MTFCA Forum

When did Ford go from one piece to two piece valve covers?

On our Canadian sourced cars, sometime between 1921-2.

Allan from down under.

That change had an unusually long crossover time when both styles were being used while the old patterns and molds were allowed to wear out and the new patterns and molds were also being used.
I believe the earliest one piece I have seen was about mid to late 1921, and the the latest two piece cover was an early 1923.
Someone having access to dates of changes might be able to pin down the early month for the one piece? I seriously doubt that anyone ever recorded the final two piece cover blocks. And of course, a two piece cover replacement block could have gotten a later number?

According to research by Bruce Mc (from his C-D Encyclopedia) here is the change date to the one-piece valve chamber cylinder block, Factory Number T-400D1, Part # 3000C . Date is just after the start of the 1922 model year Ford.

One linguistic quibble with you Dan...I wouldn't call it a change date, as qty of 100 per day is a drop in the bucket to fulfill production needs...I would consider it an introduction date

Not trying to make something out of nothing...I only mention this because you're a darn good source of information and are quoted a lot on the Forum...It wouldn't be fair to future folks to think that date was a hard change-over date. Even though it states "rate of 100 per day" which clearly is not full production, someone may try to infer something else. It most certainly is a change-date insofar as the official introduction date, but no previous revision of the drawing was obsoleted on that date. I realize you know all of this but someone 2-3 years from now may not grasp the nuance otherwise.

Thanks for being willing to share your vast knowledge and endless supply of parts and accessory info.

Hi Scott. I noticed the same thing, but you beat me to it.

Scott_Conger wrote: ↑

Sat Jun 24, 2023 10:26 am

One linguistic quibble with you Dan...I wouldn't call it a change date, as qty of 100 per day is a drop in the bucket to fulfill production needs...I would consider it an introduction date

Not trying to make something out of nothing...I only mention this because you're a darn good source of information and are quoted a lot on the Forum...It wouldn't be fair to future folks to think that date was a hard change-over date. Even though it states "rate of 100 per day" which clearly is not full production, someone may try to infer something else. It most certainly is a change-date insofar as the official introduction date, but no previous revision of the drawing was obsoleted on that date. I realize you know all of this but someone 2-3 years from now may not grasp the nuance otherwise.

Thanks for being willing to share your vast knowledge and endless supply of parts and accessory info.

Frankly that could be said about many changes on the Ford Model T, RE introduction date!

Mark Gregush wrote: ↑

Sat Jun 24, 2023 3:11 pm

Frankly that could be said about many changes on the Ford Model T, RE introduction date!

Yes, one should figure the dates given on Record of Changes sheets are engineering date, some times notes are given for when to use, for example the Record of Changes Request #9950, for the T-400D-2 block, to increase the pad size for the serial number, making the boss only 3/8" down from the top of the block and height of the boss to be 1/2" was done 8-27-23, and note says "Specified to be used on 1924 jobs."

I noted the data as from B. Mc research....if you have both the C-D or the book encyclopedia (page 417), he says the same...."It is not practical to show every change, in every year. Indeed, it is not even possible!" ...."the major components of the car, the approximate dates these components were used....be aware that there is considerable overlapping in the use of a part while it was being superseded by a new or different design."

A thing to remember is that a Ford design change was issued on a certain date on paper but it didn’t just suddenly happen all at once. As we should know the previous year parts were used up along the way also.
This comes up from time to time I guess because we tend to think of a T being a certain way when it built. My opinion over the years as come to ‘well maybe’!

On a side note, Ford had designed, and used a 2 piece valve cover as early as the summer of 1911. This drawing (courtesy of THF, Benson Research Library, all rights apply) shows the two piece covers used on the largest Ford Special racer (initial 389, then 410 c.i.). This racer still exists at THF, off display, with these early two piece valve covers. Another feature Ford incorporated with this racer that later became an important safety improvement was an under axle wishbone.

Not necessarily pertinent to this thread, except to demonstrate that Ford’s racing program developed technology that made it to production years later.

Dan thank you for you many many helpful postings. I always learn from them.

Above you posted:
10-18-21 T400D1 New design (one valve cover) to be run at a rate of 100 per day

Which is from: (ref: http://www.mtfca.com/encyclo/E.htm#eng2 ).

Just above that listing of the “Date of Change and Factory number” listing Bruce states:

“The following dates are those of Ford engineering drawings and do not necessarily indicate the date of the actual change in the part. The change could have been before or after this date.”

This is a good example of how things changed -- at least in this case. The 10-18-21 refers to the date on the factory drawing of the new block with the one piece valve cover and not necessarily the date the change was put into production.
But, the engine log listing on page 526 of Bruce’s book under the November 1921 has the note “Beginning of production of one-piece valve door engines, along with old two-door engines. And they list the number of two-door valve cover engines and one-door valve cover engines produced from Nov 1, 1921 to Mar 31, 1922. No engines produced Apr 1 or 2. With a note on Apr 3, 1922 “All one-piece doors beginning April 3.

That would have been approximately 13 days from drawing to the new part is in production. And I would guess and it is only a guess, they probably made a few practice parts to see if the process worked? From Nov 1, 1921 to Mar 31 both the old two-piece and the new one-piece valve chamber blocks were produced [same ref page 526 of Bruce McCalley's "Model T Ford."] That is approximately 5 months of overlap when both the new and old style parts were still being produced. And of course, the old-style engines that were produced on Mar 31, 1922 would have been installed some time and some place. If the two piece engine block was shipped to a branch plant for assembly it would have been later than at the main Ford plant.

Note on page 562 Bruce has the comment: “Nov 1 1921 Engine production records – First engine with one-piece valve door. The older two-door engines continued until April 3, 1922.” While the actual engine log production shows that the last two-door engine was assembled on Mar 31, 1922 with the no engines produced for Apr 1 & 2. And only the one-door engines produced starting when production resumed on Apr 3, 1922.

And that is for USA and NOT Canada or the UK. Canada cast their own blocks. England cast their own blocks without “Made in the USA” in 1920. Initially at Cork, Ireland and later Manchester England ref Page 131 “The English Model T Ford.”

Respectfully submitted,

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