Fordnatics List Archive

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Mail From: (email redacted) (Dave Williams)


-> have seen guys with claimed 12:1 CR with stock tiny radiators say "I
-> never never have any cooling problems!" and others with 9:1 motors
-> come steaming in after just a few laps at WOT.

The compression ratio doesn't really have that much to do with cooling.
A high CR motor will generally make a little more power, which means a
little more waste heat, but we're talking single-digit percentages here.
You normally bump compression when you go to a larger cam, kind of a
balancing act.


-> How do you compute the cooling requirement for a particular engine?
-> Is that as scientific as we can get, hit and miss?

Basically, yes. With a good research program and plenty of Cray time
you can model just about anything, but the modeling is not always
cost-effective compared to just poking something with a stick to see if
it barks.

For most production engines there's no problem with cooling - you just
jacket what you can, slap a pump on there somewhere, and let the water
sort of swirl where it wants to. It almost always works. Sizing the
radiator is equally simple - figure how much heat the engine will
reject, using whatever thermal efficiency you get from a dyno run, then
figure a long pull on a hot mountain day (low air density), derate the
radiator by some magic figure to compensate for age, crud buildup, and
dirt, and that's your radiator.


-> water and the oil get pretty warm 230water/210oil. I would be a lot
-> happier if the temperatures were reversed!

That's pretty cool for oil. Pennzoil recommends 250-275-ish. (they
actually won't give a specific figure - you just keep throwing numbers
at them and they say "too low", "OK, or "too high." Weird.) You want
the water >212 to boil out any water from condensation. Water looks a
little high, but if you're not boiling over or running into detonation I
wouldn't be too concerned.


-> My solution has always been, "More cooling is better than not enough"
-> and usually put the biggest continuous fin crossflow radiatior that

Apparently not all water pumps are created equal. B&A Ford's magic
bullet is the TRW aluminum replacement pump, available in LH or RH
rotation depending on your accessory drive. Gary claims the 351X motors
could overheat on long pulls, but the TRW pump eliminates all problems.

Some pumps also just plain don't work over some specific RPM.
Depends on impeller design, which can be anything from a true-form
impeller to a piece of bent sheet metal. The average car probably never
sees the high side of 4000; if it sees more, it's only for brief
periods. The pumps just stall at higher speeds, and you lose coolant
circulation. For drag racing or whatever it's no problem.


-> Various size orifices, impellers, barrel valves all seem to be hit
-> and miss.

I have some literature from Cosworth. Cosworth's magic bullet (magic
bullet is this week's buzzword) is air entrainment. Now, from what I
can gather from the DFV data sheets, the thing leaks like a seive - you
add sealer to keep it from drooling on the ground, then the combustion
chambers leak pressure into the water jacket. The Cosworths run without
a pressure cap, or with a very low rated cap. They use a "swirl pot", a
sort of centrifugal de-aerator, to pull the air bubbles out of the
coolant. Excess air is then vented overboard. Cosworth claims
entrained air causes overheating. The swirl pot sounds like a good idea
anyway - it's not unusual to see bubbles in the radiator - but you have
to find a place to PUT the thing.


-> I am curious an to other approaches.

I never much liked the thermostat-and-bypass-hose scheme, even if
most engines do it. The little German Ford V6 had a very nice system -
instead of stalling the coolant behind a closed thermostat, the pump
always circulated it full bore. When it got hot, the thermostat (a
rather complex assembly) shunted hot water out to the radiator and cool
water in.

I'd also like to experiment with a positive-displacement water pump.
Car pumps are always (as far as I know) centrifugal, so they'll just
stall with the thermostat is closed. With the positive-displacement
pump, you KNOW water is being pumped.

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Mail From: (email redacted) (Dave Williams)


-> I wish I did. I was running hot at Thunderhill just like everyone
-> else. In fact I think it contributed to my motor's demise.

From your description of the disassembled motor, it sounded like
detonation was your problem. And detonation doesn't have to be audible
to be damaging.

Too bad Carter doesn't make their Knock Eliminator box any more. It
wasn't high tech, but it was cheap, and it'd save a lot more than the
$75 it cost. How much was that new short block?

This read-only message was archived from a public mail list.
Mail From: (email redacted) (Scott Griffith, Sun Microsystems Lumpyware)

On Jul 1, Dave Williams wrote:

> Too bad Carter doesn't make their Knock Eliminator box any more. It
> wasn't high tech, but it was cheap, and it'd save a lot more than the
> $75 it cost. How much was that new short block?

Anybody got schemati or the specs on the transducer? It'd be fun to
knock one off, just to play with. Now, _there's_ a use for the "Low
Fuel" LED on that damnable graphic display panel...

-skod

- --
Scott Griffith, Sun Microsystems Lumpyware
expatriate SCCA New England Region Flagging/Communications worker
(and driver, of anything that turns both right and left,
and can pass tech...) Return Path : (email redacted)

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Mail From: chucko (Chuck Fry)

From: (email redacted) (Scott Griffith, Sun Microsystems Lumpyware)
Date: Fri, 1 Jul 1994 09:17:30 -0700

On Jul 1, Dave Williams wrote:

> Too bad Carter doesn't make their Knock Eliminator box any more. It
> wasn't high tech, but it was cheap, and it'd save a lot more than the
> $75 it cost. How much was that new short block?

Anybody got schemati or the specs on the transducer? It'd be fun to
knock one off, just to play with. Now, _there's_ a use for the "Low
Fuel" LED on that damnable graphic display panel...

I believe your typical knock sensor is nothing fancier than a piezo
microphone, and the circuitry involved is little more than a narrowband
filter and detector. The location, frequency, and activation level have
to be carefully chosen, as some mechanical noises can be mistaken for
knock. That's about all I know. Anyone out there have more specific
info?

ObFords: Does or did Ford equip any Windsor-family motors with knock
sensors?
-- Chuck

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Mail From: (email redacted) (George Chang)


> On Jul 1, Dave Williams wrote:
>
> > Too bad Carter doesn't make their Knock Eliminator box any more. It
> > wasn't high tech, but it was cheap, and it'd save a lot more than the
> > $75 it cost. How much was that new short block?

Then Chuck asks:

>ObFords: Does or did Ford equip any Windsor-family motors with knock
>sensors?

And I (and maybe Chris and a half dozen others) answer:

Yes. I have a 351W in a police car, and it has a knock sensor
close to the distributer on the top front of the engine. I tap on it as
part of the computer test for my MCU system. (My Crown Victoria is an 84
with a 2VV carburetor).

Best regards,
George

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Mail From: (email redacted) (Clifton Koch)


> > Too bad Carter doesn't make their Knock Eliminator box any more. It
> > wasn't high tech, but it was cheap, and it'd save a lot more than the
> > $75 it cost. How much was that new short block?
>
> Anybody got schemati or the specs on the transducer? It'd be fun to
> knock one off, just to play with. Now, _there's_ a use for the "Low
> Fuel" LED on that damnable graphic display panel...
>
> I believe your typical knock sensor is nothing fancier than a piezo
> microphone, and the circuitry involved is little more than a narrowband
> filter and detector. The location, frequency, and activation level have
> to be carefully chosen, as some mechanical noises can be mistaken for
> knock. That's about all I know. Anyone out there have more specific
> info?

I'd be quite interested also if anyone does have any info (i.e., post it if
anyone does). Mallory makes a knock detector, but I think it's $150+ and has a
rather large ugly control head. I'd want something I could make look stock from
external appearances.

From what I understand, a knock sensor is a piezo microphone, but I don't know
anything about what sort of output waveforms are produced by one.

cliff

- -----------------------------------------------------------------------------
Cliff Koch
Motorola Cellular Infrastructure Division
(email redacted)

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Mail From: Christopher Hoover <(email redacted)>


>>>>> On Fri, 1 Jul 1994 10:03:27 -0700, (email redacted) (Chuck Fry) said:

Chuck> ObFords: Does or did Ford equip any Windsor-family motors with knock
Chuck> sensors?

Yup. My 1989 Crown Vic police cruiser has one. It has a 351W with
Ford's 7200VV Variable Venturi feedback carb and the old MCU computer.
The ``universal'' DuraSpark ignition box has a spark retard plug which
the computer controls.

You test the sensor by rapidly banging on the intake manifold near the
sensor with a 1/2" socket extension.

- -- Chris.

This read-only message was archived from a public mail list.
Mail From: Kevin Martinez <(email redacted)>


On Fri, 1 Jul 1994 (email redacted) wrote:

> On Jul 1, Dave Williams wrote:
>
> > Too bad Carter doesn't make their Knock Eliminator box any more. It
> > wasn't high tech, but it was cheap, and it'd save a lot more than the
> > $75 it cost. How much was that new short block?
>
> Anybody got schemati or the specs on the transducer? It'd be fun to
> knock one off, just to play with. Now, _there's_ a use for the "Low
> Fuel" LED on that damnable graphic display panel...
>

Ford has a nifty detonation sensor that screws into the intake manifold
of the 2300 Turbo motors that use EEC-IV. It is used for feedback in the
engine timing loop. It is probably easy to get at the Ford parts counter
and maybe there's some useful specs in the shop manual.

I vaguely remember the trouble shooting test involved a ball peen hammer
and a flat spot on the manifold... ;^)


Kevin Martinez
(email redacted)

This read-only message was archived from a public mail list.
Mail From: (email redacted) (Dave Williams)


-> > Too bad Carter doesn't make their Knock Eliminator box any more.
-> It > wasn't high tech, but it was cheap, and it'd save a lot more
-> than the > $75 it cost. How much was that new short block?

> Anybody got schemati or the specs on the transducer? It'd be fun to
> knock one off, just to play with. Now, _there's_ a use for the "Low
> Fuel" LED on that damnable graphic display panel...

The Carter box has a single-sided PC board in it with a few
off-the-shelf-looking discrete components. The sensor itself is a
Chrysler part. I have a box I got from John DeArmond. Jay and I put
one on Monzilla back in 1981, and it's still functioning properly in his
Chevy van now.

Anyone think they can copy the circuit board? Hell, Carter doesn't
make the thing any more...