To put things into perspective, I've been following this topic since 2001. I can plainly state that there has been oil pump failures related to Steeda and other small diameter dampers that are too numerous to count.
Since their has been some confusion about the function of dampers I'll update this thread with additional info and post a couple good questions from members and the answers I provided:
Question 1:
Answer: You are confusing crankshaft deflection with harmonic transmission. Dampers are designed for the purpose of reducing both crankshaft deflection and harmonics.
The combustion in the cylinder can exert as much as 10 tons of force against the piston/crankshaft. The more flexible cast crank will twist more and absorb that shock. It is this additional flexing that requires a larger damper to retain less than .4 degrees of double amplitude. Without a damper the force of the combustion could twist the crankshaft far enough to actually break it.
Since the steal crank is harder and less flexible it handles the combustion force more affectively but the downside is that instead of absorbing the force with twist it is transferred to other parts, like oil pump gears and valvetrain parts.
Question 2:
Answer:
Good question. The flywheel has a minor effect compared to the balancer. Heres why, when combustion takes place in the cylinder the explosian hits the piston like a sledge hammer. The piston transfers that force against the throw of the crank. The force is so powerful it actually twists the crank. The crank than rebounds twisting in the oposite direction. This goes back and forth several times fast enough to cause vibration and harmonics.
The resistance against the crank that is working against the explosive force comes from the flywheel end. So you have one end of the crank remaining static with no twisting (flywheel end) and the opposite end twisting and rebounding like crazy. It is this opposite end where the damper is located that control is crucial. It is the inertial component of the dampers diameter and the extra weight that provides resistance against movement. It not only reduces the distance the crank twists but also the number of times it twists back and forth. A flywheel or better yet, a torque converter can absorb some harmonics but nothing like the work done at the business end by the damper.
Ok, with some basics out of the way let's talk about why this happens with Cobra’s and Machs and not SOHC Mustang GT’s, 5.0’s, Camaro’s and everything else that is not a high revving DOHC Ford.
All these things combine to make the Ford DOHC oil pump gears uniquely susceptible to failure. As such, the oil pump gears can fail under a variety of conditions that increase crankshaft harmonics. Over revving, forced induction and yes, inferior dampers that do not adequately control harmonics.
Here is a who’s who of the nation’s top modular engine builders that recommend avoiding small size dampers like Steeda on DOHC Ford engines:
Boss 330 Racing. Al Pappito
Modular Performance. John and Mike Tymenski
Accufab Racing. John Mihovetz. NHRA AA/AT World Record Holder
Livernois Motorsports
Pauls High Performance
Sean Hyland Motorsports
VT Engines
Here is small sample of the things they’ve had to say about small diameter dampers:
So let’s review:
If you own a Ford DOHC engine built from 1996 forward, and you rev it over 6500 RPM, every major modular engine builder in the country agrees that it is foolish to run a small diameter damper.
In addition to improper design resulting in numerous engine failures, small diameter dampers have been shown on several occasions to be out of round showing excessive run out when measured with a dial indicator. This is not only poor design but poor manufacturing and quality control. This probably contributes to the vibration many have felt at higher RPM with aftermarket, under drive dampers.
Some guidelines established by the professionals who build these unique engines are as follows:
Finally, let’s address some of the arguments presented by under drive, small diameter damper proponents:
Argument 1: “Show me proof!”
Answer: Idiot.
Argument 2: “I’ve run a Steeda small damper aggressively for a long time and have had no problems”
Answer: That’s not impossible. Varying production tolerances will make some oil pump gears more durable than others. Most people don’t want to find out the hard way.
Argument 3: We risk engine damage any time we install an aftermarket performance part on our cars.
Answer: In some cases that may be true but for the most part it simply is not. H-beam rods, forged pistons, hardened oil pump gears, ATI damper, billet oil pump gears, intake and exhaust mods. The list goes on and on. Even things like nitrous and supercharging are relatively safe when applied properly. And the inherent risk in their use is a little more tempting when we’re talking 100+ horsepower gains VS 3 - 5 hp for an under drive damper.
Argument 4: I’ve seen oil pumps fail with stock dampers.
Answer: Sure, it happens. The oil pumps are a marginal design from the factory. Increasing RPM beyond the factory limited 6800 RPM or installing power adders (nitrous, blowers, turbo) are just a couple examples of things that can increase engine harmonics. That is not a reason to install an inferior product that further jeopardizes your engine.
Argument 5: Most oil pump failures can be traced to improper damper installation.
Answer: Not true. What that statement is basically saying is that all the professional engine builders listed above don’t know how to install a damper. I don’t have to point out how ridiculous that is. Besides, it’s one bolt (new) torqued properly. Not rocket science. As a side note TheBlkMach1 had his damper installed by Steeda at their facility. He experienced pump failure with no other contributing factors.
Argument 6: Oil pump failures only occur on race engines or engines that are “over revved”.
Answer: Depends on your definition of “over revved”. Al Pappito plainly states that a small damper engine should not be revved over 6500 RPM. That’s a LONG way from “over revving” a DOHC engine that the factory designed to run at 6800 RPM for hours on end.
Argument 7: Steedas website says they worked with Ford to achieve the proper dampening characteristics.
Answer: That is the standard damper statement they’ve always used. It is meaningless. Fords Technology Transfer Program is available to anyone wanting to build an aftermarket part for a Ford. It can be used to obtain dimensional information as well as many other parameters.
Argument 8: Steeda has a new damper that is as heavy as the stock unit.
Answer: Weight is only one of several factors involved in producing a properly designed damper. The way they’ve distributed a bunch of the weight way out in front does not instill confidence. It's pretty tough to throw caution to the wind and blindly trust this company just because they've covertly admitted to marketing an inferior piece by completely redesigning it and quietly offering it in place of the original unit. Try calling them to ask about it. They wont admit to a re-design. Liability. It only took them 10 years. They haven’t even bothered making any claims regarding improved ability to control harmonics, let alone admitting to a re-design. Guinea pig it for them? No thank you.
In the end it boils down to whether or not 5 hp is worth the risk. Especially when nearly equal performance gains can be had by installing Cobra R pulley’s on the alternator and power steering pump. Even more by adding an electric water pump.
Todd
Since their has been some confusion about the function of dampers I'll update this thread with additional info and post a couple good questions from members and the answers I provided:
Question 1:
Answer: You are confusing crankshaft deflection with harmonic transmission. Dampers are designed for the purpose of reducing both crankshaft deflection and harmonics.
The combustion in the cylinder can exert as much as 10 tons of force against the piston/crankshaft. The more flexible cast crank will twist more and absorb that shock. It is this additional flexing that requires a larger damper to retain less than .4 degrees of double amplitude. Without a damper the force of the combustion could twist the crankshaft far enough to actually break it.
Since the steal crank is harder and less flexible it handles the combustion force more affectively but the downside is that instead of absorbing the force with twist it is transferred to other parts, like oil pump gears and valvetrain parts.
Question 2:
Answer:
Good question. The flywheel has a minor effect compared to the balancer. Heres why, when combustion takes place in the cylinder the explosian hits the piston like a sledge hammer. The piston transfers that force against the throw of the crank. The force is so powerful it actually twists the crank. The crank than rebounds twisting in the oposite direction. This goes back and forth several times fast enough to cause vibration and harmonics.
The resistance against the crank that is working against the explosive force comes from the flywheel end. So you have one end of the crank remaining static with no twisting (flywheel end) and the opposite end twisting and rebounding like crazy. It is this opposite end where the damper is located that control is crucial. It is the inertial component of the dampers diameter and the extra weight that provides resistance against movement. It not only reduces the distance the crank twists but also the number of times it twists back and forth. A flywheel or better yet, a torque converter can absorb some harmonics but nothing like the work done at the business end by the damper.
Ok, with some basics out of the way let's talk about why this happens with Cobra’s and Machs and not SOHC Mustang GT’s, 5.0’s, Camaro’s and everything else that is not a high revving DOHC Ford.
- First are the fragile, powdered metal oil pump gears. They simply cannot take a lot of abuse.
- Second is the fact that 4 camshafts and all the chains required to run them create a lot of harmonics in the crankshaft. That’s a problem.
- Third is the steel crankshaft made by Kellog. It’s the kind of crank hot rodders dream of but it’s super rigid and does not absorb harmonics like a cast crank will.
- Fourth is the internally balanced short block that is more susceptible to engine harmonics than an externally balanced setup.
- Fifth is the manual transmission. Gear banging and no fluid filled torque converter.
- Finally, the death blow for the powdered metal gears: High RPM. The DOHC in stock form performs best when shifted at the factory designated red line, 6800 RPM. Those are some pretty serious revolutions and there are a lot of harmonics created.
All these things combine to make the Ford DOHC oil pump gears uniquely susceptible to failure. As such, the oil pump gears can fail under a variety of conditions that increase crankshaft harmonics. Over revving, forced induction and yes, inferior dampers that do not adequately control harmonics.
Here is a who’s who of the nation’s top modular engine builders that recommend avoiding small size dampers like Steeda on DOHC Ford engines:
Boss 330 Racing. Al Pappito
Modular Performance. John and Mike Tymenski
Accufab Racing. John Mihovetz. NHRA AA/AT World Record Holder
Livernois Motorsports
Pauls High Performance
Sean Hyland Motorsports
VT Engines
Here is small sample of the things they’ve had to say about small diameter dampers:
So let’s review:
If you own a Ford DOHC engine built from 1996 forward, and you rev it over 6500 RPM, every major modular engine builder in the country agrees that it is foolish to run a small diameter damper.
In addition to improper design resulting in numerous engine failures, small diameter dampers have been shown on several occasions to be out of round showing excessive run out when measured with a dial indicator. This is not only poor design but poor manufacturing and quality control. This probably contributes to the vibration many have felt at higher RPM with aftermarket, under drive dampers.
Some guidelines established by the professionals who build these unique engines are as follows:
- The stock damper with stock powdered metal gears is good to 7,000 RPM.
- The stock damper with billet gears can operate to 7,400 RPM but is not advisable.
- Anything over 7,200 RPM should be running billet gears and an ATI damper.
- A small diameter damper shouldn’t be run in any combination over 6,500 RPM. Billet gears will hold up with a small damper but the harmonics beat up the crankshaft drive pretty good and eventually something will fail whether the pump, a camshaft gear or the crank trigger.
Finally, let’s address some of the arguments presented by under drive, small diameter damper proponents:
Argument 1: “Show me proof!”
Answer: Idiot.
Argument 2: “I’ve run a Steeda small damper aggressively for a long time and have had no problems”
Answer: That’s not impossible. Varying production tolerances will make some oil pump gears more durable than others. Most people don’t want to find out the hard way.
Argument 3: We risk engine damage any time we install an aftermarket performance part on our cars.
Answer: In some cases that may be true but for the most part it simply is not. H-beam rods, forged pistons, hardened oil pump gears, ATI damper, billet oil pump gears, intake and exhaust mods. The list goes on and on. Even things like nitrous and supercharging are relatively safe when applied properly. And the inherent risk in their use is a little more tempting when we’re talking 100+ horsepower gains VS 3 - 5 hp for an under drive damper.
Argument 4: I’ve seen oil pumps fail with stock dampers.
Answer: Sure, it happens. The oil pumps are a marginal design from the factory. Increasing RPM beyond the factory limited 6800 RPM or installing power adders (nitrous, blowers, turbo) are just a couple examples of things that can increase engine harmonics. That is not a reason to install an inferior product that further jeopardizes your engine.
Argument 5: Most oil pump failures can be traced to improper damper installation.
Answer: Not true. What that statement is basically saying is that all the professional engine builders listed above don’t know how to install a damper. I don’t have to point out how ridiculous that is. Besides, it’s one bolt (new) torqued properly. Not rocket science. As a side note TheBlkMach1 had his damper installed by Steeda at their facility. He experienced pump failure with no other contributing factors.
Argument 6: Oil pump failures only occur on race engines or engines that are “over revved”.
Answer: Depends on your definition of “over revved”. Al Pappito plainly states that a small damper engine should not be revved over 6500 RPM. That’s a LONG way from “over revving” a DOHC engine that the factory designed to run at 6800 RPM for hours on end.
Argument 7: Steedas website says they worked with Ford to achieve the proper dampening characteristics.
Answer: That is the standard damper statement they’ve always used. It is meaningless. Fords Technology Transfer Program is available to anyone wanting to build an aftermarket part for a Ford. It can be used to obtain dimensional information as well as many other parameters.
Argument 8: Steeda has a new damper that is as heavy as the stock unit.
Answer: Weight is only one of several factors involved in producing a properly designed damper. The way they’ve distributed a bunch of the weight way out in front does not instill confidence. It's pretty tough to throw caution to the wind and blindly trust this company just because they've covertly admitted to marketing an inferior piece by completely redesigning it and quietly offering it in place of the original unit. Try calling them to ask about it. They wont admit to a re-design. Liability. It only took them 10 years. They haven’t even bothered making any claims regarding improved ability to control harmonics, let alone admitting to a re-design. Guinea pig it for them? No thank you.
In the end it boils down to whether or not 5 hp is worth the risk. Especially when nearly equal performance gains can be had by installing Cobra R pulley’s on the alternator and power steering pump. Even more by adding an electric water pump.
Todd
Last edited:
op: this should be good
