Will Posted April 5, 2015 Share Posted April 5, 2015 Harmonic balancer is looked a little aged and I was thinking about replacing it. But honestly I've never bought one before, what shhould I look for or reccomendations for a 468. Thanks Quote Link to comment Share on other sites More sharing options...
cudax Posted April 5, 2015 Share Posted April 5, 2015 Lots of good ones out there. Personally, I put a TCI Rattler on my 496 and am real happy with it. Some people might consider it a negative, though I don't, is that when you shut off the engine the last thing you hear are the weight balls dropping. I think it sounds pretty cool and it doesn't bother me one bit. Look it up and compare with some of the other big name brands out there such as Fluid Damper. As long as it has proven performance, it's all personal preference IMO. Mike Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 5, 2015 Share Posted April 5, 2015 tell us more about your 468? stock crank? (my 468 is internally balanced, most are externally) just a warmed up 454? or more of a "built" serious street/strip engine? Quote Link to comment Share on other sites More sharing options...
72MC Posted April 5, 2015 Share Posted April 5, 2015 You'll never go wrong with anything from ATI. That's all I buy for any of my applications now or in the past. Very well built. Don't ever think you can overkill when it comes to balancing your engine. Vibration kills an engine. Of course the balancer is a fine tune instrument. The assembly must be balanced properly first. Just my 2 cents. - Dave Quote Link to comment Share on other sites More sharing options...
Murphy Posted April 6, 2015 Share Posted April 6, 2015 Sam, why did you go with an internally balanced crank? Have been looking at 400SB's and they are externally balanced and the advice is to go internally balanced crank on them also, I'm just trying to understand why?? Didn't mean to hijack this thread........... Quote Link to comment Share on other sites More sharing options...
Will Posted April 6, 2015 Author Share Posted April 6, 2015 She is decently built, but not extreme. Street/Mild Strip the builder called it Externally balance SCAT 9000 steel crank 10.1 compression Edelbrock victor series heads 454-R Crane cam Int 234 Exh 242 Lobe separation 112 Intake center line 107 Overlap 14 @.050 Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 6, 2015 Share Posted April 6, 2015 I would go with a ATI as Dave recommended like this one http://www.summitracing.com/parts/ati-917740/overview/make/chevrolet Quote Link to comment Share on other sites More sharing options...
Bluemalibu Posted April 7, 2015 Share Posted April 7, 2015 Will, pull the balancer and check it for signs of grind marks or drilling/filling with tungsten. Most machinists today try to shy from altering the harmonic balancer and flexplate as part of balancing the reciprocating assembly on an internally balanced assembly. This allows for these elements to be replaced as is frequently required. Should the dampner on this externally balanced engine exhibit evidence of having been altered for balance, a replacement can be created by a good machine shop... and any altered balancer should be scribed with matching marks that would identify slipping between the outer and inner parts of the dampner. Murphy, here is a pretty good explaination of the strengths of the internally balanced cranks: the differance between the INTERNALL BALLANCED CRANKS and EXTERNAL BALLANCED CRANKS is the stress levels the crank and block are put thru, (both methods work, but the internal ballance has far less stress) and keep in mind that the EXTERNAL ballance cranks normally use a 8" dia. damper which can cause clearance problems on a frame that designed to clear a 6.0-thru 7"" internal ballance damper dia.on either method the rods and pistons,are matched as to weight first to the lowest common weight to the lightest of the 8 in each seton an EXTERNALLY balanced crank the entire crank, rods pistons, are then ballanced as a unit by adding or subtracting weight from the damper and flexplate/flywheel mounted at the ends of the crank.on the internally ballanced crank, the crank itself is ballanced first, so it is equally in weight radially from the crankshaft center line then the damper and flexplate are mounted and they are match ballanced to the cranks ballancewhy does it make a differance , you ask?well if your externally ballanced the crank is constantly flexing the crank from one end to the othrer while the ends are trying to slow or speed up to absorb or release energy from the piston/rods thrust on the crank due to cylinder pressureson an internally ballanced crank that thrust force is basically working only against the individually crank throwagain, Im sure your thinking , whats differancewell it might help you get a better grip on the concept if you have a strand of UNCOOKED spageti (PASTA) I cant spell) and use a black majic marker to draw a line on one edge onlyplace a single strand between your index finger and and your thumb on each end of the strand and roll it rapidly back and forth, thats similar to INTERNAL BALLANCE STRESS, notice the line stays straitnow do the same thing but roll the pasta from only one end while holding the other end to provide resistance, notice the line spirals first in one then the other dirrection,this same flexing happends to the cranks under hundreds of pounds of cylinder pressures exerted over the four cylinder pressure points and millions of times at up to 60 times a second, , now youll have a nearly impossiable time breaking the pasta using the internally ballanced roll test because the pastas under almost no stress, but add resistance to the EXTERNAL test and the pasta SNAPS EASILYkeep in mind stress is cumulativethe internally ballanced crank has the individual cylinder exert major force over one throw, externall cranks absorb the stress over the full crank length,now add to that the fact that many cheaper externall ballanced cranks are comonly cast steel with smaller counter weights and many of the more expensive internally ballanced cranks are comonly FORGED STEEL with larger counter weights making ballincing easier,and youll find the differance in resistance to flex is a huge differance Quote Link to comment Share on other sites More sharing options...
Its Just Me Posted April 8, 2015 Share Posted April 8, 2015 That's what I was gonna say! Quote Link to comment Share on other sites More sharing options...
Murphy Posted April 8, 2015 Share Posted April 8, 2015 Thanks a bunch Doug, great effort in the explanation! Quote Link to comment Share on other sites More sharing options...
Bluemalibu Posted April 9, 2015 Share Posted April 9, 2015 Glad to help, Murphy. It wasn't really a lot of effort though, ...rather than re-engineering the wheel, I simply cut-n-pasted an explanation that I had previously seen. I am really drawn to your '71. Each time that I see it I am reminded of my first Monte that I purchased at the end of 'Nam. (And which got me hooked on the breed) It was a '72 that was pumpkin colored. Doug Quote Link to comment Share on other sites More sharing options...
Murphy Posted April 9, 2015 Share Posted April 9, 2015 Thanks Doug. The original owner bought it when he came back from NAM also (my best friends older brother) his fiancé wouldn't let him buy the 71 SS he wanted cause it had bucket seats??? Quote Link to comment Share on other sites More sharing options...
Bluemalibu Posted April 9, 2015 Share Posted April 9, 2015 ...his fiancé wouldn't let him buy the 71 SS he wanted cause it had bucket seats Sacrilege!!!! Quote Link to comment Share on other sites More sharing options...
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