How do you tune an ECU without knock control

[Bernd Felsche]

Bruce tapped away at the keyboard with:
> > I don't really feel like pulling down a perfectly-good engine to
> > check rod bearing wear.
> So your basing you statment on assumptions, OK.

> > Oil breakdown is more of a problem because of consistently-high
> > temperatures (between 95 C and 135 C). That's one reason to use
> > synthetic which lasts the usual change interval (15,000km).

> And what drives those temps high?.

No oil cooler. High coolant temperature (around 95C operating).

> synthetic has as many down sides as up.  It's greater cold *flow*
> allows more to weep off the bearing surfaces, so at cold start up
> when most wear occurs, the bearings are *more* dry.   No thanks,
> again, I tend to ignore theory and advertising hype.

The bearings are usually hot when I turn off the engine. :-)

The lube system in my car is high-flow, low pressure; if that makes
a difference.

> > Just because it works without noticeable knock, doesn't mean it
> > won't work better with light-knock. (Doesn't automatically mean
> > it'll survive knock, but that's another issue.)

> Geesh, how many ways can you reslice what you state?.

Sometimes things have to be said again. They have to be repeated if
they don't appear to be getting through. It's usually a good idea to
say important things at least three times. :-)

> You said 240K Km, and no noticeable downsides, and have done ZERO
> to document that statement.   Pull the pan and report back.  I
> made actual observations, and did the tear downs, and you still
> want to compare notes, on your assumptions.

These are not my assumptions. This is based on the research of
others like Bosch, Ford, VW, SAAB, Audi, etc. on real engines, using
test equipment you haven't even dreamed of.

I don't have to experience everything at first hand to believe it.
Pulling the pan on my car would prove nothing; there's no comparable
base-line -- i.e. a similar engine that has run with no knock at all
for the same hours and the same duty.

I can say that there was no visible damage to the piston tops or
head due to knock when the head gasket had to be replaced (after
changing "up" to 2nd gear from 3rd @ redline) at about 130,000 km.
Just a fairly-uniform, thin carbon buildup over the entire top
surface of the pistons. This surprised my mechanic as well, as he's
often remarked about the audible pinging.

I've never heard of any Digifant engines suffering excessive bearing
wear due to knock. There are several million similar engines around;
chances are; I would have heard. The short story is; it works.

> And if your engine is at the level of tune of a Briggs and
> Stratton that mutes your case in total other then as just blindly
> quoting some SAE paper.

Briggs & Stratton? Hardly.

It's not in race-tune by any stretch.

-- 
Bernd Felsche - Innovative Reckoning, Perth, Western Australia
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