Hey, I am thinking of building my bottom end very soon. I am going to go with JUN pistons and rods. These are suppose to already be balanced, so what I am wondering is if I should pull the crank out and balance everything together. (flywheel, crank pulley, crankshaft, rods, and pistons) I know that the type r's cranks are suppose to be balanced from the factory. The guy who is going to do it for me said that he can keep the crank in the block, or I can pull it out and balance everything if I want to. The car has 28,000 miles on it. Do you think it will make a significant difference taking everything out and balancing it?

 

I would knife edge the crank and balance everything. You need crank pulley, flywheel and clutch to balance everything perfectly.

 

God: I heard that knife edging the crank would shorted the life of the motor especially if the car is going to be used for road course racing.

 

I highly disagree on Knife edging a Honda Crank, I have spoken to 3 people who all build only race engines and have been doing balancing etc for over 30 years and they all agree that The way Honda cranks are made it is very hard to lighten them and then be able to balance the whole bottom end without having extremely light pistons and rods Ex: titanium race pistons with barely any skirts. Even at that weight savings knife edging would remove too much wait.

IMO Rebalancing is worth it, as it will be beneficial to engine life at the higher Rpm's (Also the crank etc is supposedly balanced by Honda but the ones I have had rebalanced were not that balanced)

 

I'd knife edge it. We did Chad's car (TodaSi) and I love the feel of it. He road races the car and has not had any problems at all even at 9500 RPM.

 

I'd be wary of having a R crank re-balanced. 95% of the shops out there don't have the equipment to balance the crank to the same degree as Honda does.

Mike

 

The counterweights of the crankshaft should match the weight of the pistons, rings, wrist pins, rods, rod bearings, and rod bolts. If you change to lighter ones, it is a good idea to have it balanced back in. Not absolutely necessary, but for longer life, slightly more power, and quicker revs.

titanium pistons? You mean aluminum, right?

 

As my esteemed collegue from Donkey Motorsports did mention, please be wary of who does this for you. Find a GOOD machine shop. Sound easy but for every 10 there is only 1 that is any good.

 

How much does it cost to balance everything, and how long does it take.. out of curiousity.

Jon

 

Dan: Do you know how long it would take and how much it would cost if I sent the parts to you for the machine shop you trust to do it.