The other day I was running my '23 Runabout around the neighborhood, and it was very hot out. I noticed that I was getting a LOT of heat coming up from the floorboards and the firewall.
When we got the car home, my brother noticed that there was smoke coming from where the wooden firewall is dangerously close to the exhaust manifold, and sure enough, it was on fire! We had to spray it down with water to get it to stop smoldering, and the wood is definitely charred and burned there.
While I could try to shave-off about a half inch or so of the edge of the wood, plus, make some kind of heat shield mounted between the firewall and the manifold, I am seeking a more permanent (and safer) solution.
Has anybody run into this same situation as well? Is it possible to replace it with the metal version of the firewall?
Your experience and input is always appreciated! Thanks!
Yes. There were low steel firewalls made late in the low radiator series production. They are a direct replacement for the wood firewalls, but, you need different firewall to frame mounting brackets to go with them. Hope this helps. Dave
Either use different firewall-frame mounting brackets or use a spacer at each screw on firewall (4 total). There was evidence that a factory spacer was used as an expedience.
I used washers as spacers.
You probably forgot to advance the timing. A wood firewall insulates and does not transmit heat to the interior. You need to figure out why it caught fire. That never happens.
I wondered the same thing as Royce. How many wood firewall cars are there out there with never any issue?
Allan from down under.
My thoughts too. Shouldn't do that. Something's wrong. It's not the fault of the firewall.
I believe there was a heat shield provided. Apparently it got lost.
Heat shield? Never seen one, if there is, pls post pic.
I'm pretty sure that one reason it's running so hot is that the timing is way too retarded, as it is lacking in power and definitely runs way too hot. Problem is that I don't really understand yet how to go in there and make timing changes, much less how to reset it exactly as it should be... I've only had the car about a month now and am a total newbie to this car and it's engine.
I know I need to spend some time reading some of the forum postings here about ignition timing, but I wonder, is there a simple way to just turn that timing cap (that is buried down there in the front of the engine) one way or the other, to do a quick change in the timing (to see if that helps)?
Explaining it can be a bit confusing. During the course of normal operation, you must retard the timing for starting and advance to run, and you SHOULD retard again right after shifting into high and advance as it speeds up. This is all during normal operation, is done with the left lever, and assumes things are set right under the hood to start with. That is a whole nuther thing. Basically, it needs to be adjusted under the hood such that when the left lever is all the way up, the engine is firing 15 deg after top dead center. This adjustment is made by bending the metal rod that connects the timer to the spark lever mechanism on the steering column. You can do a search for the specific directions on how to do this, but you really need to get THAT done before you drive it anymore. Once you get that done, start it with the spark retarded and advance it once it starts. Failure to retard for starting can cause broken starter parts (Be them mechanical or your arm). Failure to advance when driving will cause overheating and very poor performance.
Changing the timing is more important than changing the firewall, you can go to the trouble of changing the firewall and have accomplished nothing as the retarded timing will damage the engine, exhaust manifold and exhaust pipe and if the firewall is not on fire, the floorboards will soon catch.
That's an interesting approach; that is, to bend the spark lever down there to adjust the base timing on the engine. I never would have thought of that.
Does anybody have any photo(s) to share, of exactly how and/or where you bend the link, and in which direction, to either advance or retard?
And, just how would you know how to set the base timing at 15-degrees ATDC?
Bob, Google timing 9:30 mtfca and you'll find a lot of threads where setting the timing is discussed (can't link with the cell phone)
Bob -- Google is your friend. If you want to search this forum, go to Google and type in mtfca followed by whatever you want to search for. I did a quick search using the words: MTFCA timing at 15-degrees ATDC and got this.
The mixture being too lean can also cause this problem. Had a friend who built a speedster and his firewall caught fire.
the exhaust manifold was glowing red, by opening the mixture a 1/4 turn out the red glow disappeared before our eyes.
THANK YOU to all of you, for your ongoing help and suggestions... I've printed-out a whole bunch of different Forum posts here, and I will review them over the next couple of days, so that I can (hopefully) better understand the timing process!
FYI, I'm going to be replacing the timer (with an Anco kit), the timing rod, spark plugs, and then doing my measurements down there to(hopefully) get my settings closer to being correct (as in much less retardation of the timing, which is making it run extremely hot and sluggishly).
The scary thing is that, in spite of moving the advance lever all the way down the other day in the garage, it still ran pretty poorly, with slight misses and a bit of roughness. However, I've decided that the best way to learn more about resetting this overly-retarded engine is to put new parts down there (to get to a clean slate), new plugs, and then try to follow all the suggestions for how to set the base timing on this thing.
As usual, I'm appreciative of any and all advice given to this Model T Newbie!
Just keep in mind that even with new parts, you will almost certainly still have to bend that rod to get the proper initial adjustment.
Yes, I'm aware of that, which is why I've also ordered not only a new rod, but also the rod-bending tool set... and am also studying lots of forum postings about how to set the basic timing on these babies. I just wanted to also know that the plugs and timer parts are brand-new, so I also have a clean starting point from which to move forward from.
Good to go. Let us know how it works out for you.
Since replacing the old New Day Timer unit with an ANCO unit, and replacing the spark plugs, and, since properly re-setting the timing (to get rid of the over-retardation problem), the car is now starting easily, idling much better, allows me to get the RPM's way higher, and no longer overheats (or tries to start the firewall on fire)!
I was even able to take the grandkids out on a local two-lane highway today and we were probably doing around 35-mph... a far cry from when I first got this car barely a month ago!
As usual, my sincere thanks to all, for their invaluable input so far; it's all been a great help to me as I learn more about this fun little car!
Good to hear!
Hey Bob, isn't this the best place to learn about Ts? 90% of what I know, I learned from these guys (I learned on my own to carry a spare gallon of gas though)
It could be an exhaust leak where the pipe is connected to the manifold or a leaky pipe. This would be especially true if the spark were retarded and or the fuel mixture too lean. Some flames could then come out of the leaky pipe and catch the wood on fire.
Yes, Gustav, forums such as this one are always the best place for getting and sharing experience! And, Norman, I doubt it was ever related to an exhaust leak, since the entire exhaust system (manifold, exhaust pipe, attaching ring and muffler) were all just replaced by myself before the scorching incident ever happened. I am convinced that is was simply an incorrect timing issue, as suggested before, by other forum members.
As an aside, however, I will share that when I first got the car,(and prior to the firewall getting cooked by the manifold), I did find that someone had cross-threaded the attaching ring to the exhaust manifold, and therefore only had it tightened about a third of the what it should have been... but of course I've since replaced the entire system and made sure that all fittings are all nice and tight, and leak-free...