Coil placement for 42-48 Flathead

Jordan Baker · #1 25-05-12, 15:16

I found this picture of an engine being placed into or removed from the carrier and it has the crab distributor on it.

chris vickery · #2 25-05-12, 16:17

Just an FYI for those who are unaware,
the flathead motor came in 3 sequential versions;
1937-41, typical with the diver helmet distributor
1942-48, typical with the crab style distributor
1949-53, typical side block mounted distributor similar to modern style
I would think that very early carriers such as the MK1 might have the earliest block with the divers type. They were inherently known for electrical breakdown due to burning up coils due to the location deep down at the front of the motor and intense engine heat.
The 2nd version (crab) used the remotely mounted coil atop the engine to get away from this problem. You can adapt an early block to accept the 2nd model dizzy but it requires the timing cover plate from a 42-48 engine as the mounting is different.
Any flathead I have even done, I have made sure to go to the 2nd version.
Changing coils on a diver helmet type is a PITA.
Also the only way to properly time these distributors is to do them on an original timing fixture. I have had a couple arguements with guys who insist the reason their engine is running so poorly is because of this or that etc. Time and time again, it is the distributor.(bad coil)

Perry Kitson · #3 25-05-12, 22:59

I too, was under the impression that all Canadian carriers used the early Ford engine. It would make sense that all engines supplied to the army would have been kept to the early style(pre '42) to ease supply of spares. Even the parts manual only shows one style of distributor. When I was rebuilding my engine, the rebuilder suggested putting on the crab style distributor. At the time, my father mentioned that he thought that you could not swap out the front cover and fit the crab style distributor because the cam shaft was longer to drive the early style twin cap distributor. The front plate was changed, and sure enough, the crab style distributor would not sit back because of the cam shaft. Maybe someone with more flathead expertise could chime in. I would think that it is a good idea to keep the coil away from the heat. I have relocated my coil on the twin cap distributor to rad shroud to get it away from excess heat.

Perry

Jordan Baker · #4 25-05-12, 23:41

never thought of it mounting on rad shroud. That might just work for me and still keep the modern coil out of most sight lines.

Lynn Eades · #5 26-05-12, 01:23

Perry, I think the cam stays the same. It would be the dizzy mounting plate, that changed. you should be able to mount either dizzy on the same motor, with the appropriate plate (two bolt mount or 3 bolt mount)

Jordan, you can mount the coil anywhere you like.

We have had it pointed out previously on this forum, that even a NOS ford coil may be u/s. They were unreliable because of the insulation.
(search the many postings by Tony Smith (not the real one))

Jordan Baker · #6 26-05-12, 16:31

Even if you change over the front plate, the 42-48 flatheads have the cam head sitting back a bit more then the 37-41 flatheads. Although I have seen a small adaptor spacer you can buy and it then allows you to have the diversbell distributor instead.

Tony Smith · #7 28-05-12, 04:27

Quote:

Originally Posted by Jordan Baker

Even if you change over the front plate, the 42-48 flatheads have the cam head sitting back a bit more then the 37-41 flatheads. Although I have seen a small adaptor spacer you can buy and it then allows you to have the diversbell distributor instead.

Other way around. The 42-48 cam is LONGER, the 37-41 cam is SHORTER.
If you want to put a 42-48 "Crab" distributor on a 37-41 engine (221ci), besides swapping the front cover plate, you need ONE OF THESE. If you want to put a 37-41 "Diver's Helmet" distributor on a 42-48 engine, you need ONE OF THESE.

If you want to keep a Diver's Helmet distributor, but want to move the coil away from the front of the engine (or convert to 12v), you want ONE OF THESE

Virtually all of the electronic distributors require converting to a 12v system.

Bruce Parker (RIP) · #8 26-05-12, 16:57

Quote:

Originally Posted by Lynn Eades

Perry, I think the cam stays the same. It would be the dizzy mounting plate, that changed. you should be able to mount either dizzy on the same motor, with the appropriate plate (two bolt mount or 3 bolt mount)

Jordan, you can mount the coil anywhere you like.

We have had it pointed out previously on this forum, that even a NOS ford coil may be u/s. They were unreliable because of the insulation.
(search the many postings by Tony Smith (not the real one))

I'm with Perry on this one. There is a different cam (and front cover). I have an adapter that allows the short cam to be used with the other distributor but it obviously won't work the other way around.

Mac's auto has now Ford coils that are cosmetic duplicates of the old but without the 'tar' insulation problem.

Lynn Eades · #9 26-05-12, 23:28

O.K. I'm a learner. I have one of those little round adapters as well. I wondered when it was used.

If I hadn't made the comment, a lot of us would never had learned about it, on this valuable forum (Is it true we have 5000 members, and only 50 of us have helped to keep it going?)

I guess it is also good to have noted the difference between "New Old Stock" and "New Stock" (will Macs give us a discount for the advertising?)

My apologies Perry