Slo_crx1

I'm about to start the assembly on my LS block and I'm going to be taking some of the internals to have some machine work done. I'm having the stock LS rods redone with ARP bolts and then having them resized, and having pr3's pressed on for a nice bump in c/r. For now I'm not worried about the head, it's time will come...for now I want to focus on the block. This question's for those of you that have built ls/vtec's with good success...would it be worth the extra time and money to have the rotating assembly completely balanced? After some research and money restrictions I'm probably going to limit this motor to the 8500-9000rpm range, and will run near the 12:1 c/r near the final install. I'm debating on whether to just stick to a micropolish on the crank and be done with it, or whether I should get the extra balancing work done. Bearings will be clearanced on the loose side, will allow me to load the crank right away and oil's being supplied by a modified and ported 94 gsr pump. Any thoughts and suggestions?

Sepheroth86

Balance it.

The B18A/B engine was only built to rev up to 7000 rpm, after that due to the centrifugal force on the lower end, it tends to wear bearings faster, and or throw rods out of the block. Making sure that all of the lower rotating assembly is balanced puts an even pull from one end of the crank to the other.

Ive done a few LS vtec's in my day. Spend the money, do it right the first time, and you can run that bastard up to 9k no problem.

JDMFantasy2K

+1 i had my b16 balanced, it's just good piece of mind. Heh least if it blows you can say you went all out on it

Slo_crx1

I would absolutely love to build this motor the proper way, having everything balanced etc. But lately with work being shitty, and my cash getting less and less I have a feeling I'm going to end up just rebuilding the bottom as a stock LS, swapping the b16 head, and building another cheap boost setup. Kinda sux that I sold most of my stuff though :P

T3_60trim2

I have 10k miles on my ls/vtec in my 5g hatch. Gsr head, wiseco pistons, eagle rods, acl bearings, slapped it together without balancing anything and I rev the crap out of it. We`ll see how it holds.

A great man once said, balancing is for pussies. :P

Tom-Guy

All B-series cranks are balanced to 10K from the factory.

That's due to bearing design - you ever notice LS got different bearings from GSR or B16? And the rod out the side of the block deal in high rpm situations is due to breaking across the beam... as LS rods lack the reinforcement where beam joins big end, they are expecially suceptible to breaking when compression downshifting - which the much stouter GSR/ITR rod is known to do occasionally in a completely stock engine.

Or you can drop unbalanced Eagles/Wisecos onto an unbalanced LS crank and rev to 9700 with impunity... at that rpm, all the problems are in the cylinder head.

(slo... do the rod big/small end balances, and the piston balances, ---- the rotating assembly spin balancing as it's already mint)

Slo_crx1

Thanks for the info JD. As far as the piston balances goes, I'm just going to leave the stock pr4's on them and see how they weigh out. The more I've been thinking about hitting the edge of the 200hp mark with way more money spent than should be, the more the itch of boost is crawling back into my head. Still sucks though that I'll be sitting around a 9.8:1 c/r once the motor's assembled, although my b16 is right about 10.26:1 and it held boost just fine. 14psi is what worries me, although it's still sub 300hp.

Tom-Guy

Why don't you just put forgings in the bottom end and be done with it?

(Humor me, this is going somewhere constructive)

Slo_crx1

2 words...cash money...something I'm almost out of Honestly if I could afford a good set of rods and a good set of pistons, I'd have done it already and gone to a much larger turbo setup

Tom-Guy

If you can afford the pistons, I have three perfectly good LS Eagles you can have. Ben at importparts.com, or better yet Craig at Tunertoys, can get you the fourth for $80-85 shipped.