Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec Procyon Qs Any info?/???

Procyon,

You seem to have the details of duratec components down..
Can you tell me if the Jag V6 uses the same rods (or were they upgraded )as the other Duratec 2.5/3L. Nobody else has ever been able or willing to answer this...

Any idea of safe upper RPM limit for a 2.5L with the DMD?? Ever tested??

Oh, also what is the story behind the new baffeled pan for the 2.5??

Thanks

Yes, the Jaguar Duratecs use the exact same rods as the other Duratec engines.

As for the DMD...I have never been involved any any design or testing of it. My opinion is that the DMD was added more for NVH concerns than for bearing failure issues. There are DMDs now on a lot of Ford engines. I believe that all of the Modular 4.6,5.4, 6.8L engines have them now.

For your RPM limit...I don't really like the idea of raising the redline just because you're running a DMD. The DMD is not going to change your reciprocating mass. The 3.0L will have a larger recip. mass than the 2.5L due to larger pistons, larger piston pins, and slightly heavier bobweights. The Mondeo ST220 3.0L has the DMD and a 7000 rpm redline so the Duratec bottom end must be good for that. The 3.0L Lincoln LS also has a 7000 rpm redline but has a different damper (not DMD). That's all I know.

My understanding was that the new baffle is supposed to do a better job at reducing aeration.

Originally posted by procyon:

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As for the DMD...I have never been involved any any design or testing of it. My opinion is that the DMD was added more for NVH concerns than for bearing failure issues.

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Excellent info..thanks.
Just to clarify...do you not believe that the Duratec has an excessive crank whip issue that can damage bearings??? Can I ask what is your take on the reason for what seems to be a number of low mileage failures?

It is somewhat reassuring that the Duratec rods are used in the JAG. I would assume that some margin of saftey is built into that engine, which makes 240 HP and 221 lb/ft. So, the rods should be good for >250 HP. And a 7000 RPM with a larger reciprocating mass suggest that a slightly higher redline (say 7200-7300) should be OK for the 2.5...Reasonable assumptions?

I would say that the rods for the duratech must be even better than we think if the jag motor uses them at 240HP. Think about the safety factor designed into them:
you can expect critical parts to have at least a 1.5 safety factor built into them which would give another 110 ft-lbs of torque on average. This isn't a guarantee, but it means that if many rods are tested to failure and the statistical average falls around some value , say 350 ft-lbs or so, then you would expect that the majority of rods would fail at that point, some lower and some higher due to statistical variance. Using a safety factor of 1.5, you would take 350/1.50 and get around 213.

You of course risk having some of the rods that fail on the low side of our hypothetical 350, but conservative increases in torque would be ok, say 30% increase or so.

It would be nice to know the full dimensions of the rods and the manufacturing specs as well since I could look up the maufacturing process and determine the strength of the material under those conditions, then I could take the geometry into account and determine the loads they could take.
If anyone can get me this info then I will be happy to do the research/calculations to get a closer idea of their capabilities. Don't think that just because they are sinter-forged that it necessarily follows that they are weak. Also consider that sinter-forging would mean a much more consistent set of ultimate fatique limits... by that I mean the limits will be much closer to the statistical mean than cast rods, or possibly even forged rods depending on the forging conditions and 'who' is doing the forging (that doesn't mean stonger than forged).

I know it is wordy, but I am in a thinking mood. Someone provide the info and I will get to work.

warmonger

Originally posted by warmonger:

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Using a safety factor of 1.5, you would take 350/1.50 and get around 213.

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You're treating the failure strength as linear...fatigue life vs. load for a connecting rod would be a curve.

How do you plan on calculating all of the dynamic loading without some high end software even if you did have the geometry? Also, where can you get material /fatigue specs for a sinter-forged material?

Originally posted by Dan Nixon:

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do you not believe that the Duratec has an excessive crank whip issue that can damage bearings??? Can I ask what is your take on the reason for what seems to be a number of low mileage failures?

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I don't believe that all of these failures can just be lumped into a handy excuse of crank whip. There are several other things to consider...the biggest of which is contamination. It only takes little particles to screw things up. How cautious are people about foreign object damage when they are modifying their engines? In addition, what about the people with bearing problems who don't work the engine hard? It's hard to blame that on crank whip. Last item: IF the DMD is for crank whip, why would Ford only add it to the Mondeo?

Flame away Terry...but we both have our sources of Duratec information.

Warmonger I have a rod and piston sitting on the bench at home, I can get you any measerment you need. I still maintain they look very beefy, but its only looks. I can understand your reasoning although procyon is right about the complexity of determining the strength requirements. However if we can come up with a conservative measurement based on simple geometry then I'm cool with that

In reply to:

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You're treating the failure strength as linear...fatigue life vs. load for a connecting rod would be a curve.

How do you plan on calculating all of the dynamic loading without some high end software even if you did have the geometry? Also, where can you get material /fatigue specs for a sinter-forged material?

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You're correct with your first statement. I used the example to teach the concepts to anyone who will read it....not meant to be a true representation of the strengths/limitations of the rod.
As it was the post was long and wordy.

I am a Materials Science Engineer and much of my focus has been directed to 3 areas: metallurgy, silicon-on-insulator technology with burried oxide layers, and materials characterization with SEM, FESEM,TEM,AUGER, and a few others.
I may be able to get a hold of some software, but that is not really necessary to get an educated 'idea' about the strength of the rods.
My plan is to get the information on the type of material and the manufacturing process that the rods are constructed with, hopefully from someone in the 'know'...in fact I was hoping YOU could help with that, even though you may not get all of the pertinent information a little would be a start. Anyway, I can just do something as simple as start looking for abstracts from metallurgical journals that describe tests on the same type of materials. I also have some reference materials that conver sinter forging a little bit but I will still need to do some reading.
I can probably get cyclic fatigue results on the metal as well most likely from the original journal reports when the process was introduced.
AT the very least, I can research and find UTS, K1C fracture toughness and the variety of materials data that can give some idea on the material's strengths.

As far as sinter forging: Sintering has long been used to get complex shapes for a part from powdered metals while giving very consistent properties to the part throughout its entire cross section. Additionally the sintered material resists creep and distortion (ideal for high temp, high stress environments) because it is formed from uniform grains and grain boundaries which resist the movement of dislocations through the material. This also would have a great resistance to crack propogation as cracks that are less than catastrophic will be blunted by these grain boundaries (less likey to jump from one grain to another). This doesn't mean it is the 'best' material, whatever 'best' actually means. It will be less flexible and prone to catastrophic failure rather than gradual failure. Still, they are very strong...I have nice article here in one of my heat treatment magazine that shows a sinter hardened FL-4605 family of alloys that have UTS ranges from 31KSI to 153KSI with HRC values from 32-92.

I am bombarding you with this information because I assume you are a mechanical engineer of some sort and will likely understand some or all of the concepts. Forgive me if I am wrong in that guess about which engineering background you have, but hopefully you will understand my point that some 'rough maximum value' could be derived from the basic data available, even if we don't know the exact processes involved. I also am hoping to overcome your skepticism and convince you that given enough information I could do what I am claiming.

Tom
warmonger

Kinger, that is along the same lines of thought that I have. Some estimate of the material cababilities would be nice....might save someone a blown motor later.

I think the best way to do it, assuming you have the time, would be to draw pictures of the part on paper from the three principal views, top-front-side, and then take measurements and add them to the drawings. Then you can scan them and we can go from there. Once I get the geometry and maybe some idea of the type of material, I can start to gather information.

warmonger

Originally posted by procyon:

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My understanding was that the new baffle is supposed to do a better job at reducing aeration.

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CORRECTION: In my earlier post, I was referring to the baffle (windage tray) which bolts to the bottom of the block. I am not referring to the new oil pan which now has 2 ribs cast into the forward area. I have to assume that these additional ribs were added for better oil return since they don't look structural to me.