Production years for G and H 6 cly flatheads?
 

I am looking at replacing the 6 cylinder flathead in my '48 F-1 pickup with a '47 engine and am wondering if they are the same?

Re: Production years for G and H 6 cly flatheads?
 

Not sure if you're answer is here, but if you are not familiar with Mac Vanpelts wonderful sight, you should be. Enjoy... http://www.vanpeltsales.com/

Re: Production years for G and H 6 cly flatheads?
 

I have read that they share very few parts and the G is way harder to source parts for. As for me, the location of the distributor alone is enough for me to favor the H.

Re: Production years for G and H 6 cly flatheads?
 

Some of the H parts are not found growing on trees.


Bruce

Re: Production years for G and H 6 cly flatheads?
 

I've heard some very late 1947 models had the H-series 226 I6 but that may not have happened. Too many years have passed. The H-series would be the one to find. There is more stuff available for them that is specific to the type since they were the late one that was made through the end of 1951. The G-series was used from 1941 through WWII in 1 1/2-ton trucks and others so they were continued after the war through 1947. They have a different ignition system and there are other differences as well. It may fit but it may be harder to find certain parts that didn't carry over to the H-series.

Re: Production years for G and H 6 cly flatheads?
 

Some great G & H education here for me.

Sal

Re: Production years for G and H 6 cly flatheads?
 

Another thing about the H, is that it can be found in HD Ford trucks, in the 254 ci version.

Re: Production years for G and H 6 cly flatheads?
 

Is there a way to tell which H model I have without pulling the head? Casting difference, longer stroke, bigger bore?

Re: Production years for G and H 6 cly flatheads?
 

That 254" six is 'M' series and it has M cast in the head [49-51] . They are around but scarce. Newc

Re: Production years for G and H 6 cly flatheads?
 

The H and M six engines have the block part number cast above the oil pan rail behind where the generator mounts. H or M are in the part number depending on which block you have. M motors are not common and the ones around here all seem to be from 1953 two ton trucks.

Re: Production years for G and H 6 cly flatheads?
 

Thanks, Looks like mine is an H. 1HA**** above the pan rail and 7HA***** on the cylinder head.

Re: Production years for G and H 6 cly flatheads?
 

Thanks for all of the comments. I am still not sure if a '47 G engine would directly replace the existing H in my '48 pickup. Are the mountings the same??

Re: Production years for G and H 6 cly flatheads?
 

I have a very dead G laying on it's side in my woods. I have a nice H on a run stand. Both have front motor mounts. The G has a 4 speed on it. The H has a four speed sitting alongside it. It's a hard thing to measure until I mount the trans on the H. Measuring from the center of the front mount's bolt hole to the transmission's mounting surface, the G and H appear the same. Funny, we need the same info, but backwards as I want to put this '51 H in a '47 tonner. I will keep you apprised of details. There is a guy on the '47 and earlier section on FTE (Ford Truck Enthusiasts) forum also getting ready to put an H in a 47 tonner. He looks like he will know the answer soon. Some of my 46-47 tonners have the double set of front mount holes(6 and 8 cyl) and some don't. A mystery.

Re: Production years for G and H 6 cly flatheads?
 

The G engine has a crab style distributor on the front of the engine. The H has a conventional distributor on the driver's side.

M engines were installed '49 to '53 in F-6 and larger trucks. My research indicates that they were used in School buses during the same years.

The M engine has a 3.5" bore where the H has a 3.3" bore. Both engines have a 4.4" stroke.

The M has heavier H beam rods, a stronger crank and more support in the bottom end of the block. I haven't tried but I am told that all internal parts between the engines are dimensionally interchangeable except pistons.

Re: Production years for G and H 6 cly flatheads?
 

The M pistons are the same as the '49-'51 Lincoln.

3 ring TRW numbers are L908F, L846F, 4 ring L899F

Edit:
BTW, it would be interesting to sonic check a H block, to see how much "meat" is in the cylinder walls.

Since the V8 could be commonly bored .188 and sometimes .250. There might possibly be enough cylinder wall, to get .200 out of a H?

Re: Production years for G and H 6 cly flatheads?
 

When was the OHV 6 cylinder introduced? Cars and trucks the same? All I know is that it was before the OHV V8.

Re: Production years for G and H 6 cly flatheads?
 

PeteVS, OHV 6 came out in 1952 Fords.

Re: Production years for G and H 6 cly flatheads?
 

I would like to add that my H engine dropped right into my '47 tonner. Dead center on all mounts, radiator clearance etc. It is necessary to mount the battery tray on the driver's side as the manifolds are on the right. Big surprise was that the front mounts went right into the same frame holes as the V8. Not sure why about half of my jailbar frames have the other frame holes, slightly smaller dia and 3" or so further forward. I'm guessing the G might use the forward holes.

Re: Production years for G and H 6 cly flatheads?
 

Note; There is a NOS M series exhaust manifold on HAMB $300 ! They are very well designed tho compared to a stock H manifold. Newc

Re: Production years for G and H 6 cly flatheads?
 

I had a very difficult time finding a usable camshaft for an H engine. The problem was broken teeth where it drives the distributor.