And that's why you don't see them in use these days.

 

I'd like to throw in my 2¢ here on a number of subjects:

The GMC V6/V8/V12:

These did have very stout cranks. IIRC, the mains were 3.1 and the rods were 2.8" However, keep in mind that this crank was not like the early Buick V6 -- three shared throws at 120*. It looked more like a crank for a 4 main six cylinder. The paired cylinders' throws were offset. GMC made the rod journals so large because they had to consider not only the rod-main overlap for crank strength, but also the rod-rod overlap on the paired journals. However, they were a VERY stout engine. I learned to drive on one and torque was there right off idle. The gas mileage was horrible for a 305" engine, but it was very stout. I do believe that the 638 V8 kept the 60* bank angle of the 6s.


Big car engines and Hot Rod Magazine fairy tales:

Remember those big shot know-it-alls at Hot Rod Magazine, who said that the Y Block's deep skirt without crossbolting was useless because it didn't support the crank?

Even an idiot can see that, on a V8, the crank doesn't try to come out of the bottom of the block -- it will be pushed more or less at 45* to the bottom (tho each bank differs due to rotational direction). The Y Block and all other car and truck engines with a deep skirt have bracing to the main webs that counteracts this tendency. Even GM engines, such as the Small Block Buick, Buick V6, Buick Nail Valve, and Pontiac OHC 6 had deep skirts! Hot Rod didn't say that deep skirting was useless, did they?

Also idiotic was these supposed automotive know-it-alls ignorance regarding cross bolted mains, specifically on the FE 427 and the Mopar Hemi. The cross bolting wasn't put there to keep the crank from coming out of the bottom of the block. It was there to keep the main caps from shifting around when NASCAR racers were letting off of the throttles and then jumping on them as they rounded corners. When you suddenly go from putting out 400 to 500 hp to being an engine brake for a 2 ton car careening around a track at almost 200 mph, great stresses are set up in the crank and engine block. The crankshaft goes from being twisted up one way to being twisted in the opposite direction. This, in turn, stresses and bends the block, and the main caps will creep around on their seats. If crush is lost on the bearings, the whole thing goes "Kablooey" in a New York Second, leading Hot Rod Magazine idiots to conclude that the main caps couldn't hold the crank in the block.

(This is also why non-skirted blocks, like Pontiacs, Chevys big and small, and small block Mopars went to 4 bolt mains -- not to "hold in the crank," but to keep the main caps anchored firmly under different loads. You will recall that the Mopar small block had a lot of iron taken out of it when it went from Polysphere to LA form, and the Chevy small blocks kept growing in size.)

Actually, I don't think they really believed their own malarkey. I think they were paid off, if not with money, then with favors from GM's deep pockets. But so much for them.

You will notice that all of these big truck engines have deep skirted blocks -- Y Blocks, if you will, and even the straight 6s do as well. The purpose of this is not only to brace the main webs, but also to make the block stiff from the bellhousing to the timing chain, and keep the main journals straight for the crank to turn happily away for many miles.

If dumping and jumping the throttle of a 2 ton race car can cause mayhem, how do you think a 5 ton or larger truck under heavy load twists an engine around when it goes from full power to being an engine brake, not for merely 500 miles, but day in and day out on a construction or fleet job? This is why heavy duty engines, gas or diesel, are built like the proverbial brick outhouse.

If you doubt these stresses and you've been around trucks or buses much, consider how many drive shafts you have seen busted -- for the very same reason! Big loads place big stresses on big truck parts.

Chevy did use their big blocks as truck engines. I recall an elderly friend telling about a mobile home tractor that had a 409 in it. Like all of the rest of the gas powered heavy haulers, his take on it was that it was a gas hog.

International engine blocks were, as some have stated, noted for their high tin content and were very hard. Just ask the man who had to hone one!


re: Ford 332 truck engines:

There is a 332 that was an FE, and there was a 332 version of the Lincoln Y Block -- a variation of the 317-341-368 car motor. There were also 279 and 302 truck versions of this Lincoln motor.


RE The Ford V8 in Sherman tanks

This was a modification of an experimental Ford V12 aircraft engine. You can see this in the 60* bank spacing. The V8 version displaced 1100 cu in, and the original V12 displaced 1650 cu in. Some might recognize this as the same displacement as the famous Rolls Royce Merlin -- both engines shared the same 5.4" x 6.0" bore and stroke. The Ford engine had double overhead cams with bucket tappets, sort of like an Offy, with the 4 valves splayed in a pent roof chamber like Offys, Allisons, and modern engines.

Shermans also came with radial aircraft engines, a pair of the then ubiquitous 6-71 GMC diesels, and a 30 cylinder Mopar made up from 5 flathead 6s. If you do a search on "Ford GAA," you can turn up a bunch of web info on this motor. I first saw them in tractors for tractor pulls, but people like Jay Leno started dropping them in cars and they are enjoying some popularity for this.

 

I never saw the Hod Rod article you speak of, but in my opinion most automotive journalists are journalists first and at best car guys second.
At the trucking company I worked at for years I came across International V345s and GMC351s both gave good service. Some of them were used as yard totes after they were replaced and continued to give good service for many years.

 

One thing I noticed about Ford blocks is that they use softer than normal castings so I would find a truck block with high nickel or cryo the thing to bring it up to par if you are replacing the 534. I have one Dodge truck high nickel block left out of a CT900 dump truck. Stuff is getting too scarce these days. I should note that these industrial engines like the 534, HT413, 345's, 478's, 366's etc have no offset on the pistons and the pistons have compensated ring grooves. They require straight W30 oil or diesel oil. They are heavy, too. That makes them spendy! Many of those motors had between a 5 - 6+ inch stroke LOL. We all have our favorite truck motors. My favorite ford motor was the 429scj. Dodge was good but they have gone the way of Homelite - , GMC 366's still hanging in there but GM lifters were never any good

 

I still see many old 366 medium duties running around, but their thirst for fuel with todays gas prices puts the hurt on them. My neighbor has a old IH Loadstar and he's ran multigrade oil in old 345 for over 20 years without problems. The thing with old trucks like those is 50 mph cruising speed !

 

I own an old Jimmy with a 351 V-6. When I rebuilt it a few years ago, I wore out 2 sets of stones on the power hone. The GMC V-6 block was cast out of high nickle-chromium iron. VERY hard. Those engines were very tough. Strong crank (cast steel or forged, many were Tufftrided or Tocco-hardened), 4 ring pistons with a steel insert top ring groove and moly rings, 6 head bolts per cylinder, double roller timing chain on the smaller engines, timing gears on the larger versions, and the camshaft sat in it's own oil sump formed in the valley of the block. The cam was always half submerged in oil if the engine was running or not. I would say these were about the only large gas truck engines that might have been better than a 534 Super Duty Ford, but they were a newer design. I know some of the Ford V-8's over the years were known for soft iron blocks, but I don't think the Super Duty was one of them.

 

I came across many 351 V6 Jimmys back in the day, they were very tough engines. As far as the smaller gassers I consider it and the 345 Internationals to be the best.
I didn't run across many 534s, by the early 70s the bigger trucks were pretty much diesel and that meant the end of the 549 Internationals, the big GMC and Ford gas engines.

 

Negative ....

Ford tried to get into the Aircraft engine business, but the Navy already had PW Radials and the Army was invested in the Alison - eventually adopting the Packard Merlin for the P-51


but, the Army did come back with a need for a hi torque motor for the M4A3 Sherman ..... GAA - 525 HP and 1100 Ft Lbs of Torque @ 2000 RPM

I put the engine specs in desktop dyno for a guy a couple yrs ago, at 2000 RPM the GAA has already peaked and is on its way down

 

In the 60s and 70s I drove tractor trailer for a large US and Canadian freight Company. For several years I drove a C850 with a 534 inch gas engine, we also had the same trucks with the 477. I also drove our cabover Internationals with the 549 and a 66 GMC with the V12 gas engine. The ford was my favorite but that may have been because it was in a better truck.
The governor on my 534 had been disabled and it would actually rev to 4800 rpm. The international had a shifter that was actually painful to use, requiring you to reach behind you and upward to shift and our mechanics had a hard time keeping them running.
The GMC V12 had a clutch that required a strong leg to get down and odly it stalled yery easily when starting out.
My 534 would outrun a 250 Cummings diesel but in city tractors we only got about 40000 miles on any of the gas engines.
It was longevity and fuel mileage that killed the gas engines. My 534 got 4 mpg. Our diesels got 7mpg.
I once drove a 1980 something Mack 300 diesel that got 969,000 miles on the original engine.

 

For all you Chevy fans, there was a medium-duty version of their 454 V-8 sold for the years 1979 and '80 as the top dog gas engine in the C70 and GMC C7000.

The ratings for it were as follows:
1979: 245 hp @ 4000 rpm; 380 lbs-ft tq @ 2400 rpm
1980: 225 hp @ 3800 rpm; 365 lbs-ft tq @ 2400 rpm
Both of these HP and TQ ratings could've been neat for a Blue Bird All-American FE school bus with the Allison MT-643 automatic transmission (SAE #2 bellhousing).

Then, after an 18-year absence, it returned for the 1999 model year as the Vortec 7400-MD to replace the previous 366 and 427 MD V-8s. Two different ratings were available:
#1: 210 hp @ 3750 rpm; 325 lbs-ft tq @ 2400 rpm
#2: 270 hp @ 3750 rpm; 405 lbs-ft tq @ 2400 rpm

~Ben