Flathead vs OHV design

I got to thinking about flathead valve/port design the other day and investigated on the net.

Flathead intake and exhaust ports are cast into the block. Intake is relatively simple. Exhaust ports ran from above the cyl., around the cyl., down to the port below the cyl. This complicated the exhaust and coolant design. The blocks look damned complicated to design/cast. The heads look simple.

Contrast OHV. The port design is part of the heads, which are more complex. The block looks lots easier to design/cast.

Flathead design succumbed to OHV (which later largely succumbed to OHC) in the late '40's and '50's.

Per

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V8 designs have been around since 1917. Ford's mainstay V8 was the famous flathead from about 1932-1953. Obviously they got a lot of mileage out of the design, but ...

Why did they stick with the flatheads for so many, many years after OHV was afoot in the design world? Were flatheads cheaper to make? (It doesn't look like it from here).

Just curious.

Cheers, Puddin'

"Blues starts to rolling ... stops at my front do'. I'm gonna change my way of living ... won't have to worry no mo'." - from "Blues Before Sunrise", Leroy Carr, maybe 1934

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Puddin' Man
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One reason why small engine companies like Briggs and Stratton switched to OHV engines is that the fuel doesn't burn completely near the valves in flathead engines, leading to higher hydrocarbon emissions.

With a flathead design, the valve train is a little easier, too. The camshaft is geared directly to the crankshaft, and there are just lifters which directly contact the valves. No problems with push rods or rocker arms.

Jeff

Reply to
Jeff

Henry Ford was an EXTREMELY stubborn man. Juice brakes, 4 wheel brakes, and a lot of other things were late coming to Ford. Ford also stuck with the "buggy spring" long after it was obsolete.

Reply to
clare at snyder.on.ca

On Sat, 19 Jan 2008 21:36:36 GMT, Puddin' Man wrote:

The Ford 239 flattie was around a lot longer than 1953, but in industrial-only models. Last factory new 239 I saw was in a tug motor at a trucking terminal. It was built in 1963, and was, basically, the same old 239" flattie used in Ford cars and trucks until '53, but with a single bbl carb. The old Model A engine lasted about the same on tractors and in industrial applications, last I've seen being around

1966. Ford got their money out of THOSE molds, for sure...and then some.

Ford got caught last in the OHV game for a multitude of reasons, one of them being the great disarray of FoMoCo after Edsel died and the old man was floundering the company into bankruptcy. When he finally picked his grandson, Henry II (known to insiders as "King Henry II") FoMoCo was #3 in sales, had a listless product line and was losing millions on stupid pre-war projects favored by the old man previous to the war. The conversion to aircraft manufacture and other military uses during the war also took its toll, as the old man hadn't a clue as how to manage the postwar recoversion.

King Henry II came on board as FoMoCo president and immediately started trying to fix the mess. First priority was getting out of the cellar on sales...Ford was #3, and Chrysler was comfortably ahead. King Henry didn't know how to assemble a design team to "fix" the laconic product lines, so in came the "Whiz Kids," among them Robert McNamara and other luminaries who would go on to become legends in their own right. First order of business: fix the car line. The result of the "Whiz Kids'" work on that were the startling 1949 Fords and Mercs, with new IFS, new fenderless rear ends, slab sided styling (first introduced on the '47 Kaiser/Frazer line, by the way) and a vigorous ad campaign behind it. Under the hood, it was still 1932, albeit with a new Ford 2V carb, a higher lift cam and 100 BHP, later going to 110 in '53 with a small compression and cam bump. Same gearbox, too, adapted to use a "3 on the tree" shifter, and the same weak rear ends. Didn't matter...the '49-50-51 Fords sold on looks and ride immediately, and they pushed Ford past Chrysler in early 1950 as the #2 US automaker. Shrewd move by King Henry II. His most lasting legacy was the first he implemented...the Ford parts numbering system, still in use today. Prior to that, Ford's parts, engineering and warehousing systems were the worst in the world. One area where Ford managed to ace out rival Chevrolet was in automatic transmissions...the Borg-Warner three band unit was licensed by Ford as the "FM," in use, heavily modified as the FMX, until 1966 and later in some models. The cheap but limited 2 speed Powerglide was no match for the 3 speed "Fordomatic." Ford later again stayed way ahead with their C4 and C6 aluminum case transmissions, leaving GM's Powerglides and Detroit Transmission 2 speeders in the dust.

Next issue: the flattie. This wasn't as successful, but Ford managed to cobble together a new engine, the Y-block, in the same size as the flattie for the '54 model year. At the time, GM had several, with Olds, Cadillac and Buick (late '52) each having their own designs to appeal to disparate markets. GM ran rings around Ford in the design department on this issue. GM's Cadillac and Olds OHV V8s were designed to the basic tenets of "Boss" Kettering, who before WW II, said that the new GM OHV gas engines should be capable of being "punched out" to as high as 400 cu in, have a compression ratio of 12 to 1 (never realized) and be as light and strong as engineering would allow using the best available gray iron alloy.

Ford, on the other hand, kept heavy block weight as a feature of the Y-block...good for the bottom end, not-so-good elsewhere. The Y-block had severe constraints as to "enlargability", and was stuck at 312" until replaced by the far better FE starting in 1958. Overall, they were pretty good...not great...engines, but nothing like the fireballs from Cadillac and Oldsmobile in 1949. All GM had to do to leave Ford in the dust was start boring, stroking and upping the compression on their entire V8 line to keep comfortably ahead of Ford performance-wise, with Chrysler nipping at their heels with innovative "hemis" and wedges. The original 303 Olds topped out at 394, the original 287 Pontiac topped out at 389, and the original Barr-Cole Cadillac engine, probably the best production V8 ever produced in the US as far as stock efficiency went, went from 331 to 390.

Ford desperately needed yet another fix, and that was the well liked FE and FT engines of 1958-1976, one of Ford's greatest engine success stories. They were fair to middling in efficiency, but the 390 HP,

406 and 427 variants developed for NASCAR are the stuff of legend. The car 390s, 410s and 428s, especially in the CJ versions, weren't any slouches in power, either. The 332, later the 352, were the work horses of the Ford car and light truck line until 1971 (352 was gone after '67, replaced by the 360 in trucks until '76 and the enlarged small block in cars), and gained a popular loyalty among Ford buyers.

The big claim to fame on any FE or FT was durability. Many ran up to

300K miles with no rebuild, a feat GM products couldn't do...nor did they want to. The most durable of the GM car engines were the Cads and Oldses, and by 1965, they were gone, as well, replaced by cheaper, "Chevyized" new models. GM started its "fall from grace" starting around 1962, when the "less car for more money" dictum took hold after the retirement of Al Sloan, who'd built GM into the powerhouse it was during the '40s and '50s.

But wait...there's more! GM wasn't alone in aging flatties. Pontaic kept theirs (in two different, horrid 8 cylinder displacements, plus the original Oakland 6) on the market until 1955, which then was replaced by a low cost, but high output and durability V8. Pontiac was the "dowager empress" of the GM line until Bunkie Knudsen took over, and then John DeLorean...and things then started to happen pretty fast for Pontiac. Knudsen, a GM cookie cutter exec, would later go on to be a huge failure at FoMoCo in 1969, with his only legacy being trying to make the T-Bird look like a Pontiac Bonneville. King Henry II dumped him cold and gave it to a whole different legend...that of Lee Iacocca, who took the presidency of FoMoCo late in '70. Iacocca's reign really yielded nothing of great importance, other than he ran a good, tight ship that favored the sales organization over everything else. Mainly, he specialized (as he did in the mid-'80s at Chrysler) in "stretching" platforms into new models, notably the loser T-Bird into the hot selling Mark III, the doomed Pinto into the popular Mustang II, and so on. Remember, he made the bare bones Falcon into the biggest US sales sensation, the original Mustang, a lesson he never forgot.

Engineering-wise, Iacocca was no great shakes at all. He was, and is, a salesman first and foremost. As far as engines went, Ford was again in the doldrums in '70s and was reduced to simply punching out the

365-series engines into the 460, making the basic Windsor 351 into a "modified" high deck 400 and the like. Nothing much to see there. The only legendary and likable Ford engine of that era had already been designed in the '60s...the "Clevelands."
Reply to
DeserTBoB

FYI:

Although your opinions are amusing, your facts are flawed. The 385-series

429/460 big-blocks were both manufactured in the 60's, and were years ahead of the 1970 335-series 351 Cleveland engines. The Ford 400 (and 351M) is based on the 351 Cleveland design, NOT the 351 Windsor design... Although I prefer the 351 Cleveland over the 351 Windsor, the Windsor family of Ford engines 1962-1996 (221, 260, 289, 302 and 351) was arguable Fords best and most successful engine ever.
Reply to
My Name Is Nobody

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