Harmonic Balancer
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
https://secure.viewer.zmags.com/publ...9#/9455a1b9/22
Ray
Thread Starter
Burning Brakes
Joined: Sep 2020
Posts: 807
Likes: 562
Sterling Rorden (RKCRLR) sent me this link to an SAE article. Download it (it's a PDF), it's easier to read.
https://secure.viewer.zmags.com/publ...9#/9455a1b9/22
Ray
https://secure.viewer.zmags.com/publ...9#/9455a1b9/22
Ray
Thank ye
Thread Starter
Burning Brakes
Joined: Sep 2020
Posts: 807
Likes: 562
C6 harmonic balancer was junk as well. I blew it out on a track day. Hence why I'm seeking info on the C8 balancer. I'd rather replace before the fact-- if needed. Trying to determine just how big a pain in the *** it is to replace it with a high end race rated unit. I haven't quite determined how much trouble it is yet. Anyone with info, please share.
Intermediate
Joined: Oct 2020
Posts: 48
Likes: 80
My C5 balancer went out at 40,000 miles. $20 piece of junk plastic part and $600 maintenance job to get it into the center of the engine. Only real issue I've ever had with the car in 10 years of ownership. Still pisses me off GM hasn't fixed a known garbage part. Hopefully the C8 is better. Can't imagine what a Z06 replacement would cost?
Instructor
Joined: Jan 2004
Posts: 187
Likes: 122
From: Sparks, NV
Harmonic Balancers
Grey,
I didn't see anything in the SAE article link sent by rjsmith169 that mentioned anything about a Harmonic Balancer; that link article mostly described the DC Transmission,. But typically the Harmonic Balancer on Corvettes has been in the front of the engine, attached to the front-end of the crankshaft, and has been a press -fit. It puzzles me (and pisses me off) that Chevy has NOT (ever?) used a keyed crank/harmonic balancer attachmen! Any respectable race car should have this feature that would keep the balancer perfectly indexed to the crankshaft.
The high revs and torque of the modern Corvette engines BEGS to have a keyed fitting for the balancer, but GM still uses a press-fit for the attachment, which with hard use, is subject to slipping around. Even my last two C6 ZO6's with 505 hp and 470 ft/lb of torque and 7,000 rpm capability had pressed-on HB's. Go figure. Bean counters would rather have GM fix stuff than prevent failures and problems in the first place, but hopefully the C8 (and upcoming ZO6) will up their design standards. We're talking about some pretty expensive and sophisticated cars here, and the extra cost for keyed fittings on the harmonic balancer would be justified, IMHO.
I didn't see anything in the SAE article link sent by rjsmith169 that mentioned anything about a Harmonic Balancer; that link article mostly described the DC Transmission,. But typically the Harmonic Balancer on Corvettes has been in the front of the engine, attached to the front-end of the crankshaft, and has been a press -fit. It puzzles me (and pisses me off) that Chevy has NOT (ever?) used a keyed crank/harmonic balancer attachmen! Any respectable race car should have this feature that would keep the balancer perfectly indexed to the crankshaft.
The high revs and torque of the modern Corvette engines BEGS to have a keyed fitting for the balancer, but GM still uses a press-fit for the attachment, which with hard use, is subject to slipping around. Even my last two C6 ZO6's with 505 hp and 470 ft/lb of torque and 7,000 rpm capability had pressed-on HB's. Go figure. Bean counters would rather have GM fix stuff than prevent failures and problems in the first place, but hopefully the C8 (and upcoming ZO6) will up their design standards. We're talking about some pretty expensive and sophisticated cars here, and the extra cost for keyed fittings on the harmonic balancer would be justified, IMHO.
Last edited by LT4 Z51; Dec 22, 2021 at 05:01 PM. Reason: Added content
Thread Starter
Burning Brakes
Joined: Sep 2020
Posts: 807
Likes: 562
Grey,
I didn't see anything in the SAE article link sent by rjsmith169 that mentioned anything about a Harmonic Balancer; that link article mostly described the DC Transmission,. But typically the Harmonic Balancer on Corvettes has been in the front of the engine, attached to the front-end of the crankshaft, and has been a press -fit. It puzzles me (and pisses me off) that Chevy has NOT (ever?) used a keyed crank/harmonic balancer attachmen! Any respectable race car should have this feature that would keep the balancer perfectly indexed to the crankshaft.
The high revs and torque of the modern Corvette engines BEGS to have a keyed fitting for the balancer, but GM still uses a press-fit for the attachment, which with hard use, is subject to slipping around. Even my last two C6 ZO6's with 505 hp and 470 ft/lb of torque and 7,000 rpm capability had pressed-on HB's. Go figure. Bean counters would rather have GM fix stuff than prevent failures and problems in the first place, but hopefully the C8 (and upcoming ZO6) will up their design standards. We're talking about some pretty expensive and sophisticated cars here, and the extra cost for keyed fittings on the harmonic balancer would be justified, IMHO.
I didn't see anything in the SAE article link sent by rjsmith169 that mentioned anything about a Harmonic Balancer; that link article mostly described the DC Transmission,. But typically the Harmonic Balancer on Corvettes has been in the front of the engine, attached to the front-end of the crankshaft, and has been a press -fit. It puzzles me (and pisses me off) that Chevy has NOT (ever?) used a keyed crank/harmonic balancer attachmen! Any respectable race car should have this feature that would keep the balancer perfectly indexed to the crankshaft.
The high revs and torque of the modern Corvette engines BEGS to have a keyed fitting for the balancer, but GM still uses a press-fit for the attachment, which with hard use, is subject to slipping around. Even my last two C6 ZO6's with 505 hp and 470 ft/lb of torque and 7,000 rpm capability had pressed-on HB's. Go figure. Bean counters would rather have GM fix stuff than prevent failures and problems in the first place, but hopefully the C8 (and upcoming ZO6) will up their design standards. We're talking about some pretty expensive and sophisticated cars here, and the extra cost for keyed fittings on the harmonic balancer would be justified, IMHO.
I agree, Tad tougher to actually see the factory balancer and info on it seems to be slim pickings. I'm thinking I'll have my shop boys pull it off and mount a ATI Fluid unit on or clutch disk type. Researching that now. But hell for all I know it may be a major project to change it, not sure yet.
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Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,183
From: Central Illinois
Nobody is going to make a HB for a LT2, it's real deep with two sets of grooves for two serpentine belts instead of one. Plus the fact you can get belts past it, but no room for a puller or even pull the HB far enough forward to come off the crank without dropping the engine.
Last edited by Phil1098; Dec 22, 2021 at 06:05 PM.
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
Grey,
I didn't see anything in the SAE article link sent by rjsmith169 that mentioned anything about a Harmonic Balancer; that link article mostly described the DC Transmission,. But typically the Harmonic Balancer on Corvettes has been in the front of the engine, attached to the front-end of the crankshaft, and has been a press -fit. It puzzles me (and pisses me off) that Chevy has NOT (ever?) used a keyed crank/harmonic balancer attachmen! Any respectable race car should have this feature that would keep the balancer perfectly indexed to the crankshaft.
The high revs and torque of the modern Corvette engines BEGS to have a keyed fitting for the balancer, but GM still uses a press-fit for the attachment, which with hard use, is subject to slipping around. Even my last two C6 ZO6's with 505 hp and 470 ft/lb of torque and 7,000 rpm capability had pressed-on HB's. Go figure. Bean counters would rather have GM fix stuff than prevent failures and problems in the first place, but hopefully the C8 (and upcoming ZO6) will up their design standards. We're talking about some pretty expensive and sophisticated cars here, and the extra cost for keyed fittings on the harmonic balancer would be justified, IMHO.
I didn't see anything in the SAE article link sent by rjsmith169 that mentioned anything about a Harmonic Balancer; that link article mostly described the DC Transmission,. But typically the Harmonic Balancer on Corvettes has been in the front of the engine, attached to the front-end of the crankshaft, and has been a press -fit. It puzzles me (and pisses me off) that Chevy has NOT (ever?) used a keyed crank/harmonic balancer attachmen! Any respectable race car should have this feature that would keep the balancer perfectly indexed to the crankshaft.
The high revs and torque of the modern Corvette engines BEGS to have a keyed fitting for the balancer, but GM still uses a press-fit for the attachment, which with hard use, is subject to slipping around. Even my last two C6 ZO6's with 505 hp and 470 ft/lb of torque and 7,000 rpm capability had pressed-on HB's. Go figure. Bean counters would rather have GM fix stuff than prevent failures and problems in the first place, but hopefully the C8 (and upcoming ZO6) will up their design standards. We're talking about some pretty expensive and sophisticated cars here, and the extra cost for keyed fittings on the harmonic balancer would be justified, IMHO.
"The front damper has an aluminum hub and steel inertial
ring equipped with a ribbed outer surface to drive accessories via
rubber belts. A second damper at the rear of the engine connects
the crankshaft to the dual-clutch automatic transaxle. This device
diminishes torsional vibration, a concern while switching to the LT2’s
fuel-saving Active Fuel Management four-cylinder operating mode.
The rear damper is small in diameter because no flywheel
or torque converter is required with the new automatic
transmission. Extra effort was invested in locating the new
transaxle’s input shaft below its output shafts to facilitate the
lowest possible engine mounting and center of gravity."
Damper is another engineering term for harmonic balancer.
That's why I suggested printing it or viewing it as a PDF. You can see the entire article.
Ray
Thread Starter
Burning Brakes
Joined: Sep 2020
Posts: 807
Likes: 562
Nobody is going to make a HB for a LT2, it's real deep with two sets of grooves for two serpentine belts instead of one. Plus the fact you can get belts past it, but no room for a puller or even pull the HB far enough forward to come off the crank without dropping the engine.
Read my mind, I knew you had been poking around under there. I was going to give a call and ask you what you could see. Thank ye
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,183
From: Central Illinois
Le Mans Master
Joined: Aug 2000
Posts: 5,529
Likes: 1,943
From: Austin Texas
"The front damper has an aluminum hub and steel inertial
ring equipped with a ribbed outer surface to drive accessories via
rubber belts. A second damper at the rear of the engine connects
the crankshaft to the dual-clutch automatic transaxle. This device
diminishes torsional vibration, a concern while switching to the LT2’s
fuel-saving Active Fuel Management four-cylinder operating mode.
The rear damper is small in diameter because no flywheel
or torque converter is required with the new automatic
transmission. Extra effort was invested in locating the new
transaxle’s input shaft below its output shafts to facilitate the
lowest possible engine mounting and center of gravity."
ring equipped with a ribbed outer surface to drive accessories via
rubber belts. A second damper at the rear of the engine connects
the crankshaft to the dual-clutch automatic transaxle. This device
diminishes torsional vibration, a concern while switching to the LT2’s
fuel-saving Active Fuel Management four-cylinder operating mode.
The rear damper is small in diameter because no flywheel
or torque converter is required with the new automatic
transmission. Extra effort was invested in locating the new
transaxle’s input shaft below its output shafts to facilitate the
lowest possible engine mounting and center of gravity."