Pondering about flathead potentials

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Re: Pondering about flathead potentials

Post by frnkeore »

The biggest problem with the Ford FH V8, is the 1.312 diameter port. You can't do much with it and as near as I can tell buy scaling my factory drawing, the pinch point is only .83 tall.

I've played with this drawing and I found that if you tilt the block, to 36.5 degrees, you could run a 1.25 ball end mill through the port and then stop the cut, after you take 1/16" out of the bowl wall (it not very thick, as you can see). That 1.25, takes about 1/2 out of the roof, along the red, vertical line. Then make a valve guild with that same .625 R to match the bowl, then blend, couture and widen the port as much as possible. You can also widen it with the end mill, to take much of the cast iron out but, as you can see, the port walls, aren't very thick.

The only flow numbers I've seen on a ported FH is 144 cfm at .400, not the best!
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Re: Pondering about flathead potentials

Post by frnkeore »

In addition, I think the best thing you can do for the FH, is run as small a engine as possible, with the highest CR you can obtain and run in class racing.

With smaller ci, the cylinder will fill better with the limited it's flow.
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Re: Pondering about flathead potentials

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frnkeore wrote: Mon Feb 08, 2021 1:45 pm In addition, I think the best thing you can do for the FH, is run as small a engine as possible, with the highest CR you can obtain and run in class racing.

With smaller ci, the cylinder will fill better with the limited it's flow.
Agree. I have this discussion with Studebaker V8 builders. Since the heads are intake flow limited, the smaller the displacement, the more competitive in the horsepower-per-cubic-inch.

Back to flatheads - I ran across an anomaly in DynoSim while attempting to model a Studebaker Champion I6, built in both 170" and 185"; all else equal other than stroke. This is the first DynoSim I've ever encountered where it showed a higher net horsepower for a smaller displacement.

Every other time, when displacement is increased, but air flow remained constant, horsepower would usually increase slightly, but low speed torque would increase more.

Any suggestions as to why this would be showing more horsepower in the smaller displacement?

FWIW, guessing at flathead CFM without building a custom flow bench to accurately report it is akin to searching in a dark room for that black cat which might have already gone. What I've done is input known metrics and then adjust air flow inputs to game a net power result close to published data. Any other suggestions?
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Re: Pondering about flathead potentials

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What version of DynoSim do you have?
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Re: Pondering about flathead potentials

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frnkeore wrote: Fri Feb 12, 2021 3:09 pm What version of DynoSim do you have?
The Flathead Version - v4.20.0704 - so old it was for Windows 95/98Me/2000/XP. I've been pleasantly surprised it still runs.
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Re: Pondering about flathead potentials

Post by Les Kerf »

Hmmm... not sure which is more amazing, the fact that this thread went 46 pages, or the fact that I actually read the whole thing! :lol:

As a lifelong lover of flatheads, and duly noting that this thread has already been hijacked numerous times, I feel compelled to give an honorable mention to the unsung hero of low-performance flatheads, the venerable V4 air-cooled Wisconsin.

In a manner similar to my (real) horses, which are nearly ideal hay disposal units (they don't produce as many by-products to get rid of such as milk or meat, just some smelly exhaust products), an air-cooled Wisconsin is nearly an ideal gasoline disposal unit; a Wisconsin excels at converting fuel to noise with very little useful work accomplished per gallon, although there is some smelly exhaust (at least one does not need to shovel it).

In order to truly appreciate modern technology, one really should spend a summer baling hay with a Wisconsin powered baler; trying to re-start a hot Wisconsin engine with a hand-crank after un-plugging the baler out in a hay field in July when it is 100 degrees and no shade is truly a memorable experience. Oh, what I would have given for an electric starter and a modern ignition!

I still have one Wisconsin for running my little sawmill, but it does have electric start and distributor ignition. If ever there was an engine that could benefit from a good MSD ignition, this is it. I intend to keep it running just so my grandchildren can hear the annoying un-muffled staccato cackle of a Wisconsin V4 at full boogey. It builds character.

Sad to say, even Wisconsin finally knuckled under and switched to overhead valves. More's the pity.
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Re: Pondering about flathead potentials

Post by PackardV8 »

Since you took the thread in this direction, my machinist is one of the few remaining who knows the Wisconsin. The air cooling requires it's own valve guide to stem clearances, among other peculiarities. Then, in your hay baler example, the air cooling path is often clogged with chaff and I've seen them catch fire.

He's got a Wisconsin from a stump grinder sitting outside the door waiting a rebuild. He told the customer it could be a while, but the customer knowingly said, "Where else am I going to take it?"
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Re: Pondering about flathead potentials

Post by Les Kerf »

Don't get me wrong, I do love the old dinosaurs, but they have rightly earned their place in the dustbin of engine development.

My Wife's uncle tells about running a Wisconsin-powered 3-string Freeman baler in southern Idaho back in the 1950's; they did custom baling with it and had the engine rebuilt every year.

My Dad had an old Wisconsin-powered Case 2-wire baler that was HAND tied; my sister and I sat on little benches, one on each side. One person poked the wires through and the other person tied the wires. It actually made quite good bales. With one person driving the tractor it took three people to operate that contraption.

My sister had a 1959 Studebaker Lark with the little 170 CI flathead six; IIRC the bore was 3" and stroke was 4". That was the sweetest running little engine, and it was also the absolute EASIEST engine to work on that I have ever been around. Everything was right there within reach while standing on the ground, and I'm only 5'8" tall. My sister sold that car to some hippie for $50 while I was away in the Marines; I love her dearly but shall never forgive her for that!

My brother had a 56 Packard Clipper with the straight 8 flathead and automatic transmission. It ran so smoothly you could actually balance a nickel on the head while it was idling. I still have an intake/exhaust manifold for it lying in my boneyard.
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Re: Pondering about flathead potentials

Post by PackardV8 »

Les Kerf wrote: Thu Jun 10, 2021 11:48 am My brother had a 56 Packard Clipper with the straight 8 flathead and automatic transmission. It ran so smoothly you could actually balance a nickel on the head while it was idling. I still have an intake/exhaust manifold for it lying in my boneyard.
Since this is a flathead thread, 1954 was the last Packard straight eight. The Caribbean 359" (3.56" x 4.5") with a high compression aluminum cylinder head and Carter WCFB 4-bbl, made 212hp @ 4,000 RPM, possibly the highest horsepower of any OEM US flathead engine ever.

One reason Packard went broke, they spent the money for one-and-done new block, head, crankshaft, valves and pistons.

The reason for the smoothness was a huge nine-main-bearing crankshaft in a heavy block. IIRC, it weighed 900#.
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Re: Pondering about flathead potentials

Post by Truckedup »

MichaelThompson wrote: Fri Feb 05, 2021 8:13 am Just a little follow up on the Ford Flathead thing. If you think about a really stout side valve engine one cannot forget the 308” Hudson six cylinder.

Of course the Hudson has large bores and plenty of displacement for a six cylinder, but let’s not forget that the Hudson like any inline side valve has the advantage of a better point of entry for the intake port being lower on the block.
I have read that the Hudsons as tuned by Yunick for Nascar with their restrictions made north of 200 hp.
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Re: Pondering about flathead potentials

Post by Les Kerf »

PackardV8 wrote: Thu Jun 10, 2021 1:53 pm ... 1954 was the last Packard straight eight...
...The reason for the smoothness was a huge nine-main-bearing crankshaft in a heavy block. IIRC, it weighed 900#.
Thank you Jack, I stand corrected; I do remember that it was too much of a gas hog so my brother traded it for a Henry J with the little 4 cylinder flathead, then swapped in a small Studebaker V8. That woke that little Henry J right up! :D
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Re: Pondering about flathead potentials

Post by MichaelThompson »

Caught this thread late tonight so I’ll just leave this here as food for thought. Have a look at this Lycoming/Cord Flathead V8 cross section. This was about as advanced a side valve engine as I’ve ever seen.

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Re: Pondering about flathead potentials

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PackardV8 wrote: Fri Feb 12, 2021 2:24 pm
frnkeore wrote: Mon Feb 08, 2021 1:45 pm In addition, I think the best thing you can do for the FH, is run as small a engine as possible, with the highest CR you can obtain and run in class racing.

With smaller ci, the cylinder will fill better with the limited it's flow.
Agree. I have this discussion with Studebaker V8 builders. Since the heads are intake flow limited, the smaller the displacement, the more competitive in the horsepower-per-cubic-inch.

Back to flatheads - I ran across an anomaly in DynoSim while attempting to model a Studebaker Champion I6, built in both 170" and 185"; all else equal other than stroke. This is the first DynoSim I've ever encountered where it showed a higher net horsepower for a smaller displacement.

Every other time, when displacement is increased, but air flow remained constant, horsepower would usually increase slightly, but low speed torque would increase more.

Any suggestions as to why this would be showing more horsepower in the smaller displacement?

FWIW, guessing at flathead CFM without building a custom flow bench to accurately report it is akin to searching in a dark room for that black cat which might have already gone. What I've done is input known metrics and then adjust air flow inputs to game a net power result close to published data. Any other suggestions?
The 170 vs. 225 Slant Six "Leaning Tower of Power" Mopar does that too. In a Performance Trends engine sym program they flow the same air but the reduced friction and higher RPM range makes the 170 the power winner. The 170 has only 3-1/8" stroke to the 225's 4-1/8", both same bore 3.4".

Same as the Stude, because they are air limited by such small valves and poor flowing head, with optimized valve timing for the RPM range of each, 170 vs. 225, the reduction in friction of the short stroke combined with the smaller displacement having the relatively better VE/cu.in. allows the 170 to run efficiently at more than 1000 RPM above the maximum useful RPM of the 225. The 170 has more peak HP and a wider useful HP RPM range.
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Re: Pondering about flathead potentials

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Tuner wrote: Sun Jun 13, 2021 3:38 amThe 170 vs. 225 Slant Six "Leaning Tower of Power" Mopar does that too. In a Performance Trends engine sym program they flow the same air but the reduced friction and higher RPM range makes the 170 the power winner. The 170 has only 3-1/8" stroke to the 225's 4-1/8", both same bore 3.4".

Same as the Stude, because they are air limited by such small valves and poor flowing head, with optimized valve timing for the RPM range of each, 170 vs. 225, the reduction in friction of the short stroke combined with the smaller displacement having the relatively better VE/cu.in. allows the 170 to run efficiently at more than 1000 RPM above the maximum useful RPM of the 225. The 170 has more peak HP and a wider useful HP RPM range.
In the early '60s when the Slant Six was a new thing, NASCAR tried a compact class. The Pettys built a Valiant 225" Hyperpak. I remember Richard sawing the lower end in half when running at 7,000 RPM on the high bank; four mains are just not enough for that treatment.

The Jaguar 3.8 sedans and the Studebaker Lark 259" V8s were the fastest of the compact field.
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Re: Pondering about flathead potentials

Post by wwmtlineman »

I ran a slant 6 170 & 225 in a 51 Anglia in the 60s with the Hyperpak stuff on it. When they start making horsepower I had problems with them breaking the crank at the flywheel flange. The engine would still run but you werent going anywhere, After 4 of them I gave up
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