Another Small Block Crank Damper question

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Demonx2

Demonx2

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I've read lots of posts about which crank damper to use and everybody has thankfully shared their experience. I've got a 408 about ready and need to get a crank damper for it. Figure 95% track/5% street. I plan to limit the rpm to no more than 6600 rpm. Typical 408 build w/ Eddy heads and an Eagle 4" crank, solid flat cam, 10.5 CR, etc, etc. Should be in the ~500-ish hp range w/ a 3800 stall converter and a 3200# Demon.
I got the Trick Flow 19010 damper and about dropped it when it arrived! 13.5 pounds for that bad boy!! Not thinking I need all that weight 1) hanging on the front of the engine, and 2) having to be spun up at the track! Mancini has the PRP Pro Sport at 11.1 lbs and Jegs has their own #51640 listed at about 8.2 lbs (JEGS 51640: Small Block Chrysler Harmonic Balancer/Damper Internal Balance | JEGS).
I've read how some don't want anything to do with a rubber sandwich-type damper but all these engines were produced with them and let's face it, these cars and engines are not being built to go 100k miles.
So I'm just looking to see if anyone has experience with either of these or a better idea?
Thx for the input as always!
 
For no reason whatsoever: I once had a 340/ solid lifter cam/ 273 rockers in an old Landcruiser, with the factory dampener and that thing regularly saw 7K
 
Demonx2 said:
I've read lots of posts about which crank damper to use and everybody has thankfully shared their experience. I've got a 408 about ready and need to get a crank damper for it. Figure 95% track/5% street. I plan to limit the rpm to no more than 6600 rpm. Typical 408 build w/ Eddy heads and an Eagle 4" crank, solid flat cam, 10.5 CR, etc, etc. Should be in the ~500-ish hp range w/ a 3800 stall converter and a 3200# Demon.
I got the Trick Flow 19010 damper and about dropped it when it arrived! 13.5 pounds for that bad boy!! Not thinking I need all that weight 1) hanging on the front of the engine, and 2) having to be spun up at the track! Mancini has the PRP Pro Sport at 11.1 lbs and Jegs has their own #51640 listed at about 8.2 lbs (JEGS 51640: Small Block Chrysler Harmonic Balancer/Damper Internal Balance | JEGS).
I've read how some don't want anything to do with a rubber sandwich-type damper but all these engines were produced with them and let's face it, these cars and engines are not being built to go 100k miles.
So I'm just looking to see if anyone has experience with either of these or a better idea?
Thx for the input as always!
Click to expand...


The factory used them because they are cheap to manufacture and most people don't beat on their stuff.

Spend some money on a good damper. One that doesn't wear out from day 1.
 
Got two of those in use....chrome ones ......trying to remember who makes them for Jegs....want to say Powerbond........One of them is about 15 yrs old....been on a 360 and now a 408....got a second one on 408....
 
Don’t cheap out on a cheap damper. It hurts to spend $300+ on a damper but you are looking at saving that engine which is a big investment.

I would run a Super Damper... yes they are worth it. You don’t needthat thing flying off the engine at 6k.
 
I don't drag race so a standard elastomer damper is fine for me. But for your 95% racing engine, a better damper is all that makes sense. Remember, the purpose is to 'eat up' the very high frequency internal crankshaft vibrations.

These are not the vibrations of engine balance, but are much higher frequency twisting vibrations inside the crank itself. If those are not absorbed (damped), cranks can and do break. You're using this crank repeatedly in severe duty so regular car engine experience becomes a lot less applicable.

The weight is balanced around the hub so as it spins it does not put any extra force on the crank snout. So don't worry about the weight there.

And the weight is all concentrated in a small radius; due to that, the extra energy when accelerating a 4-5 lb change in damper ring weight is truly tiny compared to what the engine is having to put into the rotating mass of the torque converter and auto trans! (Not to mention the wheels and tires. Trust me, I've done a few calculations on that matter...)
 
Demonx2 said:
I've read lots of posts about which crank damper to use and everybody has thankfully shared their experience. I've got a 408 about ready and need to get a crank damper for it. Figure 95% track/5% street. I plan to limit the rpm to no more than 6600 rpm. Typical 408 build w/ Eddy heads and an Eagle 4" crank, solid flat cam, 10.5 CR, etc, etc. Should be in the ~500-ish hp range w/ a 3800 stall converter and a 3200# Demon.
I got the Trick Flow 19010 damper and about dropped it when it arrived! 13.5 pounds for that bad boy!! Not thinking I need all that weight 1) hanging on the front of the engine, and 2) having to be spun up at the track! Mancini has the PRP Pro Sport at 11.1 lbs and Jegs has their own #51640 listed at about 8.2 lbs (JEGS 51640: Small Block Chrysler Harmonic Balancer/Damper Internal Balance | JEGS).
I've read how some don't want anything to do with a rubber sandwich-type damper but all these engines were produced with them and let's face it, these cars and engines are not being built to go 100k miles.
So I'm just looking to see if anyone has experience with either of these or a better idea?
Thx for the input as always!
Click to expand...
I've been using tis on my 340 for years without problems plenty of 7,000 rpm runs , now using on my 426 stroker , it's not the best , but my factory unit lasted 15 years and this is probably a better dampner If you are 95% race go with the best you can afford it/s added insurance Pro Race Products Pro Sport Harmonic Balancer
 
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Thx guys. I've seen many of your other posts in the past and it's great to hear from so many of you that have "been there, done that." And so many of you have cars that are just awesome!! Nothing like the real world experience you have and that is what I enjoy and appreciate the most about the FABO site. Looks like we run the gamut here on what has worked for dampers. I ran the stock damper on my big block 69 Charger for years - 383 car and then 440. It lasted about 10 years shifting it at 6800 (383) and then 6300 (440) until it finally spun the outer ring. Looking forward to see where this 408 small block will want to be shifted given the longer 4" stroke.
Again, appreciate all the input!
 
A little more research should be in order.

The elastomer begins to wear IMMEDIATELY. And when it does, it starts to loose its ability to reduce harmonic vibrations.

This is a simple fact. Even ATI, the most beloved of dampers requires relatively frequent rebuilds to maintain any ability to function correctly.

You can use any metric to say these damper work, but they have a very narrow range of frequency in which they work, and a relatively narrow RPM range as well.

It's funny that Chrylser did a ton of research on this issue and they said to use a Fluidamper. I haven't use an Innovators West damper yet, but my next build will probably get one.

You used to be able to send a damper back east somewhere and they would test it. Can't think of the place now, but I had customers send back dampers that had a couple of years on them that had little ability to dissipate crank harmonics left in them.

In the grand scheme of an engine build, a damper is a very small cost. I have seen enough broken parts, fractured blocks and cranks, and all other maladies that come with uncontrolled crankshaft harmonics that tell me elastomer dampers are a short term proposition. At best.

I doubt all the guys claiming to run these things mile after mile and year after year have their dampers tested to see if they still have reasonable function.

If they did, I suspect they would be shocked.
 
Crank snouts DO break off.... luckily most Mopar cranks are strong enough to avoid this issue.
One of the shops I use is Chevy oriented (likely all of them) but one owner sez "you know the the last time I saw a Mopar crank break?.....NEVER!

Can't vouch for cheap replacements.

I'll weigh my Fluidamper and see what it weighs....
 
Krooser said:
Crank snouts DO break off.... luckily most Mopar cranks are strong enough to avoid this issue.
One of the shops I use is Chevy oriented (likely all of them) but one owner sez "you know the the last time I saw a Mopar crank break?.....NEVER!

Can't vouch for cheap replacements.

I'll weigh my Fluidamper and see what it weighs....
Click to expand...
That will be interesting to see what a Fluidamper weighs. Thx!
 
Please... seriously.... Someone explain how a balanced damper put any force on the crank snout when spinning....???

Edit to add: The answer is: If it weighs 13 lbs on the bench, it will put the same 13 lbs downward force on the crank when spinning. It's nonsense to worry about this. The tensioned belts put far more side force on the crank snout.
 
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Get a Romac. U can get them in alum/steel or alum. 5 lbs maybe. Check them out. Kim

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Appreciate that detail. Romac is one I've looked at too. Will have to add them to the serious consideration file.
 
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