MTFCA Forum

Running out of assemblies to do, so I thought I'd start in on putting the car chassis together assemblies, of course starting with mine (it's the one I know the best). Sooo, I'm starting with the Wood Firewall and since my car is a 22 and it is my understanding that the Low Cowl Wood Firewall ran clear through 23. Now, there are some 23's that have a metal Firewall, but as I understand it they were replacements for the wood ones that were discontinued in the 23 model year. Doesn't mean I'm not going to draw both the metal replacement Low Cowl Firewall and the metal High Cowl Firewall too, but first I thought I'd do all the wood ones and then get to the more "modern" ones. Funny place to start I suppose, starting with the end years, but I've got to finish up the 17-18 non starter firewall assembly as well as the 15-16's firewall assembly. And there I'm kind of running aground. So, if anybody could send me some pictures of 1914 thru 1909 Firewalls, that would be very helpful and much appreciated.


I thought since I had the engine side I might as well put in a reference to where the Switch Loom goes from and to where it connects to the Connection Block. Now some of you might wonder why the engine compartment loom isn't shown, welll, that's because there's no Engine in this drawing. When I drop the engine into this part of the frame drawing, I'll include that loom and where all the little wires go. I am approaching this very much like we're putting a running Chassis together, this seemed to me to be the only logical approach, which also means I've got to do a Frame drawing too. I've got quite a few drawings in various stages of completion, usually waiting for further information from somebody and then there is those blasted "Round-2-Its" which seem to be rarer than hens teeth....but I'll get there ....eventually.

Martynn, a couple of things I noticed are at variance with what I know of Canadian cars, which may be different to US production. In the cabin side drawing you show the firewall to frame brackets having square holes to accept the square under the head of the bolts. On the original old car I am working on at the moment, the bolts go in the other way round. They have a larger than usual head. This head is set into a relief in the wooden firewall so the firewall can sit flush against the body. The brackets are on the front side of the firewall. The holes in the brackets are round, not square.

From the engine side, there is a half circle relief in the firewall where the rain gutter terminates to accommodate the hood side panel hinge pins.
Both the steering column flange nuts and the frame to firewall bracket nuts are hex rather than square. Here in Australia, Whitworth nuts fit, but they are a little bigger in the hex. I had to order UNC nuts to get the correct 1/2"across the flats.

Hope this helps,
Allan from down under.

What Allan said. I had to fight with one of those firewall mounting bolts when the darn thing just spun in the firewall. The square nut was a bit buggered up and the nut would not come off, not a fun time to be sure.

The '19 and early-20 wood firewall had the square cutout mounted on the firewall and a single wire running from the cutout through a hole to the top right (looking from the front to the back of the car) of the slots for the idle and choke, some have shown it above the slots. Later the cutout was moved to the generator (still square a cutout) with a single wire running from it through the same hole mentioned earlier.

The terminal block was also a 5-terminal block, with there being 2 different versions, the earlier one being thicker and having rounded ends and the later being the more common squared off end terminal block, running until about 1921. I have attached some links to threads from the old Forum that show some of these features:


http://www.mtfca.com/discus/messages/50 ... 1431707948

http://www.mtfca.com/discus/messages/80 ... 1234754885

http://www.mtfca.com/discus/messages/41 ... 1391528051

https://www.mtfca.com/discus/messages/3 ... 72291.html


There was also an earlier version of the Priming Bell Crank that was used for a very short time:


https://www.mtfca.com/phpBB3/viewtopic. ... ll#p284499

Ok, made some changes, you're right the Firewall brackets should be on the engine side and not on the interior side. Don Lang caught it and I couldn't believe I missed it entirely, anyhoo, also forgot to add the Dash Choke Rod and had to change where the Dash Wiring Loom comes through the Firewall...it's one of those times where the fun truly never quits.

Martynn,

Thank you so much for all your many illustrations! Just to clarify (and it may have been done above -- but if so I missed it.) In 1923 for USA production both the metal (low firewall) and wooden firewall were used in production.

From: https://www.mtfca.com/encyclo/1923.htm

DASHBOARD(Firewall): Wood, fitted outside the front cowl, hidden by the metal cowl weather strip. In early 1923 a new metal firewall replaced the wood one for a short time (both types being used for a time), then in August a new larger metal firewall was used to match the larger hood.

See: https://www.mtfca.com/encyclo/doc23.htm where it says:

APR 7, 1923 Acc. 78, Box 47-49, Ford Archives
Letter indicates that the steel firewall was now standard. This was the "low" steel firewall.

Respectfully submitted,

Hap l9l5 cut off

There is another little part that was used during the changerover from late wood firewall to low steel firewall. Ill mention first that there are two firewall brackets one for wood and one for steel firewalls. It appears there was a short period of time that the wood firewall bracket was being used with the steel firewall. To make up the difference in the thickness of the wood verses the low steel firewalls, they used a spacer between the bracket and low steel firewall. It also appears to be a radiator mounting spring thimble cup with a smaller hole. I used to have a low steel firewall car that had those thimbles installed. The hole in the thimble for the bolt was smaller than the radiator stud. The cups on my car would fit the firewall mounting bolt but not the radiator stud. There was a discussion about the thimble cup spacers in the past. But I can not find it. I'm not sure if everyone came to a decision on it or not.

Martynn here are a couple of photos of some details from an original firewall from a 1922 Canadian RHD car.
Notice the chamfer and two mounting holes to accommodate a magneto horn, not used on this car. Note the relief on the side for the hinge on the hood. This is between the rain gutter piece a d the tacked-on side flashings.

The second photo shows the relieved firewall mounting bolt hole.

I do not know if these details apply to US production. Allan from down under.

Donnie,

You are correct that there was a metal spacer used for a short time when the low cowl metal firewall was first introduced. Perhaps this might be the thread you were thinking about? http://www.mtfca.com/discus/messages/59 ... 1456565564
In that thread Trent responded to the question: “Was the low steel firewall ever used [in production]?”

+++++++++++ Reposted from the thread listed above +++++++++++

By Trent Boggess on Thursday, February 25, 2016 - 06:49 pm:
Absolutely!!!

I found evidence of the use of the low steel dash in production while doing research in the engineering documents collection of the Benson Ford Research Center. The steel dash came out before the steel dash dash to frame brackets were available. There is about a half inch difference between where a wood dash attaches to the dash to frame brackets, and where a steel dash attaches to the dash to frame bracket. The later steel dash to frame bracket did not appear until about 6 weeks after the production began of the steel dash. In order to be able to use steel dashes when only the wood dash to frame brackets were available, the Ford engineers designed a round 7/16 inch spacer that wood go between the new steel dash and the mounting points on the earlier dash to frame brackets. Four were required per car.

Ford used these spacers as a temporary fix until the later style steel dash to frame brackets were available, then the spacers were discontinued. Anyone wanting to replace their wood dash with a steel one after that had to buy both the steel dash and the later dash to frame brackets.

I have seen these spacers in place on at least one 23 touring, and I believe a contributor to this forum may have posted pictures a few years ago.

Respectfully submitted,

Trent Boggess
++++++++++++++++ End of reposting ++++++++++++

Respectfully reposted,

Hap l9l5 cut off

Small correction to some lines that were in the wrong place and or not completed.

I haven't gotten round to the metal Firewalls yet, concentrating on all the wood ones first (and there are a bunch of those). But I can if I had pictures of one. The Low Cowl Metal Firewalls of 1923 are a might different in their hardware from the woods one. That said, if anybody has a nice clean 1923 Low Cowl Metal Firewall I'd like to see pictures of it so I can draw it. I need a full front, back, side and top. And since you were mentioning the Spacers, I need pictures of those too.

Martynn, I have nothing technical to add. But I will say that I’ve always admired these drawings. I enjoy the threads as the new ones unfold. They have also helped be get several derelict T’s going over the last few years.

Thanks!