Engine Balancing 5K

[megamannz123]

Hi all,

was going to start building my 5K this arvo as all the new bits have now arrived, but I'm still not sure if I should have the crank, flywheel balanced. I'm going to balance the pistons and rods myself more for experience and to have a bit of a play rather than performance. This is not going to be a race engine, 7000rpm max. No track days or anything just a weekend car. From what I can work out, yes there are benefits to balancing, smoother at higher revs, very slight engine power increase, longer life of engine. Still not sure if I should bother with bottom end balancing? K series are supposed to be pretty good from factory.

Any ideas?

 

Cheers

[springersrolla]

I just had my 5k done. Bit off the crank rods and pistons. Take your balancer crank and flywheel and pressure plate and do it as one. Defiinately worth it

[megamannz123]

How much did that cost you?

[filfrederick]

to do the job properly all the rotating parts need to be done individually, so the crank first, then bolt on the flywheel and balance that, then the pressure plate, then the pulley.

the pistons are easy enough to do at home, the rods should be balanced on the small end, big end and overall, it takes a bit of time to get it right but i believe it is all worth it for an engine that will be smoother and easier on all the bearings, therefore live longer. not to mention reduced stress at high revs.

 

in a side note it is very hard to get a crank to be completely balanced throughout the rev range because of the different velocity's of the various counterweights, ie. depending on the distance from the center of rotation to the center of mass of the counterweight as to how effective that weight actually is.

 

i balance cranks at 3000-4000rpm, seems to work ok.

-Phil

[springersrolla]

Couldnt tell you sorry mate but $500 was for everthing balanced lightened flywheel bored honed decked etc

[coln72]

Probably a good idea but my 5k would be pulling 7500+ With no balancing.

[GJM85]

Shouldn't the pistons and rods be equally balanced first so the counterweights of the crank can be matched?

[megamannz123]

Thanks for the thoughts guys, I think I will get it balanced. I think I would regret if in the end if I don't.

On another note Hypatec or Endurotec pistons? from what Precisions website says the Hypatec sound better but they are cheaper? I was talking to another guy who is selling some on Rolla club and he also said Hypatec are better. Seems a little starnge at half the price of Endurotec?

Anyone seen these side buy side? which is better quality?