Quote:
Originally Posted by Murf
Yes Steve, it would be easy to notice for most folks if they were looking for it. I just thought I’d mention the possibility of an adapter plate being used. Thus, the need for a spacer on the crank / flex plate.
Just trying to figure out why there would be a spacer where there shouldn’t be.
Murf
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Welcome, I spoke to Butler Performance and asked about the shim, turns out to be the way the Factory spaced the Torque Converter to Flexplate to leave, I believe to be 3/16 - 1/4" Gap that remains to couple the two together.
Then the 1/8" metal plate strengthens the Flexplates flexible hardened plate steel and sandwiches it between the Crankshaft @ the rear of the Engine The rest is here:
https://butlerperformance.com/n-1349...k-balance.html
Flexplate noise + Balancing info. I have recently replaced my Harmonic Balancer, Remanufactured my own TH 400 Trans. Over the last 2 years, Installed Remanufactured Heads and Replaced every moving wearable part inside this motor meaning from you I bought the Johnson lifters, HD Push Rods, HD Rocker arm studs and the 041 Cam. It had a dual chain Timing set. I have a new oil pump. I believe I need a Flexplate for this Automatic Trans.
When I rev up from 1000 rpm to 2000 rpm, I hear a ghost noise that sounds mechanical, after 2K the sound goes away under a load and when I rev. It up while stopped in park, it makes noise between 1k and 2k then past 2k the noise disappears and coming back down you hear the noise and at idle it's gone again. We pulled the Flexplate and we see that the holes for bolts to the Crankcase are out of round. Also, the thin and thick plates on both sides show the same ware patterns, out of round, I think they could be moving while sandwiched in between the Flexplate and the Torque Converter. By the way the Torque converter is new also, built when we built the Trans. I am interested in your HAY- 13-065 Flexplate, please advise. I have a 1967 Pontiac 428 ci HO Engine, how was that balanced from the Factory? Next, I bought a new Harmonic Balancer online and it came with the Hub, weight, spacer plate metal with holes, designed for this motor, Ames N585 Hub and counter weight- Cost $270. I used all the parts since I had paid for them- instead of using just their hub. "Will that, in itself cause a noise?". We pulled the Flexplate and there were no cracked welds or any issues other than I have "out of round holes for the bolts". You need to advise, please to whether or not my Engine is Internally balanced, for sure, from the Factory. It is my thought, from my research, that the 428 ci motor was indeed internally balanced. My Flexplate uses a spacer and a thin Shim on each side. P.S. There was first a ghost noise and that turned out to be the cracked Hub on the Harmonic Balancer, when replaced that noise disappeared. This new noise began after that change or was running simultaneously. This latest ghost noise is a knocking type, at first thought to be Ignition Timing. Timing is checked and is "OK", the noise/sound ranges from 1000 RPM to 2000 RPM and then goes away, under load when moving. Also, if I rev. the Motor up at a stop, it does the same thing, goes away under 1000 RPM. Just to paint the entire picture, I had an accident two years ago by riding over a root under an asphalt drive- way that was raised high enough to lift the Trans. The Trans. was rebuilt over the next two years by me and my roommate, successfully. The Torque Converter is a new Hughes, then the Harmonic Balancer and now the Flexplate is suspect. Sending photos:
https://butlerperformance.com/n-1349...k-balance.html Engine Balancing- Internal (neutral) vs. External (stock)
Assembly balancing is a very popular question. Balancing the crank is a method of weighing each part of an assembly and drilling the crank to remove or add weight so that assembly spins in a true rotation. This true rotation or balance makes the crank spin without any additional centrifugal forces that would cause vibrations and lead to bearing wear and possibly catastrophic engine failure.
Pontiac traditionally did a semi-internal balancing on the crank. The crank was not zero balanced but had to use the balancer and flexplate (auto trans) or flywheel (manual trans) with offset weighting to finish the assembly balance.
We no longer balance using this method. The cranks in our assemblies are zero balanced. This is also called neutral or internally balanced. This is based on bob weights of the parts used (rods, pistons, bearings, and rings. This method gives the truest balance and ensures the crank will spin true based on the exact weights of the assembly free of any external forces that could cause vibrations.
Most aftermarket cranks are factory weighted for use with aftermarket rods. These rods are much lighter than factory rods. This can cause a problem during the balancing process. The crank would need to have weight added to make the balance. This process means the crank is drilled for a heavy weight that is welded in place. This process can make the cost rise as heavy metal and labor would need to be added to the balancing costs. In many cases the cost is not far from that of a new set of rods. So, upgrading the 50-year-old rods is not much more money in the long run in most cases.
So which balance do I have?
That is not always easy to tell. If it is a factory original engine and has never been rebuilt it is externally factory balanced. If it has been rebuilt you would need to ask your builder what balance method was used.
What if I don't know the history of the engine?
The best way to tell is by looking at you're existing flexplate or flywheel. You can use the images below to identify if there is an additional weight added or material removed such as holes or cavities in a section of the part making it offset balanced.
Stock balance is also called externally balanced. This means it took an offset part on the outside/external to finish the balance. Butler balances the crankshafts without the need to finish the balance externally. This is called neutral or internally balanced.
Mikes Reply:
Butler Performance says that From the Factory, I should have an Externally Balanced Motor. They said in my case to look at the Flexplate for the 4 round 7/8" holes drilled through the outer area. They are present, there for; most likely no one has Internally balanced this Crank, Pistons and rods, as I once thought had happened, when the Pistons were modified in 1968 and the motor was stamped on the P.S. front Head. They simply moved the Pistons in the opposite direction/backward, some think it was a mistake and some say it was a race thing used in the old days. The number two piston remains in the correct orientation.
The Harmonic Balancer is a new Ames N585 Hub and counter weight- Cost $270.
Butler says that if a Motor was worked on by someone prior, who internally balanced the motor, I would have to speak to them.
I am going off the fact that the existing Flexplate is balanced to the Engine and has 7/8" holes drilled around the perimeter to prove it.
The Harmonic Balancer is set-up to be Neutral in weight, so the kit I added should not affect the Balance of things.
After speaking to Butler, I have decided to purchase the new Flexplate and the associated ARP Bolts that are used with it. My Flexplate is old, used and the inner bolt holes show egg shape and out of roundness. Better to be safe than sorry.
I intend on keeping the Thin Spacer and I will use Brake Quiet on it just in case that was my rattling noise experienced between 1000 and 2000 RPM. The thick 1/8" plate, we will use as well and I will use brake Quiet on it too, just in case. Eliminating any harmonics from the "out of round parts". This might work as well as it does on the back of brake pads. I have yet to find the shim or plate in the aftermarket, so if any of you know where I can buy those parts, I would rather replace them as well.