Ledphoot Posted April 9, 2007 Share Posted April 9, 2007 I have a ?? I should already know the answer too but don't! The harmonic balancer for a small block chevy ( exc. 400 of course) in this case a 71 350 4 bolt main. I want to buy a new harmonic balancer and I was wondering what the advantages/disadvantages were for using a smaller vs larger unit. I know 4 bolt main mtrs come with the large one but is it necessary? Does it effect torque, rpm , how fast engine revs..etc? I know my 350 is internally balanced to a zero balance damper is what I need but do I go big or little, steel, aluminium, ?? Quote Link to comment Share on other sites More sharing options...
getZ Posted April 9, 2007 Share Posted April 9, 2007 If you have 240z you probably can't go to an 8 inch depending on which motor mounts you went with. The JTR mounts will put the harmonic balancer right over the steering rack. I run a 7 inch without the body spacers I got from JTR. As far as size, this is one case I have heard bigger is better. I always thought weight influenced how well the balancer worked, so I assume smaller or lighter (aluminum) would let the engine spin quicker but lose some its ability to dampen, but that's just my two cents. You can write directly to a manufacturer like Fluidamper to get the real facts. By the way if you don't plan on a radical build (high rpm), you don't need an SFI speced damper and that will save you a few bucks. I have had good luck with the Pioneer ones from summit spinning to 6000 rpm. Quote Link to comment Share on other sites More sharing options...
Ledphoot Posted April 10, 2007 Author Share Posted April 10, 2007 Thanks getZ. I have heard the bigger balancer creates more torque but I'm not sure. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted April 11, 2007 Share Posted April 11, 2007 Check with David Vizard's books. I believe he says that a larger diameter dampner will help with et's believe it or not. In comparison tests, he says run the largest one you can find, because the car will be quicker! This defies logic, but I'm one to put faith in Vizard's research. As stated above, you'll be limited to diameter size depending on your engine placement, which should be your biggest concern--it has to fit to run first! Davy Quote Link to comment Share on other sites More sharing options...
Ledphoot Posted April 12, 2007 Author Share Posted April 12, 2007 well Davyz it kinda makes sense. I figure the initial torque needed to set the weight in motion is outweighed by the additional power created by the leverage of the rotating mass once set in motion. So once you get that balancer moving it perpetuates the force of rotation and makes it easier for all of those internal components to move. Quote Link to comment Share on other sites More sharing options...
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