SergntMac
06-30-2005, 03:31 PM
I'm starting a new thread on a topic the grew out of a discussion on UD pulleys and oil pump damage on Mach Is. As the discussion matured, it turned into a topic that needed some air of it's own. Here's the previous thread, if this is new to you it would be helpful to read here first.
http://www.mercurymarauder.net/forums/showthread.php?t=19325
Here's where we left off;
As Cyclone03 had mentioned before, I think you're talking about two separate issues. DAMPENING, and BALANCING. Yes, they're both important, but they're not the same. In an internally balanced engine, the dampner is still needed, but it's only used for DAMPENING vibrations, which otherwise would travel through the crankshaft, and into other components such as the oil pump gears. The vibration Dampener isn't used, nor needed for balancing on an internally balanced engine, which is already balanced BEFORE the vibration dampener is installed.
On an externally balanced engine, the engine internals are NOT completely balanced as an assembly until the flywheel, and vibration dampener are installed, because the dampener and the flywheel are both used to balance the crankshaft. As for heavier vibration dampeners being used on internally balanced engines, you're correct. The car manufactures are going with bigger and heavier vibration dampeners in Hi-perf applications, yes. But that has nothing to do with balancing needs. That has to do with the fact that lighter vibration dampners often do not absorb, or "dampen" the vibrations that run through the crankshaft as thoroughly (especially in a high RPM enviroment).
Those vibrations are a normal occurance in any internal combustion engine, and will always be present regardless of whether or not the engine is balanced. The vibrations stem from the exerting force of the expanding fuel/air mixture upon the pistons during the compression stroke, which in turn is transfered to the connecting rods. This force being exerted on the connecting rods, causes them to flex, and therefore vibrate BIG TIME ( connecting rod "harmonics"). Those continual harmonic vibrations travel through the connecting rods, and into the crankshaft,and the crankshaft acts as a conductor of those vibrations. And w/out adequate dampening of this vibration via a vibration dampener attached to the crankshaft snout, the vibrations will not stop at the cranshaft, but will travel into other areas, and engine components will be destroyed, and eventually the engine will fail.
As Mr. Reinhart has pointed out, some people have neglected to replace their vibration dampeners after they've removed them during the under drive pulley installation, and running any internal combustion engine in a street car w/out the use of a vibration dampener is an accident just waiting to happen. It's only a matter of time before the normally occuring vibrations produced by any engine will begin to destroy various engine components IF they aren't dampened, and it usually will not take very much time for that to happen either. But again, that has nothing to do with engine balancing. These are two separate issues (vibration dampening, & engine balancing).
Greater care in precise engine balancing is taken during hi-perf engine assembly so that the reciprocting mass will run smoother, and will create less resistence to the force of internal combustion. That translates into more power. It's the same reason why serious drag race engines are built with lightweight aluminum connecting rods, and lightweight pistons. Less resistence= more power. But that hasn't anything to do with vibration dampening. ;)
Excellent post, Billy, thank you. I agree that I may be confused. I did a lot of engine building and drag racing 35 years ago, but only recently, since owning a Marauder, have I come back into the sport. I've had to catch up with a lot of newer technology that wasn't around when I was 20, some of which you younger gents take for granted today, such as automatic trannys, triple plate high stall torque converters, electronic computerized control over the entire driveline, and so on. I've been confused a number of times here, but I'm getting better at it.
Right now, I'm confused on the difference between a crank mounted external balancer, and a harmonic damper, and I am confused, because I'm not finding the answers I expected. Billy says ^ there that they are two different issues, with two different resolutions. Others posted likewise comments in the previous thread, and I listened to all of them. However, this contradicts contemporary thought from the resources I researched in my learning update.
Randy Crowley at PER, a professional race engine builder gave me my first lesson on this, that there are crankshafts that are internally balanced, and crankshafts that are externally balanced. I've seen the proof of that too, in the Ford Racing catalogue, and I'll come back to that later. Sean Hyland gave me my second lesson in his handbook for preparing the 4.6 and 5.4 mod motors for racing, identifying internal and external balance, and adding a third "neutral balance" in crankshaft technology for the 4.6/5.4 mod motor. Both professional men homoginized the topics which leads me to believe that the two different issues are no longer two different issues, and suggest some sort of hybird resolution in new technology. Here's my reasoning.
The FRP catalogue has two pages of crankshafts to pick from. Page 72 has specs for 7 crankshafts, and only one of them is identified as internally balanced. On the next two pages, 74 and 75, are all the harmonic dampers FRP offers, and with grand variety. Choices include rubber, steel, billit aluminum, with or without internal hydraulic fluids, and one even includes removable weights for fine adjustment. But, my point is, there's not one balancer offered. Six crankshafts that will need an external balancer, but FRP offers none. But wait, there's more...
I went to Summit on-line and did a few searches. The first was on crankshafts, and over 800 products came up. I paged through a few for specs, and concluded that about half are identified as externally balanced, and will need of an external balancer. Good, now I get to see what the new technology balancer looks like. So, I searched for balancer, and what does the search produce? Over 400 products returned under the heading of "harmonic damper". The search engine didn't produce any balancers, but offered harmonic dampers in it's place. Out of the first thirty products returned, only once did the word balancer appear, and that's an ARP bolt kit for the old technology.
I did the same at Jegs, got basically the same results. The only time I saw the word balancer, was balancer accessories, such as bolts, hubs, and so on, as well as a few replacement parts for older engines, like AMC small blocks. Oh, BTW, there was a new product from Summit called a "torsional vibration absorber", WTF is that?
I found dozens of harmonic balancers, and one balancer, what should I conclude? This is how I got confused, and I guess I am still confused now. Finding this while looking for answers, doesn't help.
http://www.karkraft.com/46_damper.jpg
The pic is "46_damper.jpg", the largest and heaviest damper on FMC parts shelves, but look what KarKraft calls it? (page down here)
http://www.karkraft.com/modular_parts.htm
My thanks to Billy and Lance for trying to set me straight, but actually, I don't think I was off track to begin with. It's my conclusion at this time, that what was once two seperate issues, share one solution today.
http://www.mercurymarauder.net/forums/showthread.php?t=19325
Here's where we left off;
As Cyclone03 had mentioned before, I think you're talking about two separate issues. DAMPENING, and BALANCING. Yes, they're both important, but they're not the same. In an internally balanced engine, the dampner is still needed, but it's only used for DAMPENING vibrations, which otherwise would travel through the crankshaft, and into other components such as the oil pump gears. The vibration Dampener isn't used, nor needed for balancing on an internally balanced engine, which is already balanced BEFORE the vibration dampener is installed.
On an externally balanced engine, the engine internals are NOT completely balanced as an assembly until the flywheel, and vibration dampener are installed, because the dampener and the flywheel are both used to balance the crankshaft. As for heavier vibration dampeners being used on internally balanced engines, you're correct. The car manufactures are going with bigger and heavier vibration dampeners in Hi-perf applications, yes. But that has nothing to do with balancing needs. That has to do with the fact that lighter vibration dampners often do not absorb, or "dampen" the vibrations that run through the crankshaft as thoroughly (especially in a high RPM enviroment).
Those vibrations are a normal occurance in any internal combustion engine, and will always be present regardless of whether or not the engine is balanced. The vibrations stem from the exerting force of the expanding fuel/air mixture upon the pistons during the compression stroke, which in turn is transfered to the connecting rods. This force being exerted on the connecting rods, causes them to flex, and therefore vibrate BIG TIME ( connecting rod "harmonics"). Those continual harmonic vibrations travel through the connecting rods, and into the crankshaft,and the crankshaft acts as a conductor of those vibrations. And w/out adequate dampening of this vibration via a vibration dampener attached to the crankshaft snout, the vibrations will not stop at the cranshaft, but will travel into other areas, and engine components will be destroyed, and eventually the engine will fail.
As Mr. Reinhart has pointed out, some people have neglected to replace their vibration dampeners after they've removed them during the under drive pulley installation, and running any internal combustion engine in a street car w/out the use of a vibration dampener is an accident just waiting to happen. It's only a matter of time before the normally occuring vibrations produced by any engine will begin to destroy various engine components IF they aren't dampened, and it usually will not take very much time for that to happen either. But again, that has nothing to do with engine balancing. These are two separate issues (vibration dampening, & engine balancing).
Greater care in precise engine balancing is taken during hi-perf engine assembly so that the reciprocting mass will run smoother, and will create less resistence to the force of internal combustion. That translates into more power. It's the same reason why serious drag race engines are built with lightweight aluminum connecting rods, and lightweight pistons. Less resistence= more power. But that hasn't anything to do with vibration dampening. ;)
Excellent post, Billy, thank you. I agree that I may be confused. I did a lot of engine building and drag racing 35 years ago, but only recently, since owning a Marauder, have I come back into the sport. I've had to catch up with a lot of newer technology that wasn't around when I was 20, some of which you younger gents take for granted today, such as automatic trannys, triple plate high stall torque converters, electronic computerized control over the entire driveline, and so on. I've been confused a number of times here, but I'm getting better at it.
Right now, I'm confused on the difference between a crank mounted external balancer, and a harmonic damper, and I am confused, because I'm not finding the answers I expected. Billy says ^ there that they are two different issues, with two different resolutions. Others posted likewise comments in the previous thread, and I listened to all of them. However, this contradicts contemporary thought from the resources I researched in my learning update.
Randy Crowley at PER, a professional race engine builder gave me my first lesson on this, that there are crankshafts that are internally balanced, and crankshafts that are externally balanced. I've seen the proof of that too, in the Ford Racing catalogue, and I'll come back to that later. Sean Hyland gave me my second lesson in his handbook for preparing the 4.6 and 5.4 mod motors for racing, identifying internal and external balance, and adding a third "neutral balance" in crankshaft technology for the 4.6/5.4 mod motor. Both professional men homoginized the topics which leads me to believe that the two different issues are no longer two different issues, and suggest some sort of hybird resolution in new technology. Here's my reasoning.
The FRP catalogue has two pages of crankshafts to pick from. Page 72 has specs for 7 crankshafts, and only one of them is identified as internally balanced. On the next two pages, 74 and 75, are all the harmonic dampers FRP offers, and with grand variety. Choices include rubber, steel, billit aluminum, with or without internal hydraulic fluids, and one even includes removable weights for fine adjustment. But, my point is, there's not one balancer offered. Six crankshafts that will need an external balancer, but FRP offers none. But wait, there's more...
I went to Summit on-line and did a few searches. The first was on crankshafts, and over 800 products came up. I paged through a few for specs, and concluded that about half are identified as externally balanced, and will need of an external balancer. Good, now I get to see what the new technology balancer looks like. So, I searched for balancer, and what does the search produce? Over 400 products returned under the heading of "harmonic damper". The search engine didn't produce any balancers, but offered harmonic dampers in it's place. Out of the first thirty products returned, only once did the word balancer appear, and that's an ARP bolt kit for the old technology.
I did the same at Jegs, got basically the same results. The only time I saw the word balancer, was balancer accessories, such as bolts, hubs, and so on, as well as a few replacement parts for older engines, like AMC small blocks. Oh, BTW, there was a new product from Summit called a "torsional vibration absorber", WTF is that?
I found dozens of harmonic balancers, and one balancer, what should I conclude? This is how I got confused, and I guess I am still confused now. Finding this while looking for answers, doesn't help.
http://www.karkraft.com/46_damper.jpg
The pic is "46_damper.jpg", the largest and heaviest damper on FMC parts shelves, but look what KarKraft calls it? (page down here)
http://www.karkraft.com/modular_parts.htm
My thanks to Billy and Lance for trying to set me straight, but actually, I don't think I was off track to begin with. It's my conclusion at this time, that what was once two seperate issues, share one solution today.