I've always been a proponent of 440Source stuff. I have lots of their parts and never an issue.

However, a few weeks ago I heard a clanging noise on the return road at the dragstrip. I Couldn't immediately see what it was, so I loaded it on the trailer and brought it home.

I found out it was the 440Source balancer that was bought new when I built this engine. The two halves came apart at the rubber.

I sent an e-mail to 440Source with a pic. No response.

If you are considering one of these, you might want to look elsewhere.

I'm not a fan of any rubber band damper. If you don't want to run a fluidamper I'd run the Innovaters West unit.

That could have got ugly......

So the bottom pulley stopped this from flying off ?

There have been lots of threads on what not to use from 440source


1. I beam rods. They quit selling them because of breakage
2. Rocker arms
3 harmonic balancers. I would not put one on an engine. Never.

I wouldn't say that this failure is due to a specific brand. For racing, it is usually a good idea to shy away from the rubber dampers, as stated previously. Use a good SFI piece, whether your class requires it or not.

one night , 3rd round ..Just coming out of the water box ..
Seen something fly past me ???

They ran up, told me to shut my car off , let my opponent make a single ?

I'm like , why ?

They said, something came off your car ..

What, burnout box guy comes over with some fancy , sparkly part of a Harmonic balancer

Said, not mine .. must of been his ?


I went up to him in the pits .. yeah, I seen it, I knew it was mine ..

And you let them give you a single ??

Nice

No, there is a lip on the center part of the balancer that won't allow the outer ring to go forward! It's made exactly like the o e balancer from Mopar.

Except for the 40+ year shorter lifespan.

Yep. Visually similar. In practice not so much...

Another aspect of this is that the damper actually has a job to do(besides providing a place for the front seal to ride and to mount the lower pulley)..... it’s there to dampen vibrations in the crankshaft.

It’s unlikely this dampers complete failure happened all at once........ so in the past few months leading up to what we see is the end result...... I wonder how effective it was at doing it’s primary job?

This is my main objection to Chinese dampers in general.
I find it hard to believe they are doing any type of R&D in an effort to come up with a piece that is actually an effective vibration damper in a HP application.

There was a member that used to post pretty regularly that had a 451 in a Pacer.
At one point he put an Indy headed 511 low deck in it.
After it had been running a short time he was commenting on how a lot of the motor hardware just wouldn’t stay tight.
Intake and carb bolts, alternator, pulleys, etc.

It had a Chinese made Professional Products SFI damper on it.

He ended up taking the Australian made Summit damper off the 451 and putting it on the 511...... and the bolts miraculously stopped coming loose.

John should that read would NOT ???

I think I can remember those threads years ago.
Referring back to Mark Gates' Pacer, I believe.

Fixed it John. Thanks

Bump for relevance since I was apparently messing up a thread about 440Source's customers not getting back to them. Irony.

Anyway, I went ahead and called again today and left a message, they called back and the guy said he couldn't do anything and Brandon was out but he would talk to him about it.

Their page looks open. Might be worth a post over there too. Or not.

Apparently Brandon is the only one that can make decisions on such a large issue. I guess delegation and opportunity cost are not part of their vocabulary.


Thanks, Zippy, I honestly had never seen that Facebook page!

I think people expectations of the longevity of a non race balance r has always been a bit off.

Its good you had no problems but you race your car a good bit, id pop the $400 or so for the race balancer and never look back.

You have a nice car, take good care of it.

This engine is and always has been limited to 6400 rpm. It is a tractor engine.

I may race my car but it is far from being a race engine.

Important: despite use of the term, a harmonic damper is not a balancer.

The SEMA damper standard (S.F.I. 18.1) does not rate a damper’s effectiveness, or certify that it works at all (let alone on a specific engine) - only that it fit the designated engine, and didn’t explode during the test. Their interest is limited to safety and qualify control, not specific engineering results. I couldn't even find a requirement as to how accurately it must fit the subject crank nose.
Any bonded rubber damper lives or dies on the manufacturer's reputation. MoPar fairly good on a stock engine for quite a while. An unknown damper (China and ?) may not only disintegrate (rim flies off) but fail to properly damp the harmonics (not the reciprocating mass) of the target engine. The rubber dimensions and characteristics are the whole works: the rubber insert has specific properties, including hysteresis, durometer hardness, &c. These factors are partially chemical in nature, and not easy to analyze or modify. What the rubber is made of (how much sulfur, &c.), what vulcanizing temperature, and how much it’s compressed to fit the space all play a part. I've never heard of any test for effectiveness, only for "how bad is the condition?".
The damper’s rubber ring will naturally decay with age, mileage, exposure to hot chemicals, vibration, ozone, and ultra-violet light, and become unsuitable for even a stock engine, let alone high performance or racing use.
Visible signs of damage and potential failure include:
» the rubber is partially missing
» the rubber is discolored gray or “chalky”
» the rubber has surface cracking
» the rubber has been partially extruded
» the damper rim is dented or bent
» the damper is loose on its hub or on the crankshaft nose
» the damper rim has excessive run-out (“wobble”)
» a “squeaking” noise that defies detection
If you have any doubts about the integrity of a factory damper, remove it (and rebuild it, if you wish).
Even a high-mileage (but apparently undamaged) damper has lost some effectiveness due to hardening of the rubber parts, which also changes its frequency range. Even if not damaged, it’s not doing the job if it doesn’t “float” the inertia ring as it was designed to do, which is at specific RPM points (not continuously).
The bad ones I’ve seen that we know slipped (the engine won’t run with the ignition timing marks aligned, but seems OK if you tune it “by ear” and check for pinging) all look damaged, but this obviously only catches them when they’re toast.
If you can rotate the outer rim on its hub more than a few degrees with a strap wrench, &c., it’s gone.