dynamic timing ..??

[burnt_servo]

anyone know the dymanic timing , assuming a static timing of 1mm ( 1.6 turbo ) .

vince walden's how to page mentions 12 degree's before top dead center ... off the top of my head , that seems a bit to advanced to me  .

thanks guys

[jimfoo]

My not working well timing light hooked straight to my tiny tach transducer was seeming to show 11 degrees. You have to think, why should it be much different from a gas engine, especially with Diesel's slower flame front?
I'll have a better idea when I get my real timing light adapter.

[burnt_servo]

seems like the last few engines i've worked on  , the spec was several degree's after tdc ....

the one that easily comes to mind is the mitsubishi diesel in the d50 and ford ranger , it's spec'd at 5 degree's after tdc .


i'm just about to order some new nozel's and maybe up my pop presure a bit on the injectors , then thought i should find out what the dymanic timing should be ,  then measuing what mine actually is before taking anything  apart .

thanks man

[Vincent Waldon]

Yeah, dynamic timing info is a bit of a Holy Grail, but every once in a while I find a clue.

Brickyard's site in the UK has some spec sheets that include dynamic timing info.... for example:

http://www.brick-yard.co.uk/VehicleSpecific/T3/info/enginedata/dsl/KYdata.htm

The engines he lists are European models so not quite a 1:1 spec comparison, but the typical values are 12-16 degrees BTDC.

Sadly the AAZ page is broken   :cry:

[clbanman]

If you think about the combustion process in combination with the internal dynamics of the engine, you would never want the process to start after TDC.  If you wait until the piston has already passed TDC to fire your fuel mixture, the compressed mixture is already expanding, and your flame front is not instantaneous.  Ideally you want to initiate ignition at a point that creates maximum combustion pressure on the piston for as long as possible on the down stroke, and you can only do that by firing at some point prior to TDC.

[jtanguay]

since i have my flywheel off the motor, i was wondering if i could 'mark' the degree's on it for when using the timing light?  would be pretty awesome to get a 'real' reading on the actual injection time.  (not that it would be THAT off, but still)

i also want to mark the opposite end of the flywheel for measuring the other two injectors opening sequence.  getting a bit anal here, but opening pressures can be crucial  :wink:

[Vincent Waldon]

since i have my flywheel off the motor, i was wondering if i could 'mark' the degree's on it for when using the timing light?  would be pretty awesome to get a 'real' reading on the actual injection time.  (not that it would be THAT off, but still)

Great minds think alike... when I had my AAZ apart I punched a mark at 12 BTDC just in case.

My gasser timing light is not fancy enough to be adjustable, but that's the other option... use the TDC mark and dial the reading on the timing light.

[saurkraut]

How many teeth are on the flywheel?

[zukgod1]

Easier to get a timing light that's adjustable I would think.
At least if you don't have your trans off already anyway.

[Tintin]

With my timing light and piezo sensor I can only read the timing at idle and very low RPM, past 1800-2000rpm the piezo seems to be too sensitive to give the correct signal, much vibration interference and the timing light start to flash out of control.

On-boost at full throttle is another story than only 10BTDC, but hard to monitor.

[jimfoo]

WOHOO!!! 1 working timing light adapter arrived today. I know my timing was retarded more than it should be. Checked it, and it's right at TDC, so now I can play and find what works best, then post up the results.

[zukgod1]

WOHOO!!! 1 working timing light adapter arrived today. I know my timing was retarded more than it should be. Checked it, and it's right at TDC, so now I can play and find what works best, then post up the results.

So where did you get it jimfoo?

[jimfoo]

Ebay, of course.