MTFCA Forum

Merry Christmas All,

I am looking for information about the 16 Valves Roof heads.

Maybe someone out there can help me.
Thanks

Andre
Belgium

I will post some photos later.

Andre, I have extensive information about these Roof heads and own some of them. I am compiling a history of Robert Roof and have information from a variety of original historical sources.

Please don't hesitate to ask. There is also a good community of people here who are experienced working on them.

All the best. Merry Christmas!

Brian

Just to add a few photos of the head I have here and I want to make it work on a model T engine.
Pay attention on the mis alinging of the rocker and the push rods.
What is used to fill up the gap between the intake valves and the rockers.

Andre
Belgium

Your head is a model B, but rockers are for the racing model C. Roof modified the B rockers for the C. Upper tower was cut down on one side, and the shaft offset to one side to align with the C valves. Here is what the unmodified B rocker set looks like.

Kevin,

Just to follow up here. I exchanged a series of emails with Andre outside of the forum, mainly because it was easier to share photos and he reached out to me directly there. I think there is more going on here as well. This series of Roof rocker arms has 4 distinct parts (for both C and B / BB heads). They are 683,684,685,686 as identified by the casting marks (topside lower rockers / underside upper rockers). In mine they also have an A/B label with one each in each position (upper and lower) (eg: 683A,684B,685A,686B making up one complete tower). Interestingly his looks like they have 683 and 684 both A, which is the first I've seen this.

I agree that these seem to have the spacer that was used on the Type C racing head, which will be problematic. I also think that these parts are either misassembled and/or were all cast from a single copy set and lack the correct curvature on the pushrod side. With the space removed, the bends in the exhaust side rocker arms will likely still be problematic.

On my Type C the outer arms of the outside exhaust side arms both curve out away from the center and are nowhere near as severely bent as those on these arms. I suspect that these are either bent or mismatched pairs. Either way, my BB arms are much straighter even though the pushrod accepting side is offcenter from the arm itself as cast. The C rocker arms I have are more severely bent, but not as much as this.

I provided photos on all of the relevant parts showing this and hopefully that will help. I've offered to send him measurements from either setup as needed. I also sent photos of the extensions and caps on the valve side.

Here are the arms on my BB head:
Overall view: (firewall is temporary)
Arms on my Roof Type C head:
I suspect some bending will need to be done carefully with heat applied to get these to line up properly. He is going to take them apart and reassemble and then we'll see where he's at.

Best,

Brian

PS: For those that are interested, I would class this as a BB head as it has the 1.5 inch valve opening with the additional clearance in the combustion chamber for the larger valves. Note in the combustion chamber that the valve openings are scalloped out of the main chamber. On a B they are fully contained within the combustion chamber and lack this scalloping.

There are also some casting differences in most B, but I have at least one example where this is not the case, so I'm working to evaluate when those changes all fit in the timeline of production. Mainly on at least some (likely early) Type Bs, there is an indentation in the casting between the two portions of the exhaust manifold and above the spark plug holes. That is not present on this head consistent with all BB style heads I have seen.

This is my head

^^^^^^^^^
Roof A model head. Wicked kool exhaust ports… not sure what they were thinkin with the intakes tho. Rockers are typical of the early A and B model heads, and are prone to breakage. These used 2 piece push rods, pretty sure the valve tip links were the same on all heads

That is so great. I have been hunting for a Roof Type A as it is the correct head for my car. The Lawwell Special. It raced a BB later in its life, but originally had an A. You can see it in this photo which is from a clipping in the Roof family archive.

Shelbycsx wrote: ↑

Sat Dec 27, 2025 2:25 pm

This is my head 9693.jpeg9694.jpeg