Will this Renault PRV flywheel work (on an oddfire)?

[dieselnutjob]

I bought this flywheel (actually a flexplate) from a Renault Espace 2.7 V6. I am hoping that it will fit my older Peugeot 604 PRV.



Can MS2 Extra work with this tooth / missing tooth layout?

It appears to have three identical sections, each of 120 degrees.
Within each section you have 19 normal holes, a 1 1/2 gap and a 1 1/2 solid.
So basically it is 66 tooth with some wierdness every 120 degrees.
How would the ECU know which 120 degree section it's in?
Does it matter?
If necessary I could modify it. Should I make it into a 66-2 or something and would that work.

My 604 is an oddfire PRV V6. This means the firing pattern is 90-150-90-150-90-150 rather than the normal 120 degree firing.

thanks, Philip

[dieselnutjob]

I just compared this flexplate with an original 604 one



I won't be able to simply bolt this on.
It seems to have a different spacing between the Renault torque converter and the Peugeot one, and also the three holes that the bolts go through to attach the torque converter are a different distance from the centre.
Also the centre hole is bigger, though the holes for the screws to attach to the crank are in the same place.

The good news is that the starter ring is dimensionally the same.

I think that the easiest thing to do will probably be to cut the sensor ring off of the Renault flywheel and spot weld it to the starter ring of the Peugeot one. I guess that if this is done one weld at a time, letting it cool between each weld, then it is unlikely to distort. The starter ring is quite thick metal.

Anyway it doesn't change my original question...

[Matt Cramer]

This should work. If you need cylinder identification, you will need to add a cam sensor. I believe it will work OK for a distributor on its own.

[rickb794]

That toothed wheel appears to be a Renix 66-2-2-2 and is supported.

[dieselnutjob]

Does the fact that it is an oddfire (90-150-90-150-90-150) make a difference?
Also it has two coils and effectively two distributors, basically one for each bank.
Is that okay?

[Matt Cramer]

Does the fact that it is an oddfire (90-150-90-150-90-150) make a difference?
Also it has two coils and effectively two distributors, basically one for each bank.
Is that okay?

Oddfire and dual distributor mode both require a one tooth cam sensor when using a Rennix crank trigger.

[dieselnutjob]

thanks

I think it will be easier to convert from Renix to a simple 66-2 then, i.e. 66 teeth all the way round with two missing in one place.
Does it matter where the missing two are in relation to TDC ?

[dieselnutjob]

I can see another problem.

With 66 teeth, 90 degrees is 16.5 teeth, and 150 degrees is 27.5 teeth

Can megasquirt fire on 1/2 a tooth?

I suppose that this flywheel originally came from an evenfire V6 and so it would simply be a spark every 22 teeth.

[Matt Cramer]

For an oddfire V6, you will need a cam sensor regardless of tooth pattern. You cannot run an oddfire V6 purely off the crank sensor. If there isn't one on this engine now, an easy way to add one is to modify the distributor (or, in your case, one of the two distributors).

[dieselnutjob]

Just to clarify. It has one distributor with two king leads to the two coils.
The rotor arm has two centre contacts.
So although it is mechanically / physically one distributer, from an electrical / logical perspective I would say that it has two.
Anyway thanks for the tip.

[dieselnutjob]

I drew it on a piece of paper


I can see why it will never work on a crank sensor alone. The sparks on the first revolution of the 720 cycle do not line up with the sparks on the second revolution, and a crank sensor only gives a 360 cycle not a 720 cycle.

I did see a post where someone put a wheel on a cam here http://www.msextra.com/forums/viewtopic ... it=citroen

I guess the difference is that cam timing is half engine speed so it does give a 720 cycle.

hmm

[2cvJasu]

Did you see this?

http://www.msextra.com/forums/viewtopic ... 01&t=50878

I have tested on my V6 odd-fire engine with two coil dizzy and wasted spark, both works well. Also "the code writer" Karlo have on his engine tested dizzy with one and two coils and also COP, with same results. Better than ever compared to original setup...

[dieselnutjob]

Interesting. How do I contact karlo?

I think that I can put a sensor inside my distributor easily enough. Currently it has two contact breakers inside and so if I remove those I should have room for a half circle disc and sensor instead.

I can even feed the wires to the sensor out through where the breaker wires currently come.

There is still one question unanswered.

I am am using a 66 tooth flywheel then the ECU will be firing some of the sparks on 1/2 a tooth. Is this a problem?
I am hoping that the ECU works on a degrees basis internally rather than a tooth basis so that it can interpolate between teeth if necessary. Is this so?

[racingmini_mtl]

A 66 tooth wheel won't work because the MS2/Extra code needs a wheel with an integer number of tenth of degrees between teeth. This wheel has 5.4545 degrees between teeth so it doesn't meet this basic requirement.

Jean

[dieselnutjob]

Sorry guys but this

That toothed wheel appears to be a Renix 66-2-2-2 and is supported.

and this

A 66 tooth wheel won't work because the MS2/Extra code needs a wheel with an integer number of tenth of degrees between teeth. This wheel has 5.4545 degrees between teeth so it doesn't meet this basic requirement.

are contradictory

what is the truth?

[racingmini_mtl]

Both.

The 66-2-2-2 wheel is a dedicated mode for a very specific wheel. If you want to use the generic toothed wheel mode, my statement is correct. So if you cannot use a 66-2 wheel.

Jean

[2cvJasu]

Interesting. How do I contact karlo?

I think that I can put a sensor inside my distributor easily enough. Currently it has two contact breakers inside and so if I remove those I should have room for a half circle disc and sensor instead.

I can even feed the wires to the sensor out through where the breaker wires currently come.

There is still one question unanswered.

I am am using a 66 tooth flywheel then the ECU will be firing some of the sparks on 1/2 a tooth. Is this a problem?
I am hoping that the ECU works on a degrees basis internally rather than a tooth basis so that it can interpolate between teeth if necessary. Is this so?

Can't say anything about using sensor on flywheel. But, I can say you can use 12-1 or 36-1 triggerwheel on camshaft, so that should work fine if you make a triggerwheel with 12-1 or 36-1 pattern inside of distributor...

Ok, it isn't as accurate as sensor on crank, but do you really notice the difference? I didn't, when I looked with strobe from crank with fixed advance, the advance was constantly there where it shluod be. I think it is accurate enough for most of installations...

Send a PM to Karlo, or if he doesn't answer that, PM to me and I can give his e-mail address...

[dieselnutjob]

This is an old fashioned engine with the cams driven by a chain inside the engine. There are no external pulleys or anything. All I have is crank and distributor.

So the Renix 6-2-2 is a "special" mode by the sounds of things. Can I combine Renix mode with a distributor wheel and oddfire?

[rickb794]

It appears the code will allow odd fire settings with the Renix wheel.

I cannot verify it works, only that the setting box for the "odd fire small angle" becomes available with "odd fire 6 cyl" selected.

Is it too difficult to put a 36 tooth wheel on the front of the motor?
With that and a dist sensor to provide a cam signal you are good to go.

[dieselnutjob]

Not easy with this engine





also I am looking for as hidden an install as possible, for example the throttle body will be in the place of the existing carb and hidden under the standard pancake filter so that you can't see it.