ejin4499 Posted February 15, 2011 Share Posted February 15, 2011 Do I really need to balance the crankshaft when swaping the 33 mm crank from the vg33 for a 25 mm crank out of a vg30. I've looked at a couple of how tos and blogs and nobody mentions it. I have found both http://nissannut.com/maintenance/vg33e_upgrade/ and http://www.csc-service.com/images/swap/vg33swap.pdf I am following more of nissannuts aproach with rebuilding from the shortblock rather than modifying parts to work with vg30 accesories. Any thoughts or good search terms to work with? Thanks Link to comment Share on other sites More sharing options...
madhornet Posted February 15, 2011 Share Posted February 15, 2011 nope no balancing Link to comment Share on other sites More sharing options...
ejin4499 Posted February 15, 2011 Author Share Posted February 15, 2011 nope no balancing forgive my ignorance but wont the bigger pistons and different rods change the weight? Link to comment Share on other sites More sharing options...
sewebster Posted February 15, 2011 Share Posted February 15, 2011 I don't know anything about doing the swap, but the crankshaft should be balanced by itself right? As long as all the rod/pistons you add to it are the same I think it should work. Is the balancing step you are talking about just good practice to test a crank before installation to make sure it is still balanced? Link to comment Share on other sites More sharing options...
ejin4499 Posted February 15, 2011 Author Share Posted February 15, 2011 I don't know anything about doing the swap, but the crankshaft should be balanced by itself right? As long as all the rod/pistons you add to it are the same I think it should work. Is the balancing step you are talking about just good practice to test a crank before installation to make sure it is still balanced? I'm just getting into this myself so I'm not really sure. As far as I understand a crankshaft has counter weights built into it to balance the weight of the rods and pistons and if you change what is attached to the crank would that not change what the counter balance needs to be? Link to comment Share on other sites More sharing options...
beastpath Posted February 16, 2011 Share Posted February 16, 2011 Technically you should have the whole rotating assembly balanced before you put it in the block for optimum performance. However, from what I have read this is mostly important for high rpm applications and for applications where you produce over 250hp. If you are doing a VG34 modification - which can PERHAPS get you to 240-250hp - it might be a good idea to do it, but as you will be using the power mostly in the lower rpm bands it probably wont matter. If you do just the VG33 swap then I wouldn't think its necessary at all. Saying that, if you have the extra cash, why not? Link to comment Share on other sites More sharing options...
sewebster Posted February 16, 2011 Share Posted February 16, 2011 How can you balance a crank with rods and pistons on it anyway? Link to comment Share on other sites More sharing options...
beastpath Posted February 16, 2011 Share Posted February 16, 2011 How can you balance a crank with rods and pistons on it anyway? LOL, they dont attach the rods and pistons, they attach weights in the rod journals to simulate the weight. You should also attach the flywheel etc. http://www.fordmuscle.com/archives/2008/04/RotatingAssembly/ Link to comment Share on other sites More sharing options...
sewebster Posted February 16, 2011 Share Posted February 16, 2011 LOL, they dont attach the rods and pistons, they attach weights in the rod journals to simulate the weight. You should also attach the flywheel etc. http://www.fordmuscle.com/archives/2008/04/RotatingAssembly/ Cool Link to comment Share on other sites More sharing options...
ejin4499 Posted February 16, 2011 Author Share Posted February 16, 2011 (edited) Technically you should have the whole rotating assembly balanced before you put it in the block for optimum performance. However, from what I have read this is mostly important for high rpm applications and for applications where you produce over 250hp. If you are doing a VG34 modification - which can PERHAPS get you to 240-250hp - it might be a good idea to do it, but as you will be using the power mostly in the lower rpm bands it probably wont matter. If you do just the VG33 swap then I wouldn't think its necessary at all. Saying that, if you have the extra cash, why not? I wish I had the extra cash. That 200 means the difference between getting the beast rolling by april or by next december. Frickin get out of debt snow ball. Grumble grumble moan moan Edited February 16, 2011 by ejin4499 Link to comment Share on other sites More sharing options...
MY1PATH Posted February 16, 2011 Share Posted February 16, 2011 Idono about Nissans but In many other makes a Quality shop can balance an assembly to a smaller increment then what was done at the assembly line. ex. down to 3 grams instead of down to 10 grams. This can enhance the smoothness of the engine and increase its lifte. Both of wich will not be very noticable. Link to comment Share on other sites More sharing options...
thehuntersam Posted March 4, 2011 Share Posted March 4, 2011 You dont have to change the crank, I have a partial write up of my swap on another site, I forgot how much better this site than the ones im on lol, but if you need just ask. Hope this helps. What I put in it, A 1996 Pathfinder 3.3 V6 with around 55,000 miles on it. I have the 96 motor powered by an xterra setup I used the alternator, powersteering pump harmonic balancer, oil filter housing all from a 2002 xterra. For wiring I used a 96 or 97 wiring harness I got from the Junk yard, then spliced it to my old harness. I know I know.. I need to put up pictures! I used the original motor mounts and exhaust manifolds. I also used the new 3.3 intake on it For the radiator I ran the 96 set up to the old set up which turned out nicely. I completly got rid of the AC, I didnt really use it anyways... I have the manual tranny and I used the 96 clutch with it and it all matched up. Along the way I replaced tons of other parts, this is just a quick write up of what I did, I will make a full write up another day I did some ecu test on it and it has NO CODES!! ALL SYSTEMS GO!!! Link to comment Share on other sites More sharing options...
ejin4499 Posted March 4, 2011 Author Share Posted March 4, 2011 You dont have to change the crank, I have a partial write up of my swap on another site, I forgot how much better this site than the ones im on lol, but if you need just ask. Hope this helps. What I put in it, A 1996 Pathfinder 3.3 V6 with around 55,000 miles on it. I have the 96 motor powered by an xterra setup I used the alternator, powersteering pump harmonic balancer, oil filter housing all from a 2002 xterra. For wiring I used a 96 or 97 wiring harness I got from the Junk yard, then spliced it to my old harness. I know I know.. I need to put up pictures! I used the original motor mounts and exhaust manifolds. I also used the new 3.3 intake on it For the radiator I ran the 96 set up to the old set up which turned out nicely. I completly got rid of the AC, I didnt really use it anyways... I have the manual tranny and I used the 96 clutch with it and it all matched up. Along the way I replaced tons of other parts, this is just a quick write up of what I did, I will make a full write up another day I did some ecu test on it and it has NO CODES!! ALL SYSTEMS GO!!! Ya I found that option too in my research. I'm putting putting my engine in a 95 pathfinder. The problem for me was that I had to spend most of my build money on just getting the engine ( I bought everything but the accesories) I didn't have anything left over for a new ps pump or alternator so I had to use what I already had. I wish I had taken pics of the project but I am almost done with the engine rebuild. Just need to put the oil pump rear main seal oilpan and valve covers on and I can put that powerplant back in my blue beasty. Im also doing the automatic to manual swap at the same time. I'm so freaking stoked cause I'm going to start reasembly tomarrow. Im hoping I can have the engine and transmission in and bolted on by monday so next weekend I can spend getting it all working again. Can't wait to take this gold prospecting. Link to comment Share on other sites More sharing options...
thehuntersam Posted March 4, 2011 Share Posted March 4, 2011 Well thats great to hear you almost have it done! it's a lot of work but well worth it in the end. Post some pics and vids as soon as its done man. Link to comment Share on other sites More sharing options...
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