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Pedal Smasher
1973 Opel GT
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Discussion Starter · #1 ·
Howdy Everyone,

So, I just called Fluidampr and spoke to someone who says they don't do custom, short run jobs. I asked about consulting and the person said their engineering department is backed up. I know this could just be getting me to politely go away or it could be their actual position on custom jobs. Fluidampr was my first pick because it would be a lifetime product for a CIH and could go on any CIH. They don't use a solid elastomer which would break down over time and need to be replaced. I'm sure there are pros and cons to using a solid elastomer vs a viscous silicone to dampen engine harmonics but only a fluid harmonic damper can absorb harmonic vibrations at all frequencies. Elastomer dampers are rather specific to application. So, to create a CIH harmonic damper it would need to be rather flexible in application in my opinion.

I dug up a contact at Fluidampr from some internet searching that I will send an email to but right now it sounds like we'd be on our own here. Has anyone had a custom damper made? Anyone know what sort of equations we should start working with on this?
 

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By design, an inline four cylinder is simple to balance and not prone to excessive harmonics developing like a V8. A dampener might be nice to have for a high revving race motor, but sounds like the costs would put it out of reach for most folks.
 

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The damper style pulley is only used on 2.2 and 2.4 engines. Not needed on our 1.9 or bored 2.0 engines.
 

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Pedal Smasher
1973 Opel GT
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2,613 Posts
Discussion Starter · #4 ·
All engines have engine harmonics that need to be compensated for. You’d find harmonic dampers on pretty much any 4 cylinder made today. My engine is a 2.4L, so I do need one.
 

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Opeler
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659 Posts
Curious what all the other 2.4 rebuild owners out there have done over the years. Gil was selling 2.4s as far back as I can remember so there must be many out there running in various US Opels. Is everyone using a HB or not?
 

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1.9 do not, they have a stamped steel pulley.
 

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Opel Key Master
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5,289 Posts
Factory 2.2 and 2.4 pulleys have a balancer made in to them. So a lot of people are just running those pulleys with those motors.
Guess it’s in the end, what is the benefit to cost? I guess it’s who cares? Are we over thinking something? I’ve run aluminum pulleys on the 2.4 after running a factory pulley. I didn’t feel any differences
 

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Pedal Smasher
1973 Opel GT
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2,613 Posts
Discussion Starter · #8 ·
I don't believe this is something we're over thinking. If you hardly ever rev the engine past 3,000 RPMs, then the impact of not having a damper might be minimal on engines that only see a few thousand miles a year. If you're far more spirited when you drive and regularly go to to 5-6,000 RPMs with a 2.4L and you drive it several thousand miles a year, then it would matter a lot more. Opel knew the 2.2 and 2.4 needed a damper for longevity in daily driven cars. So, how the engine will be used is important.

Then of course are those who want to go overkill for the sake of ensuring reliability and long term use.
 

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I’d be interested in a new harmonic balancer for my 2.4. After the one on my Subie Baja failed I don’t trust decades old ones. Failure mode was belts squealing and failing due to the pulley grooves separating from the hub.
 

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Pedal Smasher
1973 Opel GT
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2,613 Posts
Discussion Starter · #10 ·
I've been doing some research on the history of the torsional viscous damper. It was invented in 1947 by Bernard O'Conner while he worked as an engineer for Maurice Houdaille as a means to extend the life of diesel engines. I've found the main equations that are involved and I'm not surprised they focus on inertia. One of the most important variables is the design RPM, not how much torque the engine produces however torque would impact rotational forces on the crank. I think the main reason why a damper wasn't used on our Opels originally was cost. They were built to be economy cars for the most part, even the higher trim levels. So Opel tried to build fairly balanced 4 cylinder engines that should last 50,000 miles, relying on the somewhat balanced nature of an inline 4. The 1.9S would probably benefit from a harmonic damper for the sake of longevity, if you planned to drive it 50,000+ miles after rebuilding the engine. That's not exactly common for restored cars. They're babied and maybe cover another 20,000-30,000 miles during the rest of their life. So, I'd say every CIH could benefit from adding a harmonic damper but you'd have to care about an aspect of your engine that you could ignore and never run into problems because you don't drive the car enough.
 

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Opel Key Master
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What about the 1000s of Opels that were driven 100-200k prior to your study? Do you think people are only going to drive their cars 20-30k?
there is a company that can rebuild the dampener on the original pulley. I’ve had some cars where they slipped, and the timing marks were off big time.
 

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Pedal Smasher
1973 Opel GT
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Discussion Starter · #12 · (Edited)
Keith, it comes down to wear and tear. That sort of mileage without a harmonic balancer would result in more wear and tear on the engine where the crank is involved. These vibrations are going to be there, regardless of displacement or the engine being an inline 4. For us, it comes down to choice. We can choose to ignore it and maybe never have a serious problem or we can choose to tackle it because we want to. You’re more than welcome to ignore it and you (and your clients) probably won’t have any serious issues. OE’s bother with them for the sake of longevity and reducing warranty claims, because for them it’s all about the bottom line. Opel obviously started to see the need for them, which could be due to the increase in stroke for the 2.2 and 2.4 or it could be unrelated to that. I have a 2.4, so I don’t want to ignore it. I was hoping Fluidampr would help because then I’d just need to provide them with important dimensions and considerations to get them made.

Again, it's all about wear and tear on an engine. Just because I'm saying all CIH engines could benefit from a damper, that is not the same as saying they must have one if you want to enjoy your Opel for a long time. I could also choose to have a stock damper rebuilt which would be the cheaper option. What I want won't automatically be the same for everyone else.
 

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Opel engines built to last only 50000 miles ? BS says me. Asconas, Mantas, Rekords and other Opels were frequently driven up to 400000km or more before scrapping here in Finland and they didn't have harmonic balancers. Likewise the old pushrod OHVs that preceded the CIHs were good for almost similar milages. And even ENEM recommended a pressed steel pulley for rallying and racing instead of a balancer due to its better durability at higher RPM.
 

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1.9 liter and 2.0 liter CIH engines can easily run 300,000 to 400,000 miles if you take care of them. They have good metallurgy, low piston speeds due to the short stroke, and good rod angularity due to the rod ratio (1.83:1). In the 1980’s and 1990’s when I worked for and later owned C & R I saw a ton of daily driver Opels with this kind of mileage on them.

The biggest issues I’ve seen on the 2.2 liter CIH is a faulty piston design. Every one I’ve pulled apart has had partially collapsed piston skirts. Usually .004” to .005”.

The 2.4’s I’ve seen to have accelerated cylinder bore wear. This is due to the longer stroke and subsequently higher piston speeds, as well as a rod ratio that is far from ideal (1.57:1).
2.4 liter engines that are run hard with standard pistons often have broken rings and ring lands.

But other than these issues, there’s generally not a lot that goes wrong unless the engine is neglected. Keep in mind the type of driving European drivers may see compared to US drivers and you’ll see the engines fare pretty well.
 

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That is what I seen with Opel engines as stated by Bob as far as wear and breakage rings broken and ring lands. Camshaft lobe wear is next item seen.
I am building a 2.2 custom pistons and rods with the narrower ring 1m, 1m, 2m for lower friction and control ring braking and movement. Engine balanced but I will use the 2.2 pulley.
 

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Opeler
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Lots of great information here and evidence that the larger CIH engines can run just fine without the HB but automotive engineering standards also indicate that it is a good thing to have as well. So given the original CIH balancers are not really available and even if found are probably not any good, I wonder if there is a universal HB that could be adapted and welded onto the stock pulley? Of course it would need balancing itself once made. Has anyone really investigated this option?
 

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Opel Key Master
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Mike, I believe that is basically what Autoholic wants, is to have a company make them for the CIH. I only mentioned why because he acts like you are going to grenade your engine if you put any miles on it or do not run one, which I disbelieve. You shouldn't have any issues finding a good 2.2 double groove, maybe even a single groove pulley with the HB. Again, if it is questionable, it can be rebuilt.
 

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Opeler
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873 Posts
Here is a balancer used on MGs from '62 - 80'. It's only 5 1/8" diameter. I found it on MossMotors.com Wondering if something like this could be fitted to the crank snout?
435961
 

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Pedal Smasher
1973 Opel GT
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2,613 Posts
Discussion Starter · #19 ·
Mike, I believe that is basically what Autoholic wants, is to have a company make them for the CIH. I only mentioned why because he acts like you are going to grenade your engine if you put any miles on it or do not run one, which I disbelieve. You shouldn't have any issues finding a good 2.2 double groove, maybe even a single groove pulley with the HB. Again, if it is questionable, it can be rebuilt.
Keith I said "We can choose to ignore it and maybe never have a serious problem or we can choose to tackle it because we want to." Does that sound like I'm saying you're going to grenade your engine if you put miles on it? No. I'm talking about bearing life here. I don't see a CIH making the enough power or revving too high in most scenarios to risk bending or breaking the crank. It could happen, but I haven't heard of cranks failing enough for it to be a common thing to look out for. So, when I said wear and tear I really don't how you get complete engine failure out of that. When I mentioned 50k miles, I was thinking of what might have been Opel's design expectations. Not that the engine couldn't last a really long time. Design expectations are often less than what is realistically possible with proper maintenance. That could have been 100k miles back in the 60's when Opel / GM designed the CIH. Cars, even in Germany, had a shorter life expectancy compared to today. Given how hard Europeans drive their cars, I'd guess a shorter life expectancy compared to the US.

For those who don't want a damper that's fine. For those that do, we don't have a good option right now.
 

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Opeler
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Well I'm not opposed to using one at all. So who has one they are willing to give up? Be happy to install it on my 2.6L.
 
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