hey everyone im pretty caught up with the dmd, except the old posts i dug up werent very clear if the 3l option would need require this? with larger displacement, is this going to make the dmd non-compliant? i saw some people talking about the 3.0l mazda 6 engines, are they the same dampener? i plan on the 3l upgrade, and it would be kind or nice if i can put it on my 2.5 and then swaped it over...
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dmd on the 3l
- Thread starter chrisl311
- Start date
warmonger
Hard-core CEG'er
DMD will work on the 3L fine.
On my first 3L the engine was very smooth with the stock 2.5L damper. On my second 3L I used a DMD because it just wasn't quite as smooth and it did help a little.
I wouldn't run out to get it but if you need a damper, maybe have some NVH (noise vibration harshness) issues, then go for it.
On my first 3L the engine was very smooth with the stock 2.5L damper. On my second 3L I used a DMD because it just wasn't quite as smooth and it did help a little.
I wouldn't run out to get it but if you need a damper, maybe have some NVH (noise vibration harshness) issues, then go for it.
Y2KSVT
Hard-core CEG'er
Have had my DMD on my 3L for 39k miles(3-1/2 years) and it's run perfect thus far. 
Mark
Mark
Yes, the 3.0L Mazda6 uses the same DMD damper.
SVT3391
CEG'er
Question:
I do feel some NVH but not terribly untolerable. My 2.5L was very smooth, my 3.0L now comes with poly filled front and back roll resistors nicely done by FastCougar. I started to feel the little constant vibration. Will a DMD help this kind of situation?
Thanks for the insight.
I do feel some NVH but not terribly untolerable. My 2.5L was very smooth, my 3.0L now comes with poly filled front and back roll resistors nicely done by FastCougar. I started to feel the little constant vibration. Will a DMD help this kind of situation?
Thanks for the insight.
TourDeForce
Hard-core CEG'er
The TL is a very nice car, but doesn't that engine use a timing BELT like my Accord EX coupe?? That's one reason for it being much smoother & quieter than the chain driven Duratec.
Gotta love the durability of the chain drive, though. Just had a member on here trying to solve a worn engine mount problem on a car with a quarter million miles on it! Good stuff!
warmonger
Hard-core CEG'er
No kidding, those chains, well the whole timing setup on this motor is about as bulletproof as you can get on a production car.
THe duratec when new was VERY VERY smooth and quiet. My SVT motor was so f'in smooth throughout my whole warranty period that I could almost never believe it was an American car. lol
The only thing that made it loud was the exhaust and intake....but I'll take that noise anyday.
I know for a fact you already have a DMD on your car.
unemployed = no money. 4wks and still haven't received an unemployment check and I've had no responses to my resume that I have been sending out.
Bradness
CEG'er
MarK: Maybe you'd like to reply as I don't believe this thread has been properly answered yet (IMO). If the 2.5 crank has a harmonic problem, doesn't it make sense that the 3.0 would not as the crank is a completely different animal?
This is not to imply that adding a DMD wouldn't smooth out the engine, but I'm specifically asking about damage to bearings and the crank from harmonics.
Anyone care to address this specific issue?
This is not to imply that adding a DMD wouldn't smooth out the engine, but I'm specifically asking about damage to bearings and the crank from harmonics.
Anyone care to address this specific issue?
warmonger
Hard-core CEG'er
Okay, the breakdown according to me
Okay, the breakdown according to me
I don't think that is an issue at all. There has been no evidence of harmonics issues with the stock 2.5L damper. THe bearings problem is most certainly an oil related issue rather than a harmonic damper one. Part of the information that supports this is:
-we've had 2.5L with DMD have rod bearings fail exactly the same as with a stock damper.
-The 3L escape motors have the exact same damper as the 2.5L contour and so far have NOT had the issue.
-Ford revised the pan several times, though I personally don't think this was the answer/solution. But it didn't hurt to try either.
-Ford used 3 oil drainbacks on the 3L engine and this may be the best improvement
-the DMD has been a hit or miss item on some engines. Some 2.5L/3L engines are so smooth on the stock damper that a DMD has had no effect. Some have benefitted and had a reduction in harshness.
So to sum up, if you have a bit of NVH, get the DMD and try it out. Otherwise save the weight, time and expense.
For the oiling issue we've found the following opinions with some circumstantial evidence to back them up:
-Add an extra quart of oil (6qts). oil doesn't drainback as fast on the 2.5L from the head and traps more of it leaving the pan almost empty at high rpm. Combine that with the transfer (Slosh) of oil that stays in the head to the sides during cornering and you can see what might happen.
-use the updated oil pan. This is supposed to help. I think just taking and drilling a couple of extra holes in the stock pan's splash shield at the edges will suffice though.
-Upgrade your rod bearings in your Duratec with Clevite77 Tri-metal. They are hands down better than the basic cheapo all-aluminum alloy bearing used by Ford. The stock bearings are harder and have no way to absorb particulates and are more likely to generate friction if the oil pressure ever does drop. This is a 100% must do IMHO if you are rough on your engine.
- Run a different weight of oil. There is a RANGE of multi-grade oils that can be used in the engine based on temperature. To my knowledge the majority of the bearing failures are on the thinner oils. THe thinner oils are only recommended for cold climates and for better gas mileage. I personally feel that 0.3mpg improvement isn't worth the reduced protection.
My recommendation is to use the temperature vs. Oil grade scale found in the owners manual and run a weight of oil based upon the time of the year.
In AZ I always ran two different weight oils from summer to winter and I still generally follow this practice.
For cold climates I would use a 5w30 and for hot climates a 10w40. I've even used 20w50 on my stock 2.5L and NA 3L in the summer and I have perfect bearings with it no matter the hard driving. I've run 10w40 on all my 3L turbo engines in summer and 10w30 in winter. I've had the opportunity to inspect my bearings multiple times and they have always been in perfect condition despite producing power levels greater than 2-2.5x stock output.
There are people on here that have slightly differeing opinions on the oil and on some of this but I don't think anyone is greatly different, and no once can absolutely refute this summary as wrong. So is that broken down enough for you? lol
Okay, the breakdown according to me
I don't think that is an issue at all. There has been no evidence of harmonics issues with the stock 2.5L damper. THe bearings problem is most certainly an oil related issue rather than a harmonic damper one. Part of the information that supports this is:
-we've had 2.5L with DMD have rod bearings fail exactly the same as with a stock damper.
-The 3L escape motors have the exact same damper as the 2.5L contour and so far have NOT had the issue.
-Ford revised the pan several times, though I personally don't think this was the answer/solution. But it didn't hurt to try either.
-Ford used 3 oil drainbacks on the 3L engine and this may be the best improvement
-the DMD has been a hit or miss item on some engines. Some 2.5L/3L engines are so smooth on the stock damper that a DMD has had no effect. Some have benefitted and had a reduction in harshness.
So to sum up, if you have a bit of NVH, get the DMD and try it out. Otherwise save the weight, time and expense.
For the oiling issue we've found the following opinions with some circumstantial evidence to back them up:
-Add an extra quart of oil (6qts). oil doesn't drainback as fast on the 2.5L from the head and traps more of it leaving the pan almost empty at high rpm. Combine that with the transfer (Slosh) of oil that stays in the head to the sides during cornering and you can see what might happen.
-use the updated oil pan. This is supposed to help. I think just taking and drilling a couple of extra holes in the stock pan's splash shield at the edges will suffice though.
-Upgrade your rod bearings in your Duratec with Clevite77 Tri-metal. They are hands down better than the basic cheapo all-aluminum alloy bearing used by Ford. The stock bearings are harder and have no way to absorb particulates and are more likely to generate friction if the oil pressure ever does drop. This is a 100% must do IMHO if you are rough on your engine.
- Run a different weight of oil. There is a RANGE of multi-grade oils that can be used in the engine based on temperature. To my knowledge the majority of the bearing failures are on the thinner oils. THe thinner oils are only recommended for cold climates and for better gas mileage. I personally feel that 0.3mpg improvement isn't worth the reduced protection.
My recommendation is to use the temperature vs. Oil grade scale found in the owners manual and run a weight of oil based upon the time of the year.
In AZ I always ran two different weight oils from summer to winter and I still generally follow this practice.
For cold climates I would use a 5w30 and for hot climates a 10w40. I've even used 20w50 on my stock 2.5L and NA 3L in the summer and I have perfect bearings with it no matter the hard driving. I've run 10w40 on all my 3L turbo engines in summer and 10w30 in winter. I've had the opportunity to inspect my bearings multiple times and they have always been in perfect condition despite producing power levels greater than 2-2.5x stock output.
There are people on here that have slightly differeing opinions on the oil and on some of this but I don't think anyone is greatly different, and no once can absolutely refute this summary as wrong. So is that broken down enough for you? lol
DMD was/is only used on CAST cranks (cost save) - i.e. Freestyle and 500 and Montego.
Forged cranks do not get the DMD - from the factory.
Only reason for the DMD was Vehicle NVH due to the CAST crank. Nothing related to bearings, oil, or any other supposed urban legend.....
Forged cranks do not get the DMD - from the factory.
Only reason for the DMD was Vehicle NVH due to the CAST crank. Nothing related to bearings, oil, or any other supposed urban legend.....
Bradness
CEG'er
Tom: I recently tore down a 2.5 which I had been told had a "no oil pressure" condition. When I got it apart, the rod bearings on 4 & 5 were shot. As I recall, 5 was scored and spun and 4 was just scored. Now if this was an oil related issue I would have expected the bearing(s) furthest from the pump to be those that failed.
As the 2.5 was replaced by a 3.0 I have first hand knowledge of both pans, windage trays (upper baffle) and pan baffle (lower baffle). Based on my knowledge of windage losses, the primary culprit for oiling problems in the 2.5 is the windage tray. If you look at the chnages that Ford made the ratio of open to closed area in the 3.0 tray is much higher allowing more oil to pass down to the pan instead of being thrown up into the rotating crank assembly. The lower baffle is slightly better with more open area too, but will allow more oil to pushed upwards under high G loads. The pan improvements are negligible IMO. 3 internal vanes and external cross hatch ribbing that the 2.5 pan doesn't have. None of these changes address oil sloshing away from the pickup.
What I did was use all the 2.5 parts with the following modifications. First, I made a pan baffle to slow the movement of oil away from the pickup during extended high G load RH cornering. I had it TIG welded in place. Then I took the lower baffle and machined a few strategically placed .75" holes and bell flared them to minimize upward movement of the oil. Then I took the upper baffle (windage tray) and machined the crap out of it, adjusted the scrapers so they were actually scraping the crank counterweights and riveted a proper stainless screen to the bottom of it with vibration proof Cherry rivets. I also run a remote large capacity oil filter. So far, so good. Of course the extra drainback holes in a 3.0 cannot be duplicated in a 2.5...
On the harmonic issue, my understanding is that harmonics are inherent to the complete reciprocating/rotating assembly. If this is correct, the 3.0 should exhibit harmonics at a different frequency than a 2.5. It wouldn't surprise me if Ford, in the interest of cost effectiveness used the same (read cheap) torsional damper. N'est-ce pas?
As the 2.5 was replaced by a 3.0 I have first hand knowledge of both pans, windage trays (upper baffle) and pan baffle (lower baffle). Based on my knowledge of windage losses, the primary culprit for oiling problems in the 2.5 is the windage tray. If you look at the chnages that Ford made the ratio of open to closed area in the 3.0 tray is much higher allowing more oil to pass down to the pan instead of being thrown up into the rotating crank assembly. The lower baffle is slightly better with more open area too, but will allow more oil to pushed upwards under high G loads. The pan improvements are negligible IMO. 3 internal vanes and external cross hatch ribbing that the 2.5 pan doesn't have. None of these changes address oil sloshing away from the pickup.
What I did was use all the 2.5 parts with the following modifications. First, I made a pan baffle to slow the movement of oil away from the pickup during extended high G load RH cornering. I had it TIG welded in place. Then I took the lower baffle and machined a few strategically placed .75" holes and bell flared them to minimize upward movement of the oil. Then I took the upper baffle (windage tray) and machined the crap out of it, adjusted the scrapers so they were actually scraping the crank counterweights and riveted a proper stainless screen to the bottom of it with vibration proof Cherry rivets. I also run a remote large capacity oil filter. So far, so good. Of course the extra drainback holes in a 3.0 cannot be duplicated in a 2.5...
On the harmonic issue, my understanding is that harmonics are inherent to the complete reciprocating/rotating assembly. If this is correct, the 3.0 should exhibit harmonics at a different frequency than a 2.5. It wouldn't surprise me if Ford, in the interest of cost effectiveness used the same (read cheap) torsional damper. N'est-ce pas?
warmonger
Hard-core CEG'er
The 3L rotating assembly being a different mass would indeed have a different resonant frequency but that doesn't prove or disprove anything in this scenario.
While I won't debate which bearings "should" have run dry first because there are too many considerations, I'll venture an explanation.
First, the bearing clearances, load on the piston at the time the oil pressure dropped, amount of time, all play a role.
Lets make some assumptions. The oiling system in the engine is not a SEALED system. Therefore pressure is NOT equal in all parts of the system. It is really a system of controlled leaks. Oil goes to the crank and the rod bearings. It also has a path to the head where the cams are, and those are also controlled leaks. The bearing clearances could be equated to a hole of some diameter. We then have something like 10 holes on the bottom end alone then in this example.
So if I may, I'll illustrate an example so you can think about it....
Think about the oil pickup in the pan and oil being drawn into it, then forced down the tube toward the system of holes. Assume that the whole oil system is at one moment filled with oil and then the pickup encounters only air. The pump draws in air and now this air bubble is moving down the line. Then a split second later the pump is drawing in fresh oil again.
The first set of Holes it encounters would be the #1 bearings wouldn't you think? Since the oil pump is on the crank right in front of #1?
The air is compressible but only to a point so it continues to push any oil out of its way and it will more quickly push through the bearing clearances than the oil will. Then the oil behind it will continue to push on through until the air is gone, then it slowly leaks out around the bearings as was designed.
So this brings up a couple of factors:
1. the amount of air drawn in or to think of it another way the length of time the pump is not pushing oil
2. the load on that particular bearing at that time
3. the frequency of incidents where air is drawn into the system
We never seem to have topend failures and people said it couldn't be oiling issue because the topend has oil all the time. YadaYadaYada. Well to me that is just plain the wrong way to look at it.
If you look at the sytem in the way I described above, it would not be able to push the air up through the galleries into the head because the air would tend to take the path of least resistance out of the system...the bearings.
We don't have main bearing failures,at least not often, but that could be that the load is more uniform across the crank and that there is enough residual lubricant to make it unlikely; or at least less likely than a rod.
Finally, the rod on power stroke has the most pressure on it and that changes every split second as the engine turns.
My guess is the bearing doesn't fail over one single time of oil starvation unless that one time was significantly long. I would think that under light to no load the engine could run significantly longer without pressure than it could with a heavy throttle load.
So if you take into account all these factors you will see that it makes logical sense that oil starvation could be behind the bearing failures; that harmonics issues are probably no issue.
With that in mind all the techniques to keep oil in the pan are okay, but the single most important quality of the oil for safeguarding the engine during a momentary loss of pressure would be the film strength of the oil. The better that film strength the longer it can withstand a pressure loss.
The film strenght or resistance to shear or whatever the heck they call it these days is going to be better on an oil composed of thicker base stock no matter what the grade is. A good multigrade oil is imperative then for this protection.
The 5wXX series oils are just too thin for my taste and I would rather take the added protection of a 10wXX oil any day.
While I won't debate which bearings "should" have run dry first because there are too many considerations, I'll venture an explanation.
First, the bearing clearances, load on the piston at the time the oil pressure dropped, amount of time, all play a role.
Lets make some assumptions. The oiling system in the engine is not a SEALED system. Therefore pressure is NOT equal in all parts of the system. It is really a system of controlled leaks. Oil goes to the crank and the rod bearings. It also has a path to the head where the cams are, and those are also controlled leaks. The bearing clearances could be equated to a hole of some diameter. We then have something like 10 holes on the bottom end alone then in this example.
So if I may, I'll illustrate an example so you can think about it....
Think about the oil pickup in the pan and oil being drawn into it, then forced down the tube toward the system of holes. Assume that the whole oil system is at one moment filled with oil and then the pickup encounters only air. The pump draws in air and now this air bubble is moving down the line. Then a split second later the pump is drawing in fresh oil again.
The first set of Holes it encounters would be the #1 bearings wouldn't you think? Since the oil pump is on the crank right in front of #1?
The air is compressible but only to a point so it continues to push any oil out of its way and it will more quickly push through the bearing clearances than the oil will. Then the oil behind it will continue to push on through until the air is gone, then it slowly leaks out around the bearings as was designed.
So this brings up a couple of factors:
1. the amount of air drawn in or to think of it another way the length of time the pump is not pushing oil
2. the load on that particular bearing at that time
3. the frequency of incidents where air is drawn into the system
We never seem to have topend failures and people said it couldn't be oiling issue because the topend has oil all the time. YadaYadaYada. Well to me that is just plain the wrong way to look at it.
If you look at the sytem in the way I described above, it would not be able to push the air up through the galleries into the head because the air would tend to take the path of least resistance out of the system...the bearings.
We don't have main bearing failures,at least not often, but that could be that the load is more uniform across the crank and that there is enough residual lubricant to make it unlikely; or at least less likely than a rod.
Finally, the rod on power stroke has the most pressure on it and that changes every split second as the engine turns.
My guess is the bearing doesn't fail over one single time of oil starvation unless that one time was significantly long. I would think that under light to no load the engine could run significantly longer without pressure than it could with a heavy throttle load.
So if you take into account all these factors you will see that it makes logical sense that oil starvation could be behind the bearing failures; that harmonics issues are probably no issue.
With that in mind all the techniques to keep oil in the pan are okay, but the single most important quality of the oil for safeguarding the engine during a momentary loss of pressure would be the film strength of the oil. The better that film strength the longer it can withstand a pressure loss.
The film strenght or resistance to shear or whatever the heck they call it these days is going to be better on an oil composed of thicker base stock no matter what the grade is. A good multigrade oil is imperative then for this protection.
The 5wXX series oils are just too thin for my taste and I would rather take the added protection of a 10wXX oil any day.