Toro-Flow- G.M. vs. Cummins

[BobBray]

Interesting read:

http://www.leagle.com/decision/19693...%20CORPORATION

[POWERSTROKE]

I'm surprised they kept coming back to the Chevy 348 V8 for comparison and the Ford D172 tractor engine.

The "409 may have been fine" according to the Beach Boys but CJ Baker really hated it, and the 348 was the 409s weak little sister. The slant top pistons but unusual bending forces on the conn rods, Lots of added surface area in the combustion chamber to bleed off heat to kill efficiency and make it tough to build compression, no quench in the chamber. Hence it's short life in the market place before being replaced with the RAT motor.

The little Ford tractor engine was better than a flat head gasoline engine and possibly as good as most other little diesel engines built at the time. Wasn't till 1968 that Ford finally bought a decent diesel to the market. Their Commander 6000 chased most customers to other brands quickly. In '68 their 8000 with the 401 engine started getting some respect.

[BobBray]

It is a strange reference in that the 348/409 were gasoline engines, and the dispute was more to do with oversquare diesel engines. Oversquare really doesn't work too well for diesels, as you stated it's difficult to build compression (vitally important for a diesel!) and I question if it puts undue stress on the crank and rods compared to undersquare diesels. In any event, there have been very few oversquare diesels.

You know, back around 1980 when Detroit Diesel introduced the 8.2L 'Fuel Squeezer', I initially thought it was some sort of a revised Toro-Flow!

[POWERSTROKE]

Originally Posted by BobBray

It is a strange reference in that the 348/409 were gasoline engines, and the dispute was more to do with oversquare diesel engines. Oversquare really doesn't work too well for diesels, as you stated it's difficult to build compression (vitally important for a diesel!) and I question if it puts undue stress on the crank and rods compared to undersquare diesels. In any event, there have been very few oversquare diesels.

You know, back around 1980 when Detroit Diesel introduced the 8.2L 'Fuel Squeezer', I initially thought it was some sort of a revised Toro-Flow!

The V-6 GMC's took over-square to a new level when they came out, allowed for big valves for good breathing, sturdy blocks, crankshaft, etc. The fact the Toro flow was such a good engine with the few changes they got proves how tough a gas engine the big V-6's were. No other manufacturer had as good of service from their converted gas engines.

I had the misfortune of driving an early '80's F-700 with an 8.2L. I loved the truck. Was like driving my F-150 except for the air brakes. Put a boat load of miles on it too. Had a 1000 mile day with that truck. All except about 15-20 miles in the state of Iowa. Poor truck only had a 40 gallon fuel tank so fuel stops came every 260-270 miles. 7 mpg was pretty good in my opinion for a truck running 60-65 mph grossing 30,000-40,000#. When we switched to the gas V-8 powered IH Loadstar with 100 gallon gas tanks I lost 5 mph and about 4 mpg, I averaged about 3 mpg. Anyhow, the 8.2 had some unusual type of injection system, different that any other engine. It was tough to find someone good to tune them up. It would drop a cylinder within a week or two of spending a week at the dealer, then drop another cylinder, then a third, finally a forth over the span of a month or two. By then it was only able to bobtail 35-40 mph back to the shop. In about 8-9 months it was gone. Guy who was a DDA service tech explained the injection system to me years ago, and why it was so fussy. I put 350 to 375 miles on that truck six days a week pulling a 45 ft trailer every foot of the way.

I checked specs on several diesel engines I thought might have been square or over-square but they all were under-square. Only the IH gas engines converted to diesel kept their under-square bore&stroke. Engines like the 6.9L & 7.3L ID I and various PSD's were just barely under square.

Anyhow, I enjoyed the article, and always enjoy discussing truck engines, what worked and what didn't, because in the 100+ years of truck engine development, just about everything has been tried with the possible exception of pure rocket power. Lots of gas turbine powered trucks in the late 1950's and 1960's. Chevy, Ford, IH, and others.

[BobBray]

Speaking of the 348/409's 'plank head' combustion chamber, are you familiar with the Ford Super Duty V-8's? They had the same head design. The Super Duty V-8's came in 401, 477, and 534 cubic inch displacements, and were basically scaled up versions of the Lincoln 'MEL' V-8's (though NOTHING interchanges). The Super Duty's were pretty good, but I don't think they were as good as the GMC V-6's. I heard rumors Ford was considering making a diesel version of the Super Duty, but instead got Caterpillar to design a diesel V-8 for them. That Caterpillar was the 1100 series, which was eventually developed into the 3208.

BTW, that injection system on the Detroit 8.2L was a similar to the unit-type injection used on the 53/71/92 series 2 strokes. When my company bought some in the 80's, we sent some guys to the Detroit school to figure out how to work on them. After the class, and seeing how expensive the required special tools were, they came back and said forget it, just take them to the dealer! The trucks were GMC 6500's with non-turbo 8.2L's. No power but we didn't have much trouble out of them.

Glad you enjoyed the article, I found it interesting too.

[POWERSTROKE]

Yes, I'm very familiar with the Super-Duty Fords gas truck engines, Before I was old enough to drive I rode Shotgun with my Dad hauling livestock to the various stocky Ardsley, sale barns, and packing plants. Sundays were always a big day at the Chicago Stock yards. Hundreds of truck loads of cattle, hogs, and a few sheep showed up for the Monday markets. It was a pretty good testament of what the best gas powered trucks of the day was. Pruitt Trucking from Litchfield, Illinois, down by St. LOUIS ran a huge fleet of Ford's. The Fords always seemed to run the fastest. I never heard of the Ford diesel project but I did hear there was a bigger, around 600 Cid V-8 in the works. IH actually made a 605 Cid V-8 but for stationary industrial uses, never made it into a truck. Guy Dad drove for slowly changed from his V-6 GMC'S to IH CO-190's with Red Diamond 450 power. It seemed like everything on the road passed us. The Interstates were under construction in those days, passing was a function of knowledge of the road, trust in the guy your passing, and pure luck, and Horsepower and gearing. Sometimes a couple attempts to pass were needed on the 2-lane state routes.
There were 6-7 livestock truckers around home, all used gas powered trucks around 1960, by 1965 they had half diesel power. By 1970 there was only about 4 companies left and everyone had some diesels. By 1975 there was two left, one all diesel and the other one kept one gas 427 Chevy for the farmers that still had to have gas trucks haul their livestock.
The guy Dad drove for traded the two CO-190s for Emeryville, and a new Chevy C-70 with a Toro flow became the local truck. It had the cab style of the GMC B- series. Dad enjoyed driving the new Chevy much more than the Emeryville. Shifting a transmission with a lever directly attached to the Trans beats that monstrosity of a linkage the Emeryville had. The lower cab height and power steering made the Chevy handle like a half ton pickups with air brakes.

Last guy I drove for that had the borrowed F-750 with the 8.2L bought a 70's vintage Loadstar 1800 with 478 gas V-8. That tiny 1/4 inch fuel line from the fuel pump to 2 bbl Holley carb had no business trying to flow 20 gallons of gas per hour but it did. It would have been considered a BIG TRUCK 20 years earlier. I've run a pretty interesting mix of 50s, 60s, and 70s vintage medium and heavy-duty trucks. I won't count the 1940s vintage Chevy farm truck I drove one load of corn to town in. Remember the ones the starter pedal was right on the starter next to the gas pedal?

Speaking of Super-Duties again, my 1978 Ford factory service manuals still have the service procedures and specs for the Super-Duty engines. Like you said, Nothing in common with any other engine. My Uncle had a 56 F-750 farm truck. MY cousin still has it, has many many miles. Their local Ford dealer had a Super-Duty powered Ford semi-tractor he hauled livestock with, kinda a rolling advertisement. He passed EVERYTHING on the road. He sold several trucks & tractors every year. One customer complained his truck didn't run like the dealers. After 4-5 trips in for service, tune-ups, this nearly new truck had the carb removed, set on the floor and smashed with a 16 pound sledge hammer. It was sent in for warrantee stating simple " broken". The truck ran MUCH better with the new carb.

Are you familiar with the Ford GAA engine? 1100 Cid, 500+ hp tank engine. Another neat piece of automotive history.

[BobBray]

Yes, there is a military vehicle museum near me and they have a Sherman with a GAA and another GAA by itself on display by itself. The GAA was actually a V-8 version of a aircraft V-12 Ford was working on. The Ford aircraft engine was unsuccessful, but Ford was able to salvage a lot of the design for the GAA tank engine.

[POWERSTROKE]

Yes, the Allison and Packard Merlin and the huge radial engines were the aircraft engines chosen to use over the V-12 Ford.

A guy who competed in tractor pulls back in the mid & late 1960's and early 1970's used a GAA in a Farmall M. Going from a 248 Cid 1450 rpm 36 hp 4 cylinder to a 1100 Cid V-8 running 3500-4000 rpm caused excess stress to his drivetrain but he drove it like his engine could shred his transmission in a heartbeat. The guys with the Allison and Packards got all the attention but the guy with the GAA did a great job of buidling his tractor. It looked almost factory built.

The GAA has some induction problems, caused plug fouling problems, but today's better understanding of induction and the tunability of fuel injection make those issues a minor annoyance.

What amazes me is the number of these huge gasoline engines produced in decades gone by. Their ability to convert gasoline into burnt hydrocarbons was so great. It's a wonder we have any gasoline left.

[10Thumbs]

[QUOTE=POWERSTROKE;67153]I'm surprised they kept coming back to the Chevy 348 V8 for comparison and the Ford D172 tractor engine.

The "409 may have been fine" according to the Beach Boys but CJ Baker really hated it, and the 348 was the 409s weak little sister. The slant top pistons but unusual bending forces on the conn rods, Lots of added surface area in the combustion chamber to bleed off heat to kill efficiency and make it tough to build compression, no quench in the chamber. Hence it's short life in the market place before being replaced with the RAT motor.

The little Ford tractor engine was better than a flat head gasoline engine and possibly as good as most other little diesel engines built at the time. Wasn't till 1968 that Ford finally bought a decent diesel to the market. Their Commander 6000 chased most customers to other brands quickly. In '68 their 8000 with the 401 engine started getting some respect.[/QUOTE

Interesting anecdotal story about the 348-409 engines: when they first came out, the head of the Chevy division asked NASCAR engine guru Smokey Yunick what he thought of them. Smokey's reply was "they were the dumbest, stupidest engine design he'd ever seen. He then enumerated a large number of reasons why he thought this, some of which are contained in this thread. The head of Chevrolet division never spoke to Smokey again, because this man had been one of the main instigators for the design chosen.

[POWERSTROKE]

Originally Posted by 10Thumbs

Interesting anecdotal story about the 348-409 engines: when they first came out, the head of the Chevy division asked NASCAR engine guru Smokey Yunick what he thought of them. Smokey's reply was "they were the dumbest, stupidest engine design he'd ever seen. He then enumerated a large number of reasons why he thought this, some of which are contained in this thread. The head of Chevrolet division never spoke to Smokey again, because this man had been one of the main instigators for the design chosen.

Ahhhh, Smokey was The Best! I could never get enough of his wisdom about all things mechanical. I read and reread every one of his "Best Darn Garage in Town" articles in Popular Mechanics. He wrote feature articles in Hot Rod frequently too. The man forgot more about engines than most engineers today will ever know.

You have to admire a person that clearly answers questions when asked.

There's a few great engine builders today that have expanded our understanding of how to make horse power, but Smokey wrote the book most follow now days. Truely a great mind in understanding how an engine works.