Vibration

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I haven't heard back from the original owner. Hes out of town for work this week. I appreciate the help guys. I've been wracking my brain over this for quite some time.
 
nm9stheham, I was asking about the the stickshift flywheel the crank was originally balanced with. I have seen shops make corrections on the flywheel instead of the crank. If that were the case here, then the b&m flex plate ,while being correct for a 360 would not work in this case. You are correct in the fact that the crank is where corrections should be made. I recently went through this with a 331 sbf. The guy was going from auto to stickshift. The shop that built it did it on the flexplate instead off the crank. The guy brought me his new flyweel & the flexplate the motor was balanced with. In order for him not to have to tear apart a good running motor , I was able to make his new flwheel match what the original shop did to his flexplate. I have a Pro-Bal balancing machine updated with turner technologies electronics in 2014 in the shop. I balance a couple of cranks a week.
 
nm9stheham , I am a grouch until I drink my pot of coffee in the morning, and my last post makes that clear. I know we are all here to help "smooth" out the op's problem.
 
Hey no problemo....I am too dumb to know when I am being lectured, so no harm LOL! I found your explanation very informative, and it's something I had not thought of at all; indeed, sometimes the 'should have happened' is not what actually does happen.
 
OP, I confess I had not listened to your video before..... I just did and the audio is not all that clear and is very muffled. But from what I can hear, my first innocent guess from the audio would be that there is a miss in one or more cylinders; again, the audio is muffled, but it does not sound right. But, it could be the audio device just distorting the actual sounds.

Do you have any better audio?
 
Off topic I know, but speaking of being dumb, my dad has always had the saying "If your dumb ,you gotta be tough." My wife says I'm the toughest guy she knows!
 
Just got a reply from Phil. (Original engine owner) Looks like its on the flexplate end like said...

Kane
The engine rotating assy required external balancing. The crank front damper is specific for the 360 engine, and it was included in the rotating assy balance. The flywheel was also included in the rotating assy balance, which is why your auto-trans flexplate balance needed to match the flywheel balance that I had on the engine.
The pistons are all matched to the same weight, same with the connecting rods. So they could be used with another crankshaft.

Are you still having balance issues? If you want, I can call the shop that balanced the rotating assy and get the balance weight numbers from the owner, Jody. I believe he keeps records of all his machine work.
Let me know. Phil
 
Well we see your problem. Flywheel balanced, torque converter, flex plate not.
 
needs to rebalanced with auto trans in mind. :burnout:MT
 
The important question to ask the PO's balance shop is if any material (and how much) was taken off of the flywheel as part of the balancing process (as Sam wisely mentioned), or did they leave it as just a stock 360 flywheel. The PO is not clear on that part. ALL stock 360 flywheels and damper have intentional imbalance to them.

The PN for the B&M flexplate that you list should match the intentional imbalance of a stock 360 flywheel. But, if they changed the balance of the flywheel, then yeah, you have to match that. Yes, you could possibly add/change that on the flexplate, but knowing where and how much is the key before figuring out how that can be done.

Do you have the flywheel? The standard 360 I do believe has 3 largish holes in the back of the flywheel about halfway out on the radius. Like this:
http://www.summitracing.com/parts/dcc-4529110?seid=srese1&gclid=CKn98L74uMgCFQ8WHwodoTICTg

(And if they changed the flywheel weighting, then they very likely they changed the damper weighting too. But you have that part.)

BTW, I listened to your new video several times.... hard to say how smooth the engine is firing from inside, with the horn ring rattling.
 
I do not have the flywheel. Not thinking, I sold the flywheel due to the fact that I'm running an auto. Never thought about the balance situation before selling....Obviously. Lol

It's not audible from outside the car. You cannot actually hear the imbalance.... It's just the feel and sights once sitting in the car.
 
I saw those before...... I don't have a stock 360 damper right here to see if those are normal or not. Maybe skep or someone has one and can look.

If the 360 damper's stock imbalance was modified, then likely the flywheel's stock imbalance was changed about the same. I have not added up the bobwieghts yet, but just looking at the piston weights, they are quite a bit lighter than stock. Same thing for the rods. That being the case, the bobweights are likely going to be a lot lighter and some material would be drilled out of the crank counterwieghts. I guess you could do that on the damper and flywheel/flexplate. But you end up needing the damper and wheel/plate kept; a poor way to do it, IMO.

The hard part to tell even if you had the flywheel is that, in addition to the 3 holes in the 360 flywheel for the intentional imbalance, there are a set of small holes around the periphery used to fine tune the balance (or imbalance for the 360). Hard to say which would be factory and which would be any added ones, if any.

The key will be info from the PO's balancing shop to see if they modified the flywheel and damper. If so, then perhaps the damper could be taken off and spun to find the new imbalance point for that, and perhaps duplicate that on the flextplate end. Presumably they would take off approximately the same amount on each end.
 
BTW, I just did a quick bobweight calc and came up with 1812 grams; that won't be exact as I estimated some weights like bearings and rings, but it'll be close. The rods and pistons you have are a lot lighter than stock so not a shock.

The stock bobweight is in the low 2100 gr range. That light a new bobweight would require a fair amount of weight to be taken off the counterweights or damper and flywheel/flexplate.

BTW, did you ever take the fan belts off and try it as suggested?
 
OK... still looking for the easy fix..... hate to see yo go deep into it for no good reason. Any further thoughts on the TC being out of whack?

BTW, did you have a pix of the clutch face of the flywheel.... just curious. Any chance you could buy that back and put it in, with no TC installed? If it was modified, the buyer may experience issues if he/she is expecting it to be a stock imbalanced 360 flywheel. You could start the car and see what that does.
 
Options 1. Get old parts back and stick with what you had.
Option 2. Get machine shop records and potentially throw money away trying to match it up
Option 3. Take motor apart and send off balancer. Rotating assembly. Converter.
Option 4. Sell engine and trans to go big block.
Option 5. Go to tire shop and buy stick on wheel weights. Weld on after.
Option 6. Don't do anything with the car for a couple years and dump it to someone on Fabo
Option 7. Install neutral balance flex plate and add tire shop sticky weights to converter.
Option 8. Go to a nickelback concert and realize it could be worse.
 
Without the flywheel, you'll have to rebalance the rotating assembly. Whoever you take it to should Knock off some $s since the rods and pistons are already match weighed. If not send me a PM and I'll help you out.
 
Although if it's balanced. Shouldn't it just take a internally balanced harmonic balancer and neutral balanced flex plate?
 
No, the external balance engine is 'balanced' as well as an internally balanced engine, but some of the balance weight is outside the engine in the flexplate or TC or flywheel, and in the damper. (I.e., the flexplate/flywheel/TC and the damper are intentionally imbalanced so that there is a net external rotating weight that works with the crank and rods/pistons,etc, for total end to end balance.)

You are thinking of an internal balanced engine, where both the flexplate + TC (or flywheel), and the damper, are all perfectly balanced by themselves (neutral balanced). The engine innards are then separately balanced to each other.
 
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