why does this industrial 300 have no harmonic balancer?
- Thread starter sdiesel
- Start date
Our engines are internally balanced. Technically you could get away without running one, however it does do a good bit of vibration damping.
An industrial engine is usually one that's set somewhere, turned on, and forgotten about until it doesn't need to be run anymore. However, a vehicle engine will translate any vibration into the frame and body of the vehicle.
I doubt anyone would really recommend running an engine without a balancer, as you'll end up fatiguing your welds and such, but it could be done.
An industrial engine is usually one that's set somewhere, turned on, and forgotten about until it doesn't need to be run anymore. However, a vehicle engine will translate any vibration into the frame and body of the vehicle.
I doubt anyone would really recommend running an engine without a balancer, as you'll end up fatiguing your welds and such, but it could be done.
our sixes dont have balancers, they are internally balanced
the 300 has a damper, probably to take out a high frequency torque pulse at higher rpms, acting more like a flywheel absorbing torsional energy
the 240 (mine, at least) doesn't have the damper on there at all, the industrial 300 probably wasn't made to be run at higher RPM's so they left it off.
the 300 has a damper, probably to take out a high frequency torque pulse at higher rpms, acting more like a flywheel absorbing torsional energy
the 240 (mine, at least) doesn't have the damper on there at all, the industrial 300 probably wasn't made to be run at higher RPM's so they left it off.
An internally balanced engine still requires a harmonic balancer if it to live for any reasonable amount of time. The internal balancing refers to the fact that the balancing is set within the crankshaft itself and not by using counterweights on the flywheel or harmonic balancer.
The harmonic balancer is used to lessen the resonant forces or frequencies within the rotating assembly. These occur on any piston engine at certain engine speeds and at other engine speeds are almost non exixtsant. In industrial or stationary engines, the engine speed is almost constant and doesn't continually change rpm the way an engine does in a passenger car or truck so they can be used without a balancer/damper if they are operated within that specific rpm range. I too have seen this on stationary engines and never really got what the benefit of not using one is, but they do it. We also would not run a balancer on drag cars in the olden days to help the engine rev quicker but it is not a good idea and the benefits are minimal compared to the risks.
The harmonic balancer is used to lessen the resonant forces or frequencies within the rotating assembly. These occur on any piston engine at certain engine speeds and at other engine speeds are almost non exixtsant. In industrial or stationary engines, the engine speed is almost constant and doesn't continually change rpm the way an engine does in a passenger car or truck so they can be used without a balancer/damper if they are operated within that specific rpm range. I too have seen this on stationary engines and never really got what the benefit of not using one is, but they do it. We also would not run a balancer on drag cars in the olden days to help the engine rev quicker but it is not a good idea and the benefits are minimal compared to the risks.
hmm i may be fuzzy on the balancer/damper terminology
i thought the device you are calling a 'harmonic balancer' is more commonly called a 'damper' because it is damping a torsional vibratory mode, and the term 'balancer' would be more aptly applied to something correcting for a radial-plane balance issue
i agree 100% with the description, just semantics really... as an engineer I would call it a damper... well, technically a flywheel i guess, but i don't know what the more common automotive world term would be. I try to sound as much like a not-idiot as possible, just want to know if i've been using obscure terminology.
i thought the device you are calling a 'harmonic balancer' is more commonly called a 'damper' because it is damping a torsional vibratory mode, and the term 'balancer' would be more aptly applied to something correcting for a radial-plane balance issue
i agree 100% with the description, just semantics really... as an engineer I would call it a damper... well, technically a flywheel i guess, but i don't know what the more common automotive world term would be. I try to sound as much like a not-idiot as possible, just want to know if i've been using obscure terminology.
As a matter of fact, MY use of the term harmonic balancer is probably dated and damper is certainly more correct in its description. As you said it really is semantics not unlike the whole motor/engine thing. 
Be it a vibration damper/dampener or harmonic balancer or any combination of these silly terms, its all the same animal and faithfully does its magic without our knowledge or consent.
Be it a vibration damper/dampener or harmonic balancer or any combination of these silly terms, its all the same animal and faithfully does its magic without our knowledge or consent.
.ok i am learning things
here is a question .
this new engine has 2 hours on it its a 5 speed truck
i am getting a remarkable vibration at certain rpm's increasing as the engine does but at idle it is just a veryslight miss.
the propane timing fuel adjustments are not completely right yet so i accuse the idle stumble as a timing /fuel thing.
the rpm vibration might well be a flywheel , clutch issue it feels that stron really shakes.
i doubt it is the damper, but could it be a harmonic issue?
damper marks are right on
help fellas!
flat cam?
bad crank?
there is no knock or rattle
the crank is steel.
thx
here is a question .
this new engine has 2 hours on it its a 5 speed truck
i am getting a remarkable vibration at certain rpm's increasing as the engine does but at idle it is just a veryslight miss.
the propane timing fuel adjustments are not completely right yet so i accuse the idle stumble as a timing /fuel thing.
the rpm vibration might well be a flywheel , clutch issue it feels that stron really shakes.
i doubt it is the damper, but could it be a harmonic issue?
damper marks are right on
help fellas!
flat cam?
bad crank?
there is no knock or rattle
the crank is steel.
thx
Have you checked your compression reading in each cylinder to see if they are close? Also check for a bad plug or plug wire, bad cap, too tight of valve lash.
Bubba is trying to suggest that the engine may have a dead or weak cylinder and that is a very good starting point. A quick way to check this is to start the engine and while it is warm and idling, remove the plug wires one at a time with INSULATED pliers and note what happens with the idle speed. If all cylinders are firing properly you will notice a notable drop in idle speed. If you remove a plus wire and the idle doesn't change, you have found a dead cylinder and can further diagnose from there.
Harmonics are not something that can really be felt. If it is shaking rocking and generally throwing the engine around, it is either a misfiring cylinder which you can detect like I just described, or it is a full on imbalance issue. The imbalance could be from a bad or non existent balance job when the engine was built, or could be as simple as having an incorrect flywheel or harmonic balancer/damper on it. As stated earlier, these engines are internally balanced and if an externally balanced flywheel made its way on the engine after it was rebuilt, well... That'd do it.
Harmonics are not something that can really be felt. If it is shaking rocking and generally throwing the engine around, it is either a misfiring cylinder which you can detect like I just described, or it is a full on imbalance issue. The imbalance could be from a bad or non existent balance job when the engine was built, or could be as simple as having an incorrect flywheel or harmonic balancer/damper on it. As stated earlier, these engines are internally balanced and if an externally balanced flywheel made its way on the engine after it was rebuilt, well... That'd do it.
i'm running (about 250 miles so far) on 5 cylinders... its rough, shaking and general rough running
easiest way to find a dead cylinder, starting with a cold engine, fire it up and let it run for 2-3 minutes, take a squirt bottle full of water (or spit on it) and spray each of the exhaust runners, they will steam off really quick, one will be noticeably slower to steam off.
takes a lot less time and less risk of shocking the crap out of yourself than the spark plug pulling method.
plus as i noticed, the truck runs about the same with 4 or 5 cylinders, once you're down to 5 it is running so rough, its hard to tell which cylinder makes it worse or better.
easiest way to find a dead cylinder, starting with a cold engine, fire it up and let it run for 2-3 minutes, take a squirt bottle full of water (or spit on it) and spray each of the exhaust runners, they will steam off really quick, one will be noticeably slower to steam off.
takes a lot less time and less risk of shocking the crap out of yourself than the spark plug pulling method.
plus as i noticed, the truck runs about the same with 4 or 5 cylinders, once you're down to 5 it is running so rough, its hard to tell which cylinder makes it worse or better.
good idea on the exhaust temp
i have a laser type thermometer i will use on it
.
i have it in my mind to do both a compression check and a temp check on exhaust manifold yet have not done so
but no more lollygagging i'm going to do that today.
my lash is set too tight , or the cam is bad on one lobe (due to excessivly difficult first start),then i already have a suspect.
i have a laser type thermometer i will use on it
.
i have it in my mind to do both a compression check and a temp check on exhaust manifold yet have not done so
but no more lollygagging i'm going to do that today.
my lash is set too tight , or the cam is bad on one lobe (due to excessivly difficult first start),then i already have a suspect.