harmonic balancer on BB

-

trudysduster

FABO Gold Member
FABO Gold Member
Joined
Aug 24, 2009
Messages
5,072
Reaction score
242
Location
Corinth, Ky.
If you were going to change the balancer on a 440 from factory and go to a fluid one, which one would be best for this. I have a feeling that this one could be part of my problem.
 
which one would you go with for a 440 Rusty. I noticed the other day when I backed the car out of the garage. I started it up and let it idled for awhile and then I brought the rpm's up a little at a time and as it came up I could feel a little something like was off balanced. I am thinking that maybe my vibration problem in this car could be the balancer on the crank. I have not gotten down and checked it because of the lack of room in there but there isn't a lot of options that it could be doing that. The torque convertor is a new Hughes. The balancer is 1976 factory. that would also eliminate the problem of timing as I would have some kind of marks to time it with. so what fluid damper would you suggest guys. Thanks
 
what about the PRW 2544001. would this work for my 1976 440 engine. Right now it has the # 3830482 bullet style balancer on there.
 
what about the PRW 2544001. would this work for my 1976 440 engine. Right now it has the # 3830482 bullet style balancer on there.

can`t go wrong w/ a fluid damper. but for the $ , you ought to look at 440source, they use to have an sfi approved fluid damper, made in america for way less $. I`ve got one on my 505 ' stroker. haven`t fired it yet due to f.a.s.t 2.0 F. I. problems .
 
I had a CAT (probably same manufacturer as 440source) on my 451, neutral balanced, worked fine. No change from OEM damper but it was new, and shiny. Dont think mine was SFI or the sticker came off.
 
The 76 440 bullet nose damper is a cast crank set up. The 440 source fluid damper specifically states they are for internal (neutral balance) only. Your engine is external if it is factory. The PRW unit reads like it has to be balanced to the assembly

From their web site
"SFI-Rated FluidGel Harmonic Damper - Mopar 383-440 1958-79, 7.25″ OD, Black Anodized, Internal Balance.

These dampers are made with an internal steel inertia ring that is surrounded by a high viscosity silicone gel. The inertia ring “floats” in the silicone get to combat the engine harmonics at all RPM ranges. External balance applications feature a removable hub in order to accurately blueprint the engine and balance the assembly. These products are available in black epozy or polished steel with an epozy clear coat."

I would contact them to make sure of what is required to use it. May be able to just throw it on and go but a few minutes on the phone may save you some grief later.

Here is a new stock style http://www.bpeusa.com/HB440CAST.asp
 
thanks Dubob, that may be what I need to go with. I don't have to have a SFI approved fluid damper, but I thought it may be an option. I didn't see one on 440 source for external but I am going to call them before I make a purchase. That would eliminate one more possible cause of a driveline vibration. thanks.
 
You should verify what you have and be 100% sure which way the engine is balanced. These engines are old and it may have been internally balanced.

On a side note, I don't believe there is a fluid type balancer made for an externally balanced engine. I could be mistaken about that. If that's the case and yours is externally balanced, I suggest a Romac balancer. They are Australian made and extremely high quality.
 
"I started it up and let it idled for awhile and then I brought the rpm's up a little at a time and as it came up I could feel a little something like was off balanced. I am thinking that maybe my vibration problem in this car could be the balancer on the crank."

I am not familiar with your set up. I know you've been chasing this vibe for a while. Is this something that just started recently and showed up all at once or has it been slow and started getting worse? Is there anything contacting anywhere? Exhaust, headers. Is it possible the engine mounts are worn. I know you changed trans mount. Might also try pulling accessory belts off and doing what you did here as far as bringing rpm up slowly. Of course don't run it to where it gets hot. Headers clear of steering box etc. just tossing some ideas around.
 
I have herd that fluid dampeners are NOT good for the street due to the up and down of the RPM. They have a tendency to brake the crank with fluid movement. Just my 2 cents.
 
Rusty, I know 100 % that this engine is a 1976 factory engine. I had it rebuilt and I know the damper on it is a 3830482 cone type balancer. I don't know about internally balanced. I don't know how it would be balanced internally. would a machine shop have to do that. I know this engine was not put together at a shop. an asshole buddy of mine put it together. this problem has been getting worse over the years that is why I am thinking that the damper is bad. I don't have headers and the mounts are fairly new and I don't see anything hitting. it starts from about 1000 RPM's. I am guessing as I don't have a tach. how would I find out if it was internally balanced. The crank in it is the one that came with it so I am inclined to believe it is externally balanced. I bought this engine complete years ago and had it taken apart and checked and bored and put back together by a so called friend I used to race with back about 2000. over time I believe it has been getting worse. cannot pin point it exactly. That is another reason I believe it could be the balancer. from what I have read, a 1976 440 is definitely externally balanced and on the 440 source website, it shows my damper part # 3830482 as the same one as the one on the car now.
 
If you can get a picture of the balancer, that would be a big plus. I don't know what you mean by "cone type" balancer. If it's externally balanced, it will have an obvious counterweight on the balancer. I assume that since you are chasing engine balance problems, that the vibration occurs in neutral and park while sitting still?

I am assuming you want this fixed. If so, you need to verify what's there, regardless of what you "know". That's proper diagnosis. Unless you do that, you may end up chasing your tail. It would be important enough to me that I would drop the oil pan to see exactly which crank I had. Forged or cast. Because the truth is, unless you built it, you really DON'T know.
 

man I knew there was something about that damper that rung a bell. Bullet nose Cast crank externally balanced. No fluid damper for you unless you balance the internals and go neutral. Did the rebuild guy replace this or was it the original?
1001048-1.jpg


BUT good news, they sell a 'convertible" for either neutral or 'Detroit' balance (external) $99
2001128c.jpg
 
I was thinkin that's what he meant, but wasn't sure. If it's shakin, there's a reason. I would be snatchin that pan. Just me.
 
that's the one I have on there. the one pishta posted up there. the bullet style. who sells that external one posted up there. is that a PRW one. have they had any problems with that balancer that you know of. I am assuming that being factory it could be going bad enough to be the problem.
 
Rusty, motor is not really shakin. I just feel enough of a quiver when the RPM's come up to make me think that there could be a problem with the balancer. I posted awhile back about a quiver in the car when I would take off. I believe this is where it could be. it didn't all come together for me until this problem with the vibration in the driveline . if that IS the balancer causing the quiver I feel, it could very well be transferring through the driveline. I need to get this straightened out before I go on to the rest I believe. It didn't register to me until I was getting ready to back out of the garage the other day and as I brought up the RPMs that the quiver I posted about when I would take off in the car is doing it while I was sitting still. when the weather changes and I park the car, we are going to repaint it again over the winter. I have a notion to just pull the engine out and go through it again and freshen it up. Its been 14 years since it was built. just depends on how many projects that are coming in over the winter. But I am leaning towards this balancer as a problem.
 
well I just got home from the tranny shop and I am a bit relieved and a little pissed at the same time. took Brian for a ride and then put it up on the lift when we got back. it seems that the tranny mount I just put in less than 100 miles ago is shot. he lifted up on the tailshaft and the back of the tranny lifted probably an inch. tranny is resting metal on metal. that is why things were changing on me. as you know I just put this in and I didn't expect that would be shot this fast. It was an Anchor brand, what everybody calls for. so I guess I will go with a poly mount or something else. I still not convinced that is all the problem but maybe. what kind of mount would you guys go with. would the Prothane 4-1603 be a good one from Summit Racing. is there anything better than a poly mount. what are some of you guys running in a 727. guess I will start there. thanks,Bill
 
as a side note

externally balanced engine vs internally balance

internally balanced, forged crank, neutral harmonic balancer (no offset weights/holes), flexplate is neutral balanced, converter also. no weights on the converter.
if it's a stick same is true for the flywheel

externally balance... typically a cast crank, harmonic balancer has offset or holes in it, in stock the flexplate is neutral the converter has weights. for aftermarket neutral converter you have to get a special flexplate that has the offset so you can use the neutral converter
 
thanks. I put a 2800-3000 Hughes torque convertor in there awhile back. I would have to go back and pull the paperwork and see which one it was.
 
if it was neutral balanced with no weights you either need to get weights welded on, or (easier) replace the flex plate with one of these:

Part #10237
Fits 1971 and newer Chrysler, Dodge, Plymouth Torqueflite A727 automatic transmissions. Bolts onto 383 cid, 400 cid, and 440 cid engines with an externally balanced cast steel crankshaft. Has 10 inch and 11.125 inch bolt pattern

10237.jpg
 
I am not 100% sure but I think I did when we put the new TQ in. will have to check the paperwork and ask the boys. I am getting the 2 cars mixed up. I know we did on the Dart Sport and I am pretty sure we put a new one on the Duster but I will make sure.thanks
 
I have herd that fluid dampeners are NOT good for the street due to the up and down of the RPM. They have a tendency to brake the crank with fluid movement. Just my 2 cents.

commercial diesels as in tractor trailers use them. They go a ton of miles and make more vibration and harmonics than any A body is going to make.


Fluidampr. They aren't cheap, but if I was trying to correct a problem, I would want the best.

yes, yes, yes. I ran one on my last 440. Very nice but you will pay.
 
-
Back
Top Bottom