Why don't I like Honda K20's

[KingK_series]

Slight off topic: How do you go about getting a gearshaft made then? Isn't it rediculously expensive?

- like the gears, it means making a drawing, designing the teeth, getting that sent to gear cutter on DXF file and making it.........

yes expensive, but less so than buying off the shelf from Quaife,

[BiggestNizzy]

Turned forging, then you will need a couple of hobs made up.

[KingK_series]

That level of tuning/power to peoples existing engines would be a good comparison to the k20 engine conversions, price wise, reliability and driveability which is much more important than how and engine is built imo.

I agree - except that it is 'how ' an engine is built that 1/ makes it reliable, and 2/ gives it the drivability ie revvyness, torque, grunt.


the problem has been that so many of the tuners - this is S Scuffham's experience - and a few others on here I am sure...... have not understood K or tuned it so badly the engine broke. It is still happening, though my battles have brought some things,,, balancing, bushing LEs properly, peening heads into common practice, though some hate to admithat....

[KingK_series]

Honda updated and lightened the flywheel as part of the UK CTR facelift, so whats that 2004, mine certainly is not like that, has lots of machined holes in it although i dont have a picture of it.

Ok so here is the K20A2 crank, massively heavy and very undercounterweighted



here by comparison is a Stock Rover crank


most of the counterweight in a crank actually balances the weight of the pin, since the piston and rod are mostly inertia loads, and the crank only balances 50% of these forces or in an I4 engine 47% because fluid forces actually act against inertia. - look at the Honda even without doing a CFD analysis or single piston test [both verify what I am saying BTW] you can see the physical mass of the pin is considerable and the mass of the crank webs is small..............

.........compare to the Rover, the counterweight webs are much taller than the Honda plus the webs narrow either sides of the mains, where mass neither contributes counterweight or stiffness [clever optimised design the Rover, unlike the Honda] and yet we know the Rover is undercounterweighted, hence all the hot air propagated on Seloc. In fact all production I4 engines pretty much, are very undercounterweighted - this serves to make them lighter and more responsive. Vibration that results is dialed out by engine mounts, a certainty because no I4 engine can ever be refined like a straight6 or V12. Similarly flat plane V8s.

- Why post this? - because it serves to illustrate that undercounterweighted cranks ARE the norm, are no disadvantage really [unless you can produce an ideally counterweighted crank without making it heavy - and the answer to that is yes you can but it requires a lot of design and machining to make in steel] and that the HMI argument is a nonsense [it was originally done to assess what would be needed in a new design of steel crank that Steve Smith and I were trying to produce way back in 2002] plus there is always the risk of tungsten coming loose and destroying the engine [that has happened!]] but also despite the lack of counterweight the honda K20A2 crank is still mindbogglingly heavy, not least because it doesn't adopt the clever Rover design of waisting the webs either side of the mains]

[KingK_series]

So what was Honda's answer to this? The K20A2 was heavy unresponsive [very very slow to rev] and unrefined because it was both undercounterweighted, not well balanced and has massive secondaries because of the heavy pistons.

- they needed to make the engine, smoother, freer revving and without adding more weight which was counterproductive -

answer the K20Z1 -

Here is the Z1 crank,


- two missing webs!

- how can that be???
well Honda have taken some of the work done to counterweight inertia forces out of the crank and put it into balance shafts running in the sump, these also damp some of the nasty secondaries caused by the monstrous honda pistons. - Result a lighter more responsive crank and therefore engine, and a more refined engine because the balance shafts are acting against both inertia loads and secondaries. - the penalty? - a great lump of extra weight in the sump, plus extra friction in the balance shafts, see below -

[KingK_series]

here are the balance shafts





- which is one reason I don't like hondas...............I prefer Rovers with their light piston which is designed not to cause horrid secondaries albeit that OEs are good only for 7000rpm, and the very nicely designed well balanced crank that spins up so much faster than the honda and is capable of 9500rpm safely without modification.

[r10crw]

INteresting stuff Simon.
The Z1 crank just looks plain weird, Im not experienced in this stuff so its to the untrained eye.

[KingK_series]

INteresting stuff Simon.
The Z1 crank just looks plain weird, Im not experienced in this stuff so its to the untrained eye.

Yes it does look strange.......but it also illustrates that Honda were well aware of the issues with the K20A2 and significantly redesigned the engine in an attempt to improve matters.


The interesting thing is that those who advocate the honda route do not like the K20Z1 on the basis that the Z1 has a "poor rod" which snaps and makes lovely peep holes in the block......I don't believe that, I don't believe there was any cost down in the rod at all - and K20A2s throw rods as well. I suspect what is happening is the conversions that have used the Z1 have ditched the balance shafts in an effort to lose weight and friction, but have in the process exposed it's weakness - maybe????

[KingK_series]

Returning to the crank, the Honda K20 has oilways emerging at the pins at 90 deg to TDC, in addition they are crossdrilled, putting where it is not doing as much to protect the crank as it might - wasted in fact.



this means that no oil cushion is formed on top of the pin as the piston rises towards TDC and the charge is fired, which is good modern OE and ALL modern competition practice

below a pic of a stock K series with the oilway emerging about 23 deg BTDC - good modern practice, this will ensure less load and thus less fatigue wear to both pin and rod journal

[KingK_series]

Add to that the Honda K20 uses a very small oil pump, with relatively low capacity, add that to the costed down pin oil drillings and you have an engine rev limiting issue without modification of these parts. Needless to say the Neil Brown Honda K20 BTCC engine features revised oiling in their steel crank, a higher capacity oil pump, and BTW a proper water pump. That engine nonetheless was rev limited to 8500rpm in class.

compare below, high capacity OE K series oil pump, my all steel wire eroded pump, and the tiny Honda pump.

[Scuffers]

Another inferior, overweight Honda...



Really un-reliable too, this ones only done 3 full seasons racing in the enduro championship etc.

http://vimeo.com/33092326

[philthy]

Hp graph looks like it was drawn with a ruler impressive.

[KingK_series]

Another inferior, overweight Honda...



Really un-reliable too, this ones only done 3 full seasons racing in the enduro championship etc.

http://vimeo.com/33092326

I am really surprised you have not got a lot more out of a blown 2L

- when you get 600bhp, then I'll start taking your engine seriously............ apart from the weight bit that is..

In the mean time try reading this - one of your MSC SC Hondas bested by an unmapped K.

* Report this post
* Reply with quote

Re: K Series S/C kit

Postby hiscot » Mon Dec 12, 2011 8:19 am
Sadly way over priced but I expect it is quite labour intensive and the bits soon add up
I did come across this a very long time ago and it will be either the tt190 or tt 220 (as the tt260 was only in about 7 cars total either S1 ( based on the 190 ) or exige , + a 340r )

" Finally! I got to test drive a Honda powered Elise. I awoke to a
gloriously sunny Saturday morning, just perfect for a test drive of
Maidstone Sports Cars' (MSC) converted Elise S1. They have swapped
out the original K series engine, gearbox etc and replaced these with
a Honda V-Tec engine and 6 speed gearbox.

I drove there in my Turbo Technics (TT) converted Elise S2 with
supercharged K series engine and was really looking forward to
comparing these two rockets back to back. I had previously only had
a passenger ride in one – the very first Honda conversion that Ian
Wilson brought to Folembray in summer 2003. I had been impressed by
that car, and felt it offered very similar performance to mine. Both
conversions also cost about the same.

On seeing the MSC Honda conversion, I was immediately impressed by
the quality of the workmanship. To my mind, it look much better than
the Folembray car and could pass for factory fit – just like the TT –
except that the Honda engine is much more compact, albeit a little
heavier. I've had MSC work on my car previously and can certainly
vouch for their attitude to quality of workmanship. I should also
expect the Honda engine to be reliable.

I was driven out in the Honda Elise, and as soon as we turned out of
the long driveway, the MSC driver floored it. OH MY GOD!!! This car
just took off, wailing like a banshee, kicking me in the stomach at
each gear change. Was I impressed? You bet! Impressed and awed by
the sheer speed of this beast.

Suffice to say, I've no idea why, but the MSC Honda felt a lot faster
than the Folembray one.

We then swapped over so I could drive. The first thing I noticed was
the poor gear change though. It felt vague and woolly. The car was
supremely tractable however and the engine was very easy to use even
at low revs, pulling happily in top gear.

But that's not what I came to test, and as soon as I floored it, I
realised how awesomely fast this car is. It is quick, scary quick.
It reminded me of my old Caterham Superlight R (475kg and 190bhp with
a 6 speed box). Not as quick as the Superlight R, but not too far
from it and the power delivery felt remarkably similar. A car that
can't fail to both impress and terrify passengers!

In one sense, the car was depressing, as I felt pretty sure mine
could not keep up with it.

In a nutshell the Honda Elise is very impressive, and extremely
fast. And the sheer power of the thing makes up for the gearshift,
which I'm sure any owner would get used to quite quickly.

As an aside, I have also driven the factory standard S2 111R (and S2
Exige) with a Toyota engine and quite frankly the 111R would be left
eating the Honda's dust. They are like chalk and cheese. The 111R
is more Porsche Boxster in feel, and is refined and relatively
comfortable. The Honda Elise simply feels like a racer.

We got back to MSC and decided to try a head to head, just to see how
much faster the Honda would be. Admittedly it would not be a
controlled test from a standing start, but it should be fairly
conclusive if one car was clearly faster. I was now pretty confident
the Honda would beat mine, albeit not by too much, and so hoped for a
draw. MSC were so confident in the result that they decided to send
a passenger in the Honda, and also wanted to start in front so as not
to be held up.

The Honda Elise led in front with a rolling start at about 20 mph,
with 3-4 car lengths between us as I followed waiting for him to
floor it (I was in second gear). He hit the loud pedal! I followed
a second later as I saw the Honda open the gap to 4-5 car lengths.
My senses felt obliterated by the noise and fury of these cars, as it
felt like both cars had suddenly gone to Warp! What happened next
was wholly unexpected though.

The TT gained on the Honda, faster and faster as speed increased,
until I had to brake gently to avoid running into the back of the
Honda. Terminal speed was around 120mph.

I couldn't believe it, and it took a few minutes to sink in. The TT
was faster, and more so at higher speeds.

I offered a second run, but MSC conceded that the TT would be quicker.

The factors that make the test unscientific however, were the
following:

- S1 vs S2 (weight difference favouring Honda)
- Honda had a passenger (weight difference favouring TT)
- Honda had a head start (so the TT had to catch up)


In summary, as tested, the TT car caught the Honda fairly easily and
was quite noticeably quicker. The difference in acceleration was
sufficient that we believed a controlled test (S1 Honda vs S1 TT,
with equal start) would show the TT ahead.

So, how do I explain the difference in feel between driving the two
cars? After the head to head, it is clear that the Honda feels
faster than the TT. This is due to a number of factors, key amongst
which is the very linear and constant power delivery of the TT versus
the almost turbo-like kick in the stomach offered by the Honda. The
Honda seems to develop two power surges, one at around 6000rpm and
the second immediately before the rev limiter at around 8000rpm.
This makes occupants feel it is much faster accelerating. The two
cars simply deliver their power in different ways.

The other factors were that the Honda generated more noise inside the
cabin and also offered a harder "twitchier" ride than the S2, even
with Lotus Sports suspension fitted. As configured, the S1 felt more
responsive to steering input whilst also feeling more twitchy and
nervous on the road. The S2 felt more stable. However, the reader
shouldn't set much store by that finding as I am without a doubt
infinitely more used to the S2's feel and handling, as it's my own
car.

To summarise, both cars are incredibly fast, and whilst the TT is
quicker, the Honda feels quicker.

Would I recommend the MSC Honda conversion? Yes, and without
hesitation! A truly fantastic rocket powered car that will leave the
vast majority of cars eating its dust, and a huge grin transplanted
to your face!
bob

[tut]

This should liven up the afternoon..........

tut

[hiscot]

Simon I very much doubt the honda was boosted in my post re k series S/C kit
I do not understand why the rover k and the honda are always compared performance wise ,one is a 2 ltr with a six speed box and the other a 1.8 with five gears