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Discussion Starter #1
I was just about to place an order for a Probe-based CHP 347 rotating assembly, and was stopped short when it came to the issue of balancing the assembly. I really want to use their in-house balancing service, since it is such a good deal and I trust their practices. But here's the problem...

It is my understanding that in an ideal situation with externally balanced engines, the complete rotating assembly should all be balanced together with the exact same flywheel and dampener that are going to end up on the engine. The thing is though, I already have the 164 tooth flywheel that is required for my 4 speed top loader's bellhousing. Also, they only offer 157 tooth flywheels to begin with, so those wouldn't work for me.

What I'd really like to know is if there's anything necessarily wrong with just ordering an externally balanced rotating assembly without the flywheel, and just slapping my own flywheel on when I get it? Is this going to throw the balance completely off?

There's nothing on CHP's site preventing me from ordering a balanced assembly in lieu of the flywheel, so it must be at least doable (I assume they'd just be balancing it with one of their own flywheels or flexplates as a placeholder). On top of that, I'm well aware that flywheels and flexplates of all varieties are ROUTINELY swapped out and replaced on all kinds of externally balanced SBF engines, and I've never heard of that being an issue before. If a flywheel needs replacing, they obviously aren't going to tear the whole engine down just to re-balance it, and it seems to work just fine.

On top of all that, this is going to be a street-only sub-6000 RPM motor. I'm not going to be revving the thing to the sky on a regular basis, even with the 4 speed, so I'm thinking an absolutely perfect balance isn't entirely necessary.

Anyway, is what I'm planning on doing here inadvisable, or should I just go ahead and do it? The alternative is to deal with a local shop which may or may not provide quality workmanship, and will likely charge a great deal more either way.

Either way, I'm probably overthinking it, right? :D
 

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No issue with having them balance so long as you use the correct balance flywheel and balancer that engine was balanced for.
 

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Discussion Starter #3
That's sort of what I thought.... so essentially, as long as I'm matching a balanced 28oz bottom end to an off-the-shelf 28oz flywheel or 28oz dampener, then everything should be fine? I didn't know if they would typically add/remove material from the flywheel itself as part of the process.
 

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You got it.
 

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When I ordered mine I had them balance it. I will have it rebalanced locally with my balancer and flywheel when I get to that point. It my not be needed but Im gonna do it for my own peace of mind.
 

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Here's a crazy idea, call them. :eek: Seriously, these guys (and gals) are nice folks and were very helpful from start to finish with me. They'll answer your questions and work with you on this kind of thing. I picked up my short block up from their shop in Torrance, CA since it's local to me. It is a real shop with real people inside. I have to say that it's not always easy to get someone on the phone, I had left messages at times but they called back, or I did. They do get busy up in the front office where the sales and tech people are so be patient.

John
 

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How much is it roughly to get a rotating assembly balanced ??
Do you mean locally? Typically around $200, give or take some. If it needs Mallory (heavy metal) for more weight on a crank throw, it will be much more due to the high cost of the metal.
 
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