LilCivic04

i have a z6 block built with wiseco pistons, scat rods, all clevite bearing and thrust washers. i've brought it to the machine shop and they said it didn't needed to be balanced, but he didn't have no paper to show me. i just want to know if my motor will be ok, my blocks been put together already. at what rpm do you think my motor will start shaking, i have a fully built head and i want to rev it up to 9k rpm. please give me your personal experiences with crank balancing.

NathanMorris

honda cranks are (for the most part, I think it's the case with the z6's as well), pre-balanced at the factory. If he checked it, you should be in good shape. Sometimes they come out of balance for various reasons....and would need to be rebalanced hence the reason you often see people listing it as a mod.

- Nathan

Jim Truett

Tha last A6 I built needed to be lightened by only a couple of grams on one rod lobe. I didn't even bother with the D15B.

LilCivic04

how many rpm is the stock crank balanced

SOHC4life 96

What reasons do you have for wanting to rev to 9,000 rpm? Unless you plan on making power up that high, its pointless.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LilCivic04 &raquo;</TD></TR><TR><TD CLASS="quote">how many rpm is the stock crank balanced</TD></TR></TABLE>

Huh? Do you mean to what rpm is the stock crank balanced?

MrTodd

Of course ANY rotating assembly will be balanced at the factory! It's when you mess around with the weight characteristics that things need to be re-balanced. Honda definitely does a good job at factory to begin with, but there are limits.

The natural redline of the Z6 bottom end is 7200 rpms, but I've heard of people bringing it up to 8k daily without any problem (after headwork, but no bottom end work). Anything above 8k, IMHO, it SHOULD be balanced!

I would tell the machine shop of how high you plan to rev your motor, and that they need to check the rotating assembly to make sure it will be okay. It sounds like this guy (at the shop) couldn't care less about what you plan to do with the motor. Personally after all the work that you've done I wouldn't dare even take it to 8k, much less 9. Get it balanced at another shop if these guys are still being retarded - but who knows, maybe you got a freak crank that just happened to be perfect for your rod/piston/flywheel combo..?

mucter

When I went to have my crank balanced, the machine shop told me it was already balanced to within half a gram. Which, imho is plenty balanced... They were able to rebalance the pistons/rods tho as a couple of them were off by 1 or 2 grams.

This was all out of a d16y7 block.

Jim Truett

Additionally, will your cam allow you to make any meaningful power near 9000rpm? Wouldn't it be more reasonable to set a power goal rather than simply wanting a high revlimit? If your cams die off at 8000 to 8400 is there really a need for the extra revs?

Realize that the pressure plate and flywheel will be more of a factor in balance and vibration than the crank will ever be. You will need to first balance the crank, then balance the flywheel to the crank, then balance the pressure plate to the crank/flywheel assembly. The weight of all of the bolts will need to be equalized.

I have had more than 20 grams removed from a pressure plate to balance it.