I'm trying to figure out if I have a problem with my harmonic balancer. I'm hoping someone may be able to help me figure it out. Prior to me disassembling the engine I noticed the harmonic balancer was wobbling, for lack of a better word, and I took the following videos: (There are two videos: 1 thumbnail and 1 link. For some reason, Y outube wouldn't let me create a thumbnail for the second video.) https://youtube.com/shorts/SwiU45_vlYI?feature=share My engine builder took some measurements of runout at different locations on the balancer. Below are some pictures of the balancer with the location and magnitude of the runout he measured. As part of my engine build the block was align honed, the crank snout was checked and is okay, and the crank was machined. So in my mind, the only thing left that would cause the "wobble" would be the balancer. I just want to make sure I don't put a bad balancer on the new engine. Also, I did notice how badly the water pump pulley is wobbling. I obviously have to address that, but I think the harmonic balancer wobble is an independent issue from the water pump pulley wobble. Please correct me if I'm wrong. Thanks, Jim
I think you're on the right track. To isolate the balancer as the culprit, you could remove it and check crank snout runout. If that's ok, then the balancer is the only thing left to blame. What type of balancer is it? That might help figure out what the failure mode is if the balancer really is the problem. Devon P.S. Also check balancer hub ID to see if it's a true cylinder. A poor fitting balancer's ID can become even more distorted over time (kind of like an hourglass shape), and even when fully torqued down can still act crazy. P.P.S. Ooops, I see snout runout has already checked OK...time to take a close look at the balancer itself, in my opinion.
The reading off of the damper hub/seal surface should be accurate. The reading from the OD of the inertia ring should be accurate, and might represent deterioration of the rubber between the hub and inertia ring. Not so sure about the reading from the lip on the front of the damper hub. Goofy machining of that lip could easily cause .025 of indicated runout where little or none actually exists. That doesn't appear to be a stock damper. Was the engine re-balanced when that damper was installed? Buick pounds steel pins into holes in the stock damper as a "final balance"; when the damper is replaced, the new one has to be match-balanced to the original to maintain the "factory" balance. But given Buick's crappy factory balance, the engine should get a proper aftermarket balance job if performance is a priority, and with ALL the custom correction done on the crankshaft instead of punching custom balance holes in the flexplate, and pounding pins into the damper.
It's a Romac harmonic balancer. It was on the car when I bought it. The engine was balanced when the previous owner had it built. The balancer wobble smoothed out just off idle and the engine ran very smoothly all through the RPM range (other than at idle, because of the cam). Is it possible the inertia ring is out of round, but the balancer is still functioning properly?
Balanced..... I balanced my motor during the process the flex plate and the balancer was on the crank.... Means the balancer is part of the crank.... I can't put on a different balancer on the crank......... In other words there is a balancing slug in the balancer....
I remember looking into Romac before I bought one years ago...and then I remembered something about serviceability, then found this on their website: So, maybe time for a look inside? Or maybe that's something Romac's supposed to do. Devon
I myself know that....... Mine is at the machinist getting sleeved.. Had some oil squeezing past the seal...The sleeve will be just a tad bigger so its snugger around the seal...
That is exactly why idiots who customize the balance by dicking with the flywheel/flexplate, or the damper, should have their fingers broken with their own tools. The proper way to do this is to modify the crankshaft counterweights, not the external parts. Of course, it's cheaper/easier to balance by screwing with the external parts, and it looks just as good on the balance machine. Doesn't WORK as well in real life, and it makes parts replacement a hassle--and both the flexplate and the damper are normal wear parts.
Unfortunately, I don't have much faith in Romac. I can't find a phone number for them anywhere on the web or on their website. They have an email address, but I emailed them with a question over two years ago and still haven't heard back ... I'm about to stop holding my breathe. I did notice the water pump pulley. I will address that with the engine build. However, my machinist did measure 0.015" of runout on the inertia ring. I don't know if that's something that is just visual and the balancer will function fine, or does that mean the balancer is bad.
I know where your going with this, but the reality with this engine and the available parts, namely flexplates, is something else. Since the inception of SFI flexplates for the 455 Buick, there has not been one of them that had the correct offset weight, in the correct location. They also were flat, vs the offset that the orginal was designed with.. This made replacement of the flexplate nearly impossible, because every one it weighted differently.. and if you take a couple teeth of the ring gear, then their is no way to 'match balance" with another assembly. So for decades, we balanced every assembly to a "master" flexplate. We would then bolt on the new flexplate and add or subtract weight to bring the assembly back into balance. This allows us to then use any rotating assembly, and produce a "corrected" flexplate that will not alter the balance. I did two JW Racing "the Wheel" flexplates on one assembly once, and it took different weight removal/addition on each to correct it back to the OE master flexplate. The good news is the latest SFI flexplate from PEP, is an exact match to the OE flexplate. It also has the offset, so it correctly locates the converter mounting surface, as well as the ring gear, and I have used about of dozen of them, they are spot-on to my master flexplate. Bad news is they have been missing from the aftermarket for about a year now, just one of the many parts that are not available right now for our Buicks. Far from being cheap and easy, I paid extra to have this done, to the tune of 40-50 bucks per assembly. JW
Mr. Weise, that's a whole-different philosophy than what I'm complaining about. YOU are doing it right. You are trying to CORRECT improperly-built parts so they match a standard. Having spent time, money, effort, and enthusiasm to achieve the "standard" balance of that improperly-made flexplate, any other standard-balanced flexplate could be substituted without upsetting the engine balance. That's the way it's SUPPOSED to work, at least with most engine families. The crappy balance-job destroys what "should" be a standard balance of the flexplate, in order to custom-balance the flexplate to suit an individual engine, then when that flexplate (or flywheel, or damper) gets replaced, a standard-balance part can't be used. The new part has to be match-balanced to the goofy-balanced previous part. And--as you said--if the "old" part is so damaged that it can't be used to match the new part to...the engine owner is pretty-much screwed. This is why the wear-parts (flexplate, flywheel, torsional damper) shouldn't be custom-balanced to correct the crankshaft, the crank counterweight(s) should be corrected, leaving the wear parts at whatever the standard design balance is--which might be neutral-balance, but often is a manufacturer-specified "official" imbalance.
