M_R_205 5 1 Cars Posted January 24, 2008 In an effort to save money im going to balance the pistons and rods on my engine build myself, question is how well ballanced should they be, at present the weights are, pistons, 358, 360, 360, 361 rods (rod, cap) 510 - 170, 510 - 171, 511 - 170, 513 - 172 I can easily get them all to xxxxg but should i be looking more towards xxxx.xg??? Obviously il get the crank and f/wheel balanced by a pro Thanks Paul Share this post Link to post Share on other sites
ericdean 0 Posted January 24, 2008 Hello mate I've never done this myself but a chap at work balanced his pistons and rods on a cosworth engine to xxx.xg Hope this is of use Eric Share this post Link to post Share on other sites
brianthemagical 1 Posted January 24, 2008 i think it's to within half a gram. you need scales that are accurate to at least .1 of a gram, preferable more. if you are going to make it worth while then you will need accurate scales, but there expencive. Share this post Link to post Share on other sites
309PUG 2 1 Cars Posted January 24, 2008 I'm sure it's not just a case of getting everything to weigh the same, you have to get them all balanced end to end I think the term is phrased. I'm sure somone will elaborate for you, it is a skilled and thankless task to get spot on. I think you need to be to a minimum of 0.5g Chris Share this post Link to post Share on other sites
Beastie 1 Posted January 24, 2008 As already pointed out they need to be balanced accurately for big end and small end weights as well as for overall weight. Here's one way that a surprisingly large number of people in the trade use which works well at home: Drive a couple of nails into a piece of board at the correct centres for the rods. With the board held vertically suspend each rod from the nails with a pair of nice stretchy elastic bands (the weaker the better so long as they don't break or reach the end of their elasticity). Mark the board for the position of the small end and the big end for each rod so that you can find the overall lightest rod. Then balance the other rods to it so that they all reach exactly the same position on the board. Change the elastic bands from time to time and recheck all the rods. It sounds Heath Robinson but it actually works very well and if you work methodically is very accurate. Share this post Link to post Share on other sites
SPGTi 2 Posted January 25, 2008 Obviously il get the crank and f/wheel balanced by a pro Thanks Paul If you are going this route you will probably find it is not much more for your pistons and rods to be done as well. Probably less than the cost of an accurate balance. Autosprint quote £84.50 to balance crankshaft, front pulley, flywheel assembly, con rod and pistons and will lighten a flywheel from £57.50. ( taken from advert in PPC). Steve Share this post Link to post Share on other sites
M_R_205 5 1 Cars Posted January 28, 2008 Well over the weekend i did all the pistons, then now all weigh 358.2g, the scales i used were very acurate ones that we have at work for franking mail Now im goign to start on the rods, should i try and balance them equaly on each side?? Share this post Link to post Share on other sites
