Thread: balance the motor or not?

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The last one I had done was $165 - and he b!@#$ed loudly as he quoted me firm price and it was a lot more then expected regardless of the fact that he had everything in hand first.

Pat's response is what you need for an answer - it varies by area

Originally Posted by IC2

The last one I had done was $165 - and he b!@#$ed loudly as he quoted me firm price and it was a lot more then expected regardless of the fact that he had everything in hand first.

Pat's response is what you need for an answer - it varies by area

that not bad ...really on price . i not going to post how much i get for a job but it,s abit north of that. some jobs can be a real pain in the ass if it .s been pluged up and welded you have to cap stuff off and make sure your not opening up someones plugs .can be a real can of worms . some of the great deal cranks do not have counter weight were it needs to be alot of drilling or truning the counter weight in a lathe or need more weight. heavy metal$$$. bad thing is some race cranks are starting to come this way with a very lite counter weight .so at this point we start to drill ream for a press fit plug of heavy metal like this

Wheelkid,
First, though you did not mention being new here, welcome to CHR. We look forward to hearing about your projects and seeing what you're working on as time goes by.
On balancing, it sounds to me like you're focused on the balancing of the reciprocating weight - the pistons, pins & rings, but not really considering the rotating weight and the dynamic balance. From my limited knowledge on the subject, the basic balance is three pieces - the reciprocating weight; the rotating weight or "bob weight"; and the oil weight, assumed to be 4 grams. Here's a link to a Ford Muscle overview that I found quite helpful in understanding the process - Engine Balancing and Crankshaft Balancing - FordMuscle
After the engine is balanced the flywheel, clutch & pressure plate are generally balanced, too, so that the entire assembly is considered. Once that process is complete, if you have to modify things later then you are working from a balanced starting point, and it's generally not necessary to re-balance the entire assembly - you can simply work from the base numbers, and modify your replacement parts to match, like changing out a piston you can match the weight of the one removed, as close as possible. No one is going to argue with you about the distribution of oil being less than perfect, but it's the starting point that's important. If you have a few grams of oil moving around would you rather it be from a very closely balanced base, or is it OK to have it being added to an imbalance of ten, twenty, fifty or more grams that's causing the crank to flex? I'd rather start from a solid dynamically balanced base, giving a much smoother engine. Others who have more experience in this arena may shoot me down on this, which is fine. I love to increase my understanding of these processes!!

Reading the above regarding Smokey.

1. Smokey's time was in the 60's /70's, equipment has come a long way since then;

2. Smokey mentions weights in grams. How would you know the weights? Unless it was disassembled and each part of the rotating assembly weighed!

In Smokey's defense of the above, he's already done the heavy lift and is now discussing maintaining a given balance. (IMHO)

In regards to the balance variable shifting in the rpm range. This is called harmonics and is a college course study in itself! Notwithstanding this fact, it is still far better to make every attempt to cancel out any vibration(s) for added longevity / reiability.

Seems Roger types more words... but alot faster!!

Originally Posted by 34_40

Seems Roger types more words... but alot faster!!

Mike, my thought was that you said much the same thing much more efficiently!!

OIL ? this is abit of a joke with some of my freinds we know were the oil is THE OIL PAN ? just not were it.s at 8000 grand and harmonic s first post on this site i realy pist some guy who is not on hear any more about harmonics frequencys I was not going to go there in a small post and what happens in a oil pan or cylinder bores . rods big ends piston pins. push rods can flex go out of round ,aluminum heads were is the seat when the heads hot ? all things about can move from power . heat . distortion and at times harmonics . from were bolts are when tighten up some things we do things to insure stuff stays round when you bore or hone a block but we can not use the real heads . we can not bore and hone the engine under load but many do the best we can do . some way better then others smokey was one but he was off abit off on the 10 pound rule . same with the crank we do know oil ropes the crank we try to stop this . but at the end of the day you do the best you can and get the mass balanced. it will affect the engine very low speed if off alot. at the end of the day with all new parts we try to get them very close add for some oil on parts. pistons are alumiunum takes alot to throw a crank off for a fly cut for valves after going to a bigger cam .pistons they all are going to be even with same weight . as they were balanced before you cut them?? better to have a crank heavy then to lite so pistons you can go less gram piston all in match sets .but not one or 3 pistons heavy there ways to make things work if you get in to a engine that lost one or 3 pistons should buy a new set but it happens were the new pistons will not be the same weight piston pins can use a heavy or thin wall pin .pin end of the rods can be re worked . every part of a engine and action in it self is a science. the way we machine a engine is a science . the more you know the less you know about whats really going on. many know nothing

Originally Posted by pat mccarthy

OIL ? this is abit of a joke with some of my freinds we know were the oil is THE OIL PAN ? just not were it.s at 8000 grand and harmonic s first post on this site i realy pist some guy who is not on hear any more about harmonics frequencys I was not going to go there in a small post.

every part of a engine and action in it self is a science. the way we machine a engine is a science . the more you know the less you know about whats really going on. many know nothing

Charlie, you upset someone?? Nah.. don't believe it!!

And sometimes.. ignorance is bliss! HAH!!

Originally Posted by 34_40

Charlie, you upset someone?? Nah.. don't believe it!!

And sometimes.. ignorance is bliss! HAH!!

charlie ? mccarthy Thanks you knew my greatgrand dad from Cork Ireland. or are you saying i am wooden dummy with someones hand up my back side ?

Originally Posted by pat mccarthy

charlie ? mccarthy Thanks you knew my greatgrand dad from Cork Ireland. or are you saying i am wooden dummy with someones hand up my back side ?

Forgive me Pat.. I musta had Charlie on the brain.. 8-)

Now I feel like the wooden dummy!

So--------------while you guys been talking on the web about it---I've balanced 3 engines plus going out of town for 3 days--------

but-----------keep in mind that the oil going arond with the crank is ain a fluid condition,and will not affect the balance of the mass of solid materials

Originally Posted by jerry clayton

So--------------while you guys been talking on the web about it---I've balanced 3 engines plus going out of town for 3 days--------

but-----------keep in mind that the oil going arond with the crank is ain a fluid condition,and will not affect the balance of the mass of solid materials

OH and i have not ??? your not the only guy on here that like hitting his head on the wall Jerry ..oil hanging in the wrist pins .. oil can fill drill holes in the crank and gets thrown out ?. oil is still weight i know were splitting hairs

Originally Posted by pat mccarthy

..oil hanging in the wrist pins .. oil can fill drill holes in the crank and gets thrown out ?. oil is still weight i know were splitting hairs

Maybe this is that 0W-20 oil with no mass, Pat?? Kind of like Coke Zero, no calories, no caffine, nothing there but wet and a taste!! F'n MAGIC!!!

Jus' kiddin', Jerry, Jus' kiddin'!!

http://www.me.cycu.edu.tw/~merc/%E8%...Crankshaft.pdf

Originally Posted by jerry clayton

http://www.me.cycu.edu.tw/~merc/%E8%...Crankshaft.pdf

no go joe... let me think it a post saying oil has no weight ok its working