TimZ Posted March 7, 2003 Share Posted March 7, 2003 It's a DAMPER. Not DAMPENER or DAMPNER. It DAMPS crank torsional harmonics' date=' it doesn't dampen or dampn them. Damper damper damper. Or harmonic balancer.[/quote'] I would contend that in this context, dampen is a synonym of damp, dampner is a contraction of dampener. I will concede that I'm not sure whether dampener or dampner is correct, but I think it's pretty CLEAR what I was describing. What I don't get is how you can get all pissy about damper vs. dampener/dampner, and then say it's okay to call it a harmonic balancer. While I think it could be easily argued that it does dampen torsional harmonic vibrations, IT DOESN"T BALANCE ANYTHING, at least not on our motors. Even on external balance motors, it is not 'balancing' the harmonics that we are concerned about. IMHO, this is far more misleading. This can and does lead people to believe that it's okay to use a solid crank pulley, so long as the engine is internally balanced. In fact this is exactly the reasoning that Unorthordox (incorrectly) uses to sell their pretty but poorly engineered (yes I'm saying it out loud) solid crank pulley setups. This is what I was talking about earlier when I mentioned that it should worry you that they don't even understand the problem. Quote Link to comment Share on other sites More sharing options...
clint78z Posted March 7, 2003 Share Posted March 7, 2003 Agreed it is very irresponsible to run a solid crank pulley, I seriously doubt that it would provide any benifit in power. To describe what is going on here to others, I will give an example. Any crankshaft has a given mass and length. The type of metal and mass have certain resonant frequencies say 1mhz and 5mhz (I am making this up). So if you had a loud stereo and played either of these frequencies the crank would start to dance or vibrate. Now when revving your engine at say 3500rpm and 7500rpm it hits these frequencies. You crank starts to dance by itself, this will try and twist your crank like a pretzel. The longer the crank is the more twisting action. It's like the pictures dancing on your wall if you turn your stereo way up. The solution is to use a vibration damper, this attaches the crank on one end to a outer ring with a weight on the outside. When the nasty little vibration occurs at the magical rpm, the rubber ring twists and absorbs some of that twisting vibration. So it is key to have that good rubber ring, it will save you crank from twisting itself in half. This is the main factor that limits the L6 rpm capabilities, not valve float or piston slap. Quote Link to comment Share on other sites More sharing options...
SHANE Posted March 7, 2003 Share Posted March 7, 2003 how about just shifting at 6000rpm? there is NO need to spin the engine higher than that. run more boost, toss the cam in the trash and go with a stocker. add nitrous and problem is solved. if you are trying to be fast unboosted than buy a V8 (250 RWHP fast does not make). its not a damn honda, there is no sense in trying to spin a SOHC 2V motor to 9 grand. an inline 6 is torquey by design, use that. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 7, 2003 Author Share Posted March 7, 2003 Getting back to the original problem I'm having... I have took the sugestion of a fellow HybridZ'r with this fix. It allows the pully mounted in rubber to still flex as it should, but not allow it to spin. I drilled all the way thru with a 13/64 bit, then used a couple sizes bigger bit to drill only thru the pully portion. Then I tapped the 13/64th hole for a bolt to run down inside it, then ground it off in the v groove. This allows like I said, for the pully to still move and float as before... I will try this out and hopefully, it will be the end of the spinning alt/wp pully on the solid part of the " DAMPER " Quote Link to comment Share on other sites More sharing options...
Synlubes Posted March 7, 2003 Share Posted March 7, 2003 J. Now what about the ballance of the modified pully ? Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted March 7, 2003 Share Posted March 7, 2003 I would contend that in this context' date=' dampen is a synonym of damp, dampner is a contraction of dampener. I will concede that I'm not sure whether dampener or dampner is correct, but I think it's pretty CLEAR what I was describing. What I don't get is how you can get all pissy about damper vs. dampener/dampner, and then say it's okay to call it a harmonic balancer..[/quote'] Just trying to help! "Dampener" is NOT synonymous with "damper", and "dampner" is an in-between non-word people use because they're not sure. The correct term is "damper". I prefer "damper" to "harmonic balancer", but both terms are acceptable. J. Soileau, it appears you're pinning the damper such that the two metal parts are rotationally locked to each other. Seems to me that prevents the damper from performing its function of damping crank harmonics. Or am I missing something? JeffP, is the Euro damper the single groove one? I wonder why it should be any more durable. So now I've got another thing to be nervous about... Pissy to the end, Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 7, 2003 Author Share Posted March 7, 2003 It was modified already, with the metal shaved off the backside, then the Electamotive Tec2 ign. wheel put on it. To be honest I never really worried about that. Maybe this is why I have so much trouble with dampers Should I try and find a place to spin ballance just the damper?? Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 7, 2003 Author Share Posted March 7, 2003 J. Soileau, it appears you're pinning the damper such that the two metal parts are rotationally locked to each other. Seems to me that prevents the damper from performing its function of damping crank harmonics. Or am I missing something? I guess I really don't understand the harmonics stuff to well All I can say is, the pully still is suported by the rubber, and it still can rotate back and forth (very little though). All I have done is stake a pin in the solid part, allowing the pully to stay as it would normally be, but not be able to sheer the rubber. The pins do not touch the suspended pully, unless it was to twist quite abit... THANKS FOR ALL THE IDEAS Does this make any more scense ?? Quote Link to comment Share on other sites More sharing options...
jgkurz Posted March 7, 2003 Share Posted March 7, 2003 Hi J. Soileau, I'm just curious, what RPM range does your engine operate in? Thanks, Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 7, 2003 Author Share Posted March 7, 2003 umm, let's see...... around 0-7300 rpm.... Quote Link to comment Share on other sites More sharing options...
David K Posted March 10, 2003 Share Posted March 10, 2003 Ok guys, you all got the greenlight to do the drill and stud thing on the outer water pump pulley. I drilled 4 holes like a cross and pounded some studs in there and then grinded them off. The car runs great!!!!!! I did this after i lost the pulley on the new z i got 2 days ago. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 10, 2003 Author Share Posted March 10, 2003 I hope it works out for ya... I got mine all back together this weekend and so far the pully appears to be spinning... Quote Link to comment Share on other sites More sharing options...
David K Posted March 11, 2003 Share Posted March 11, 2003 Jeff, Ok from what i read is that you guys are also having problems spinning the crank pulley. All of you also have much much more hp than i do. I have a stock engine in that new 280zx i got and it runs perfect and i choose to keep it that way. The pulley went south so i studded it. Does HP play a role in how bad the vibration on the crankshaft is? Since you guys have more hp, would it be worse in your engines than mine if i run a solid pulley? Thanks Quote Link to comment Share on other sites More sharing options...
David K Posted March 12, 2003 Share Posted March 12, 2003 Ok, I called around all afternoon yesterday to a few z shops and this is what i found out. There is no real danger of running a solid pulley. There is no magical vibration that would destroy the crank. The 2 guys at one shop i spoke to told me they have run race cars for years with solid pulleys. They never had anything happen to the engine and it still purrs even when they turn it on nowadays. Then i think to myself. What possibly can a tiny strip of rubber going to do to a vibration that could destroy your engine?!?!?!?! If there was real danger of this happening, im pretty sure Nissan would have went different lengths to handle this problem instead of using a petty peice of rubber. Anyway, the only vibration i see hurting anything it the vibration of the crank going to the water pump and alternator. Even the rubber belt would absorb most of that. Ive been thinking about this for 3 days now, and very hard on top of that and i dont see any way and any PROOF that running a soild, balanced pulley, 2 groove or 3 groove, would do ANYTHING to harm your engine. Quote Link to comment Share on other sites More sharing options...
TimZ Posted March 13, 2003 Share Posted March 13, 2003 I called around all afternoon yesterday to a few z shops and this is what i found out. There is no real danger of running a solid pulley. There is no magical vibration that would destroy the crank. The 2 guys at one shop i spoke to told me they have run race cars for years with solid pulleys. They never had anything happen to the engine and it still purrs even when they turn it on nowadays. Man, I bet that if Nissan ( and EVERY OTHER OEM ON THE PLANET) read that, they'd feel pretty stupid for wasting the money on those complicated magic dampers all these years. I know I do. They should have called that Z shop and got set straight. Think of the millions of dollars they could have saved. I give up. Do what you want. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 13, 2003 Share Posted March 13, 2003 I called around all afternoon yesterday to a few z shops and this is what i found out. There is no real danger of running a solid pulley. There is no magical vibration that would destroy the crank. The 2 guys at one shop i spoke to told me they have run race cars for years with solid pulleys. They never had anything happen to the engine and it still purrs even when they turn it on nowadays. Them folks are what we call "HIGH-TECH REDNECKs!" Quote Link to comment Share on other sites More sharing options...
johnc Posted March 13, 2003 Share Posted March 13, 2003 Oh God. Confusion is starting again. Go back and read again what JeffP has posted. He's right. There has to be some type of DAMPENING DEVICE on the front of the L6 crank. Whether that's the stock peice, an ATI, or the new one that Jeff helped design it really doesn't matter that much from the crankshaft's point of view. Jim Thompson has lots of stories about BMW 325/328 racers in the SCCA World Challenge Touring series breaking crankshafts after intalling Unorthodox solid crank dampers/pulleys. When they went back to the stock part the cranks would last all season. ITS racers regularly run at 7,000+ rpms and they almost universally run(Keith, step in here) the stock single pulley small diameter damper. They also get inspected periodically and get replaced regularly. And they do fail. I've seen one punch through the hood of an ITS 240Z, fly over two cars, and go through the windshield of the third car in the draft. Quote Link to comment Share on other sites More sharing options...
katman Posted March 13, 2003 Share Posted March 13, 2003 Yeah, what John said. Racers often get away with things like solid engine mounts and solid dampers because they inspect things all the time or xome of them even expect things to break because they're racing" ("I was making so much power I blew that engine", yeah, meanwhile I was trying not to spin your mess on my way to victory) but to me that just means they're GETTING AWAY WITH IT. Don't make it right, don't make it last. I'd never run a solid front pulley on L6, and I don't even run solid engine mounts in the classes I'm allowed to anymore- got tired of hardware coming unscrewed all the time and welding fatigue cracks in tube chassis and engine blocks. Plus, I guarantee you OEM's would find a way to drop the expense if it didn't have serious merit. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 13, 2003 Author Share Posted March 13, 2003 So whats the verdict on what I did to my damper to try and solve my sheering the rubber problem? That was the question I was hopeing to get answered... Quote Link to comment Share on other sites More sharing options...
David K Posted March 13, 2003 Share Posted March 13, 2003 and im also hoping these guys would answer my simple question as if a solid pulley is ok on a stock engine instead of giving a life story. Quote Link to comment Share on other sites More sharing options...
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