How much can be milled off the Cylinder head?

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

Only short update:
CH was mounted in the weekend and with original cam timing the valves seems to go free.
Well, original but some 2-3 degress too late due to the too long cam chain now.
The total height of the cylinderhead is now 126,6 mm, which is 2.5 mm off compared to std.
After advice from my machine shop, I also checked how spark plugs are in relation to the piston and in fact the exhaust side plug is about 2.6 mm under gasket surface. (inlet plug is still fully over the gasket surface)
Fortunately, the lowest part of the side electrode is a bit inside the piston bowl, so it goes free still.

Dieselstarter fitted without problem and turns the engine fine so that I got full oilpressure after a while and hope that all valve lash adjusters are filled correctly now. :-)
I will take off the valve cover again though to check if its the case to be sure of no valve clashes once more.
Next weekend will be the exciting start up, if no unexpected happenings like snow-storm or such occurs.

Update: Unforunately I found a small crack in the exhaust manifold, so things are delayed a bit until I get it too sorted..:
http://www.smartmaniacs.co.uk/showth...anifold-or-not

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

OK, all worked fine for 20 minutes! Engine started fine, seems a bit more vibration as should from the higher compression ratio, but also stronger and more agile.
I was standing and waiting for the last boubles to come out in the expansion tank, with the front up on a pile of gravel on my yard, when the engine suddenly just stopped.
Impossible to re-start. Not until it had cooled down again, all was OK and it started.
Here are the stories about that..:
http://www.smartmaniacs.co.uk/showth...seems-dead-%28
and
http://www.smartmaniacs.co.uk/showthread.php?68752-Engine-dies-when-becomes-warm-%28-dont-want-more-training-by-walking-home-now/page3

Now, when the faulty cps-sensor is replaced 2 weeks later.., I had the first opportunity to make a longer testdrive, and also push the engine a bit more, in order to see what the change of CR gave.
Even if there might be a small effect of a new silicon TIK from Forge, I must say that the car never had been this powerful to me.
It really feels different, pulls strongly in all the register, and definately stronger on low revs before the turbo have started to kick in.
Following the problem with the cps-senosr, I thought first that there was some problem with the fuel supply, so I put in 5l of pure E85 in an almost empty tank.

This I had forgotten today, and when I first started it up, I didit even think of that it should be quite difficult to get started cold on 100% E85, even when its about 18 deg C outside.
Now, it was not more than 10 degC (Swedish summer is making a walk back to winter...), and the difference in this case is normally hughe.
Normally the engine would be extremely difficult to start now, since I still didnt fix any extra coldstart enrichment (can be easily done by connecting a different resistance in series with the coolant temperature sensor, in order to lure the ECU that its much colder than it is).
But now, it was starting directly almost, and the reason must be the higher CR, giving enough extra heating up of the coold spirit during compression phase, making it able to be ignited during crank.

While reving, there was some blue smoke first, but it seems to have disapeared now, probably it came from the oiled-in new exhaust manifold.

So, no major problem in fact, runs like a charm!

[madDan]

Re: How much can be milled off the Cylinder head?

What did to do with the timing being out by 2-3º ?

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

What did to do with the timing being out by 2-3º ?

Nothing!
Seems quite OK!

[tolsen]

Re: How much can be milled off the Cylinder head?

Do like on some Renault engines and fit crank shaft sprocket without any key. Very risky but seems to work most times for Renault. Perhaps the easier way is to elongate bolt holes for cam shaft sprocket so you can get timing spot on.

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

Need to elongate the pressed recess then in the cam sprocket. I really dont think its neccessary for 2-3 degress later timing.
Earlly intake opening gives better bottom torque, but I have definately no issue with the bottom end torque now. Stronger than ever.

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

Update:
After 2 weeks of use I cant complain at all!
Car runs perfect, once its warmed up (I will make a cold start resistance, to lure the ECU that its colder than it is, the first 30 seconds or so), but thats about it.
I have a very promising fuel consumption too,
The first tank, I ran often about 120 km/h or more, and then the consumption was 6.8 l/10km.
When I calmed down a bit to get comparable figures from before I now got it down to 6.1 l/10km.
This is mainly motorway/highway driving, with a normal speed of 110 km/h.
I find a very good figure, 6,1l/10 km is eqvivalent to only 4,35l std gasoline (with 5% ethanol)/ 10km if you look here:
http://etanol.nu/forbrukning.php
(And in town, I guess the consumption is even lower, motorway driving is not the best dicipline of the high Smart 42...)

From my notes before the increase of compression ratio, the same driving used at least 7.2l E85/10 km, so it seems that I gained some 15 % in fuel consumption!
And this in combination with much better low end torque, and over-all power.

[Thrumbleux]

Re: How much can be milled off the Cylinder head?

From my notes before the increase of compression ratio, the same driving used at least 7.2l E85/10 km, so it seems that [B]I gained some 15 % in fuel consumption!
.

Just to clarify here ES. The 15% improvement in fuel economy was from the increase in CR (from 9.0:1 to 13.0:1) and nothing else? No lean burn as yet, just from the increase in CR?

Good result BTW.

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

Thanks Thrumbleux!

Correct, no lean burn or optimization of the ignition timing yet!
I will though continue a while and measure several tanks in order to give an more exact figure.

I know that there is another 15% or so to gain with a N/A engine if the ignition is tuned too, and with a stressed turbo like the Smart, I have seen logs showing that on full power, there is extra fuel injected already from about 3000 rpm...
All such extra cooling fuel, or at least the most of it, can and will be erased since the cooling effect of alcohol is so much greater than from gasoline.
So during more inspired driving, the gain in our case can be maybe 50%, compared to std CR and gasoline in the tank.

[Thrumbleux]

Re: How much can be milled off the Cylinder head?

I know that there is another 15% or so to gain with a N/A engine if the ignition is tuned too, and with a stressed turbo like the Smart, I have seen logs showing that on full power, there is extra fuel injected already from about 3000 rpm...

I've noticed you mention this aspect before and I'm curious as to when the enrichment begins and to what extent. Presumably as the boost rises - is the extra (over) fuelling linear with boost? Only above 3000rpm? Is there an rpm related pattern? How rich does it get?!

Are you on your car ES monitoring Lambda and/or boost? By which method - X-Gauge (or similar via the OBD port?

TIA.

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

I've noticed you mention this aspect before and I'm curious as to when the enrichment begins and to what extent. Presumably as the boost rises - is the extra (over) fuelling linear with boost? Only above 3000rpm? Is there an rpm related pattern? How rich does it get?!

Are you on your car ES monitoring Lambda and/or boost? By which method - X-Gauge (or similar via the OBD port?

TIA.

I dont log anything currently in my Smart, I have no broad band lambda yet, and issues that makes my MB-Star non-working with my computer (the com-port problem..).
I intended to install a piggyback from Civinco, but have found it incapable of advancing the ignition, only retarding is possble for more than 2 ignition channels.
A Smart have three channels, as well as my AMGC36, so im evaluation other options for now.
But about the enrichment, I got some interesting info in an example that Civinco made:
http://www.civinco.com/pdf/Ett%20ins..._Smart_005.pdf
On page 5 there are some logs, I know all is in Swedish but just use Google translate, and Im sure that U will get it:

3. Man ser också att motorn verkar lambdareglera upp till ca 2900 rpm för att sedan ligga med fetare
blandning. (Detta ser man på att Lambdasignalen slår mellan högsta och lägsta värdet när den ligger på
rätt lambda. Konstant hög nivå tyder på fetare blandning.)

Means:
You can also see that the engine seems to run cloosed loop up to about 2900 rpm, after it will start to enrich. (You can see this on the lambda signal, which is pending between highest and lowest value (around 0.45V my note). Constant high level, around 0.9V means rich mixture)

The log is on 3d gear on WOT, so what is on lower throttle angles we dont know so much about.
Would be very easy to find out though, only measure the voltage from the lambda sensor, as long as it is pending around 0.45V, its stoichiometric, when it becomes constantly higher, the clooses loop is left for cooling down the engine, and to start wasting fuel...

[Thrumbleux]

Re: How much can be milled off the Cylinder head?

Thanks ES. I'll take a proper look at the 'link' and comment on it later.

A question for you. With hard link throttle connection (mechanical cable) throttle plate angle is synonomous with pedal travel. But a fly-by-wire system isn't compelled likewise. Given that at say, half the rpm of the rpm of maximum torque only needs the throttle plate to be 50% open - even if the pedal is floored - do you suppose or know if the ECU only opens the throttle progressively with increasing rpm concordant with the requested pedal input?! It would alter air speed at a specific point in the induction system and could similarly affect any pulses - beneficial or not, if it behaved differently to a hard link system. One of the benefits of fly-by-wire?

I'm looking into getting the Torque app. Would answer a lot of my questions I think...

[ethanol-smart]

Re: How much can be milled off the Cylinder head?

Thanks ES. I'll take a proper look at the 'link' and comment on it later.

A question for you. With hard link throttle connection (mechanical cable) throttle plate angle is synonomous with pedal travel. But a fly-by-wire system isn't compelled likewise. Given that at say, half the rpm of the rpm of maximum torque only needs the throttle plate to be 50% open - even if the pedal is floored - do you suppose or know if the ECU only opens the throttle progressively with increasing rpm concordant with the requested pedal input?! It would alter air speed at a specific point in the induction system and could similarly affect any pulses - beneficial or not, if it behaved differently to a hard link system. One of the benefits of fly-by-wire?

I'm looking into getting the Torque app. Would answer a lot of my questions I think...

I think I can read in the end of the example:
http://www.civinco.com/pdf/Ett%20ins..._Smart_005.pdf
, that the throttle in original is normally a constant of the gas pedal position. (Not also in relation to rpm or speed)
See log on page 11.
On page 9, Steg5, point 4:

4. Vi skapar nu en kurva i PWM_Load som varierar beroende på gaspedalsläget.
a. Tex kan man låta värdena vara 75% upp till 65% gas och sedan öka linjärt upp till maxgas.
Detta gör att motorn blir bränslesnål (slö) upp till 65% gas och sedan finns fortfarande all
effekt vid maxgas.

I think this shows that the throttle is not following the rpm, it would be disastrous for fuel economy if it was partly closed when it didnt have to.

In Smart, a closing throttle with a floored gaspedal, is only possible in gear shifting, limphome or Thrust(+) or ESP operation.
Anyone have another info?

[Thrumbleux]

Re: How much can be milled off the Cylinder head?

I've skim read the Civinco piece (a struggle as not all words translate) and so far I've seen, as you say, the ECU go to closed loop at 2900rpm and the Lambda read 0.8-0.9V. If 0.45V is stoich', what AFR is 0.8-0.9V? Just how rich (fat) does it go?

Re fly-by-wire: page#9 dealing with methods of boost control has this:

''Step 5
Another step is to connect into the accelerator and let the boost pressure can be controlled by how hard you step on
gas. The prerequisite for this is that the e-gas, that an electrical signal from the accelerator, which in no way
proportional to throttle position.''

Which I interpret as: stamping the gas pedal to the floor (at lower rpm) does not immediately open the throttle plate to wide open.
Thus the gas pedal position is a driver command indicating the torque output he/she requires and the ECU opens the throttle plate with that command in mind and according to how much air the engine can actually inhale at its instantaneous rpm. (The directness of the gas pedal command being the raw signal to up boost level). Make sense?

Beyond that I need to re-read. PWM and PID confusion and a translation into 'damper' and 'gate'. Is 'gate' wastegate, throttle plate, other? Damper? Plenum?

Looking at the (first) log on page#5, the first 5 or so seconds shows fluctuating MAP and fueling- why? The fueling looks to be responding to the MAP - correct? The Lambda to the fueling, or the increased air with increased MAP? And the first 12 or so seconds shows wildly fluctuating Lambda despite the fueling and MAP between 5.3 and 10.5 seconds being stable, even though increasing rapidly. Why all the oscillations?
Last question - TOT fuel. What is TOT?

An interesting piece ES - thanks.

[Kapt. Q]

Re: How much can be milled off the Cylinder head?

What an amazing thread. What you have accomplished is fascinating.
I am interested in water/methanol injection for the Smart and we sort of cross paths there.
I will aim to replace the 'cooling fuel' with the W/M mix.
I assume you will not be able to dial all the 'cooling fuel' out without knocking, and therefore will still have to run a little rich under load for combustion chamber cooling?
Is the ignition system at all stretched by the modifications? Do you run regular sparkplugs or colder ones?
Cheers!