In doing a ls/vtec swap on a b18b with 80,000 kms on it, would I need to balance and knife edge the crank ?.. note that the car will be running high rpm consistantly for long periods of time (car is only used as solo 1 and track day event, nothing else, not even street).

also If I do need to do this, where can I get it done? Anyone know any places in Canada or close to the canada boarder ?

 

How high are you planning on revving? You know Honda cranks come balanced from the factory. I just started building my ls\vtec and I don't plan on doing anything to the crank. I'm not saying its bad to do it I just don't think its necessary. Good luck with your build!

 

if you're going to run it significantly over the factory redline of an ls motor, i would have the crank re-balanced with the new redline in mind.

There's no such thing as a perfectly balanced crank - there are just tolerance levels. a few oz of imbalance at 7000rpm can turn into a pound of imbalance at 9000rpm.

 

I had mine balanced...

 

well.. if your switching from a b18b non vtec to a vtec system the redline bumps up from 7000 to 9000 no ?

how much did it cost to balance the crank ?

basically I want to build this motor properly so it dosen't detonate on the track after 2 hrs of use. Its either that or swapping in a B18c5 which is expensive on its own.

 

Inline 4-cyl engines vibrate less and are easier on bearings with heavy cranks.The acceleration suffers slightly with the heavier crank,but if your operating in a small rpm range this is not a problem.If nothing has been modified on the crank (such as knife edging) I would not pay to have it balanced.Micro-polish,clean and assemble.
Glenn

 

Balance the crank, and make sure you run ARP rod bolts. If you're revving to 9k+, I recommend you get a main girdle. If your LS bottom is bone stock, you're still stick with the LS rev limit... if you want it to be a reliable build.

Why are you worried about detonation? What kind of compression do you plan on running?

Cheap and Fast won't be reliable
Reliable and Cheap won't be fast
Fast and reliable won't be cheap.

 

i would like to run 12.0 - 12.5

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ^AnDre^ &raquo;</TD></TR><TR><TD CLASS="quote">i would like to run 12.0 - 12.5</TD></TR></TABLE>
Detonation should not be a problem with race fuel and/or longer duration cams and proper tuning.
Glenn

 

I have not met someone yet that can balance the stock crank better then honda. If the crank is modified of course but a bone stock crank is the best your gonna get.

 

I just want to know plain and simple... would a stock b18b crank with a vtec swap done to it and 12.0 compression pistons as well as a cams will run without a problem at a consistand 5000-9000 rpm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ^AnDre^ &raquo;</TD></TR><TR><TD CLASS="quote">I just want to know plain and simple... would a stock b18b crank with a vtec swap done to it and 12.0 compression pistons as well as a cams will run without a problem at a consistand 5000-9000 rpm.</TD></TR></TABLE>

With a good set of rods and rod bolts, and provided all your clearances are good, and everything it torqued to spec you should be fine. (bottem end wise)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ^AnDre^ &raquo;</TD></TR><TR><TD CLASS="quote">I just want to know plain and simple... would a stock b18b crank with a vtec swap done to it and 12.0 compression pistons as well as a cams will run without a problem at a consistand 5000-9000 rpm.</TD></TR></TABLE>

I'd recommend this:
Rotating Assembly balance
Eagle rods (LS)
Main Girdle
P30 pistons
2 Layer head gasket
Ported PR3 head
Crower/Ferrea valvetrain
ITR Oil pump
ITR Waterpump

This will get you a little over 11.8:1 according to C-Speed, and you'll be safe at high RPM.

 

i agree wholy that if you are going to balance anything get the entire rotating assy balanced together ... rods pully flywheel ... blah ... but if you dont want to do that i would just leave it stock ... i have heard a lot of guys that dont like to knife edge

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ^AnDre^ &raquo;</TD></TR><TR><TD CLASS="quote">i would like to run 12.0 - 12.5</TD></TR></TABLE>

if you are running new pistons, which i assume you are. get the entire rotating assembly balanced, not expensive, sub $200 US.