Reply to "4.6 advantages or disadvantages?"

> Ford is being hush hush about the architecture of the motor, but one story
> I read a while back specifically stated the motor would retain over head
> cams and 3 or 4 valves per cylinder.

If they do that, sell your stock. I still wonder if they aren't looking
at a dual cam pushrod design with either 3 or 4 valves per cylinder. GM
originally looked at that for the LS7 but decided the 2 valve route was
simpler and would meet their goals.

> Ford has produced both a 351 cubic inch V10 and a 427 V10 based on the mod
> motor. But for some reason they seem reluctant to put them into production.
> I'm guessing its the cost.

Cost, size, weight and they still don't match the power of GM's (the 6.8L V10
is still down 40 HP to the equivalent GM pushrod truck V8). The Mustang is a
porker with the mod motor V8's and would be much worse with a V10.

> The impetus for a new motor is all about cubic inches, and not about any
> deficiencies in the design of the modular motor, don't be surprised if the
> new motor is nothing more than a bigger mod motor.

It's precisely the design deficiencies of the mod motor that has put them
in this situation. The small bore spacing limits the maximum displacement
and the valve area and therefore the cylinder head flow.

> You can still purchase parts for a flat head, but you have never been able
> to buy the proper thermostat for a Cleveland. LOL...

I've never had any trouble buying the proper thermostat.

> Overhead cam engines have two advantages, one in the RPM limit of the valve
> train, and the second in the freedom to design ideal intake & exhaust port
> architecture.

True.

> I think this remains true today, although the limits of both architectures is
> higher today than in decades past, and I would not argue with you Dan that an
> OHV design can be made to rev plenty for a street car, and make good bhp
> numbers too.

Agreed. Torque follows displacement and horsepower follows RPM (and airflow).
Reliability is inversely proportional to RPM (squared). On a big inch pushrod
V8 street engine, there's little need for extreme RPM so the valve train is
not the limiting factor. The D3 pushrod heads outflow the best mod motor
DOHC heads by over 100 CFM and the D3 heads are not an all out pushrod design
head. They are constrained by NASCAR rules limitations. If one were to
revise the intake port to have an entry more like Gurney Weslake, it could
be improved on. Also, the inherent compactness of a pushrod V8 provides more
room for efficient exhaust within production car constraints.

> Oh, and by the way, the 4.6 was used in a front wheel drive car, the Lincoln
> Continental.

Yes but the vast majority of them are in rear wheel drive vehicles.
The limitations placed upon the mod motor design to make it FWD friendly
has severly limited the engine's potential.

> But maybe, just maybe, people are dissapointed in the Mod motors because
> they approach them like they would and old school V8?? Maybe instead of
> trying for more cubes, which you can't get, go for more RPMS instead.
> Build it like you would a formula one engine. De-stroke it, put in variable
> cams and variable intakes. Put in needle bearing main bearings. Balance
> everything within an inch of its life. Shoot for a 16,000 RPM redline.

"The candle that burns twice as bright, burns half as long (and you have
burned so very brightly, Roy)".

Dan Jones