51 flatty 6 valve train design w/valve stem caps

Well, I bought this M-254 engine, but was too busy to tear it down so I took it to a machine shop (my sledge hammer was too light). haha!!

Recently, after hearing a friend say that in 1951 Ford design engineers went to upgrade the valves train to allow the valves to roate, it came to my recollection that I was missing all of the I valves (some were cut out with a torch due to rust), and only had 5 rusty E valves, 6 rusty valve stem end-caps; so I assumed caps were for the E-valves only. They may have had 12 caps originally.

In any event I made a photo of these parts and sent it to Fred, and he has posted it below.

In any event I laid out the parts and began to try and understand what would make the valves turn, and I concluded that the design may have been to prevent the valves from turning, if the valves were turning due to rotating tappets/lifters. Seems the caps might tend to carry a bit of oil, open end to the upside, and as the lifters would turn that rotational force would be transfered to the end-cap (rather than directly to the bottom of the valve stem) and tend to slip between the stem-end and the lifter, thus transferring less, if any, of the rotation to the valve stem.

If the valve spring is causing valve rotation, then I don't see the advantage of the caps!

Anyone see any advantage OR disadvantage of utilizing the valve stem caps? I see no readily-apparent advantages; seems the lighter the valve train, the better; the caps seem very light though.

The Chilton's manual for my 300 makes mention of the Heavy Duty 300's having valve rotator gadgets; I have never so much as seen one myself, and I am also puzzled as to why they are necessary due to the obvious rotation of the stock units I have observed while adjusting the valves.
Joe

Well, I have verified it from page 31, the "Ford Industrial Engines and Power Units book (Parts Catalog), 1951-1953", part # 6550, stem caps, for the E valves; looking at pages 31 & 32, only the Exhaust valves had the caps (6).

This drawing showed it for the "254" so I don't know if the 226 had them or not; my 1951 226 car eng did NOT have them.

We may never know the purpose (s), but I suspect that it may have been related to heat factors, perhaps, or the idea to eliminate/enhance the exhaust valve rotation??

I wire-brushed the caps, to remove the rust, and they are black; caps may be composed of or made of a sintered metal composition somewhat similar to that of valve guides ?

Looks like Comp Cams makes an Exhaust Valve rotator Eliminator, probably just for race engines:

http://www.partstrain.com/ShopbyBrand/C ... Eliminator

I talked with my contact in Ft Lauderdale today, and he said that he thought the caps were designed for stock engines to make the valves rotate (he indicated that in race engines they don't want the valves to rotate); I assume Ford wanted them to rotate, as flatford6 and Fred have also indicated, but what is the advantage or rationale since all the valves must/should be seated during the building phase? Maybe they thought it was to help keep the faces cleaner of carbon buildup. But with today's UNLEADED gas, would the spinning valve be an advantage or disadvantage?? I think a disadvantage, either way, because if the valve is "free" to spin/rotate, then each time it comes to a halt it is causing drag forces on both the hardened seats and the valve faces and will result in premature maintenance on the seats/faces. IMHO,,,, my inclination is not to use the caps. Your thoughts, please.

Sorry about the slow post, I just checked my email today.
You should be able to click the image to get the full size picture.


My memory is that Ford added the rotateable exhaust valves to the engines in 51. I thought that the caps were there to take the force from the lifter and transmit it to the valve spring, leaving the valve free from the force of the spring. This would allow the valve to rotate on its own. If the lifter acted directly on the valve, the valve would always be under the force of the valve spring and therefore would not be able to rotate. I think the factory shop manuals have nice picture of both setups, at least for the V8 motors. I don't have any of my manuals here (during the semester).

This is a very curious discussion about ex-valve stem caps on the M-series 254 cu inch motor. I must admitt you now have my undivided attention about this. So, tomorrow i shall uncover the side covers on one of my M motors just to see wether or not there IS stem caps on the ex-valves. If there is, i shall get back to all as to why they are there. Vinny G