chris @ bhj Posted August 14, 2008 Share Posted August 14, 2008 Just as a reminder, I posted photos and more info on the BHJ dual-pulley harmonic damper here: http://forums.hybridz.org/showthread.php?t=127184 Cheers, Chris @ BHJ Quote Link to comment Share on other sites More sharing options...
1 fast z Posted August 14, 2008 Share Posted August 14, 2008 I See you offer a 60-2 wheel. Since EDIS is more popular now, do you offer a 36-1 wheel? Quote Link to comment Share on other sites More sharing options...
Daeron Posted August 16, 2008 Share Posted August 16, 2008 Bravo!!!! I was wondering what your response to that question was going to be, and I must admit I had a bit of a sly grin.. "how is he gonna handle THAT curveball??" Your response was beautiful, honest, businessmanship. (is that a word?) Thanks for being up front and not BSing about anything. (even though I have no direct interest in any of this at the moment) You can buy the BHJ damper through your engine builder, Rebello, or any performance shop and in some cases you can get it for less than buying it directly from BHJ. We have an established "Racer Net" (retail) price, which we use for sale to the general public. If a reseller wants to sell BHJ harmonic dampers for a lower price, it is their right to do so. So shopping around is a good idea and is by no means discouraged by BHJ. You'll find this is the case with many other products and manufacturers out there. Cheers, Chris @ BHJ I would say that honesty like that more than compensates for any difference in price, and I will keep this in mind for future reference. Quote Link to comment Share on other sites More sharing options...
Clifton Posted August 16, 2008 Author Share Posted August 16, 2008 An optional 36-1 wheel would be great for alot of people. Chris, do the single groove dampers use rubber or spring for damping? Bryan and I have a little debate going. Quote Link to comment Share on other sites More sharing options...
chris @ bhj Posted August 22, 2008 Share Posted August 22, 2008 I See you offer a 60-2 wheel. Since EDIS is more popular now, do you offer a 36-1 wheel? We do not currently have one, but give me a shout and we can get to work on one. Chris @ BHJ ph. 510-797-6780 Quote Link to comment Share on other sites More sharing options...
chris @ bhj Posted August 22, 2008 Share Posted August 22, 2008 Chris, do the single groove dampers use rubber or spring for damping? Bryan and I have a little debate going. BHJ currently only manufacutres elastomer-style harmonic dampers. We use various types of elastomers, including rubber, depending on the tuning combination of any given damper. Physical size and design constraints of the hard parts are key elements in deciding which specific elastomer is used. A damper using springs would be referred to as a mechanical-style harmonic damper. These are typically larger (and often heavier) than elastomer dampers, due to the extra space needed to fit the mechanism into the damper. If anyone is interested in some in-depth (dare I say, "unbiased"?) harmonic damper tech, you can download our PDF Tech Document from the page linked below: http://www.bhjdynamics.com/index.php?main_page=page_3&zenid=amjn8brccr018bvjnf4hfc6de2 When you get to this page, click on the second link, titled "BHJ Harmonic Damper Technical Information Document" (230K PDF). This should provide plenty of fodder for good discussion. Cheers, Chris @ BHJ Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 22, 2008 Share Posted August 22, 2008 Ya know, with Chris on this thread, it might be a good place to ask about the '7500 RPM Limitation on LD Cranks' comment that floats around the internet all too often... As if some irreprable harm will come to catastrophic end should someone deign to rev their 83mm stroker L-Engine over 7500... Just a passing thought... Quote Link to comment Share on other sites More sharing options...
1 fast z Posted August 22, 2008 Share Posted August 22, 2008 Ya know, with Chris on this thread, it might be a good place to ask about the '7500 RPM Limitation on LD Cranks' comment that floats around the internet all too often... As if some irreprable harm will come to catastrophic end should someone deign to rev their 83mm stroker L-Engine over 7500... Just a passing thought... Rev Limiter is set at 8300 for awhile on the Twin car. Hits it all to quick also. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 22, 2008 Share Posted August 22, 2008 I know Bryan, that's why I mention it... Chris doens't have any vested interest in perpetuating any internet myths, and stands as a recognised expert in crankshaft torsionals... I, for one, would really appreciate his informed opinion about the orders, frequencies, critical speeds, and torsional issues inherent in the LD (or any other Datsun L-6 counterweighted) crank. Quote Link to comment Share on other sites More sharing options...
chris @ bhj Posted May 13, 2010 Share Posted May 13, 2010 (edited) Below is the new link for the Harmonic Damper Tech Document referred to in post # 26. The original link is dead: http://www.bhjdynamics.com/downloads/pdf/tech/BHJDynamics_Damper_Info.pdf Cheers, Chris @ BHJ Edited May 13, 2010 by chris @ bhj Quote Link to comment Share on other sites More sharing options...
JohnH Posted May 15, 2010 Share Posted May 15, 2010 (edited) I would not buy a BHJ dampner ever again. At least the ones with the aluminum hub. I have had one fail due to the aluminum hub. Completely wrecked the crankshaft keyway. Aluminum hub on a steel crank = fail. I'm not the only one on this board who has had this happen. I'm currently using the SFI spec, single V, steel hub dampner from Powerforce Professional Products with the special bolt/washer sold at MSA for half the price. Edited May 15, 2010 by JohnH Quote Link to comment Share on other sites More sharing options...
ctc Posted May 16, 2010 Share Posted May 16, 2010 I would not buy a BHJ dampner ever again. At least the ones with the aluminum hub. I have had one fail due to the aluminum hub. Completely wrecked the crankshaft keyway. Aluminum hub on a steel crank = fail. I'm not the only one on this board who has had this happen. I'm currently using the SFI spec, single V, steel hub dampner from Powerforce Professional Products with the special bolt/washer sold at MSA for half the price. John, Do you know why it failed? Were you using the special bolt/washer with the BHJ damper of the stock crank bolt? Quote Link to comment Share on other sites More sharing options...
JohnH Posted May 16, 2010 Share Posted May 16, 2010 John, Do you know why it failed? Were you using the special bolt/washer with the BHJ damper of the stock crank bolt? I believe mine failed due to the inherent rockwell difference between the crankshaft & the dampner hub materials. Having removed & installed the dampner a few times loosened the press fit of the hub. NO mention of a special bolt/washer combination was made in the information/installation materials from BHJ on this specific dampner. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 17, 2010 Share Posted May 17, 2010 (edited) It's common knowledge amongst L-Engine Builders that the stock bolt-washer combination is unsatisfactory in any sort of performance application. If you were using a stock fastener steup, you take the blame for the consequences. This has been in performance building literature for the L-Engine for over 20 years now, there is no excuse for not using an upgraded bolt and washer since they are readily available. Line-Line fit is not what holds the components in place (This is actually discussed recently in another thread...), it's clamping force between the washer and bolt head being pulled onto the end of the crankshaft, and the stack of components behind the damper---there is absolutely no axial limitation on the tolerance stack it changes build to build and differs if the oil slinger is used or not, knowledgable builders will measure the axial dimensions of the components before buildup to determine if the washer or crank bolt end will need machining to keep it from bottoming before exerting full clamping force on the shoulder of the pulley, and at the same time the timing gear, and crankshaft oil, slinger. If the dimension of the 'stack' is incorrect from the shoulder on the crank snout where they 'bottom out' then longer bolts, thicker washers, higher torques are all called for in performacne applications. These parts ARE a 'consumable' item as well. Anybody thinking they last forever and will never have to be replaced is simply misinformed. Crank Pulley Damage Link In this post, both TimZ and Braap mention is directly: If you are seeing woodruf key problems, it's due to inadequate clamping forces. It's from pulley movement, and that results from inadequate axial clamping load. This is basic engineering. There is a reason Nissan Motorsport has sold a special bolt and washer setup for competition usage forever and a day, and even that isn't an optimal design. There is an internal link in the above post which has more detailed information about alternate pulley retention hardware. It's not suggested in performance applications, it's mandatory. Edited May 17, 2010 by Tony D Quote Link to comment Share on other sites More sharing options...
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