Why don't I like Honda K20's

[KingK_series]

............... and this is why the honda does not deliver that quality to me...



the honda piston

437gmm.............. a ton

that means two things, it's one hell of a mass to hang on to..........for rod and crank

it makes for very high secondaries - Secondary forces off vibration are particularly insistent [nasty] because they happen at twice the frequency of engine speed - in laymans terms this engine is not refined at all.

[KingK_series]

By comparison a k series piston



297gmm, that means the issue with secondaries is not an issue, the engine runs smooth, plus the rod crank are not nearly so stressed hanging onto it, and the crank therefore needs much less counterweight, which means a lighter engine and a more responsive - freer revving engine

[KingK_series]

The problem with the Rover piston is this ;-



because it is so light and a casting, like the honda but without the thickness between the lands, at engine speeds above the 6900rpm design limit, the second land breaks

- not surprisingly.

[woody]

Perhaps Honda have to look at a whole different set of requirements for a production engine Vs a hand full of hand built engines? Or indeed a Rover K. Perhaps if Austin Rover had persued a more conservative design they'd have had a more reliable, cheaper to produce, product.

[KingK_series]

Perhaps Honda have to look at a whole different set of requirements for a production engine Vs a hand full of hand built engines? Or indeed a Rover K. Perhaps if Austin Rover had persued a more conservative design they'd have had a more reliable, cheaper to produce, product.

Well I don't like conservative, cheap engines either, on the other hand I love engineering, I love engineering that works, and the lightweight K is manner from heaven, whereas the K20 is crude in many ways, rough, heavy and built in tiny numbers. The K series build was 6 million.

[KingK_series]

So here was my solution



this the two ring 1.8L piston - for dry sumped engines that weighs even less than the OE K series, that means less vibration, less stress, and with it's own rod [longer for again less secondaries and less skirt loading/friction] and a very carefully ideally counterweighted crank - ie all parts designed to work TOGEATHER which has never been previously done in the aftermarket, I get a crank that is 2kg lighter, fully conterweighted for the first time, faster freer revving, and much less stress in the engine, much less friction, much less vibration

..... and vibration and friction = lost horsepower and heat.

[KingK_series]

And now to the rod



left honda K20A2 rod, middle K series 1.4L rod, right K series 1.8L rod

note how the honda rod is narrower than a 1.4L K series rod, and Rover saw the need to beef that up for the 1.8L!

the honda also uses the anachronistic 20mm pin, not seen in modern production or competition engines for 40 years!

- so what happens, honda rods beak under the pin, this piston and broken roda out of a Honda'd Elise competing in Lot, it made a mess, caused a big fire, and it is NOT uncommon, I have 5 honda blocks that have thrown rods all out of Elises.

[KingK_series]

In addition.......



A K20A2 piston next to a K series OE - look at how little metal there is under the gudgeon pin on the honda, that has to hold onto the piston at the top of the stroke - has to take all the inertial loads of a crude heavy heavy piston, and guess what, - it breaks.....

Got one here that did just that, again out of an Elise, broke the valves, trashed the head, broke the rod, holed the block, set the car on fire......

can't find that piston to photo at the moment, but it is here so picccies coming..

[KingK_series]

And here is where it all begins........

the monster of the honda crank

undercounterweighted, 365gmm at rear, 185gmm at nose out of balance, not doweled and 17.2kg



and here is the OE K series

- undercounterweighted, 80gmm at rear, 20gmm at nose out of balance, doweled, 12.6kg

[KingK_series]

..... more to follow....

[BiggestNizzy]

Excuse my ignorance, what do you mean by doweled ?

[tut]

I think the dowels lock the crankshaft to the flywheel.

tut

[Ferg]

Out of interest, do these features become more evident on later K series engines? I ask as if the Kseries run was that big in number, there may have been development over time. Something that's less likely on a small run of engines.

I have to say, having only experience of Cosworth engines in pieces, the K closer resembles some of the design cues than the Honda. The ones you've pointed out anyway.

[KingK_series]

I think the dowels lock the crankshaft to the flywheel.

tut

Exactly.

which is why it is such hard work to balance a stock honda crankset............you'd have to make machine up for and fit a blind dowel. -

crank dowels are always hollow, because they musn't add mass to the crank, even that small amount is enough to completely throw the dynamic balance...

[KingK_series]

Out of interest, do these features become more evident on later K series engines? I ask as if the Kseries run was that big in number, there may have been development over time. Something that's less likely on a small run of engines.

I have to say, having only experience of Cosworth engines in pieces, the K closer resembles some of the design cues than the Honda. The ones you've pointed out anyway.

- no they were always there, K suffered cost downs in early life, like the wretched plastic head dowels, but there was a huge amount of work that went into the euro4 engine.....new head new water pump, new longbolts, new production machining .....400 were made before the collapse.

honda production run was very small, but the development of the K20A2 was the Z1 a much better engine in my books, with it's balance shafts - the honda guys don't like it, I keep hearing they think it was costed down and breaks - personally I don't think that's true, anyway A2 and Z1 production is finished now


the K series took it's cue from the Coventry Climax F1 engines, .... like all current F1 engines and the better modern production engines