first, im curious why the itr crank has larger counterweights than the gsr. shouldnt a lighter crank be better for performance?

and also if i were to change the rods and pistons to forged aftermarket in an itr block, would i have to get the crank rebalanced to compensate for the loss of about 100grams per cylinder?

how does balancing the rotating assembly work? is it balcing the crank with the the flywheel, clutch, pp, crank pulley, and rods/pistons connected? or can i just have the crank balanced and everything else will be balanced as a result?

thanks

 

hope this helps a lil

https://honda-tech.com/zerothread?id=1056981

i would imagine you would get the rods and pistons balanced as well as the crank..make sure the rods are equal in weight..same with pistons.

 

thanks, thats funny you posted the same question earlier, i only ran search for "crank balance" so it didnt come up.

im confused about this the same way you were, if lighter flywheel allows faster revs then the actual lighter crank should have the same effect. so i dont see why honda would have lightened the itr flywheel, then raised the crank weight, seems counter prooductive.

unless the crank counterweight had to be greater to reliably sustain the higher rpm in the itr, then honda only lightened the flywheel that few pounds to compensate for the added rotational mass of the crank.


anyway, to now expand the question further, assuming i stay with my itr crank and the crank is in perfect balance now, if i had a micro polish done to help resit oil accumilation, would i need to have it rebalanced again? i trust hondas factory balance more than i would trust the job of a local machine shop.

also, regarding the pistons and rods, how much weight differnce is acceptable, i have 2000g digital scale that measures in whole grams.
if i weighed each piston and rod seperately, then removed material so all pistons and rods were the same weight to the whole gram. (for example 510g, not 510.00g) would that be close enough?

if all the pistons and rods did weigh the same, and the crank(seperately) is in perfect balance, then would it be pointless to get the bottom-end balanced as a whole?

sorry for the long-winded posts, but i need to have peice of mind about this before i continue. thanks

 

take your crank, rods, and pistons to dan benson @ benson's in santa ana, ca.

he will not only answer your questions, but he can do all the work your looking for..and a great job.

read featherweights response on my thread. his, IMO, explains the best out of all the replies about the itr crank and it's heavier counterweights.

 

yea after reading that thread i do see the logic behind the heavier itr crank, i will be using the one i have.

regarding benson machine shop, im out on the east coast so thats a no-go.

can anyone recommond respectable shops i can trust out here that deals with imports? anywhere from boston down to washington DC area. i need valvejob too.

 

ttt

 

still hoping for more information

 

id use the lightest stuff i could get.... rotational weight is bad. the stability thing that was talked about in the other thread is kinda useless to me. build it right and you wont have any problems. its 180deg crank.. you cant balance a 180deg motor anyway, just make sure all the rods are the same, and all the pistons are the same weight..

 

im going to use the itr crank.

im still not sure if i need to get the entire assembly balanced though. if the crank is in perfect balance and the pistons and rods are all equal weight do i still need to get the whole whole bottom end put together and balanced as a unit? anyone?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">im going to use the itr crank.

im still not sure if i need to get the entire assembly balanced though. if the crank is in perfect balance and the pistons and rods are all equal weight do i still need to get the whole whole bottom end put together and balanced as a unit? anyone?</TD></TR></TABLE>
might as well. IMO cheap insurance..especially IF you're going to rev past 9k a lot. then again i don't know your budget.

 

Pm earl he works with dan benson and is a reptuable source for the information you are seeking.