Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary

wrote in message
...
Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary

Better motor mounts - and truck shock absorbers?

If nothing else, less wear on the rings and better valve adjustment.

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

Ignition might be less effective on older engine (missing "bangs"
leading to more shakes)?
Something out of balance? I had a blade come off the fan at speed on a
truck once - the resulting vibration was astonishing.

"Jordan" wrote: Ignition might be less effective on older engine (missing
"bangs" leading to more shakes)?
^^^^^^^^^^^^^^^^
OP is asking about a diesel engine. *Probably* not an ignition problem.

Leo Lichtman wrote:
"Jordan" wrote: Ignition might be less effective on older engine
(missing "bangs" leading to more shakes)?
^^^^^^^^^^^^^^^^
OP is asking about a diesel engine. *Probably* not an ignition
problem.

More likely unequal compression . More compression equals bigger power pulse
..
--
Snag
none to one to reply

Diesel still ignites the fuel. Poor ignition could be from any number of
things. Injectors/injector pump, compression, valves, carbon build up.
They just don't have an electrical ignition system. Or at least that is how
I read that statement about less efficient ignition??
Glenn
"Leo Lichtman" wrote in message
...

"Jordan" wrote: Ignition might be less effective on older engine
(missing "bangs" leading to more shakes)?
^^^^^^^^^^^^^^^^
OP is asking about a diesel engine. *Probably* not an ignition problem.

Probably several things , like motor mounts, cab mounts and such. The fuel
injection system has a lot to do with it. With age the injectors and the
fuel pump wear. The cylinder balance changes and you have irregular fuel
outputs to each cylinder. New engines which are more stringent emission wise
are new and have more exact fuel outputs , thus a smoother engine.
Once had a new Mack exhibit right front tire imbalance. Replaced tire and
rotor. Nothing helped. Around 45 mph the truck would start vibrating. Pulled
injection pump and the fuel balance was off. The engine would rock in it's
mounts giving you the sensation the right tire was bad.

A newer computerized diesel will have better fuel metering and
atomization. Also, tighter injection timing. Not to mention better
engineering of the engine mechanicals, better balancing, etc.
No mystery.
JR
Dweller in the cellar

wrote:

Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary


--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
If you're not the lead dog, the view never changes
Doubt yourself, and the real world will eat you alive
The world doesn't revolve around you, it revolves around me
No skeletons in the closet; just decomposing corpses
--------------------------------------------------------------
Dependence is Vulnerability:
--------------------------------------------------------------
"Open the Pod Bay Doors please, Hal"
"I'm sorry, Dave, I'm afraid I can't do that.."

Have to agree here diesel computer controls are dam good today, the after
market chips/sensors that bolt onto modern truck diesels will pump up the
power of stock trucks alot. You can get some BIG power gains with
chips/sensor upgrades. This is common on the smaller trucks but I am sure
the larger trucks are using tight controls also, all in an effort to save
fuel. 1 MPG gain would mean a **** load of money to a big fleet.
"JR North" wrote in message
.. .
A newer computerized diesel will have better fuel metering and atomization.
Also, tighter injection timing. Not to mention better engineering of the
engine mechanicals, better balancing, etc.
No mystery.
JR
Dweller in the cellar

wrote:

Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks gary


--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
If you're not the lead dog, the view never changes
Doubt yourself, and the real world will eat you alive
The world doesn't revolve around you, it revolves around me
No skeletons in the closet; just decomposing corpses
--------------------------------------------------------------
Dependence is Vulnerability:
--------------------------------------------------------------
"Open the Pod Bay Doors please, Hal"
"I'm sorry, Dave, I'm afraid I can't do that.."

wrote in news:nr6l42dk9piggu2iph2vtpks8ofqqjd92q@
4ax.com:

Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary

Much tighter tolerances on the parts, including balance influencing
issues such as piston and connecting rod weights and clearances. There
has been a large jump in injector technology, meaning better atomized
fuel. The EPA regulations have required a change to a much higher
compression ratio, and this has resulted in basically a brand new design
of the engines from the ground up. In order to take the increased loads,
all the other parts of the engine have to be beefed up, which damps
vibration.
Gone are the aluminum pistons with a cast ring insert, replaced by, at
first a 2 piece steel/aluminum skirt piston combination, and as the
latest round of EPA tightening came into effect, an all steel piston.
There is another round of EPA tightening due this year, which will
require changes beyond that as the diesel manufacturers again bump
compression ratios in order to clean up exhaust emissions.

The side benefit to all of this, is a more powerful engine that uses up
to 20% less fuel than it's predecessors.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

Think about 20% fuel savings. In todays world that is a great selling point.
"Anthony" wrote in message
. ..
wrote in news:nr6l42dk9piggu2iph2vtpks8ofqqjd92q@
4ax.com:

Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary

Much tighter tolerances on the parts, including balance influencing
issues such as piston and connecting rod weights and clearances. There
has been a large jump in injector technology, meaning better atomized
fuel. The EPA regulations have required a change to a much higher
compression ratio, and this has resulted in basically a brand new design
of the engines from the ground up. In order to take the increased loads,
all the other parts of the engine have to be beefed up, which damps
vibration.
Gone are the aluminum pistons with a cast ring insert, replaced by, at
first a 2 piece steel/aluminum skirt piston combination, and as the
latest round of EPA tightening came into effect, an all steel piston.
There is another round of EPA tightening due this year, which will
require changes beyond that as the diesel manufacturers again bump
compression ratios in order to clean up exhaust emissions.

The side benefit to all of this, is a more powerful engine that uses up
to 20% less fuel than it's predecessors.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

"Anthony" wrote in message
. ..

The EPA regulations have required a change to a much higher
compression ratio, and this has resulted in basically a brand new design
of the engines from the ground up.

My dad's 63 190d had (from memory) a cr of 21:1. Are today's diesel engines
any higher?

Anthony wrote:
wrote in news:nr6l42dk9piggu2iph2vtpks8ofqqjd92q@
4ax.com:

Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary

Much tighter tolerances on the parts, including balance influencing
issues such as piston and connecting rod weights and clearances. There
has been a large jump in injector technology, meaning better atomized
fuel. The EPA regulations have required a change to a much higher
compression ratio, and this has resulted in basically a brand new design
of the engines from the ground up. In order to take the increased loads,
all the other parts of the engine have to be beefed up, which damps
vibration.
Gone are the aluminum pistons with a cast ring insert, replaced by, at
first a 2 piece steel/aluminum skirt piston combination, and as the
latest round of EPA tightening came into effect, an all steel piston.
There is another round of EPA tightening due this year, which will
require changes beyond that as the diesel manufacturers again bump
compression ratios in order to clean up exhaust emissions.

The side benefit to all of this, is a more powerful engine that uses up
to 20% less fuel than it's predecessors.

Seems rather obscene to say the EPA is driving such improvements(?)

wrote:
Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks
gary
Electronic Fuel Pump instead of mechanical ?
New Dodges have that and are quiter than their older counterparts,

"Mike" wrote in message
m...
wrote:
Why does an older enginr(class 8 diesel) vibrate more than
a new(newer) motor, same manufacturer?

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?

thanks gary
Electronic Fuel Pump instead of mechanical ?
New Dodges have that and are quiter than their older counterparts,

Totally different fuel system: High Pressure Common Rail - the same basic
system used on the Navistar [Ford] and Isuzu [GM] light diesels and not
applicable to the engines used in a Class 8 [Peterbilt, Kenworth, Volvo,
Freightliner] truck.

Carbon buildup, ring wear [non-uniform compression loss], uneven rod bearing
wear, bad valve timing from extended Jake-brake use ... any/all could be
factors in addition to motor-mounts and, even, front shocks.

"Dave" wrote in news:1145795896.721699.324220
@u72g2000cwu.googlegroups.com:
to 20% less fuel than it's predecessors.

Seems rather obscene to say the EPA is driving such improvements(?)


Nope..tis the fact of the matter.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

"jtaylor" wrote in
net.ca:


My dad's 63 190d had (from memory) a cr of 21:1. Are today's diesel
engines any higher?


Yup. But, I am not sure of the exact number. The change to a special steel
alloy was to prevent melting of the piston at the much increased
compression ratios.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

"Anthony" wrote in message
...
"jtaylor" wrote in
net.ca:


My dad's 63 190d had (from memory) a cr of 21:1. Are today's
diesel
engines any higher?


Yup. But, I am not sure of the exact number. The change to a special
steel
alloy was to prevent melting of the piston at the much increased
compression ratios.


--
Anthony


Steel pistons ? - that's a new one for me !

AWEM

Andrew Mawson wrote:


"Anthony" wrote in message
...
"jtaylor" wrote in
net.ca:


My dad's 63 190d had (from memory) a cr of 21:1. Are today's
diesel
engines any higher?


Yup. But, I am not sure of the exact number. The change to a special
steel
alloy was to prevent melting of the piston at the much increased
compression ratios.


--
Anthony


Steel pistons ? - that's a new one for me !

Looking at the caterpillar site their engines seem to have around 17-18:1
but they're also turbocharged.

AWEM

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

"J. Clarke" wrote in
:



Steel pistons ? - that's a new one for me !


Yup...been that way for a few years. Like I said, at first it was a 2 pc
steel crown with an aluminum skirt. Now they are 1 pc steel.


Looking at the caterpillar site their engines seem to have around
17-18:1 but they're also turbocharged.


Yes, and they run quite a bit of boost.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

Jordan wrote:

i.e. what changes are happening as an engine ages/wears
that increases vibration/shake?


Ignition might be less effective on older engine (missing "bangs"
leading to more shakes)?
Something out of balance? I had a blade come off the fan at speed on a
truck once - the resulting vibration was astonishing.

When a Diesel misses, it produces HUGE clouds of white smoke (oil mist)
out the
exhaust. Also, by the sound, you will definitely know something is
really wrong.
Due to the much greater noise of the combustion in the cylinder, when it
misses,
that little silence really stands out.

Jon