Full Force

I have a merc 260 hp in my boat right now,I have a friend building a stroker for his car and I want to use his forged roller shortblock,I know his was prof. built and balanced and I am not sure how the balancing is on a chevy,what are they stock? I can find out how his was done this week.what is the boat eng balance??

magnum

Your stock merc 260 would be externally balanced,meaning the flywheel and harmonic balancer are balanced.If the short block you're looking at is internally balanced you'll have to have the fly wheel neutral balanced.Not sure about the harmonic balancer,I bought new ones for my 355,s.Hope this helps

Full Force

Does anyone know what the external balance is? I do all ford engines so I know them,not chevys,they are 50 oz stock on a 302 ho and I did a custom 28 deal on mine,that is ford world.I need to see what the engine balance is in the one I am getting,I need a balance number on a stock 260.Thanks...

magnum

sorry,can't helpyou there.

BillK

245,
There are several different configurations of balancing on Chevy small blocks. All 350's with a 2 pc rear main oil seal are internally balanced, meaning that the flywheel and damper do not have any type of weight on them. The later (after 1986) on piece seal 350's use a flywheel that has a wieght but the damper does not.
The problem that you are going to run into with your friends stroker short block is that it could be either. The only way to know is to find out who balanced his engine and ask them. If he has the flywheel that he was using, just see if it has a weight on it. A lot of strokers are made using a 400 Chevy crankshaft, which was externally balanced with a wght on the flywheel and damper. But ... you can also buy crankshafts that have the counterweights designed so they will balance without the weight on the flywheel.
Ok ... totally confused ???? The only way to know which flywheel you will need with the stroker is to find out how it was balanced .... period.

Big Block Billy

If the motor you plan to use is a 350, get the matching flywheel. Hopefully it is a standard shift, and you can just leave that flywheel on it. otherwise, one can be matched up. If you feel that everything was externally balanced(which is rare) including the flywheel that was on it, even if it is a flexplate, can be matched balanced by a good machine shop. What year is the replacement motor. If it's the newer one piece rea seal, you will need a 599N flywheel or if 2 pc rear you will need a 456N . A great source of parts like flywheels is www.car-part.com . You can get one for as little as $10 , Also ring gears can be had for new from Autozone online, Part # Pioneer FRG168S

Full Force

The engine was in a 92 camaro,pulled rebuilt and put back in,it was done right by a good shop,they have done all my engine machining too,the engine is a one piece rear main,the engine was in a auto and is still 350 CI can I bolt my boat flywheel on it?

Big Block Billy

Ok You will need a 599n flywheel. If your motor is an '86 or newer with the one piece seal, you can just swap the flywheel. Older 2pc and newer 1pc style have different bolt circles and are not interchangeable. If you need a flywheel let me know, BBB