to the cylinder. It's my understanding that Ford put it near the exhaust valve, to keep it clean but, with modern extended plugs, I don't think it's relevant now.

As for the valves and getting flow, since there is virtually no flow over the valve, you need to work with the curtain. Larger valves, have larger curtains so, I would install the largest valves possible at a 85% ratio and work the contour around them on a flow bench. Everything needs to be as tight as possible in the chamber but, give the transfer and the area around the valves, everything they need. i.e. min piston to head and min head gasket shape and min clearance for the valve head, to back of the chamber, to promote forward flow.

I would also use as large a radius as the top ring to top of the piston will allow, to gain flow in the transfer area.

we can put the spark plugs wherever we want, and uses many as we want. Maybe I will start out with two separate locations test each.

[allrightmike]

Barron offered a high dome head&piston design that used a full radius piston dome with a raised hemi shaped combustion which made for much improved breathing.He copied from a Harly Havidson design for flat track racing.

how high of a dome was at? Was it a partial hemisphere all the way around, or did it have any irregularities to the shape?

I believe the dome was a true radius of the piston diameter with no features. I remember it was critical that the chamber had to be true on center with the cylinder so a very close quench could be maintained.

[Hemi Joel]

That Navaro blower head loos simpler than the Harley KR heads.   

I need to see more details on the JR. dragster stuff. That is VERY interesting, considering 1.96 hp per cube naturally aspirated.

We are building the heads on the cnc machining center. there will be a bottom and a top plate with water jackets and support ribs milled in between, with O-rings as needed.  We are thinking the top plate will fit multiple different design bottom plates, so we can experiment with different combustion chambers but reuse the tops.

[Heo]

Barron offered a high dome head&piston design that used a full radius piston dome with a raised hemi shaped combustion which made for much improved breathing.He copied from a Harly Havidson design for flat track racing.

how high of a dome was at? Was it a partial hemisphere all the way around, or did it have any irregularities to the shape?

Here you have the High Dome head

https://handhflatheads.com/product/navarro-high-dome-heads/

[gt350hr]

   Air doesn't like to turn so a radius chamber helps air flow because of the "arc" instead of a sharp 90*corner.

[Heo]

   Air doesn't like to turn so a radius chamber helps air flow because of the "arc" instead of a sharp 90*corner.

I figure the right shape of the chamber roof is important for the flow

I think there was a British guy named Ricardo or something like that.
That worked a lot with combustion chamber shapes, and Diesels
If my memory is correct lost a lot of my memmory after my strokes

[Heo]

I know you said you dont want to modifie the block a lot.
But here is a interestig video look how packard angeled the valves
toward the cylinder almost 45 degrees. I think that benefits the flow
a lot, but i could be wrong
https://www.bing.com/videos/search?q=packard+v12&docid=608043034507937497&mid=613D99F4D1AEA6791B39613D99F4D1AEA6791B39&view=detail&FORM=VIRE

[FErocious]

I like the 1936 Cord with the Lycoming-type valvetrain. With some work this is something that could be utilized on the Ford block. I would like to see a Ford flattie with a 5-main mod (like Uncommon Engineering performs) and the ghost-main billet crank modified for oil feeds at the "extra"  main journals. It would be a fun project.

 I tried to attach images from my computer, but........
Here are the links, I hope.

https://www.speed-talk.com/forum/download/file.php?id=23446&mode=view

https://www.speed-talk.com/forum/download/file.php?id=23447&mode=view

[frnkeore]

The Cord / Lycoming system, is diffidently the best but, I think you'd have to start with a clean sheet of paper for the block, as well as the heads.

I don't think the 3 mains are a problem if, you use a 180 crank. The Novi (Indy engine) was reliable with 3 mains at 8k+ rpm.

[cammerfe]

The above files won't open for me.

KS

[frnkeore]

Here you go:

[cammerfe]

Thanx!!

KS

[cjshaker]

Interesting concept. I thought Lycoming was only involved in airplane engines.

[pbf777]

      Lycoming, Continental and Hercules, and there were others, were particularly popular engine suppliers to the as were sometimes referred to as "component-car" or "assembly-manufactures" in the passenger car and "light" truck market; the height of popularity for this process being practiced between the wars, and fading as many of the smaller vehicle manufactures faded in the thirty's due to the economics of the Depression (e.g. E.L. Cord folded Auburn, Cord and Duesenberg into one, before they then as a whole folded) and the weeding-out of the marketplace of the then labeled as "Independents" post W.W.II.             

     Scott.

[FrozenMerc]

The angled valve concept is good, but definetly tough to pull off if you have to stick to a stock Lincoln block.  Packard even did it on their big straight 8's, though I think the angle was only 10 deg, much less than the V12's.



Also, Don't overlook the Seagrave / American La-France / Pierce Arrow V12's for inspiration.  They tried some really unique setups, like in the 906.  Is this a OHV, or a flathead???