2004 5.0GXi-E Cam Retard Angle Spec.

[ripjmk]

I can't seem to find the spec. for the cam retard angle on my 5.0 GXi-E engine! Does anyone know what it is or where I should look to find it?
Thanks

 

[Bondo]

Ayuh,..... Welcome Aboard,..... What, Exactly are ya tryin' to do,..??

 

[alldodge]

cam retard angle

Has me scratching my head in the term. The motor is a GM base engine, may be able to find the cam specs from the local GM dealer

 

[ripjmk]

I'm just checking the distributor position, and I believe the Camshaft retard angle is the most acurate way to do that. I have the angle read out through my NMEA200 engine gateway. It would be no effort to check it if I only knew what it is supposed to be? I've read somewhere that earlier 5.7's it was 45* +/- 2* but that it is engine specific!

 

[muc]

I'm just checking the distributor position, and I believe the Camshaft retard angle is the most acurate way to do that. I have the angle read out through my NMEA200 engine gateway. It would be no effort to check it if I only knew what it is supposed to be? I've read somewhere that earlier 5.7's it was 45* +/- 2* but that it is engine specific!

Yes it is engine specific.
Volvo didn't publish this spec for your engine. Starting with the 5.0GXi-F they do include it in the manual as 45° ± 5°

I seem to remember some numbers in the 60s but don't remember what engine that was on.

What are you seeing now?

 

[ripjmk]

I can't remember off hand, but i'm going to start the engine on muffs tomorrow and will check then.

 

[ripjmk]

I just compared the GXi-E and the GXi-F components on Marine Parts Europe and the crank sensor, crank sprocket, camshaft spocket, camshaft and distributor are all the same part numbers. Doesn't this mean the cam retard angle would be the same?

 

[muc]

I just compared the GXi-E and the GXi-F components on Marine Parts Europe and the crank sensor, crank sprocket, camshaft spocket, camshaft and distributor are all the same part numbers. Doesn't this mean the cam retard angle would be the same?

Pretty sure there is a difference that you missed between these 2 engines. The ECM is very different. E model used MEFI 4 and the F model used EGC.

One of the big differences between MEFI and EGC engines that use a cam sensor. With MEFI you can unplug this sensor and the engine will start and run normally (might take 2 extra revolutions to start) with EGC cam sensor unplugged it won’t start.

From a Volvo EGC class book;

This publication covers all non-catalyst equipped Volvo Penta EGC fuel
injected engines built from May 2005 through the M models. For older MEFI
(Delphi) fuel injection information and basic speed density fuel injection system operation
please refer to the MEFI Product Training Student Reference Book

NOTE: Distributor position is important for proper engine operation. Cam retard on a
running 5.0/5.7L engine should read 120 - 150 if the distributor is installed and adjusted
properly. 4.3L engines with the 3X reluctor read -40 to -70 all the time,
​​​​​​​

So I'm not sure. It will be interesting to see what your engine is running at.
​​​​​​​Please update us.

 

[ripjmk]

Ran the engine on muffs today and the cam retard angle at idle is 43.95* - 45.0* at 1,200 rpm it is steady at 44.65*. I take this to indicate the spec angle for the 5.0 GXi-E is the same as the 5.0 GXi-F.

If I understand it right, the cam retard angle is the angle the ECU calculates that the crankshaft moves after the crank position sensor is triggered to the time the camshaft sensor is triggered on the compression stroke. The ECU only uses the triggering of the cam sensor to detect the compression stroke and then sets ignition timing from the crank position sensor being triggered. But this cam retard angle does give an accurate indication of the rotor tip to cap lead pins alignment.

As the two position sensors are mechanically connected if two engines have the same components connecting them (sprockets, camshaft and gears) the ideal cam retard angle will be the same provided the range of spark advance is not wildly different. From what little information I can find the advance range is form 10* to 40* for small block GM's.

I find it interesting that there is no mechanical advance of the rotor separate from the cam sensor. Being a V8 there is only 45* between pins in the cap, with 30* between min and max spark advance. This results in a difference of 15* rotation of the rotor when the spark jumps, but the rotor and cap pin pass each other at the same crank angle every revolution! So the only time they are in perfect alignment when the spark jumps is at 25* of spark advance (if cam retard angle is set correct). It is easy to see that at the ends of the range if the distributor is rotated even a little bit from the correct position a missfire to an adjoining cap pin is possible! Didn't have this issue in the old days as the rotor was advanced along with the spark advance by flyweights and springs LOL.

Next time I'm on the water I'll see what my spark advance range is.

 

[muc]

Interesting, I hadn’t thought about it that way. Makes sense that these spark switches are so touchy when you do the math like that.

I also remember having to drill and install a bushing in the pivot point of those flyweights, and replacing fatigued and broken springs. Guessing that’s why modern engines don’t have distributors anymore.