One of those times the picture says it all… but I’ll summarize it. Today my goal was to drive the car to get lunch - come hell or high water. So between 9 am and 3 pm we replaced the front wheel bearings, remade the radiator mounts, got a support rod made, fixed the handbrake, fixed the water pump, and without testing anything at all, fired the car up and hit the highway. It was a relatively short round trip, just a few miles, but it felt great to finally have the car on pavement. The trip was pretty uneventful, the car did fine, and lunch felt very well deserved. I am getting a pretty persistent misfire under load. I tried playing with timing & fuel mix to no avail. I think the problem is electrical. We noticed when the car is running, taking a reading at the battery wigs out the multimeter (over voltage) like the coil is somehow feeding voltage to the battery. I realized on the way home today that when I wired the car, I followed the original Model A diagram - which is positive earth - but the battery is set up negative earth. Not sure if that’s the problem but it warrants a good think. I also better rebuild that distributor. It’s an original ‘32 dist and I didn’t really do anything to it other than making sure the weights moved. The points were crispy - though cleaning them didn't help much - & the condenser is probably toast just from age… The radiator is in just the right spot, but I need to make some tweaks to get the shell to sit a little lower. But I'm not worried about that right now.
Spent some time reviewing the wiring with a friend & cannot see that the pos/neg earth switch up could be the problem. However, I think the coil that's on the car is a random tractor coil that has been overheated a few times. I have ordered a matching coil & condenser and will be adding a ballast resistor to the ignition circuit. Hopefully that will improve things. Also got a two-bladed radiator fan since the four-blade stamped ones are notoriously dangerous and a new terminal box lid. Millworks has it all... all except points for my B dist. I'll just dress mine.
Congrats on the drive! Misfire, disconnect each plug, one at a time. Same = the problem cylinder, Worse = not the problem cylinder. Driving a hundred yards with it disconnected (or shorted with a jumper to ground) shouldn't hurt it. On the voltage thing, try the following; Disconnect the charging system, then run engine. It should be battery voltage slowly dropping. Reconnect and check to see if it's charging (more than battery voltage, but not excessive and not freaking out meter). Check if any other electrical stuff is working properly. The model A dist. is wired so a mechanical (ground) connection is made to switch it on. Check this for issues.
We did all that, yeah. We are seeing excessive voltage at the battery with or without the gen hooked up. It may be that something in the distributor is causing the misfire - points, condenser, rotor, cap, wires… and the coil output has to go somewhere, so it goes to ground & we see it at the battery.
After being told a hundred times that the four-blade fan on my car is a ticking time bomb and I should replace it ASAP, I finally found a two-blade fan! Which is, apparently, also a ticking time bomb to be replaced ASAP... I'm gonna run the two-blade because it looks cooler and if it blows up, it blows up.
Jim Linder said something about ge effects of wiring a coil backwards but for the life of me I can’t recall what the effects were. This was on the Ford Barn many years back when someone changed from POS ground to NEG ground on a EV8.
Is that an original 2 blade fan? If it is, don't run it! They get fatigued and blow up! What's wrong with 4 blade? I run nothing but 4 blades on my Model A's and have for MANY years. Never a problem. Do check for cracks tho. Dave
I’ve heard the same about the 1933/34 service replacement bolt-together 4 blade fan, which is what’s on mine! I’m planning to get a cast alum fan but currently they are all backordered (or were a few weeks ago when I looked, and when I ordered this one a few days ago). Mainly, I am hoping it fits with my radiator setup just a little better. The four blade fan is scary close to the top tank on the T-bucket rad and I am worried it could flex and nick the tank.
My four-blade has treated me well for many miles. I believe it's an old accessory piece. Either way, I like how your two-blade is looking!
Dave, I’m sorry to say I should have listened!! It lasted all of 30 seconds. My four blade fan is also catastrophically worn… so I thought maybe I’d run this one until the cast ones became available again and sneak by. It was not to be!
In the before photo it looks like it's cracked running down the blade? This is really making me think I need to address my 2 blade fan.... Dang
There were no observable cracks before I painted it - actually where it failed is a spot weld at the root. I have read rust builds up between the layers but this one is clean inside, the motherfucker just broke. What can ya do? This is probably a new record for the machine gods serving me crow. I can't even be mad. I should have listened but I was cocky
Sadly enough, this is how we learn. When all the old guys say "I wouldn't do that" its because we've found out the hard way. Myself, I never listened to anyone. Had to do it my way and been learning the hard way since 1961!
Yeah he was pretty cool when it happened. He said...oh well! And took the radiator and fan blade off and tossed it aside and walked off! I should have videoed it!
@trevorsworth got any updates since? you made it to the first drive but i havent heard about it again.
I haven't really touched the car since the rad popped. Not for lack of desire... The couple times I've been over there since my last post in this thread, we were more focused on getting his car buttoned up and running, since it has been neglected while we worked on my T. I ordered a new radiator and it is just sitting in my garage. Robin got sick after our roadtrip to pick up a front end for his car, so I didn't go over the week before Christmas. Obviously Christmas weekend I didn't go, and now I just got sick and can't go over tomorrow. Just terrible timing lol. I'll get back on track with it soon enough.
sounds good to me, keep up the good work on it, that roadster is badass. cant wait for the quarter mile time
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