What kind of valve adjusters are these? 2 different types on same engine.

[ScreaminJohnny]

Back home with the bird now. I started her up ran her for about a minute and shut it off so I could pop off the valve covers and make sure there’s adequate oil. On the drivers side of the engine I see what I’m used to - standard jam nut valve adjusters for a flat tappet.

On the passenger side I see some really odd, new looking, nuts. They’re not even jam nuts. I’m worried that these wouldn’t even keep an adjustment. I’ll attach some pictures. I was going to adjust valves now that I’m here but I’m stumped. On the plus side, I have plenty of oil on both sides!

[ward 57]

The second photo shows original adjusters. They are held by friction. I have no idea what is on the other head. Definitely not stock.

[ScreaminJohnny]

Oh that’s odd I thought it was the other way around. I’m used to jam nuts. Well I suppose I can order some new ones for the driver side. So the silver ones are stock?

[Machinehand]

The first image shows the early style Y Block jam nuts. The second image are the later friction style. Both work fine.
I have both...but not on the same engine. It is easier to adjust the lash with the friction type but I like the security of having a jam nut to lock it in.

[ScreaminJohnny]

Okay that makes sense. I’m not sure why only one side was changed. I don’t know the history of this bird. The car is a ‘55. What style is original to the car? My diesel had the jam nut so that’s what I’m used to. I’m assuming that the jam nut is original to the car because it matches the rest of the valve train. The later friction style look really out of place.

[55blacktie]

Machinehand is correct. Although the early type requires a bit more effort and dexterity, they are preferable.

[Machinehand]

One of your cylinder heads may have been swapped out at some point. I would check to make sure all the rock ratios are the same. There are two different rocker ratios for the Y Block. 1.43 and 1.54.

The castings with EAN are FoMoCo '54 or '55 units and are 1.43 ratio. 5751066 are also FoMoCo, but they are from '58 - '64. These are also 1.43 ratio. For '56 and '57, rockers will have the casting letters ECG and are 1.54 ratio.

[MarkR]

There’s appears to be more than enough threads open on the late friction style to add a thin profile back up jamb nuts. My 55 has had friction style since 2004 with no problems. (No jamb nuts)

[ScreaminJohnny]

I can’t find the part number or anywhere that sells the jam nut style. Does any know know where I can get a set of the jam nut valve adjusters for the passenger side to replace the one piece?

[55blacktie]

Try John Mummert (ford-y-block.com). You'll have better luck contacting him by calling.

[ward 57]

I would do what machine head said. Check to see of the rockers match. If they don't, Hills may have a complete rocker arm assembly #6563. No price but to call.

[55blacktie]

John sells new rocker assemblies as well. You could also contact Rocker Arms Unlimited (rocker arms.com) in Redding, CA. Tim McMaster (yblockguy.com) in Hanford, CA also reconditions rocker assemblies and pressurizes them (watch his video). He's another guy that you'll want to contact by phone.

Go to ford-y-block.com, click on YOUTUBE in red, click on Videos, and scroll down to Ford Rocker Arm Adjusters.

[MarkR]

I can’t find the part number or anywhere that sells the jam nut style. Does any know know where I can get a set of the jam nut valve adjusters for the passenger side to replace the one piece?
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If your rockers do match, I wouldn’t worry about the jamb nuts. Leave well enough alone. The “friction fit” was used starting in 1957. From what I’ve heard they were referred to as an interference fit. The rocker and adjusting screw used a different thread taper causing the adjuster to bind and hold.
I’ve never heard of any problems with them.

[ScreaminJohnny]

Forgive me if I’m mistaken. But EAN rocker arms have to use the jam nut style? And ECG rockers have to use the stud type? They aren’t interchangeable?

[Machinehand]

Forgive me if I’m mistaken. But EAN rocker arms have to use the jam nut style? And ECG rockers have to use the stud type? They aren’t interchangeable?

I don't think that is true. I have several sets of EGC rocker assemblies with both. I think the rocker threads are the same.