Why the switch to domed pistons in 36-37?
 

Did Ford announce the switch to domed pistons as an improvement, and did they say what was better about them? They continued until the end of flathead production through several other major revamps of the engine, and the heads had to be more difficult to make, so it seems they saw a clear reason for doing so. I don't recall seeing anything in the literature that I've seen for that era that mentioned this, does anyone here know this?
I've always sort of thought that flat would be better for performance, and it's clearly better to achieve uniform piston to head clearance. Ford never did anything at random so I'm curious about Ford's reasons.

Re: Why the switch to domed pistons in 36-37?
 

Higher compression??
Paul in CT

Re: Why the switch to domed pistons in 36-37?
 

Hey Don Rogers. Jump in here and answer the question. You are certainly the go to guy on 35-36 Fords. Lawson

Re: Why the switch to domed pistons in 36-37?
 

I seem to recall reading once that Ford went to domed pistons to improve 'quench'.

Re: Why the switch to domed pistons in 36-37?
 

Schools of thought and conventional wisdom were still in a state of flux in that time frame. The dome actually increases the surface area of the piston so it allows for more downward pressure during the flame front. It has a tendency to arrest any swirl in the cylinder while the flame front is still expanding which isn't always a good thing but it depends on the shape of the combustion chamber. In the case of the side valve design, it's not all that detrimental to the burn so it doesn't have much of an effect in this application.

Re: Why the switch to domed pistons in 36-37?
 

I'm not so sure that is true. It seems to me that the increased surface area would not offer an increase in pressure, as the diameter of the piston itself remains unchanged. To look at it another way, if it were true, then in theory, the higher the dome, the more pressure available. Think also of the weight of a liquid in a funnel shaped vessel. The sides of the funnel support the weight of all but the area directly above the mouth of the funnel.

Re: Why the switch to domed pistons in 36-37?
 

A domed piston is stronger and can consequently be made lighter, thus saving material, thus being cheaper to make, thus lasting longer, thus making for more satisfied customers.
Flat is better for racing. More compression can be had. The flame front can travel faster over a flat surface.