Thread: balance the motor or not?

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was wondering if i should have the 355 balanced or not let me know what you guys think about having a motor balanced !!!!

I wouldn't spend the money for a quality build without having it balanced. If nothing else it improves long term life and reliability.

X2! If it's out / apart, it's worth the money & effort!

Runs smoother and last longer.

I can't imagine spending the bucks for a bore, new pistons and rings and maybe a set of rebuilt rods, possibly a crank grind etc without a few more $$ for a balance.

The last Ford 351W I built had some real interesting machining marks after it was balanced - more so then any other that I had had done by this guy so can only imagine how rough it would have been had it not been done.

Balancing is an essential part of engine building. If an engine builder tells you it is not necessary, walk away and find a reputable builder.

Thanks for the question and for the answers as I will put my hand up and admit I wasn't sure of the advantages.

stock engines are far from close ??? what is close??? this is what you should ask when spending money for a balance job. how are the hell you going to check it? as many on line shops sell.. GREAT DEAL Kits.. there mass balanced using not the real parts for weight . but number of what it could be as it.s a averaged out could be off as much as 10 grams or more a end . on stock stuff that ran other then new pistons . many guys balance the rods and pistons match stuff up this is the least i do if the guy will not spend the money for a full balance job. its not always the machine shop. if i have a machine i am paying for taking up space in my shop. i like to get paid to use it . but some guys are cheap . all new parts and big stroke cranks can get very intense$$$$ with cutting down counter weight to plugging heavy metal in the crank . so whats is close for me it is under 1 gram per end of the crank

how much does a balance job run for the motor

Originally Posted by Southernboss84

how much does a balance job run for the motor

you will have to talk to the machine shop you use locally as there no set price state to state . my price to do a balance job may not reflect what the cost is locally for you

If I'm not balanced ....... I fall down. Just Sayin'

Originally Posted by pro70z28

If I'm not balanced ....... I fall down. Just Sayin'

Hmmmm so your telling us now your not well Balanced ....

Originally Posted by pat mccarthy

Hmmmm so your telling us now your not well Balanced ....

Your not the first one to mention that. If I eat right though & in moderation I never fall down, but sometimes I learn toward junk food.

Originally Posted by pro70z28

Your not the first one to mention that. If I eat right though & in moderation I never fall down, but sometimes I learn toward junk food.

sorry my down fall is soda pop

Smokey Yunick in his book Power Secrets- "Frankly, I think engine balancing is anything but an exact science, and you don't need to get upset if things are off a little.
There's no such thing as an engine that is perfectly balanced at all engine speeds. You can determine a recommended balance weight according to the formula that the crank manufactures use, and pick a crank speed-say 5000rpm- to put in the formula with a different crank speed-say 7500rpm- the recommended weight will be different. So, at best you can only gain a "true" balance within a very narrow crank-speed range.
And from what I've seen, this true balance is at best a approximation. When you look inside the oil pan as the engine is running at high rpm, there is a tremendous amount of oil caught up in the windage from the spinning crank and wrapped around the crank throws. This oil has a lot of weight, and as the engine runs, this oil will migrate all over the assembly. Sometimes it hangs around the front throws, someetimes it is in the middle. The pattern is totally random and the size of the oil cloud can get larger or smaller. All of this happens in a test engine sitting on a dyno, so who knows what it's like when the engine is in a moving car and you have all sorts of front, rear and side loads in the picture.
This oil cloud must affect the balance of the operating assembly- and there is no way to account for it- so I little reason to worry much about engine balance. If you have to replace the pistons in an otherwise intact assembly or you have to do some machining or grinding- as is occasionally the case when you change a cam and a little more piston-to-valve clearance- I don't think you have to go to the trouble to rebalance the assembly if you can get the weight on the piston end of the rod within about two grams of the original balance weight. If you can get the replacement weight slightly less then the original balance weight, I'm sure you won't have any trouble. However, if things get out of hand-more than about three grams difference- you should get the assembly rebalanced to be on the safe side.