Subject	Shrug. I took 8# out of the crankshaft on my engine >>
Posted by	Ash's Z on February 14, 2006 at 7:02 PM
	This message has been viewed 290 times.
In Reply To	Titanium rods. Worth it? posted by ZisLuv on February 14, 2006 at 06:03 PM
Message	I built this milling fixture from two block girdles and a Cushman steering box (for gear-reducted rotation of the crank in the mill). Link to all milling fixture images: The "Crankinator" [ http://ashspecz.com/Image%20Gallery/Crankinator/ ] The crank in this picture isn't in my engine - the crank pictured is even LIGHTER at 30# (10# taken out). I'm saving this for my NA VG30 engine project. This is the crank in my engine. I knife-edged the counterweights, took 1/4" out of the total radius of the counterweights, milled the rod bolsters, smoothed and semi-polished just about all of it, and ball-end milled both the front and rear rod bolsters (you can see it as the bore plunged into the far right of the crank - 0.750" dia). In the balancing process: Balancing results: Left end @ -0.6grams and Right end at -0.5grams. (This was the closest I could get it - I started seeing variations in the measuring capabilities of the machine at this point. Typically if it is balanced within 1.0grams you are good to go. :) I used the Pauter Chrome-Moly rods in my build, which are already a good bit lighter than the OEM rods, not to mention they have better windage benefits (aerodynamics). 8# is 3,629 grams. Most of this weight is far from the center of the crank so the gains are going to be more appreciable than weight losses in the rods. $800 a piece for the Ti rods, X6, @200 grams lighter, total of 1200 grams less. I dropped 3X that much in my rotating assembly mass in areas where it really counts and although there is a notable difference in how the engine revs compared to any other Z I have worked with, I couldn't substantiate some $5000 invested in Ti rods for 1/3 of the weight reduction. If it came down to it, I'd mill a crank to my specs for half that much. Cliffnotes: No, it isn't worth it. There are much better things that you can do to it that wont cost as much and have better reduction in mass. [ ashspecz.com ] [ agpowers@bellsouth.net ] Enthusiasts soon understand each other. --W. Irving. Are you an enthusiast? If you are out to describe the truth, leave elegance to the tailor. Albert Einstein
Follow Ups	Titanium rods. Worth it? - ZisLuv 18:03:58 02/14/06 only if you plan to rev past 8000 rpm then it is. (n/m) - AzHeat 18:16:15 02/14/06 Here is an example for you... - Shawn300zTT GT28R MD 18:31:34 02/14/06 From my recollection, Pauter rods are considerably lighter - Ash's Z 20:20:00 02/14/06 Maybe it was the Carillo that were heavier, one of - Shawn300zTT GT28R MD 00:18:24 02/15/06 Pauter =625g (Ti=418g) - Shawn300zTT GT28R MD 11:54:24 02/15/06 Shrug. I took 8# out of the crankshaft on my engine >> - Ash's Z 19:02:13 02/14/06 Hmmm..... - WAGGZ 19:11:06 02/14/06 fully built race engines, that's what you should sell. (n/m) - SnowManZ(aka Snowie) 19:37:05 02/14/06 You know, that sounds like a really good idea... - Ash's Z 20:28:51 02/14/06 would you be interested in doing some work - Shawn300zTT GT28R MD 00:19:34 02/15/06 Great advice. Thanks a lot. - ZisLuv 19:37:50 02/14/06 To be fair.... - RSR 08:52:12 02/15/06 True. Time and hard use will tell though. I will probably - Ash's Z 09:18:25 02/15/06
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