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Discussion Starter · #1 · (Edited)
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.

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.


  1. First are the fragile, powdered metal oil pump gears. They simply cannot take a lot of abuse.
  2. 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.
  3. 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.
  4. Fourth is the internally balanced short block that is more susceptible to engine harmonics than an externally balanced setup.
  5. Fifth is the manual transmission. Gear banging and no fluid filled torque converter.
  6. 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:



"Do you rev your engine over 6500 rpm? If you do you should worry...The next time you blast through the gears might be your last"
Al Pappito

"We do not install small dampers on any DOHC engine builds. All our engines get Innovators West full size dampers"
Livernoise Motorsports

"There is alot of harmonic vibration on the front of mod. cranks. The small dia. dampers do not adequately control the vibration"
Al Pappito

"The net of all this information is to use the (stock) '96-'01 Cobra balancer (F6ZZ-6312-AB) on all manual transmission, forged crank applications"
Sean Hyland

"It appears that if you want your engine to live a happy life keep your stock vibration damper/pulleys"
Al Pappito

"Cheapo balancers just do not work with powdered metal gears"
J. Mihovetz

"Food for thought..I just rebuilt a '98 cobra it has spent the last five years as a road race car. The bone stock engine had never had a wrench on it, including the rusty stock damper sitting right where it was bolted in 1998. 20,000 mi at full throttle. This thing was totally worn out .guess what....The flats on the crank and the stock pump looked great.
In contrast...A slightly famous Factory stock cobra after a mid season NMRA teardown showed a problem. After 500 street miles and about 35 quarter mile passes the rotors had beat depressions about .040.'' deep into the drive flats where the pump contacts the crank. That engine was wearing a small dia. underdrive damper"
Al Pappito

"There also seems to be increased instances of oil-pump failure when some brands of underdrive pulley kits are used. I believe this is due to inadequate damping with the reduced-diameter harmonic balancer"
Sean Hyland

"I have experience with just about every dampener available for the Modular engines. Seen plenty of failures. For sure the smaller lighter dampeners will cause shorter oil pump life."
J. Mihovetz

"After building truckloads of modular engines a pattern has emerged. Most all oil pump failures involve underdrive pulleys"
Al Pappito

"If anyone will spend $5000+ to rebuild an engine, $400 for a damper should be one of the first things. I'm using an ATI"
VT Engines



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:

  1. The stock damper with stock powdered metal gears is good to 7,000 RPM.
  2. The stock damper with billet gears can operate to 7,400 RPM but is not advisable.
  3. Anything over 7,200 RPM should be running billet gears and an ATI damper.
  4. 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 3 - 7 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
 

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Good info ... I heeded the advice of the guys in the know and installed one of these on my Cobra.:joy:



 

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and both of my engines have this:


and one of these for extra insurance:



i did it for all the reasons listed above... why risk thousands of dollars in engine, by spending 100 bucks on a damper. Yea the pics above are expensive... but for a reason.
 

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ATI on mine. I bought an 8 rib but run a 6 rib belt on it. I was on the fence 6 or 8 rib setup. Went with 6 but I have an option to change.
Erich
 

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Discussion Starter · #5 ·
Yep, I'm over 6500 RPM with the short runner all the time so the ATI SD is money well spent.
 

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The first order of business is to completely understand how the dampener works. I have experience with just about every dampener available for the Modular engines. Seen plenty of failures. For sure the smaller lighter dampeners will cause shorter oil pump life.

There are companies that make good stuff and there are those that make cheap shiny stuff. Pretty simple rule on dampener choices. Higher rpms and power require heavier dampeners sometimes larger as well.

I only use ATI dampers. The last off brand (and on this page) dampener I used supplied by a customer failed, broke the pump, crank sprocket and the end of the crank on a bad ass GT 500 engine. I made him aware that I did not want to use it before I built the engine in writing. I'm not gonna feel bad when he gets the bill for the repair. Probably $5000 to fix it. I'm pissed off because I knew better. Anyone that thinks the customer is always right better not shop here.

Bottom line is I will not build or work on an engine here unless it has an ATI dampener. Besides that all my stuff has to be SFI anyway. If the customer can't afford it then he certainly won't be able to afford me either.

Cheap always costs more!


John Mihovetz
 

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I got my IW damper after talking to John Tymensky... he said both the ATI and and IW were nice pieces, but he prefers IW because while they are both multi-piece the IW doesnt have the elastomer or whatever it is in it. He sells em both for the same price, but he personally liked the IW better. I trust him.
 

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Another question, what happens to the harmonics when an Aluminum flywheel is used. If you think of the crankshaft as a torsional spring and the flywheel as the weight, as the flywheel is lightened the natural frequency will increase. Will this affect the oil pump gears if the stock damper is used?

Paul
 

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Discussion Starter · #9 ·
Although it does increase harmonics, the aluminum flywheel has not presented a problem for the stock damper.
 

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If I had a 4v I wouldn't run one period, I have a SOHC combined with a ATI and 5800 rev limiter. I recommend one for SOHC combined with alum D/S, alum F/W and 15lb 17" wheels, acceleration is fantanstic
 

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Well that answers the question I had. I bought a Hypertech pulley kit for about 70 bucks when I was considering a 5.4 3V.
I now have almost 6k into a 98 4V and I was trying to decide if I was going to use it.
After reading this I definately invest in an ATi or IW.

Thanks to the OP.
 

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What about Romac damper? Are they amy good?
 

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Discussion Starter · #13 ·
I dont know alot about Romac but most dampers that have as much diameter and weighs as much or more than the stock unit is going to be decent.
 

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Anybody have a good source price wise for either of these dampers?

The best I am finding is about 400.00.

If I have to spend 400 I will, I definately am not putting something on my new motor that could shorten its life.
 

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Discussion Starter · #16 ·
Anybody have a good source price wise for either of these dampers?

The best I am finding is about 400.00.

If I have to spend 400 I will, I definately am not putting something on my new motor that could shorten its life.
Not an easy part to find discounted. I had to pay the full 400 when I bought mine. Did you install billet oil pump gears during the rebuild? If you did you can run the stock damper to 7200 without a problem. Even higher in most cases. If you have the stock powder metal gears you can still use the stock damper to 7000 RPM all day. Anything over 6800 RPM is a good candidate for a good quality damper but the stock unit is not bad.



Does anyone know stock pully dimensions? I am not sure what is on my car.
6.78"
 

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Duplicate post...
 

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Where does the March 1158 pulley fit into all this?
It IS sfi approved.
 

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Discussion Starter · #20 ·
It's a small diameter damper so that always raises a red flag but the fluid is supposed to compensate for the lack of harmonic control inherent in the smaller diameter. I have not heard of any failures and I suspect it is fine for an engine that stays under 6800 RPM but its not a part taken seriously by most performance engine builders.
 
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