Who makes one for a 1pc seal crank? I bought one but it was for external balance and now that the shop got it to balance internaly they need a neutral.

Thanks

KM

 

Can't they drill holes on the opposite side to offset the counterbalance? I need a counterbalanced flywheel and about a dozen holes later the neutral balanced flywheel was counterbalance. Going the other way should be the same and the flywheel will be a little lighter.

 

There is no such thing as a neutral balanced flywheel! The balancer is neutral, then when the rotating assembly is in the process of being balanced weight is removed from crank and flywheel at different places. A flywheel will be neutral to the rotating assembly that is neutrally balanced for. if you changed any part of the rotating assembly, the process will have to be redone.

Yedi

 

Try star engineering they have an aluminum flywheel with the counter weight screwed on the flywheel

 

I may have this all screwed up, but I'm going to try and explain it the way I understand it. The engine balance came in with just the Neutral Dampener and the removal of a little weighgt from the Bob weights. The flywheel I need is like the older regular 350 2pc internaly balanced ones, except I need one like that for a 1pc crank.

I should be able to change my balancer or my flywheel without having to rebalance everything! as long as they are neutral. All of my internal parts were within about a 1 or 2 grams of each other pistons,rods,etc...

Someone correct me if I'm wrong! but this is my understanding.

KM

 

Confusing, contradictory and dead wrong!

"There is no such thing as a neutral balanced flywheel!" Wrong.

Many engines come from the factory with neutral balanced flywheels and flexplates. The 427 BB Chevy is one example. All internally balanced engines are neutral on BOTH ends - hence "internally balanced".

"If you changed any part of the rotating assembly, the whole process will have to be redone" Wrong.

Neutral balance simply means that when the item is placed on the test fixture and spun up, no one side is heavier that the other. i.e. neutral.

So, say, if you damage the teeth on your flexplate (rotating) because the starter wasn't shimmed properly, you can simply replace the neutral flexplate with one from any auto parts store with any rebalancing.

Same thing with a harmonic damper.

Some engines come with a neutral harmonic damper, like the 427 BB Chevy, and others have counter-weights, like the 454 BB Chevy. Some engines have both the flexplate/flywheel and damper neutral, others have both ends counter-weighted and still others are hybrids (with one end neutral and the other counter-weighted.)

You can take a counter-weighted flexplate or flywheel, have the weight removed and the item spun up and made neutral. You can also take a neutral flexplate and do just the opposite.

Some engine builders over-balance the damper and/or flexplate/flywheel to "tune" the engine for a particular RPM range.

In any event, your shop should give you a bob-weight chart when the balancing is complete so that if, in the future, you need to replace a particular part - such as a piston or rod (reciprocating) - you can have the replacement part matched in weight to the chart and a rebalance job won't be required.

Hope this helps.

Jake

 

Confusing, contradictory and dead wrong!

"There is no such thing as a neutral balanced flywheel!" Wrong.

Many engines come from the factory with neutral balanced flywheels and flexplates. The 427 BB Chevy is one example. All internally balanced engines are neutral on BOTH ends - hence "internally balanced".

Jake[/QUOTE]


After you have read this you decide which definition of balancing you want to be the standard for your motor.

http://www.moparsunlimited.com/artic...balancing.html
Yedi


[Modified by yedister, 7:51 PM 11/17/2001]

 

I run a 408 that is internally balanced. It uses a Fluid Dampner (neutral balance), and a SPEC aluminum flywheel (with the balance weight removed - neutral balance). All components are internally machined such that there is no balance required on either end. And yes, if I screw up the flywheel or the dampner (who knows how one might do that), I can simply install another neutral balance component and not have to rebalance the rotating assembly.

All components were within 1/4 gram of each other. The motor is very smooth. No funky vibrations anywhere.

Best of Luck,
Aaron

 

I'm sure most of you have heard that "A little knowledge is a dangerous thing"; well, what we have here is a prime example. So let me put my cards on the table.

This and other boards have all types of information on them. Mostly "Good" but some "Bad!"

There's probably no issue that can occur with the SB Chevy engine that hasn't come up before at one time or another and a "fix" has been found. So there's no need to re-invent the wheel every time someone has a problem with or question about their engine. The difficult part is recognizing and distinguishing the "Good" info from the "Bad" info when you see or hear it.

The bad information - mis-information - is posted out of ignorance.

The other kind of bad information - dis-information - is posted with the intent of causing further harm, and fortunately isn't posted that often.

Not including Steve's bad info in this thread, here are a few examples of mis-information that I've seen or that was recently posted which are DEAD WRONG:

1. Use Loctite on the rod bolt threads to keep the nuts from coming off

2. It doesn't matter where you place the end gaps on your rings when you install pistons in the block

3. Installing head bolts with an air-powered impact wrench speeds up assembly. Head bolts installed on aluminum heads without washers.

4. Main negative cable from the battery not connected then consternation as to why little current flows from the battery resulting in hard starting. The alternator was diagnosed as the source of the problem. (This particular ground cable had a second much smaller ground wire which was connected).

5. Slosh tubes in the wrong fuel bowl of a Holley carb; not understanding what the fuel in the bowl is actually doing when the car leaves the line

6. Plans to buy a $500+ radiator to cure over-heating when the existing radiator is clogged dramatically with all sorts of gunk and rubber-like material

7. When you advance the cam using your new Jesel setup you don't have to reset the ignition timing - For that matter, confusing cam timing with ignition timing; thinking that cam timing and ignition timing are the same thing because they are both "timing".

8. Change the fuel pump was the advice given when no fuel pressure was present at the fuel rails. Problem was the pressure line was connected to the return port on the fuel rail and the return line to the pressure port.

9. There's no such thing as a Hi-Volume oil pump for the SB Chevy

10. And the beat goes on.

My daughter is a freshman at Harvard and sent me a video tape of the welcome ceremony for the class of 2005. The Keynote speaker, one of the professors, dedicated his entire presentation to one topic - Recognizing B.S. (my words, not his). He said if the students of the class of 2005 took nothing else away from their four years at Harvard he would hope they take away the ability to recognize B.S.

He went on to say that many times, B.S. is surrounded by credible info, which, on the surface, would make the B.S seem "correct".

Think of it as a hamburger. You've got your basic two piece bun with a meat pattie in the middle. The bun represents "good" info and the pattie is the B.S. When you take a bite you get both good and bad. So don't let the presence of some "good" info blind you to the presence of the B.S lurking within.

To run with the big dogs, one needs to spend the requisite amount of time as a pupil BEFORE presuming to become a teacher. To do otherwise is a good example of the "Blind leading the Blind".

My father had a saying: "He knows not that he knows not".

So cultivate your ability to recognize bad info when you see or hear it and your life will become immensely less complicated.

One can't subscribe to several 'hot rod' magazines and talk to a few Tech guys on the phone and then become magically elevated to a position of being qualified to give advice to others based on the fact that it was 'read' somewhere or 'so-and-so' said so. These are good training tools though, but just that, training tools. Time and hands-on experience coupled with some trial and error helps broaden your knowledge base.

Some will never have the aptitude or ability to grasp the intracacies of the internal combustion engine, much less be in a position to correctly advise on the SB Chevy engine. As "Dirty Harry" said, "Man's got to know his limitations".

I keep that in mind whenever I consider responding to a post. If it's outside my area of knowledge (if I'm ignorant on the topic), I leave it alone: like questions about transmission rebuilding or setting up a ring and pinion, etc. What I do in cases like that is, if I know, refer the poster to a source where 'good' info can be found.

There's no problem in not knowing something; no one knows everything. It's not knowing that you don't know and then giving advice based on your ignorance that's the problem.

We shouldn't be here to try to impress others with our knowledge, but simply to help others in need.

Identify your strengths and max out in those areas; leave the other areas to those who have strengths in them.

'Nuff said.

Jake





[Modified by JAKE, 2:15 PM 11/18/2001]

 

“Bolt on”! How many have you have experience this state with a part that will only bolt on after you grind, notch, curse a few time to inspire the bolt on to actually do it? How many of you have gotten a set of rings that the box gives you one size (specs) but when you try to put it on the piston, it does not fit correctly because it was package incorrectly.

I have an internally balanced 350 flywheel SFI approved. According to the place I purchased it from it was “Neutrally balanced” I was told that internal balanced and neutral balanced are the same thing.
When I was having my rotating assembly balanced, Hank The Crank told me to send it to because it was part of the process. When the Neutrally balanced flywheel came back those was 4 places where metal was removed. It turned out that the flywheel was not neutral after all. I guess that the manufacturer-balancing machine was off that day or maybe they went by factory specs or maybe the flywheel lost it neutrality during shipment.

I read in automotive rebuilder an article on engine balancing that basically said that balancing is the only way to verify manufacturer claims on the rotating assembly, also rapid bearing wear can be cause by an unbalanced rotating assembly, which I experienced not too long ago.

88-406, let the person that is balancing your assembly determine what is neutrally balanced after all he can give you the before and after data. Claims are just claims without the paper work to prove it. The name of the is to sell thats why it is called sales.

Yedi

 

First of all, Steve, your last post has little to do with what you originally posted.

You posted "There is no such thing as a neutral balanced flywheel". Which is dead wrong!

Secondly, you posted "If you changed any part of the rotating assembly, the process will have to be redone". Which is also dead wrong.

The nitro burning boys regularly exchange rods and pistons between rounds and the process is not "... redone." In addition, one of the advantages of having an internally balanced engine is that damper and flexplate/flywheels can be changed if they become damaged WITHOUT having the assembly rebalanced.

Dampers and flexplate/flywheels are interchangeable from the same family of engines. But, if you have some odd-ball balancing done to your assembly, then unless you have replacement parts of the same weight as the ones being replaced, yes, you'd have to rebalance the assembly.

There are Winston Cup and NASCAR teams that use an over-balancing technique to "tune" their engines for the RPM band in which the engine will be operating. Between, say, 6000 and 9500 RPM the engine will be in balance, but below 6000 it will be out of balance. This kind of stuff is left to only a relatively few engines though. "Tricks" like this aren't for a street driven engine expected to operate from idle to redline.

Based on your incorrect, inaccurate and imprecise information, everytime someone damages a flexplate because of, say, running over a big rock, he'd have to have his engine torn down and rebalanced. What about engines that have the elastomer separating from the damper due to age; again your position is that the engine must be torn down and rebalanced. Both are rotating parts of the assembly.

Your information is inaccurate at best and only serves to mislead and confuse those looking for correct, accurate and precise answers.

Bottom line: You don't understand what you're talking about and are trying to defend an indefensible position.

In the interest of not confusing others even more, personal integrity dictates that you just admit you're wrong and move on from there.

Jake

 

Question:
"Who makes one for a 1pc seal crank? I bought one but it was for external balance and now that the shop got it to balance internaly they need a neutral.
Thanks"

Well the shop has got themselves into trouble here.ALL one piece rear main seal Chevy small blocks use a external balance rear flywheel or flex plate.They should get you another crank.The flywheel you have will work.It is external balance.Those later engines used a internally balanced front dampner with the external balanced flywheel.
Sounds like you have bought a SCAT crank.Only the two piece rear main seal cranks from SCAT will internally balance.
Does this answer the original question thoroughly?If the shop is in doubt of this ask them to call SCAT .They will set them straight.

edited to ask if you are are using an old 400 2 piece seal block with the part to convert it to 1 piece rear main seal?


[Modified by mountainmotor, 7:12 PM 11/25/2001]