Slight Hold Back With New Head Fitted

[wardy18 33 1 Cars]

One point to consider though, my way of checking for Fuel mixture is the state of the Spark Plugs, you know what they should look like (black and sooty around the edge with a charcoal/brown electrode)

 

at the start of my event satde the plugs were cleaned so i could get a solid reading from them, they started off very lean with no soot at all so throughout the day the carbs were richened until the desired characteristics (above) were showing

 

is this not a suitable (old school) method for fuel mixture setting

[petert 586]

The next step then is to find out how i convert the multimeter readings to stoich readings??

 

It's near impossible to use a digital multimeter. Find an analogue meter, or make a 0-1V panel meter.

 

0.6V - 14.7:1

0.9V - approx 12.5:1

 

Get it in that range and it will be sweet.

[wardy18 33 1 Cars]

i think to be honest i only a week to get this system bought, delivered and fitted as my last main event is in Alderney and the boat loads Next Tuesday 15th!! a little too rushed i'd say as i also have a Hillclimb this satde 12th!!

 

i think its more suitable for me to save my pennies over the winter and get one of the Wideband kits from the USA (about £150ish deliverred) at least then a proper accurate system is fitted ready for next season

 

thanks for the advice and ideas though, im always very grateful for different ways for enhancements

 

ill stick to reading the sparkies as i go for the remainder of the seasoni think

[DrSarty 90 1 Cars]

And who remembers 'Colortune'?

 

I learnt a lot of my basic mechanical knowledge by reading 'Car Fix It' magazine, cover to cover in its weekly instalments from about the age of 15!!

 

Colortune was a spark plug with a clear glass view window to actually watch the burn colour such that you could adjust accordingly.

 

Showing my age here I guess.

 

And back on topic...

[Saveit 0]

It's near impossible to use a digital multimeter. Find an analogue meter, or make a 0-1V panel meter.

 

0.6V - 14.7:1

0.9V - approx 12.5:1

 

Get it in that range and it will be sweet.

 

Could you elaborate? Perhaps a link for some quick guide?

[welshpug 1,657]

And who remembers 'Colortune'?

 

 

Me! never used one myself though!

[TT205 42]

Me! never used one myself though!

 

Me too!

 

I might even still have one somewhere from my moped days centuries ago lol

[wardy18 33 1 Cars]

can i please confirm that 205 spark plugs are 10mm?!

 

Many Thanks

[DooBeDooBeDo 1]

And who remembers 'Colortune'?

 

I learnt a lot of my basic mechanical knowledge by reading 'Car Fix It' magazine, cover to cover in its weekly instalments from about the age of 15!!

 

Colortune was a spark plug with a clear glass view window to actually watch the burn colour such that you could adjust accordingly.

 

Showing my age here I guess.

 

And back on topic...

That takes me back - I used one to tune my first car, a MK1 Ford Escort, the car was the same age as me .

 

I wish the 205 had the same amount of space in the engine bay...

[wardy18 33 1 Cars]

ok im sure now that the plugs are 14mm, NGK plug number start with BC which means 14mm thread!!

 

I ordered the Gunson Colortune from Demon Tweeks this morning, only cost about 20quid

 

Should be with me by friday

 

I was thinking that there no point in getting one if im going to get the wideband kit over the winter but i again thought that because im on carbs and each individual chamber will have a different setting that this Colortune will be ideal because it means i can test each chamber individually for fuel mixture whereas the Wideband Lamdba kit will tell me how the engine as a whole is running mixture wise.

 

So colortune to set each mixture screw on the carbs individually and then the Wideband Lambda Gauge to maintain the cars mixture as whole through the rev range should be spot on!!

[DrSarty 90 1 Cars]

I like your (retro) style there Simon....

 

...although - and there is complete sense in what you're doing IMO - I don't think I recommended Colortune as such. Although it is reassuring that it's still produced and sold so it must be quite useful.

 

And in practise - providing you're not colourblind and can assess the flame colour against the chart - what better/more simpler way could there be of assessing the mixture and burn type in a single cylinder?

 

I think Saabs and other cars have part of their management (Saab calls it SDI*) using ionisation or some voodoo sh1te like that via the spark plug to assess burn and detonation and adjust accordingly. That's pretty funky. *Saab Direct Ignition

 

So good luck there Si. I like you're ingenuity. You should take some pics of you Colortuning. (Excuse the constant use of the US spelling .)

[DamirGTI 342]

Can read out a lot of things from plugs (high rmp. mixture , idle mixture , ignition timing deg. etc.) , but , that needs a little bit experience and good magnifier .. and , for reading out high rmp. mixture (as it's most important) you'll need to switch off the engine with the key during the driving at the full throttle .. and coast down to the near junction without starting the engine afterwards , then remove the plugs out and take a look (so without starting/running the engine at idle cos then they'll be coloured by the idle mixture and that's not of our interest here ..)

 

By the way what's the "Colortune" ?!

 

Damir

[DrSarty 90 1 Cars]

By the way what's the "Colortune" ?!

 

Google is your friend Damir. Colourtune by Gunson.

 

[DamirGTI 342]

I see , so it's for combustion chamber (piston crown) coloration examination that might be interesting i used to analyze piston crown coloration too with the small "pencil flashlight" trough the spark plug holes .. i managed to diagnose cracked liner once with this "flashlight approach"

 

Damir

 

EDIT : hang about , i just read out the whole pdf doc - it's for checking the mixture while the engine actually works anyone tried this tool before ?!

Edited September 9, 2009 by DamirGTI

[Saveit 0]

Ive bought one aswell. Going to do the same as wardy. Bought the 4 wire narrow band lambda and will use that with a multimeter, and then i have bought the Colortune to check each cylinder. That combo should get me close enough.... i hope

[wardy18 33 1 Cars]

I tell you what peeps im getting damn excited about the Hillclimb this weekend, i have perfect Ignition Timing for the first time on this engine, brand new better suited (bigger) carb jets to compliment the new flowed head and the new Colortune to set the mixture right on the mark!!

 

Oh and i only found out the other day that i am the FASTEST FRONT WHEEL DRIVE car/driver to compete in our Hillclimb, how good is that, my competition can stick his 440bhp Full Race M3 EVO, ill keep my 205 any day!!

[Saveit 0]

Thats great wardy BTW whats the distance of these hillclimbs?

 

Im currently wiring up the electrics for my xu10 converted car as i am going to race it this weekend. I have no idea whether the mixture is right as i havent received either the lambda or the colortune yet and i probably wont receive it in time.

Edited September 9, 2009 by Saveit

[wardy18 33 1 Cars]

I cant remember the exact distance, ill find out for you, i do it in 34.1 seconds

 

Cool, hope it all goes well mate, one good thing about running carbs with no management is the serious lack of wiring and mayhem under the bonnet, love it!!

 

Ill let you know how the colortune goes over the weekend

[wardy18 33 1 Cars]

Colortune is here, going to use tomorrow when i set the car up so will get some shots as i go

[DrSarty 90 1 Cars]

Read and understand the instructions well.

 

(What on earth have I done?)

[wardy18 33 1 Cars]

dang........it says multi cylinders engines with multiple carbs are best tested with a colourtune in each cylinder, THAT WOULD BE IDEAL but costing about £100 for 4 of these....ouch!!

 

Ill just need to do one by one and try my best to compare and duplicate the same colour flame in each...ideas, ie Camera shot so you can look back as you move on

[wardy18 33 1 Cars]

Seems pretty easy to be honest, to base set cylinder you need to richen mixture to show a yellow flame inside the cylinder and then back off (lean) the very point at which this flame turns to Bunsen Blue, this is then the ideal Idle setting!!

 

Part acceleration (raising rpm very slowly) will show a slightly blue flame due to a leaner mixture for improved economy.

 

From then on as Full or Rapid Throttle Acceleration the flame should be yellow meaning it is Rich to keep up with the extra air being sucked in so it burns efficiently

 

Will try tomorrow, cant wait!!

[Saveit 0]

Sounds easy. Looking forward to receiving mine.

[sutol 0]

Make sure you have some carb cleaner or something like to clean the glass after each use as it gets black sometimes and you cant see the flame in the cylinder.

Otherwise, should get it tuned to your requirements instead of what the ECU thinks is best

[jengis 0]

I used colortune to check fueling when I swapped to XU10 using the 1.6 jetronic setup. It was a useful 20 quid. It showed quite a bit of variation in the cylinders so I cleaned injectors and now its much more even. Meant I could set the part throttle mixture quite accurately, although it can't show high rpm full load conditions - best to look at plugs for that.