variable valve timing, variable intake plenum length, variable displacement, flexible fuel options, hybrid options, with gas going to $4 it's going to happen.

 

QUOTE: "It alternately fires odd then even cylinders -power feels like when I disconnected right side Fuel Injectors."

When you 'tricked' the V-10 motor into running in this mode, does that shut off the fuel injection on the alternating "dead" cylinders or just kill the spark?

 

4wd,

Good question - I don't know yet for sure! My thought is that at least the fuel Injectors are cut off as there was no black smoke at the tailpipe as might appear if a raw fuel mixture was being exhausted.

I will find out for sure.

 

To get into "limp home" I disconnected the CHT (cylinder head temperature sensor) and substituted a Trimpot to simulated rising engine temperature.

When the Temp Gauge hit the upper RED area (driven by a simulated input) the engine went into the "fail-safe cooling" mode. IE: A/c shut off, Temp Gauge stayed at RED (even when I removed the simulated input) and the engine wiggled a bit as it went into a series of "Fire the Right Bank" then "Fire the Left Bank". (These are the characteristics describe in the owner's manual).

I could hear a change in pitch at the tailpipe as it cycled from side to side. Also had low power when I tried to drive it.

The answer to your last question has yet to be answered!

 

He disconnected the fuel injectors, not the COPs, at least that's how I understand this thread.

 

The first test I did was to just disconnect the 5 left side Fuel Injectors.


When I "tricked" the system to go into "Fail-safe cooling" mode I had all Fuel Injectors and COPs in place. I hope that makes things clear so far!!!!

 

And please keep us posted. This fail safe mode is new to me, No one ever talked about it or mentioned it to me, and I never read it in the manual. And I've owned two of these V-10 super duties. You'd think Ford would describe this in great detail to customers, giving all the nuts and bolts behind the system, and use it as a sales feature avail. at no extra cost.

 

Richard 2212 - Thanks much for the feedback.

I definitely buy into the idea of using the limp-home mode for a test of this type for four main reasons. One is as you have stated, that if the engine is engineered to travel 50 miles with minimal coolant, then having more coolant can only help. The other is that since the computer is calling the shots now, it will presumably not only turn off the fuel flow to the unused cylinders, but it should logically also not fire them either; plus - and I personally think this is the biggest deal - the idea of alternating between banks of cylinders, should keep the cylinders from running "dry"; and last, with the computer in control of the limited cylinder firing, it should recognize and compensate to counter the argument previously presented that the exhaust will run lean from the extra oxygen in the exhaust. It will of course, but the computer won't care.

So far, so good. But if our V-10's don't have solenoid-actuated valves, they can't be under computer control, so the unused cylinders, wherever they are, will still be compressing air and expelling it - i.e., no "spring" effect as mentioned by a previous post that GM(?) employs.

So with the cooperation of the computer control, it might just be possible that there would be no engine damage - at least if the engine is NEVER taxed with a load or rapid acceleration.

The remaining question though is the greatest to me. A prior post indicated that other manufacturers are claiming only a 10 to 20% mpg improvement from this technique. Seems low to me, but I'm sure they would claim as much as can be documented. So if they only get maybe 10% improvement - and they do vent their unused cylinders to reduce the workload - you might actually get WORSE gas mileage!!

On the other hand (!), the manufacturers of these inferior vehicles, would dynamically select the number of cylinders to eliminate the performance penalty when accelerating. So maybe running full time on the 5 cylinders (no load, careful driving) would deliver a mpg improvement after all.......

You have GOT to keep us posted!

 

Actually, there's still the argument about the extra oxygen screwing up the catalytic converter.......... That may be the basis of the 50 mile limit?

 

I think the concern with the cat would be from dumping unburned fuel into it.

 

My plan incorporates a Vacuum switch to get in and out of the 5 cylinder mode as load drops (ie: idling,etc) and as load increases (ie:acceleration,etc).
I will use an adjustable vacuum switch to tweek in the ideal switch point. I have vacuum gauge in my Excursion now and it looks like the switch point will be between 5 and 10 in.HG. I also have to modify the "fail-safe cooling" mode to Keep A/C on, eliminate Key off/key on to get out of FSC mode, keep normal timing advance and maybe something else I don't know about yet.

 

There shouldn't be any unburned fuel as the dead cylinders do not get fuel. The Computer controls Cat Temperature via the O2 sensor inputs.

I think the 50 mile suggested limit is more related to running with low or no Coolant. I guessing at this point. I will know positively before I am ready to run in this modified 5 cylinder mode.

 

The 2000(?) Cobra R used a N/A 5.4/4valve that was rated at 385HP.

Pretty sure the 5.4/4valve is still available in Australia (BigF350??)


I believe the question was basically that there is/was a DOHC 4 valve 4.6 and 5.4 why not make new 5 cyl castings to do a DOHC V10.

The only thing I'm wondering is if the balance shaft would be a hinderance in a DOHC head.

 

The Navi motor made around 300HP the Cobra R was closer to 400.


You and I are in total agreement;

The 3 valve heads with electronic solenoids controlling hydraulics and a TOTALLY new casting seems to be waaaaay more expensive then refining 4 valve heads that have been bought and paid for (DOHC heads are around 13 years old!!)


Truck schmuck, the more complicated VVT 3 valve heads are basically where the 4 valve heads left off (even though the Navigator DOHC seems to have better performance numbers than the current 3 valve with near HP and torque ratings) Not to mention the F150 seems to be last in every objective performance category.


The money would have been better spent refining the DOHC head with VVT like Nissan/Toy..........then we would have some bragging rights (Have learned bragging rights only seem to be important when we have them...V10)


We are obviously wrong, Ford knows better.........they would never change architecture just for the sake of change... or would they?

 

I do not believe there has ever been a 5.4 in a Mustang, other than the very rare 2000 Cobra, all the other Cobra R's had a supercharged 4.6, it made 390 hp. The only 5.4 4V other than the GT/2000 Cobra was in the Navigator.