Honda Power Unit Hardware & Software

[godlameroso]

Even if a cylinder is skipped, the turbo is still there helping the whole thing along, as is the MGU-K, maybe these things can work together to set up the extra bang that makes the whole thing worth it in the end. Now how to time the whole orchestra? You'd have to start thinking about wave tuning and intake ports, cam angle separation, lift duration, and valve angles and blow off valves, and compressors. Hurts my head just thinking about thinking about it.

That Honda made so much progress in 3 years is astounding, the results don't do their effort any justice. I feel like they're just a few reliability tweaks from them really showing people something special.

[restless]

history is written by winners...

[Brian Coat]

People are inferring a lot from very little in the last few pages (and why not?!).

Nonetheless, I am really entertained and impressed by the high level and quality of creativity! =D>

[ringo]

No mention on the parts of the crank outside the crank case?
Maybe the pulleys and other attachments are thinner. Or cams driven the back of the block nearer the turbo.

[roon]

For a shorter block? I believe the bread crumbs we've received so far are limited to:

-shorter crank (was longitudinally or diametrically meant by this? short could also refer to height, either as misdirection, clever wording or mistranslation)
-unique journals
-unique harmonics (was exhaust sound or vibrations meant by this?)
-some timing sequences

[ringo]

Could a very lean combustion create the nasty sounds that we are hearing from this engine?
Maybe as little as possible fuel is being injected to idle the engine, and the sound may be related to the prechamber?

[glenntws]

Could a very lean combustion create the nasty sounds that we are hearing from this engine?
Maybe as little as possible fuel is being injected to idle the engine, and the sound may be related to the prechamber?

The sound is a result from the weird ignition timing when the engine uses cylinder shutoff.

The pre-chamber is just a different way of igniting the fuel, but it adds a little bit to the "raspiness" of the sound because the ignition gets completed far quicker than in a normal engine.

Lean combustion doesn't make any sound difference at all in my opinion.

[glenntws]

For a shorter block? I believe the bread crumbs we've received so far are limited to:

-shorter crank (was longitudinally or diametrically meant by this? short could also refer to height, either as misdirection, clever wording or mistranslation)
-unique journals
-unique harmonics (was exhaust sound or vibrations meant by this?)
-some timing sequences

Shorter crank could only be related to width. Height can just be reduced with less weighting parts.

Unique journals reffers to the fact of the fork-style rods and maybe the concave shaped form.

Unique harmonics on exhaust and on firing order I am sure. This would also result in different harmonics in the engine.

Yeah the timing sequences are obviously very important for the new concept, but 1-4-3-6-2-5 and 1-2-3-4-5-6 seem to be the two options, which between Honda decided to use under high/full load operation.

[gruntguru]

. . . Also, 'sealing' the bearing is not necessarily helpful in high speed engines - you should actually be looking at encouraging flow out of the bearing in order to remove heat quicker - this is typically achieved by increasing the crush relief height and adding grooves in the side of the rod for crank guided rods.

I certainly wasn't advocating sealing the ends of the bearing (the rod-crankpin thrust interface) only the rod-rod interface.

On reflection there is probably little benefit since the peak hydrodynamic pressure in the two rod bearings will be out of phase, so the peak pressure can still leak across to the low pressure are in the other big end.

[gruntguru]

A problem of TJI spark plug nozzles when used with petrol is soot blocking them up.

Interesting. Your source?

http://papers.sae.org/2011-01-1870/

You can click preview to see the paper.

Ok, Seems my memory mislead me a bit. This paperis about passive prechamber sparkplugs NOT the Mahle style with the injector in the pre-chamber. Correct me if I am wrong here, but I can still see soot still being a problem on the Mahle style pre-chamber even if it is just a small depositt, as we assume a richer environment in there? Maybe these spark plug nozzles are changed each race (are they even allowed to be changed?).

The pre-chamber mixture is not that rich. Probably in the region of 0.9

[gruntguru]

Re - firing order.

There is only one firing order possible. (and the reverse if you want to be pedantic.) Essentially we have two 3 cylinder inline engines with one firing 90* after the other.

3 cylinder engine "A" has firing order 1A, 2A, 3A (yes pedants - it could be 1A, 3A, 2A. Either way the firing starts at an end cylinder, then the middle cylinder then the other end.)

3 cylinder engine "B" has firing order 1B, 2B, 3B

Combined V6 has firing order 1A, 1B, 2A, 2B, 3A, 3B.

Wazari's "firing orders" are actually "skip-firing orders". Skip firing is only used at partial loads. Injection (and perhaps ignition) to a cylinder is skipped to reduce engine output. This is to avoid operating any cylinder at significantly reduced load (which would reduce combustion efficiency). It also avoids or reduces throttling (which creates pumping losses). The skipping is done on a rotational basis to keep all combustion chambers at optimal temperature.

[wuzak]

There is only one firing order possible. (and the reverse if you want to be pedantic.) Essentially we have two 3 cylinder inline engines with one firing 90* after the other.

Surely you can rotate the crank the other way so that bank 2 fires 270° after the bank 1?

[gruntguru]

You numbered your banks incorrectly! (You say Tomayto, I say Tomarto)


No. You are right. Don't need to rotate the other way. Bank B can be either 90* or 450* behind depending on whether 1B goes "bang" or "suck" after bank "A" goes "bang".

[Tommy Cookers]

Re - firing order.
There is only one firing order possible. (and the reverse if you want to be pedantic.) Essentially we have two 3 cylinder inline engines with one firing 90* after the other.
3 cylinder engine "A" has firing order 1A, 2A, 3A (yes pedants - it could be 1A, 3A, 2A. Either way the firing starts at an end cylinder, then the middle cylinder then the other end.)
3 cylinder engine "B" has firing order 1B, 2B, 3B
Combined V6 has firing order 1A, 1B, 2A, 2B, 3A, 3B.

conventionally viewed, the above statement 'only one firing order is possible' is surely wrong ?

and this 'end-to-end' 1 2 3 bank order seems reminiscent of textbook examples of disadvantage to crankshaft design
as possibly/likely to increase the torsional vibration of the crankshaft and so reduce its life

anyway different firing orders must be possible
one 'obvious' order is 1 6 5 4 3 2 - (in the terminology as above - 1a 3b 3a 2b 2a 1b)
as used by Buick in many millions of (the first mass-produced 90 deg 3 simple crankpin) V6s
similar millions of engines by the PRV combine used 1 6 3 5 2 4
EDIT - NOTE TO SELF - but the 65 deg Fiat Dino was a 6 throw crank (as apparently were all race Dinos ever ie 1956 on)

NB it might appear that Nissan etc use a 1 2 3 4 5 6 firing order (and presumably these are not 3 simple crankpin engines)
official Nissan info attributes firing order enquiry as plug lead identification/positioning (as mechanics needs to know) - not firing order
and redundant spark ignition conceals the actual firing order with ambiguity (2 cyls simultaneously sparked, which 1 is firing ?)
anyone got the firing order for the F1 turbos of TAG Porsche, Honda, Renault etc ?

one reason for an actual 1 2 3 bank order might seem to be possibly better equalisation of charge induction from the plenum airbox
are there examples where some crankshaft design-disadvantageous but induction design-advantageous firing order has been used ?
the mandatory minimum crankshaft journal diameter might (by accident of course) have the effect of building in such a crankshaft design margin

[godlameroso]

There is only one firing order possible. (and the reverse if you want to be pedantic.) Essentially we have two 3 cylinder inline engines with one firing 90* after the other.

Surely you can rotate the crank the other way so that bank 2 fires 270° after the bank 1?

Engine must spin clockwise.