celticsam

I'm building the car to (hopefully) participate in the Power Tour 2026. I've participated before (before the specter of Covid) and HIGHLY recommend driving in at least part of one. A very good time. In any case, the tour pretty much requires 4 - 6 odd hours of driving on each leg of the tour. I would only trust a battery for 3 or 4 hours without charging it, and the 6 volt system on a '49 Coronet isn't up to the load of stepping up to 12 volts and keeping up with charging a battery being drained by a stereo and an air conditioner (or even just the AC). Its a great idea if you limit your cruises to local events, not so great if you are planning any distance driving....

OK. I found this (link below) which suggests that this is a solution to making the gyromatic 12v compatible. Anyone have any experience? 1949 -1953 Chrysler DeSoto M-6 transmission 12 to 6 volt solenoid reducer/relay -M612K2

I am going to convert my 49 Coronet to 12V. I have been scouring the net for information on how to handle the servo on the Gyromatic tranny, but have only come up with "it can be done" - which just encourages me to find a way. Before I mess up the tranny (or force a larger project), does anyone know how this can be done? Looking at the wiring diagram, if I use a 12V to 6V converter or ballast resister on the red wire off of the coil (and switch it to the + side), that will power the transmission circuit with 6V negative ground. Will this work? Has anyone done anything that has? Before all the 6V faithful chime in, due to my wife's asthma, AC is a necessity. Not a luxury. That makes 12V also a necessity. That goes before all the "brighter lights" and "modern stereo" arguments. Sure was easier on my old 49 SD 3 on the tree ....

Its a bear to find a V-belt that uses the wider belt configuration...these old topkicks do. By old, I mean 79-84. The larger belt is, I suppose, due to the air compressor or other accessories (ie, hydraulic pump, ect...). In any event, these are V-belts...not serpentine. Problem is, they appear deeper than the stock belts, and the angles on the outer edges may not match up...mine is to worn to tell for sure. Trying to figure how to drive a modern alternator and AC compressor without changing the crank and water pump pulley...I don't think any narrow belt pulleys are readily available for the old flatheads... Neil

Now that my engine mounts are sorted out (or soon will be...), I am converting the engine over for use as a semi-daily driver...which means 12 volts and AC. I've been looking at the AC compressor from a GMC topkick (truck) which uses either a 1" (actually 1.09" per Gates) or a 1 1/4 inch V-belt (year dependent). I'm thinking that the 1" belt would most likely work, but wanted a few opinions. As for the alternator pully...I'd like to use one that matches the same belt...these belts being fairly easy to find in various lengths. If it makes a difference, ac compressor will be mounted where the generator is stock with the alternator directly above it....the fan will be electric dual speed (freeing up a small amount of power from the belt driven fan). Engine is a stock, fairly fresh 218. Neil

As an aside...I tried (again) to talk my wife into a straight automatic. No dice. I guess when her car is done, I'll have to build something for me...but that will be a few years...

Don, those pictures are great. Here's what I have figured out, from the pictures. I am missing the U-bolts and the rear bolts, and the front rubber "biscuit" has seperated (actually, there is no rubber left), allowing the mounting plate (?) to have fallen out...but it is in one of the boxes along with the fluid drive's linkage and the carburator linkage. The 2 rear rubber mounts had solidified ...something... filling the middle holes. With some work, the holes are now there...I was just afraid to put some muscle into it. So, here's the next question...the car was originally a 3 speed. The current transmission (bolted to the replacement engine) is a Fluid-drive. I suspect I will have to move the rear mount back a bit, but does it use the same rubber mounts, or is this something "custom"? Is there any way to leave the crossmember in place for this? Finally, someone mentioned upgrading the U-joints from the ball and trunion design...I wasn't aware they made a conversion for this...any info would be appreciated. I must say, I am actually glad I didn't start modifying the 48 for the 318 that I had (and traded for the flatty and fluid drive)... Neil

But does anyone have info on the mounts themselves? I have the front plate with 2 bollts into the crossmember and 2 bolts into the plate...but the engine seems to sit in a horseshoe shaped U with nothing holding it in place but the weight of the engine...and the 2 pucks at the rear crossmember are also solid. No provision for bolt holes. I haven't blasted them yet, but, unless the crud in the holes is extremely solid (as in, I couldn't probe through it with the scraper when I started cleaning everything up), they are not present for some reason. I know it can't just sit there by gravity, but there is no place to put any bolts. Like I said, I'm missing something... Neil

Unfortunately, the car will be for my wife to drive. At 5' (and with short legs), she has a hard time with the clutch in most stick cars...she specifically asked for an automatic. The fluid drive was a comprimise, as I like the stick, personally. If I had my way, I'd either keep the 3 speed or use a T5...

I have a 48 P15 (Special Deluxe) that was bought with the engine and transmission removed and damaged beyond repair by the previous owner and his "trusty" sledge hammer. I just bought a 49 Dodge flathead (yes, its longer) and fluid drive to replace the original engine and transmission. That said, How does the engine mount into the car? The mounts look like they just sit there by the weight of the engine...that can't be right. The front (H) mount bolts to the crossmember and the engine bracket, but that bracket does not bolt to the engine (semi circle pad...with no apparent holes). The 2 wafers or pucks back at the bell housing also have no hole in them. I know that I am missing something, but I can't find any pictures or diagrams to show how this goes. Also, any diagrams showing the proper way to connect the Fluid drive's linkage would be appreciated. I've changed a few newer engines, but never anything older than around 1965... Neil Littlestown, PA

Yeah, its going to be a driveline swap, engine to rear, and everything in between. If I can use the disc brake setup, I'll take that, too. The 5th Avenue was hit HARD in the right front, so everything is currently depending on the engine being intact....I find out today or tomorrow. Neil

It appears that this project will be on an indefinite pause. The flathead 218, while basically solid, will need quite a bit to rebuild. At least for now, I am opting for a small block Mopar drivetrain (mostly due to much lower initial and maintenance costs), and am going to keep the flathead for a (as yet unknown) future project. At some point, I'll rebuild it and TBI it...it will just be low on the list. To bad, as this would have been a fun project.

I have access to an 87 Chrysler 5th Avenue. I am taking the drivetrain, and was looking at the rear. Anyone swap an M-body rear into a 48 Special Deluxe? The car isn't here yet to measure everything, but if I can keep the entire driveline from one vehicle, it will improve compatibility issues and future maintenance headaches. As always, being a newbie, any help is GREATLY appreciated.

The Omni/Horizon has a rather complicated injection system...overly so. rugged, reliable, but complicated. The 218 is roughly 3.5 liters...the 230 is 3.8. With the 3.8 lies the answer. The 3.8 was available in a TBI form in a few platforms...most notable G-bodies. The system only relies on a MAP sensor, an O2 sensor, and a temp (coolant) sensor, an AC circuit sensor if needed, an HEI type distributor, and, depending on year, a throttle position sensor, a speed sensor, or both. For our engines, a MAP sensor at the base of the TBI, a coolant sensor which can also send to a gauge, a Stovebolt Engines HEI distributor, and a Holley 2 BBL style TBI unit would do the trick nicely. The missing piece was supplied earlier...Manifolds by Moose! I e-mailed him, but if he can do a TBI flanged single exhaust manifold, a O2 bung placed at the convergence of the 6 pipes, and away we go! Shoot, I could even put an aftermarket cat converter on it to make it fuel effecient and clean.

I had sat down and figured this pretty much through. Direct port injection would be very difficult with the siamesed intakes runners on a flathead. However, using a MPFI setup, as in the GM 2.8 would work very well. 6 injectors in the intake manifold, set up as batch fire (1,3,and 5 inject on one crank revolution, then 2,4,and 6 inject on the next). Since the displacements are similiar, the computer would read the O2 sensor, adjust the injector pulse width, and have the engine running close to correctly. The problem that I see with this setup (and the reason that I decided on TBI) is the fabrication of a proper fuel rail, Poor injector placement (fairly far from the valve and angled poorly), along with the GM computer's known lack of flexibility and difficulty with tuning. With TBI, all that you need is a MAP sensor, an O2 sensor, a temperature sensor, a throttle podition sensor, a 1 BBL to 2 BBL adapter, a 2 BBL to TBI adapter, an inline fuel pump, the Holley TBI unit, and a computer with harness (Holley or, say, a 88-93 Chevy truck harness) Electronics, I can do. Metal fabrication....not so much.