cheaterparts Posted June 1, 2006 Report Share Posted June 1, 2006 The weight saving from the crank is some where around 4 pounds. I'm not sure how accurate my scale is. But it said my crank weighs 36lbs. And it said that a stock crank weighed 40 lbs. My machinest said it took 8 hours to do the knife-edging and balanceing. Very impressive. I'm also curious to hear about the pro's and con's of this. Then I just have to find a machine shop around here capable to doing this. Chris. after following both the knife edge and short stroke threads it got the better of me so I chucked a 2Lt crank in the lathe and roughed it out they start life at 37.5 lbs and an hour latter it was 34.1 lbsand the balance just sitting on a couple of straight edges looks closethere is probly another 1/2 + that can be removed this will need to be done by hand and will take a lot more time than the lathe work so a 4 lb + removal from a 2 lt crank is also very possable cheater Link to comment Share on other sites More sharing options...
TurboRaider Posted June 2, 2006 Report Share Posted June 2, 2006 Might want to see how these first two cranks hold up before anyone else tries this. Theories are good on what should work and what wont, but there is nothing like putting a few miles on a setup to really know. If you are running lighter rods and pistons some counterweight removal is good. If the counter weights don’t matter why run them at all? On early VW flat fours the crank was not counter weighted at all. In theory it was balanced since the two sides of the motor canceled each other. With no counter weights the forces to cancel out the acceleration of the pistons was not contained locally (next to the rod throw) but had to be transmitted through the center main of the crank. This is fine until you start to rev the motor past what it was designed for ( forces go up with the square of the speed). At higher RPM’s the motors pound out the center main bearing. My point is you may gain some acceleration from reduced mass but increase loading on the mains. It may be fine, but I would wait to hear how well these motors work out. Kevin Link to comment Share on other sites More sharing options...
MontyTSI Posted June 2, 2006 Report Share Posted June 2, 2006 where did you get your crank nitrated? Link to comment Share on other sites More sharing options...
TurboRaider@work Posted June 2, 2006 Report Share Posted June 2, 2006 where did you get your crank nitrated? I got the crank nitrided at Accurate ion http://accurateiontechnologies.com/default.asp There are crank shops near the nitrider that can grind, nitride and polish your crank. The total cost of having them do the work is usually less than dealing directly with the nitrider. Try Velesco crankshafts. I think I posted info on them before. Kevin Link to comment Share on other sites More sharing options...
TopDawg_43 Posted June 2, 2006 Author Report Share Posted June 2, 2006 where did you get your crank nitrated? No, didn't see a need to. Saw no need to. I believe the journals are where it counts, and they are still stock spec. FYI- There is a SQ out there making very high numbers that has a knife-edged crank. That is 88whiteStarion's 456hp car. Link to comment Share on other sites More sharing options...
TurboRaider@work Posted June 2, 2006 Report Share Posted June 2, 2006 where did you get your crank nitrated? No, didn't see a need to. Saw no need to. I believe the journals are where it counts, and they are still stock spec. FYI- There is a SQ out there making very high numbers that has a knife-edged crank. That is 88whiteStarion's 456hp car. Good to hear that others have had sucess with the weight reduction. Since the stock turbo crank was salt bath nitrided from the factory your right, no need to do it. I used a caravan crank because I was having a hard time finding a good used Starion crank. The down side is the caravan crank is not hardened. I chose ion nitriding because it less likly to distort the part, I only have one crank to heat treat and if it comes out wrong I'm SOL. The surface came out super hard, I am very pleased with the results. Kevin Link to comment Share on other sites More sharing options...
Boosted_One Posted June 2, 2006 Report Share Posted June 2, 2006 where did you get your crank nitrated? No, didn't see a need to. Saw no need to. I believe the journals are where it counts, and they are still stock spec. FYI- There is a SQ out there making very high numbers that has a knife-edged crank. That is 88whiteStarion's 456hp car. yeah it's the journals that count.... the DSM cranks are nitride treated too and I know there's been plenty out there who had problems when they cut the JOURNALS and didn't re harden it. But the counter weights will be fine. Knife edge is the way to go! BTW the only other person I know other than Dave and a couple others that had the knife edging done is pumpedtsi. Link to comment Share on other sites More sharing options...
supturbo Posted June 3, 2006 Report Share Posted June 3, 2006 they could have taken more off the crank-i wish I had pics of mine, but they took off 13lbs and dosn't even look like then same crank..The detail(mushroom looking things on yours-well mine look rectangle but the edges look the same however they knifed edged both sides. - However not even close to 400.00 with balancing the whole assembly. Link to comment Share on other sites More sharing options...
TurboRaider Posted June 3, 2006 Report Share Posted June 3, 2006 they could have taken more off the crank-i wish I had pics of mine, but they took off 13lbs and dosn't even look like then same crank..The detail(mushroom looking things on yours-well mine look rectangle but the edges look the same however they knifed edged both sides. - However not even close to 400.00 with balancing the whole assembly. Why not completly remove all four counterweights if its just extra weight? Link to comment Share on other sites More sharing options...
TopDawg_43 Posted June 3, 2006 Author Report Share Posted June 3, 2006 - However not even close to 400.00 with balancing the whole assembly. More or less?And do you think the gains were worth the cost? Link to comment Share on other sites More sharing options...
supturbo Posted June 5, 2006 Report Share Posted June 5, 2006 It was around 250.00, and yes its worth it - car revs so much faster. I have hardly no lag when I get on it. My 2cents worth;;;lol Link to comment Share on other sites More sharing options...
TheMonkeyProject Posted June 6, 2006 Report Share Posted June 6, 2006 CHAMP cars have no counterweights on the crankshaft, but that's a whole new ball game Link to comment Share on other sites More sharing options...
TurboRaider Posted June 7, 2006 Report Share Posted June 7, 2006 CHAMP cars have no counterweights on the crankshaft, but that's a whole new ball game I think the XFE uses a 180º crank... So it does not need counterweights on the crank for first order vibrations Link to comment Share on other sites More sharing options...
TheMonkeyProject Posted June 7, 2006 Report Share Posted June 7, 2006 CHAMP cars have no counterweights on the crankshaft, but that's a whole new ball game I think the XFE uses a 180º crank... So it does not need counterweights on the crank for first order vibrations xfe, that's the cosworth right? I knew there was some reason for it. Link to comment Share on other sites More sharing options...
cheaterparts Posted June 11, 2006 Report Share Posted June 11, 2006 after following both the knife edge and short stroke threads it got the better of me so I chucked a 2Lt crank in the lathe and roughed it out they start life at 37.5 lbs and an hour latter it was 34.1 lbsand the balance just sitting on a couple of straight edges looks closethere is prob another 1/2 + that can be removed this will need to be done by hand and will take a lot more time than the lathe work so a 4 lb + removal from a 2 lt crank is also very possablecheater http://img85.imageshack.us/img85/5026/crankshaft11jy.jpg work in progress cheater Link to comment Share on other sites More sharing options...
heefner Posted June 11, 2006 Report Share Posted June 11, 2006 :shock: Wow thats a lot of material removed. Intrested to see how this performs. Link to comment Share on other sites More sharing options...
TopDawg_43 Posted June 12, 2006 Author Report Share Posted June 12, 2006 That looks to have more removed then what was taken off mine. If you get your car running before I do, let me know how it runs. Link to comment Share on other sites More sharing options...
MontyTSI Posted June 12, 2006 Report Share Posted June 12, 2006 CHAMP cars have no counterweights on the crankshaft, but that's a whole new ball game amazing when the crankshaft naturally balances at 18,000 rpm, lol Link to comment Share on other sites More sharing options...
cheaterparts Posted June 12, 2006 Report Share Posted June 12, 2006 That looks to have more removed then what was taken off mine. If you get your car running before I do, let me know how it runs. it will be matched to a 9 Lb 10 1/2 dia flywheel and tilton 2 plate 7 1/4 clutch I hope to have the rest of the polishing done this week so I can send it out to my balancing guy the crank weighs in at 33 Lb atm with some old bearings still taped to the journals and its a 90 mm stroke crank cheater Link to comment Share on other sites More sharing options...
artinist Posted June 12, 2006 Report Share Posted June 12, 2006 i am not an expert in this but i think there is more to this than just a balanced shaft sitting around on a table looking all calm and nice. its another story when there is a heck of a lot of force and vibration pouning on it only from one side in a 4 cylinder engine. i just think there needs to be a certain amount of mass to counteract those forces. it seems to me that if there is not enough couterweight to sling the crank around in reaction to the rods coming down, it will instead transfer the forces in a more of a straight up and down motion onto the main caps a lot more than it does normally. Link to comment Share on other sites More sharing options...
cheaterparts Posted June 13, 2006 Report Share Posted June 13, 2006 i am not an expert in this but i think there is more to this than just a balanced shaft sitting around on a table looking all calm and nice. i just think there needs to be a certain amount of mass to counteract those forces. it seems to me that if there is not enough couterweight to sling the crank around in reaction to the rods coming down, it will instead transfer the forces in a more of a straight up and down motion onto the main caps a lot more than it does normally. the balance factor will change there is no dout that is why you need to remove weight from the big end journal as well but when you think about it the counter weight is less than needed to balance out the the piston / rod at top and bottom or it to much weight side to side when the counter weight is balancing the big end and no piston and half a rod as the rest of the weight is moving at 90 deg to the counter balance a lighter piston and rod a** will help but there is no dout that there will be more load on the bearings cheater Link to comment Share on other sites More sharing options...
Boosted_One Posted June 17, 2006 Report Share Posted June 17, 2006 Awesome thread. I think you guys will be just fine, you still got counterweights, just lighter. Who's to say the crank is optimal weight stock to begin with??? Link to comment Share on other sites More sharing options...
angryhero46 Posted August 15, 2006 Report Share Posted August 15, 2006 bump?Hows the knife edging going guys.I was going to get mine done and wanted to see how this turned out Link to comment Share on other sites More sharing options...
TopDawg_43 Posted August 15, 2006 Author Report Share Posted August 15, 2006 bump?Hows the knife edging going guys.I was going to get mine done and wanted to see how this turned out My car is not running yet. Have a few more parts to get, should be running by the end of the month. Link to comment Share on other sites More sharing options...
claurance2 Posted August 15, 2006 Report Share Posted August 15, 2006 Hey Will give me a holla and come on down when the ride is ready. I got a new number and sent a pm. later James Link to comment Share on other sites More sharing options...
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