Roof 16 valves cilinder head.

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AndreFordT
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Joined: Sun Jan 06, 2019 12:25 pm
First Name: Andre
Last Name: Valkenaers
* REQUIRED* Type and Year of Model Ts owned: 1926 ; 1922 ; 1915.
Location: Scherpenheuvel

Roof 16 valves cilinder head.

Post by AndreFordT » Thu Dec 25, 2025 4:56 am

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.


Ujustwaite
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Joined: Fri Nov 22, 2024 6:39 pm
First Name: Brian
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* REQUIRED* Type and Year of Model Ts owned: B.H. Lawwell Special (1917-1921 Fairgrounds Racer)
Location: Catonsville, MD

Re: Roof 16 valves cilinder head.

Post by Ujustwaite » Thu Dec 25, 2025 8:14 am

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

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Topic author
AndreFordT
Posts: 549
Joined: Sun Jan 06, 2019 12:25 pm
First Name: Andre
Last Name: Valkenaers
* REQUIRED* Type and Year of Model Ts owned: 1926 ; 1922 ; 1915.
Location: Scherpenheuvel

Re: Roof 16 valves cilinder head.

Post by AndreFordT » Thu Dec 25, 2025 1:04 pm

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
Attachments
P1050485.JPG
P1050483.JPG
P1050482.JPG
IMG_8174.JPG


Kevin Pharis
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Re: Roof 16 valves cilinder head.

Post by Kevin Pharis » Thu Dec 25, 2025 1:50 pm

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.
IMG_1829.jpeg
IMG_1830.jpeg
IMG_1792.jpeg


Ujustwaite
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Re: Roof 16 valves cilinder head.

Post by Ujustwaite » Thu Dec 25, 2025 10:58 pm

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:
PXL_20251225_210342027.jpg
PXL_20251225_210344798.jpg
Overall view: (firewall is temporary)
PXL_20251225_210427099.MP.jpg
Arms on my Roof Type C head:
PXL_20251225_210211487.jpg
PXL_20251225_210255920.jpg
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


Ujustwaite
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Re: Roof 16 valves cilinder head.

Post by Ujustwaite » Thu Dec 25, 2025 11:04 pm

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.


Shelbycsx
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Re: Roof 16 valves cilinder head.

Post by Shelbycsx » Sat Dec 27, 2025 2:25 pm

This is my head
9693.jpeg
9693.jpeg (49.1 KiB) Viewed 108 times
9694.jpeg
9694.jpeg (49.65 KiB) Viewed 108 times


Kevin Pharis
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Re: Roof 16 valves cilinder head.

Post by Kevin Pharis » Sat Dec 27, 2025 2:35 pm

^^^^^^^^^
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
IMG_2682.jpeg
IMG_2683.jpeg


Ujustwaite
Posts: 26
Joined: Fri Nov 22, 2024 6:39 pm
First Name: Brian
Last Name: Waite
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Re: Roof 16 valves cilinder head.

Post by Ujustwaite » Sat Dec 27, 2025 7:14 pm

eng18.jpg
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

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