inline6 Posted January 10, 2014 Share Posted January 10, 2014 (edited) With my recent engine build, I used a Rebello BHJ crankshaft damper (a used one). The engine has about 600 miles on it and is apart for other reasons. At the time of build, the damper had some visible wear/markings on the ID of the hub, but we decided it was good enough still to use. Given the photos of the "damage" that happened within only about 600 miles of engine tuning, and what my engine builder said after removing it from the crankshaft: "Your harmonic damper now has only .0002 interference fit to the crank snout. .0005 is the accepted minimum on non "problematic", internally balanced engines. .0007-.0012 is preferred for most engines and .0015 is the maximum which requires careful chamfering of components and the use of E.P. grease for installation. I weighed your damper and it was about seven pounds total weight (bathroom scale). It might be of benefit to obtain a damper with an inertia ring with a higher weight (moment of inertia)." I am faced with making a decision. Either pursue getting a new hub for this damper, which I do not know is even possible at the moment. Or, buy a new one of the same part number from Rebello (It is the BHJ street version) Or, go with another brand, such as ATI. My engine is basically the same as a Rebello 3.0 L engine (but with an 88mm bore instead of 89mm which puts it at about 2.9 L instead) with a lightened and balanced crankshaft (only about 3-5 lbs lighter than a stock L28 crankshaft), and a 7800 max RPM Kinetic Sunbelt cam. I've read various posts in the forums regarding "tuning" of dampers. I'd like to understand this tuning better so I can make as informed of a purchase decision as possible for my specific application. I would appreciate any guidance. G Edited January 10, 2014 by inline6 Quote Link to comment Share on other sites More sharing options...
ctc Posted January 10, 2014 Share Posted January 10, 2014 Contact BHJ, they will answer all you questions. They also have explanations on their web site. Mine is of exceptional build quality. Just as a note the Rebello damper will rust, so take steps to keep it clean if that kind of thing bothers you. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 13, 2014 Share Posted January 13, 2014 With my recent engine build, I used a Rebello BHJ crankshaft damper (a used one). The engine has about 600 miles on it and is apart for other reasons. At the time of build, the damper had some visible wear/markings on the ID of the hub, but we decided it was good enough still to use. Given the photos of the "damage" that happened within only about 600 miles of engine tuning, and what my engine builder said after removing it from the crankshaft: "Your harmonic damper now has only .0002 interference fit to the crank snout. .0005 is the accepted minimum on non "problematic", internally balanced engines. .0007-.0012 is preferred for most engines and .0015 is the maximum which requires careful chamfering of components and the use of E.P. grease for installation. I weighed your damper and it was about seven pounds total weight (bathroom scale). It might be of benefit to obtain a damper with an inertia ring with a higher weight (moment of inertia)." I am faced with making a decision. Either pursue getting a new hub for this damper, which I do not know is even possible at the moment. Or, buy a new one of the same part number from Rebello (It is the BHJ street version) Or, go with another brand, such as ATI. My engine is basically the same as a Rebello 3.0 L engine (but with an 88mm bore instead of 89mm which puts it at about 2.9 L instead) with a lightened and balanced crankshaft (only about 3-5 lbs lighter than a stock L28 crankshaft), and a 7800 max RPM Kinetic Sunbelt cam. I've read various posts in the forums regarding "tuning" of dampers. I'd like to understand this tuning better so I can make as informed of a purchase decision as possible for my specific application. I would appreciate any guidance. 100_0722 (640x426).jpg 100_0723 (640x426).jpg G Since you are using the Nissan Comp bolt and heavy duty washer, it's worth noting that you _really_ need to make sure that you have proper installed clearance between the washer and the crank nose. As delivered (at least on mine), the washer's round "centering" section was too thick and was contacting the crank nose (I found out the hard way). When this happens the bolt cannot be tightened further, and the washer is providing NO clamping force on the timing chain gear/oil pump drive/oil slinger/crank dampener stack, and the woodruff keys are then the only thing that hold these pieces in the proper position. This will pretty quickly lead to failures. If you add up the depths of the lower timing gear, oil pump drive gear, oil slinger (if you are using one) and crank dampener and compare this to the length of the crank nose, you should find the nose to be shorter than the resulting stack, by more than the depth of that round section on the washer. If this is not the case, you can either machine the washer, or simply flip it over, to ensure that you get proper clamping force. Hopefully that made sense... Quote Link to comment Share on other sites More sharing options...
inline6 Posted January 18, 2014 Author Share Posted January 18, 2014 Yep. Learned that the hard way when I used the bolt and washer with a Euro damper many, many years ago. Never want to hear that death rattle coming from an L series again. G Quote Link to comment Share on other sites More sharing options...
inline6 Posted January 19, 2014 Author Share Posted January 19, 2014 BHJ is making me a new hub that is sized for my crank, which is a tad undersize. $300 and we'll be back in action. Quote Link to comment Share on other sites More sharing options...
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