Driveability issues single plane vs dual plane

[promachine]

Kahuna, I have heard all the claims of 200 plus hp but have never seen one run yet. I have dynoed 20 to 30 flate Fords in the last few years and 160 to 175 has been about tops.
However, this sunday I have what is supposed to be a 220 hp race flatty for B-vill coming in for a dyno. I can`t wait.
I see you live in nor-cal, maybe you will stop by and check it out.
The best I have pesonally built was 180 hp for Street Rodder magazine.
Isky max one cam, Sharp heads and manifold, ported and releived, all the normal stuff.
We originally ran it with 3 Strombergs but it didn`t like it so we pulled one and just ran two and she liked it.
I have allso run maney blown flatties and depending on the type of blower and the boost we have seen 200 to 300 hp.
Landy built a pretty trick peice a few years ago that made 600 hp using an vintage ford block as per SCTA rules, and went 300 mph in a liner.
Good luck with your project.

[bigjoe1]

The reason that magazine road tests get such fast times( 0 to 60, ect) is because the do it all by GPS. I got involved with an old 409 Chevy drag race car some years ago. we were at the Pomona drag strip so the magazine do their acceleration readings when I made a pass down the quater mile. The drag strip readings were VERY MUCH differant than the GPS readings. As I recall, the GPS quarter mile was SEVEN TENTHS FASTER than the actual drag strip time slips. I feel this is why the car magazines get very quick acceleration times from new cars they test as apposed to the way they used to test 30 or 40 years ago. I am talking about comparing a Honda to a 426 Hemi. OH WELL>

JOE SHERMAN RACING

[Kahuna]

Promachine, I sent you a PM

[Kahuna]

PackardV8: I sent you a PM

[Dodge Freak]

lets not forget these new cars speedometer are control by the computer, unlike the old cars that used a cable from the trans.

I drove a 2000 Crown Vic once on the express way--flat out ..your going a steady 100 mph and you punch it, the speedometer starts climbing up fast but I could feel darn well the car wasn't picking up the speed that quick.


These newer cars when you think how smog friendy they are, aren't too bad but they are more a mirage of what you think its doing, than whats really happening. They are nice for long drives at steady speeds and they get pretty good mpg too.

[PackardV8]

Hi, Dodge Freak,

New car speedometers are NOT driven off "the computer." Most get their speed reading from a ABS sensor directly off the wheel and it has a resolution several orders of magnitude more accurate than the old cable drives back in the day.

I said earlier EFI, crank triggers and computers were magic, but aerodynamics is the big mojo of the twenty-first century performance cars. The old barn-door Dodges with that wide, rectangular grille hit the wall at about 135 MPH and it was hard work and lots of money to make them go much faster. The current Mopar SRT8 is a genuine 175 MPH ride right off the showroom floor.

thnx, jack vines

[panic]

The 200 hp figure has been the upper end for a long time. The comments about higher specific power than .7 hp per cubic inch, IME when traced back, turn out to be either:
1. OHV theory applied incorrectly to SV as a prediction (not a test)
2. fuel, and I don't mean methanol
3. blown and methanol
4. complex sponsored project with almost 100% fabricated parts (Flatfire)

The KR engines were the pinnacle of SV development, perhaps 60 hp at the shaft out of 45", but that was a purpose-built race engine with no original (std. commercial model) parts and (as Gordon Jennings said) "40 years of development" - literally, the extra power only went up perhaps 1 per year during 1955-65. That's about $100,000 and 100 hours of shop time per horsepower.

You're not using anything to give you an advantage over Jocko's Porting from 50 years ago - why would it be faster? They didn't have flow benches - they simply tried every port config they could think of ("Change this - did it work? Let's find out"), and the better ones were duplicated.

The cam wasn't state of the art in 1955, unless it's a mushroom - yes?
The high rigidity of the Ford valve gear allows it to spin very fast, except it blows up, and it has no VE at all at high speed.
I'm not aware of a modern high accel/high vel computer generated cam using the largest possible mushroom diameter, but there are people here who can answer that.

I agree, 75% VE is a more realistic estimate (216 hp), but the amount of cam you'll need for this will be unpleasant.
We use old profiles in 45" H-D motors:
Dur. @ .010" 294°, @ .050" 270°, lift .377" (limited by original lobe height, more = better) - this is streetable with enough compression if you keep the IVC under control. Th problem with SV is how to hide enough duration to give good area under the curve TDC-BDC without extending IVC (and ruining DCR) or IVO (too much overlap will run very rough in a SV due to low compression).

I'm not familiar with a 2 × 4 manifold, is this a fabricated piece?
My preference would be to use carbs with a total CFM rating closer to what you need to keep air vol and speed at the venturi within design limits and not whack the fuel curve to 1 side.

To be honest, a blower is a lot more practical.

[panic]

Current thought is to "herd" mixture towards the exhaust valve, which is where the plug sits (see Widmer). IDK of any Ford heads that do this?
I'm not sure that current port/relief theories work, either. I exchanged some comments elsewhere, and when I showed what seemed to me to be an intuitive improve the conversation stalled. Conclusion: a great deal of "development" consists of walking backwards 50 years and "doing what they did".
Cutaway of Ford port at guide:



Material added to for a ramp to the guide, and to improve SSR:



I have a gut feeling that the relief where it intersects the bore is a waste of compression, and that a shallow angle away from the seat on the bore side is by far the most important. Much testing will be needed to see where mixture following the relief reflects off a ledge or shelf in the head and is then directed down to the bore - there is no correlation now AFAIK.
Mental picture? Think Schneurle loop.

I think the Navarro 4-71 manifold might be an interesting donor for a tunnel ram - good port runners, exposed open box, nice casting. Add a top with a Holley 390.

[Kahuna]

Panic
Thanks for the input and the pics. While I don't entirely agree with your conclusions that we go back 50 years and duplicate what was done then, I certainly am sure that more than 200 hp is attainable w/o any power adders and still be streetable. I may be wrong, but I'm gonna give it a try. Re the valve gear-where did you ever hear of the valve assys blowing up? Mushroom cam is not necessary, but was available, as were roller cams. Still never heard of valve gear blowing up. Adjustable lifters, maybe? Yes, the manifold is a one-off. Agree that the customary relief is a waste of time and effort. Don't know anything about herding flow to the exhaust valve side, unnecessary IMO. AFAIK, there is no "magic bullet" for a flathead- it's as it's always been. A combination, where everything that can be improved is, at least to the best of one's ability and wallet
Jim

[panic]

Referring to block, rod, main cap, crank failures.
The maximum velocity (greatest area under the curve for a fixed duration) is almost a straight function of the width of the tappet's contact surface. This means a mushroom (for flat tappet), which was done long ago but not with a modern profile taking advantage of the stiffness of the Ford valve stem vs. a pushrod - many profiles are "adapted" from OHV engines (especially SBC) because of all the available lobe shapes and profiles on the shelf (i.e. time and money spent). Isky spoke 40 years ago that one of the few advantages a SV had was the stability of the valve gear - he meant more RPM, I mean more aggressive profile.
Re: plug location - this research has been done as far back as Ricardo, and (surprise) efficiency is not even on the list for plug placement for most passenger engines. The important factors are:
1. wrench clearance
2. minimum casting scrap rate
3. proximity to existing water passage
4. enough thickness for thread perch
5. angle for wires to clear exhaust

The big reasons why it's not done differently:
1. people are sheep: they will not lead, but they may be lead
2. you get laughed at - unless you win
3. for many racing venues it's illegal - that's all the proof I need that it works.

Have you read Blair's stuff on flathead design? Very strange - not at all what I expected to see:



The Kohler 16 has had much R&D also, and it looks remarkably like KR - except the quench ledge placement is based on some factors I don't understand. Adapter from Vogel machine:

[Kahuna]

Hi Panic
I'm not aware of block/rod/crank failures in a well prepped engine. Re: agressive cam profiles, these have and are being done with rollers not associated with the SBC. Very agressive.
No, i haven't seen the Blair stuff, but am familiar with the Harley and other design "stepped" cylinder heads. I also think Jocko had it wrong.
I guess I'll know how well my guesses work in a couple of months.
Appreciate the info and discussion. Wish I had more answers.
Regards
Jim

[Keith Morganstein]

Do we need a flathead thread???

I guess everyone knows of flathead jack?

http://www.flatheadjack.com/

Supposed to the guy for parts. It's amusing that he sells 3/4, full and comp full race cams.

[panic]

"block/rod/crank failures in a well prepped engine"

Read the amount of work done to some of these. The blown/gas engines produce perhaps what you expect - and they still break:
http://www.35pickup.com/mulligan/drags.htm

[PackardV8]

Hi, Kahuna,

I'm not aware of block/rod/crank failures in a well prepped engine

hasn't been around many racing flatheads. Back in the day when flatheads were scrap iron and scrap iron was cheap, there was a very large pile of broken block/rod/crank failures behind every garage which raced them. The three-main flathead crank whips like spaghetti. The 4.125" stroker Mercury crank really didn't like higher revs.

Here's a round-track race trick which isn't seen much any more. IIRC, because of the way the generator and distributor mounted, it was easier to pull the right side head than the left side. The tracks in Alabama had a maximum bore and stroke limit. The guy who taught me most of my basic stuff was from the Smokey school of rule interpretation. We bored the left bank to the max, 3.375", I think, and kept the right side to the rules. Top three places in the feature race had to be physically measured, and we always passed. It kept frustrating him he couldn't find a crank grinder who could do an offset stroker. When the even-fire Buick V6s came out, he called me and said, "See, I told everyone it would work!"

thnx, jack vines

[panic]

If you can fit an .855" roller you can use the H-D grinds, lobes up to about .440".

I have some negative thoughts about the intake/exhaust bias on all the older SV Ford cams I've seen - symmetrical (matching duration). A few thoughts:

The H-D engines (all street and race since at least 1932) have far better exhaust porting than intake - individual (not shared), good shape and size, large radius curve. The factory racing dep't. started with conventional thinking in the mid 1930s and used symmetrical in & ex, resulting in 1 of 3 outcomes:
1. short duration: not enough peak power
2. long duration, early IVO: too much overlap
3. long duration, late IVC: no DCR
The cure was the same intake duration with shorter exhaust timing, about 30° less. This was followed for the next 20 years with all porting shapes, cylinder castings, static CR, carb type etc.

My conclusion:
1. the Ford end exhaust ports (1, 7, 2, 8) may work as well as the intakes, or better. If yes, their duration should be reduced to either conserve working cycle % (later EVO) or control overlap (earlier EVC).

2. The Ford center ports (3, 4, 5, 6) aren't so good. They may need the full intake duration or more for blow-down. In addition, the siamese nature suggests examining Vizard's (Mini) stagger pattern cam theory.