DIY_EFI Digest V5 #105

[Bernd Felsche]

Ken Thompson writes:
>Kevin Jaeger  kjaeger at superflow.com.au

Who?

>So long as my bum (arse) points to the ground, K-Jets will always be a dog.
>Must have made MB a huge packet of $$ in spares in places like South Africa.
>I refer to areas of SA, that might be visited by the Leyland Brothers.
>"Leyland Bros Do SA", might be a good title. They had better have their RAC
>cards with them, if running a K-Jet fitted vehicle. A friend used to run the
>service department for a large Mercedes dealership in South Africa. How
>would you like to do the service call for one of your best clients, who asks
>you to come and fix a dead MB? The twist was that

Wow, so my driving a car with K-Jet for about a quarter of a million
km without any problems (other than a worn fuel pump), and the
similar experience of the many others I know with K-Jet prowered
cars counts for nothing.  K-Jet must be a monumentally-unsuccessful
system to have been chosen by such a large number of car makers with
at least 20 million installed units over a period of around 10 years.

I think you've inferred too much from my reply. 
This is all I've said:
	>> K-Jet is beautifully-simple. It's the electronic addons and

i.e. I was expressing an opinion as to the design elegance.

I don't doubt that K-Jetronic systems can fail. MB is probably the
only manufacturer who bolts the thing on the side of the engine and
runs the meter in down-draught. Audi, VW, Porsche, BMW, SAAB and
Volvo use it with up-draught metering, according to the original
Bosch design. That is not to say that that particular difference
leads to unreliability.

>I do not need Probst's book to understand the operation of the K-Jet fuel
>system. I am sorry you misunderstood my comment in relation to ECUs and
>water. I was not referring to an ECU that may or may not be fitted to a
>K-Jet
>to operate it's accessories. I have had many of these things in pieces and
>have built many pieces of test equipment to monitor / test the operation of
>K-Jet components and K-Jet systems. We used to have a mock up test bed where
>we could set up the air / fuel regulator, injectors and fuel pump etc. The
>test fluid was white spirit. Clair would know well why white spirit was used
>in place of petrol. Every function of operation could be tested. The worst
>enemy of K-Jet is bad fuel and water and you want to advise Clair to install
>such a system to her boat?

No. I wasn't advising Claire, nor anybody to install K-Jet.

>Bernd, you have acquainted the LUCAS fuel system to the Prince of Darkness.

Ken, cut down on the coffee.

You don't need to pretend why I made that comment. Nor should you
pretend to ignore the SMILEY.

>> LUCAS - "the prince of darkness" :-)

I have no idea why my comments make you feel that your comments were
worth any more or less.

I was contributing my (albeit limited) experience on the subject
matter - LUCAS *automotive electrics* included.

>Ray Hall's engines have either won or been runner up in the World
>Championships in his class of boat, for as long as I can remember. They won
>and were runners ups at the last World Championships. Ray Hall is a DOER not
>a talker. Are you a reader (of Probst) and just a talker or are you a doer?

What precisely is wrong with reading? What is wrong with talking and
discussing?  Do I not "qualify" to be a member of this mailing list
if I haven't been hard-chroming bits of fuel distributors, running
huge dynamometers, etc, etc on a "professional" basis for 20+ years?

The purpose of the mailing list as I see it is to share ideas.
It is to learn from what others have to say, and occasionally
contributing with what you have to see - be it wrong or otherwise.
We are all wrong at one time or another; it's best to find that out
as soon as possible.

Chill out; Kevin.

You might think I don't know what I'm talking about because you
don't agree with what I say. That doesn't become my problem until
you go over the top in a forum such as this.

>I want to hear what YOU have done, not what Probst has done. Click here
>Bernd www.turbofast.com.au/img/eng1.jpg and check out one of Ray's 1,500 HP

That's just a picture. Could be a digital rendering as far as I'm
concerned. Tells me nothing. Other than that you have the alternator
way down on the thing so it won't last if there's much water about
==> LUCAS - Prince of darkness all over again. :-)

As for what I've done; I would rather not start. You want to be a
clever chap; go and find out. A small proportion has been published.
Most is entirely irrelevant to this list because EFI is my hobby.

>I have gotten our gear into almost every serious race engine shop in
>Australia, including Holden Racing Team and General Motors Holdens. We are
>already measuring the type of physical phenomena that you are TALKING about
>measuring. We have already made the measurements and comparisons that you
>read about.

So? You do that for a living. You are obliged to be on the bleeding edge.

There are other phenomena which I will not discuss here, which you
most likely won't be measuring.

If you want me to discuss them, email me privately and I'll arrange
for NDA, etc, as well as my standard consulting fees.

>I would have thought a Corvair engine, a LUCAS fuel distributor and a ripper
>set of Triumph throttle bodies would have been a pretty good place to start
>with Clair's conversion ?

Did I deny that?

>Please provide us all with the logic you used to make your assumption
>(scientific evaluation), which places LUCAS on the Dark Side?

It really looks like you haven't been in the industry for 20 years.
What does "the Dark Side" have to do with it?

>I am busting to hear your reasoning on that one.

>The people at Kinsler made a statement, it is in their bible.

I have no idea who those people are.

>One thing I ought to add in relation to air flow through K-Jets air valve
>and air box. Reminds me of the air box and air cleaner on my 20 year old
>Briggs and Stratton lawn mower engine. Both have the most diabolically bad
>air flow dynamics, known to man. Is bad air flow good, when applied to
>performance related engine development?

What air valve? Are you referring to the metering plate?  Are you
comparing a production engine with a run-of-the-mill road car
engine?  Where are the other designs for a _purely-mechanical_ fuel
injection system?

>I'll slip this one in as there has been a lot on turbos, measuring turbine
>speeds as one of the physical pheno for the ECU to crunch. Hmm? I hear talk
>of tuned runner lengths (which is great, all about better cylinder fill and
>wave motion). What differential pressure (induction wave) is about the best
>we can achieve in a highly tuned normally aspirated racing engine, sitting
>on its maximum torque RPM? So now then, lets start induction boosting. At
>what boost pressure does this wave action become less significant /
>insignificant when running the same engine?

You talk too fast. What's your point?

The air moving into the cylinder has inertia. That inertia depends
on the flow velocity and the mass of the air.

When you close the valve, you get a pressure "pulse" travelling away
from the valve. The peak of the pulse depends on the inertia of the
gas and the rate at which the valve closes. If you time the
reflection of that wave, or that of another so that the valve is
just opening as the pressure peak arrives, then you'll get optimal
filling. 

The over-pressure that's been recorded in practical engines is about 
40kPa, achievable over a fairly narrow range for a short time, but
it results in better cylinder filling and flushing of exhaust gases.
Volumetric efficiencies in excess of 100% are possible provided by
the dynamic supercharge.

The boost pressure you apply over the top of that will not nullify
or cancel the dynamic supercharge. It will add (and amplify).

You can work out for yourself when the 40kPa becomes "insignificant"
noting that the inertia of the moving gas increases with increased
boost. I could sit down and work it out; but that's too much like
hard work.

That's my educated guess. I could be wrong, and as I haven't seen
the colour of your money, you shouldn't take it as professional
advice. EFI is not my business. It's my hobby.

>Regards,
>Kevin.

Or is it Ken Thompson?  I'm confused.

>> Date: Thu, 16 Mar 100 16:09:02 +0800 (WST)
>> From: Bernd Felsche <bernie at perth.dialix.com.au>
>> Subject: Re: DIY_EFI Digest V5 #104 / CFI
>>
>> >From: Kevin Jaeger   kjaeger at superflow.com.au
>>
>> >I was with you Re your comments on "stoic", but K-Jet is a diabolically
>ugly
>> >mouse trap. It does not like the slightest contamination when in a
>Mercedes
>> >Benz car and therefore would hate your boat. Tuning will not be very
>easy.

>> K-Jet is beautifully-simple. It's the electronic addons and
>> cold-start junk that's the bug-bear.

>> >I guess one can get away with a lot on land (in a car), where the ecu
>lives
>>
>> K-Jet has no ECU until you go for KE-Jet.
>>
>> The purely mechanical K-Jet isn't all that difficult to set up if
>> you have the equipment and know-how. Probst's book describes the
>> system well.

>> >in the kick panel, away from corrosion. The same exposed GM ecu in a boat
>> >would not live long at all. A friend who I have heard mentioned here on a
>> >number of occasions, builds 1,500 HP boats, I refer to Ray Hall
>> >www.turbofast.com.au Now in this situation, money is no object so the ecu
>> >does not get wet and it stays cool and if the boat crashes and sinks,
>they
>> >build another one.

>> The reservation I have about K-Jet on a boat is the zinc castings.

>> >I think there is still a place for carbies in this world and you
>situation
>> >is a likely candidate.

>> Nothing wrong with a good TDI on the water. :-)

>> >In Australia the wreckers do no want Triumphs fitted with LUCAS systems,
>> >you'd have to pay the wrecker to take the car. Rigging up a LUCAS system
>> >would be much easier than K-Jet and is certainly much more compact. I

>> LUCAS - "the prince of darkness" :-)

>> >wouldn't know a Corvair if I fell over one, but I think that the Triumph
>> >butterfly sets would be easy to adapt, than Bosch's "fuel / air" valve
>> >system.

-- 
Real Name: Bernd Felsche
    Email: nospam.bernie at perth.DIALix.com.au
     http://www.perth.dialix.com.au/~bernie - Private HP
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