Continental N62

In the process of putting the N62 back together and noticed something weird, at least I think it is. The spark plugs are over the valves, not over the pistons like case and Deere. Figure it is right as the head only goes 1 way. What benefit or downside is there to this design?

Thanks for the wisdom.

I've seen lots of Briggs/Strattons like that.

Piston doesn't hit the plug if you install the wrong plug! LOL
The flat head 4's in the Ford N's had the spark plug more over the
valves. I was told it helped keep the plugs from fouling since they
weren't in direct line of the piston if it were to pump oil.
I really don't know if that is a valid statement or wive's tale.
Seems oil would fill the chamber to me, just like the gas fumes.

You are used to dealing with OHV engines. What you are NOW dealing with is the norm for flathead/OHV, or whatever you want to call "em inefficient out of date engines

normal.. as said...

Old side valves L head - spark plug more toward valves as that is the combustion chamber area- Ricardo research in 1930s showed this was about the most practical arrangment espically if compared to T head designs. need to visualise the sidewise ? of head and piston -the valves are in the 'loop' of ? and when piston is a top of stroke the charge is forced into the 'loop' with a swirling action. this swirl mixes the fuel air and when a spark is put close to the center of the swirl, then the flame front does a mostly even burn with minimal detonation. The burn fuel/air pressure gets to top of piston at edge and power to crankshaft is a bit offset, lesser then a 'tighter/rounder' OHV design capable of - but making the compact L head with valves to side has less parts, much simpler head casting needed, less valve train needed and valve lubrication simple vapor and splash works mostly. One OHV advantage is airflow at higher rpm means more power- but if you're only turning 1300 to 3000 rpm that isn't a big deal. Other advantage of OHV is possible higher compression and tighter piston to cylinder clearance, direct flame front and pressure to top of piston- this is definite advantage but consider your intended use- is it worth the extra maintenance and castings? Ford 8N or IHC A, B, C, AC B engine about same size 113/125 cubic inch- Ford lower cost for a bit less but usable power means lots of Fords sold- and IHC Cubs, AC G, Massey Ponies got along with the L heads a long time- you're still fixing them aren't you to use in playing in the dirt? RN

If you look at how much space there is in that combustion chamber, the piston nearly touches the head. The displacement is so small there isn't a whole lot of area for the combustion chamber to cover and still have a decent compression ratio. I rebuilt on last year, and the guy a the machine shop just shook his head when I walked in carrying a 4 cyl. block.