On this forum we spend most of our time talking about the flat head V8, I have been considering fooling with an inline flat head six, any comments about these motors good or bad

 

More torque than a V8 with no parts to be found for the G series. That said, I like mine okay. Simple is best.

 

As mentioned, more low speed torque than the V8. The six was the engine of choice for the off road log trucks of the era in my area of western MD.

 

The H series, which is very similar, but with a couple "upgrades" (5 more HP, newer type dustrib) is a bolt in for the '41-47 G series. My '46 has an H that was done long ago, very good motor, very smooth. The fame of the V8 over shadowed the 6. I say go for it.

 

I have 2 '46 tonners that have the G series 6 cylinder flatheads. One of the trucks was purchased new by my grandpa in early '46. When I got the truck it hadn't run in over 45 years and the engine was stuck. Got it freed up but wouldn't run due to rings being stuck to the pistons. I pulled this engine and totally reconditioned it....bored out .060, new pistons, rings, rod bushings, valves, reground crankshaft, new bearings, new camshaft bearings, new lifters, new gaskets, you name it...it was pretty much returned to 'as new' condition. As mentioned above, the parts were very difficult to find and they came from every corner of the U.S. In some cases they were pretty costly, too. For instance, 6 pistons were $660 and were found in New Jersey. (I live in Nebraska) If this truck would not have been my grandpa's, not sure I would have spent over $2500 on the parts and machining for the engine rebuild (I disassembled and reassembled it myself). But it is family history and my 90 year old father got to ride in the truck again after the almost 60 years since he had driven it. The other '46 truck I purchased at a very reasonable cost has a frozen engine. I found a used one that runs real well for $400 that I will put in it. Mine is a long story but I have learned so much about these engines. Good running G Series 6 cylinder flatheads engines do come up for sale from time to time as people pull them out to put in more modern engines. They were also used in cars so quite a few of them around. I love these 6 cylinder flatheads, they run very smooth and start very easy on the old 6V systems. They are not made for high speed, great for lower speeds with torque for pulling. The '47 H Series do have the distributor on the side of the engine vs the distributor on the front of the engine as in previous years. But the '47 H engine was not available very long as overhead valve engines came along very soon after. The distributor on the front of the G Series are a little difficult to service when on the engine, but you learn that they are easy to remove and reinstall when service is needed. No re-timing is necessary as this is all fixed in place when you bolt the distributor back on. I can tell you the block type distributor caps for the G engines are almost impossible to find. The distributor rotors are scarce too, but the points are the same as used in the V8 flatheads. If you go this route, be patient. It will test you but the end result can be awesome!

 

I second that..

There is also the 254 M series:

https://www.ford-trucks.com/forums/5...thead-six.html

 

There is a 6 here on the island that may be available. Said to be good condition and is on a stand. Is the G or H designation determined by distributor location? Thinking of it for my tonner pickup, which is sort of rough and rusty and has a badly cracked V8.

 

GB, the distributor location is the main distinguishing characteristic when you look at them. Although, the engines look almost the same, they both have various parts that are unique to each design and are not interchangeable. For example the G engines have pistons that have a slight dome, the H engines have flat top pistons. The cylinder heads are machined differently due to the piston design and one will not work on the other. Parts for the G are most hard to find but parts for the H can be a challenge, too. As long as each engine is complete with all the additional things like manifolds, carbureter, air cleaner, water pump, etc you might have a good chance to make one work. From what I could decipher from my numerous hours trying to hunt down G engine parts, they both use the same motor mounts and have the same bell housing configuration. The radiator for the 6 will be different from the V8 as inlet/outlet locations are not the same. Battery tray location is on the opposite side than a V8 but there might be room to leave it alone. Guessing they wanted to keep the battery away from the exhaust manifold so put the tray on the driver's side. Hope this helps.

 

GB, you will need a 6 cylinder transmission if you want to put the 6 in a truck that originally had an 8. The 6 has a specific bolt pattern than the 8

 

GB, I think I remember us talking about a transmission for a 6 cylinder down in the weeds behind your shop. I remember us looking at a trans when I was there.

 

Yes, but that tranny was full of water and a seized up POS... Why would ford do that??? I do have a 1/2 ton jailbar panel with a one outlet radiator (I'll check battery location) that has a 4 speed trans. Is there a good identifier for the six cyl type 4 speed as compared to the 8 cyl four speed?

 

Somebody must have put Rambler fluid in that trans! Too bad. I will have to defer to someone else on the transmission identification. Guessing that it maybe has more to do with the trans to bell housing adapter configuration. Wonder if the 4 speed trannys might be the same but need to swap out the adapter?

 

The 6 trans isn't a "perfectly" round circle pattern like the 8. It has a little bump out on the side to accommodate the starter. The trans will bolt to G & H series. My '46 had the original '46 trans and a later H series in it.
I should note my '46 was a 3 speed, but I'd bet the 4 spd would be the same situation.

 

Thanks, 46fordtruck! Do you recall if one will need to swap out the transmission bell housing adapter on the V8 trans to the adapter for a 6 cylinder?

 

The '48 and later "H" six used the same transmission as the V8. They use a stamped steel engine half bell that is about an inch taller that a V8 half bell.
Mark