[v12-engine] Just an idea

V12-Engine
1

Just returned from a business trip, during which I rented a brand new Ford
focus (UK… piece of c**p!).

While bored somewhere, I started reading the user’s manual, just out of
curiosity, and read some security feature that “perhaps” could be
interesting for our V12:

Supposedly, and in the event the engine starts running low on coolant (in an
emergency) and starts getting very hot, the engine management system will
stop the spark to 2 of the 4 cylinders, which will allow the engine to keep
working (at reduced power, etc) but not destroy itself. What this does
(according to the manual) is allows the other 2 pistons to act as an air
pump, and cool the engine enough to survive.

I was thinking that is probably not very difficult to implement into our
ignition systems, and it could be a good alternative to all these dropped
seats (I know the best way to avoid overheating is having a good cooling
system + centrifugal advance); but as an engine-saving emergency measure; it
could be OK.

Ideas/Comments?

Carlos '86 V12

2

This sound like it would lead to a Cat fire if you don’t shut off the
injectors as well as the ignition.
Martin-----Original Message-----
From: Cat [mailto:cat@laugel.freeserve.co.uk]
Sent: Wednesday, March 29, 2000 11:41 AM
To: v12-engine@jag-lovers.org
Subject: [v12-engine] Just an idea…

Just returned from a business trip, during which I rented a brand new Ford
focus (UK… piece of c**p!).

While bored somewhere, I started reading the user’s manual, just out of
curiosity, and read some security feature that “perhaps” could be
interesting for our V12:

Supposedly, and in the event the engine starts running low on coolant (in an
emergency) and starts getting very hot, the engine management system will
stop the spark to 2 of the 4 cylinders, which will allow the engine to keep
working (at reduced power, etc) but not destroy itself. What this does
(according to the manual) is allows the other 2 pistons to act as an air
pump, and cool the engine enough to survive.

I was thinking that is probably not very difficult to implement into our
ignition systems, and it could be a good alternative to all these dropped
seats (I know the best way to avoid overheating is having a good cooling
system + centrifugal advance); but as an engine-saving emergency measure; it
could be OK.

Ideas/Comments?

Carlos '86 V12

3

At 14:19 2000-03-29 -0800, Martin Runneals wrote:

This sound like it would lead to a Cat fire if you don’t shut off the
injectors as well as the ignition.

Actually, that’s what you’d do: shut off the injectors, not the
spark. Easier to implement too, though the remaining cylinders would end
up running LEAN because the ECU would be detecting the additional oxygen
from the cyclinders pumping air, and lean the apparently rich mixture -
this in turn would cause the engine to run hotter. Easy enough to work
around if it was developed into the ECU, but externally (as would be the
case for a retrofit to the V12), you’d probably have to implement a
switched resistance on the oxygen sensors, to make them appear leaner, so
the ECU doesn’t try to lean them out.

If I were to implement something like this, I’d probably alternate which
cylinders did and did not get gas - run ‘x’ cycles on odds, then same count
on evens or something like that, just to spread the wear.

I think there may be an issue with providing a proper load on the injector
harness as well.

If someone REALLY wanted to do this, they could probably do it fairly
easily (well, considering). Personally, I’d just as soon pull to the side
of the road when the temps got up and wait for a tow. I’ve infrequently
had the need to drive someplace so badly that the need outweighed the
preservation of my car.

I vote for Carlos to perform the proof of concept. Anyone second that?

— http://jaguar.professional.org/
Sean Straw '88 Jaguar XJSC 5.3L V12 (LHD)
Marin County, California '69 Buick GranSport 455 V8

4

In a message dated 3/29/2000 2:52:54 PM Eastern Standard Time,
cat@laugel.freeserve.co.uk (Carlos) writes:

<< Supposedly, and in the event the engine starts running low on coolant (in an emergency) and starts getting very hot, the engine management system will stop the spark to 2 of the 4 cylinders, which will allow the engine to keep working (at reduced power, etc) but not destroy itself. What this does (according to the manual) is allows the other 2 pistons to act as an air pump, and cool the engine enough to survive.

I was thinking that is probably not very difficult to implement into our
ignition systems, and it could be a good alternative to all these dropped
seats >>

It would probably be much more prudent to implement such a scheme by
disabling some of the fuel injectors. It shouldn’t be terribly difficult to
construct a digital circuit which could selectively allow the engine to run
on 12, 6, or 4 cylinders using divide-by counters and SCR’s to enable/disable
the injectors. Simply gating the ignition would be very wasteful of fuel,
would undoubtedly violate emissions standards, and could quite possibly cause
a catalytic converter fire, not to mention drive the ECU crazy trying to
adjust the mixture to compensate for the raw fuel being dumped into the
exhaust.

Giving further thought to the matter, I feel that it would probably necessary
to run the ECU in the open-loop mode, due to the extra oxygen introduced by
the cylinders pumping only air. This would help to prevent fuel starvation
and resultant detonation in the remaining cylinders which are still providing
motive force. Of course, this would also throw fuel economy out the window,
since the ECU would effectively be taken out of the loop.

However, I believe that Cadillac has implemented a similar scheme in their
Northstar ™ engine, which allows it to operate at reduced power up to 100
miles from initial detection of overheating. Perhaps this is something which
is worth looking into for long-range Jaguar drivers. Unfortunately, my
proposed solution would have no merit for carbureted V12’s, nor would the
proposed interruption of the ignition circuit have merit for SIII E-type
owners (you can’t change the primary ignition on the SIII E-type V12 without
suffering dire consequences, per the ROM)

Regards,
Steve Wilke
'88 XJ-S H&E Conv.,57kmiles

5

How quickly we forget the infamous 4-6-8 Cadillac had wrought! I’d definitely
want balanced loads here, no extra fuel to the cats and some way to add an
override to the mess. I think I’ll just stay away from these kind of
mods…-art-

Sean Straw wrote:> At 14:19 2000-03-29 -0800, Martin Runneals wrote:

This sound like it would lead to a Cat fire if you don’t shut off the
injectors as well as the ignition.

Actually, that’s what you’d do: shut off the injectors, not the
spark. Easier to implement too, though the remaining cylinders would end
up running LEAN because the ECU would be detecting the additional oxygen
from the cyclinders pumping air, and lean the apparently rich mixture -
this in turn would cause the engine to run hotter. Easy enough to work
around if it was developed into the ECU, but externally (as would be the
case for a retrofit to the V12), you’d probably have to implement a
switched resistance on the oxygen sensors, to make them appear leaner, so
the ECU doesn’t try to lean them out.

If I were to implement something like this, I’d probably alternate which
cylinders did and did not get gas - run ‘x’ cycles on odds, then same count
on evens or something like that, just to spread the wear.

I think there may be an issue with providing a proper load on the injector
harness as well.

If someone REALLY wanted to do this, they could probably do it fairly
easily (well, considering). Personally, I’d just as soon pull to the side
of the road when the temps got up and wait for a tow. I’ve infrequently
had the need to drive someplace so badly that the need outweighed the
preservation of my car.

I vote for Carlos to perform the proof of concept. Anyone second that?

— http://jaguar.professional.org/
Sean Straw '88 Jaguar XJSC 5.3L V12 (LHD)
Marin County, California '69 Buick GranSport 455 V8

6

Supposedly, and in the event the engine starts running low on coolant (in
an
emergency) and starts getting very hot, the engine management system will
stop the spark to 2 of the 4 cylinders, which will allow the engine to
keep
working (at reduced power, etc) but not destroy itself. What this does
(according to the manual) is allows the other 2 pistons to act as an air
pump, and cool the engine enough to survive.

My LS1 had a similar feature, it would shut off 4 of the 8 cylinders in a
limp-home mode, and it would alternate the cylinders to keep any set of 4
from getting too hot. Fortunately I never tested it.

I was thinking that is probably not very difficult to implement into our
ignition systems, and it could be a good alternative to all these dropped
seats (I know the best way to avoid overheating is having a good cooling
system + centrifugal advance); but as an engine-saving emergency
measure; it
could be OK.

I think you would need the cylinder rotation feature or you’ll just ruin the
firing cylinders anyway. Not just spark but also fuel.

Cheers,
Bry

7

Carlos,

Sorry to appear to be the Devil’s advocate on this… but if the Focus
was such a piece of c**p… then how come you’re instilling the virtues
of a novel, and potentially engine saving, over temperature protection
system that is fitted to this technologically advanced car ??

Also, how can a ‘piece of c**p’ become segment leader… surpassing the
VW Golf ??

Don’t forget that the premium car segment and the entry level ‘C’ car
segment are entirely ‘different kettles of fish’ !

I was involved in the design and development of the Focus, and can
vouch for the precision of the handling, the comfort on long journeys,
the high speed stability… and the stability of the ABS at 120 mph !!

If I didn’t have the XJ6… there’d be a Focus in my driveway.

Regards,

Steve & the LPG '93 3.2 XJ40____________________________________________________________
Do You Yahoo!?
Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk
or your free @yahoo.ie address at http://mail.yahoo.ie

8

At 10:12 2000-03-30 +0100, Steve wrote:

Sorry to appear to be the Devil’s advocate on this… but if the Focus

Hmm, from what you say below, you’re not the Devil’s advocate - you’re his
employee. Or do you just consult for the Devil?

was such a piece of c**p… then how come you’re instilling the virtues
of a novel, and potentially engine saving, over temperature protection
system that is fitted to this technologically advanced car ??

Easy: such things are needed because it is assumed that the market for the
product is of the mentality to actually continue to drive the car even
after the idiot light has sprung on indicating an overtemp
condition. Todays society seems to be of the mind to not bother checking
any fluids at all - the only thing most people deal with is adding
petrol. If you don’t believe me, take a look at the other people at the
service station the next time you’re filling up. Does even a single one of
them pop the hood to check fluids, or pull out a tyre gauge to check for
proper inflation?

Do they even bother putting in a temp gauge in the things these days, or is
there just a “replace engine” lamp?

Don’t get me wrong here - I’m not bashing the Focus as an individual car –
the same can be said for “100,000 mile tuneups” and the Cadillac STS
run-it-dry engine - manufacturers don’t pay for the engineering for these
things because it’s a nifty thing – they do it because experience shows
that there are a significant number of people out there that screw up their
cars from neglect. In fact, chances are that these people manage to do it
within the factory warranty period, which gives the financial incentive to
the company to do something to head it off.

If they simply put something in to kill the ignition on a severe overtemp,
they’d probably get complaint letters from people bitching about how they
were stranded on the side of the road when they really wanted to get somewhere.

If I drove a car 50 miles without any water, even if the manufacturer
claimed the engine could go 100 miles in such conditions, I’d be seriously
concerned about how many tens of thousands of miles AREN’T left on the
engine as a result.

Also, how can a ‘piece of c**p’ become segment leader… surpassing the
VW Golf ??

There’s no accounting for taste or sensibility?

Hopefully you weren’t involved in the “asthetic” design of the car,
because, IMHO, it is one butt-ugly piece of workmanship with it’s ass way
up in the air. Granted, most cars these days are, which makes me wonder if
designers are actually setting their goals on a puggy looking car these days.

Don’t forget that the premium car segment and the entry level ‘C’ car
segment are entirely ‘different kettles of fish’ !

Mmmmm, Lutefisk or pickled Herring?

I was involved in the design and development of the Focus, and can
vouch for the precision of the handling, the comfort on long journeys,
the high speed stability… and the stability of the ABS at 120 mph !!

Hmm, from the looks of the thing, I’m not so sure I’d want to be in it when
it is going 120, good breaks or not. Then again, I’m not fond of cars where
my kneecaps are resting against the dashboard when I’m riding as a
passenger. I’m not a huge guy either - just 6’ 2" - but it seems cars are
being designed for people much shorter than that, which is odd given the
trend in recent decades of a taller population.

Cripe, I can barely clear my knees under my wife’s steering wheel (she
drives a 1993 Ford Mustang convertible). You should see me in a compact. Ick.

I try not to commit the imagry to memory, but isn’t the Focus the car in
the commercial where a group of morons pull into a parking space that is
crowded out by the adjacent cars, and they crawl out the hatchback? Yea,
you too can crawl out your trunk. This same feature was available in
station wagons of yore, but I’ll bet you never saw that being advertised.

If I didn’t have the XJ6… there’d be a Focus in my driveway.

Well, gosh, park it out front on the street! (The Focus, not the XJ).

— http://jaguar.professional.org/
Sean Straw '88 Jaguar XJSC 5.3L V12 (LHD)
Marin County, California '69 Buick GranSport 455 V8

9

Steve,

I did not mean to hurt anybody’s sensibility here. The focus is a piece of
crap, when you compare it to a well tuned XJS, as most other modern cars
are. I find the focus to be functional, practical and fast; which is what I
want from a rental car. I was amazed at the amount of gadgets the car has,
including the ultrasonic parking distance meter, etc. Is it a bad car… NO,
is it crap, compared to the golf… NO, is it crap compared to my
XJS…DEFINITELY

Hope you get the spirit of my message.

Regards, Carlos '86 V12----- Original Message -----
From: Steve jagbuff@yahoo.co.uk
To: Cat <@Cat>; v12-engine@jag-lovers.org
Sent: Thursday, March 30, 2000 10:12 AM
Subject: Re: [v12-engine] Just an idea…

Carlos,

Sorry to appear to be the Devil’s advocate on this… but if the Focus
was such a piece of c**p… then how come you’re instilling the virtues
of a novel, and potentially engine saving, over temperature protection
system that is fitted to this technologically advanced car ??

Also, how can a ‘piece of c**p’ become segment leader… surpassing the
VW Golf ??

Don’t forget that the premium car segment and the entry level ‘C’ car
segment are entirely ‘different kettles of fish’ !

I was involved in the design and development of the Focus, and can
vouch for the precision of the handling, the comfort on long journeys,
the high speed stability… and the stability of the ABS at 120 mph !!

If I didn’t have the XJ6… there’d be a Focus in my driveway.

Regards,

Steve & the LPG '93 3.2 XJ40

Do You Yahoo!?
Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk
or your free @yahoo.ie address at http://mail.yahoo.ie