The "restification" of a 98 6.5 TD...

[NVW]

Most big trucks around here have them, there are moose and elk running around. One trucker said a big mule buck caused him $10k damage.

 

[88gmctruck]

I think a thief would be just as confused with Kodiak handles, not to mention they are much more stout and I don't think you'd be able to get into them quite as easily.

My 88 has keyless, I pulled the lock rods out of it long ago.

 

[bfourman]

I've always liked the TJM/ARB style bumpers. I'm a bit biased, my 01 Cherokee and my 96 Grand Cherokee both have ARBs and my Sub has a brushguard.

I have been into the offroad look/lifestyle since I was a kid though...

 

[greengreer]

AFAIK Slee offroad still has a few of the polished aluminum TJM bull bars in stock. I too am interested in something along those lines. Really like the ARB but the price of the TJM and the weight advantage of aluminum seem to make it a winner. I still haven't been able to find any info regarding either of these bumpers with the 6.5 and it's extra airflow needs.

sleeoffroad.com/products/tjm_sale.htm

 

[great white]

I like that TJM bumper. Good price too. Too bad I'm flat right now....would cost over a grand by the time I got it anyways....

 

[great white]

Just some tech reading:

Indirect injection engines
Many different types of combustion chambers have been
developed for IDI engines but the most successful recent designs
have used some variation of the Ricardo Comet swirl chamber
design shown in Figure 4.2.
During compression, air is forced at high velocity, from the
main chamber, through the narrow connecting passage, and into
the swirl chamber, or prechamber. As this air enters the
prechamber, the chamber shape turns the flow and induces a
strong swirl in the chamber. Fuel is injected into the swirling
flow and ignited after a brief ignition delay. The fuel-air ratio
in the swirl chamber is relatively rich, because only about half
of the trapped air is present in the swirl chamber. This rich
combustion keeps the NOx emissions low. As the pressure in
the swirl chamber rises because of combustion and the pressure
in the main chamber falls because of piston motion, the burning
gases expand into the main chamber where the CO and unburned
hydrocarbons burn with the remaining air.
Indirect injection engines have been popular for light-duty
diesel applications because of their lower NOx emissions, wider
speed range, and quieter operation. However, the high flow
velocities in the swirl chamber and connecting passage produce
greater heat transfer losses for IDI engines than for DI engines.
These engines generally require compression ratios greater than
20:1 for reliable starting and acceptable fuel economy. Most
IDI engines still require some form of starting aid such as a
glow plug located in the swirl chamber. Because of the high
swirl rates in the prechamber, IDI engines can achieve the fuelair
mixing rates required for high-quality combustion with lowpressure
fuel injection. Most IDI engines use relatively inexpensive
distributor-type fuel injection pumps and either singlehole
or pintle-type injectors.
Many variations of the Ricardo Comet design have been
developed. Jones et al found that by varying the orientation
of the connecting passage they could decrease the piston heating.
They opted for a side outlet from the prechamber as shown in
Figure 4.3; it directs the hot gases emerging from the prechamber
into the valve pockets rather than directly onto the piston crown.
Jones also found that the optimum location for the injector was
inboard, closer to the cylinder bore axis, with the fuel injected
in the direction of the air swirl. This location provided the lowest
NOx and noise, high priorities for their programme, but they
found it necessary to use a fan-shaped multi-hole nozzle to
achieve their power and unburned hydrocarbon goals. Jones,
along with other engine developers, found that directing the
fuel spray toward the centre of the prechamber gave lower
unburned hydrocarbon emissions but resulted in large increases
in NOx and combustion noise.
Amano et al designed a prechamber with a sharp edge that
disrupts the swirling flow, achieving lower NOx emissions. They
attributed this effect to lower maximum combustion temperatures
resulting from weaker swirl. Swirl chamber design requires
optimization of swirl chamber geometry, injection nozzle location,
injection rate and timing, the throat area of the connecting passage,
and compression ratio.
4.1.4.3 Comparison of IDI and DI engines
As mentioned earlier, the DI engine has up to 20% better fuel
efficiency than the IDI engine . Most of this loss is due to
greater heat transfer losses in the swirl chamber and connecting
passageway and to thermodynamic losses because of the late
combustion process that occurs as the rich swirl chamber mixture
expands into the main chamber. Throttling losses through the
connecting passageway are sometimes cited as a loss term.
However, these passages are usually large enough that the pressure
difference between the main chamber and the swirl chamber is
not large, and this effect is partially offset by the fact that the
IDI engine does not have the pumping losses associated with
the inlet port generated swirl typical of DI engines.
Both IDI and DI engines require small clearances between
the piston and the cylinder head. This clearance restricts the
timing of exhaust valve closing and intake valve opening unless
valve cutouts are provided in the piston. These cutouts increase
piston cost and adversely affect the in-cylinder flow field.

Some theory behind why the 130 gph pump is better at keeping the 6.5 cooler:

At lower flow rates (upper graph) there is reasonable agreement
between the measured and predicated data at low surface
temperatures. As the surface temperature is increased the heat
transfer coefficient is increased owing to the onset of nucleate
boiling but above 160C a reduction of heat transfer occurs as
a result of the presence of excessive vapour. This is not true film
boiling, but is due to the accumulation of vapour bubbles in the
narrow coolant passage. Similar phenomena can occur in the
drilled coolant passages of highly rated engines (particularly
IDIs). If the coolant velocity is low, the collapse of the bubbles
can lead to cavitation erosion.
At higher flow rates, nucleate boiling is suppressed. For flows
over the range 1-3 m/s (which is the range found in most thermally
critical areas), agreement between measurement and prediction
is excellent.

 

[great white]

Couple more "thinkers":

The first one gives me pretty good idea where the power is going given a similar amount of fuel in both a DI and IDI design.

The second one is very telling for the valve bridge cracks the IDI design suffers from. You can see the heat spike in the region in the IDI but not in the Di. Reason being (I'm guessing) is the proximity of the DI injector and a cooling effect of the fuel spray. The IDI has to rely on coolant alone.

And then the heat spikes even higher int he region of the precombustion chamber and it's heat retention issues, where the DI just drops right off.

Talk about thermal stresses across a structure.

The more I read/research, the more evident the limitations become.....

 

[great white]

One last bit:

IDI combustion systems with two separated combustion chambers (volume ratio about 1:1) which are connected through one 'throat' (swirl chamber) or several 'blow holes' (prechamber) were the
standard until the late 1980s. These concepts are still utilized in
the majority of current passenger car diesel engines.
During the compression stroke in an IDI diesel engine, air is
forced through the passages from the main combustion chamber
into the swirl or prechamber. Thereby, highly turbulent air flow
is generated in which the fuel is injected at the end of the
compression stroke. The compression itself and the intensive heat transfer from the hot walls of the swirl or prechamber,
result in a very high temperature level at the start of injection
and thus a short ignition delay and low combustion noise
excitation. After the onset of combustion, a rapid pressure increase
occurs in the air-fuel mixture which is rich at high engine loads.
The unburned or partially burned gases are subsequently blown
through the passages into the main combustion chamber, where
the second stage of the combustion event takes place. During
this second combustion stage, further mixing of the relatively
rich gases from; the swirl or prechamber with the pure air in the
main chamber is essential. This second stage mixture formation
is accomplished through a suitable design of the throat or the
blow holes between the swirl or prechamber and the main
combustion chamber together with a carefully optimized design
of the piston bowls which are typically very shallow.
Over the years, these well-proven IDI combustion systems
have been continuously improved. Figures 22.2 and 22.3 show
two IDI system examples. BMW concentrated on the optimization
of the Ricardo Comet V combustion chamber layout and
introduced a modified shape of the piston bowl (V-bowl) to
improve the second stage of the combustion process1. Through
this design change, it was possible to improve the air utilization
and to increase the full load performance at constant smoke
emission levels.
Figure 22.3 shows another modification of the classic Ricardo
Comet V swirl chamber design with a glow plug installed in a
vertical position2. Relative to the air motion in the swirl chamber,
this is downstream of the injection nozzle, while the traditional
horizontal position is upstream of the injector. With this modified
glow plug position, the impingement of the fuel spray on the
glow plug is reduced and thus the mixture formation is improved
with the result of a reduced primary soot formation.
Mercedes-Benz also improved its prechamber combustion
system by modifying the general shape of the prechamber crosssection
to a more round design and by inclining the injector
relative to the combustion chamber axes (in the traditional
prechamber design, the prechamber axis and the injector axis
were identical). Together with a carefully optimized design of
the so-called impingement pin, which exhibits an inclined flat
surface on one side, a more controlled tumble motion, rather
than an 'uncontrolled' highly turbulent air flow pattern, is created
in the prechamber. Similar to the swirl chamber combustion
system, the fuel is injected in the direction of the tumble motion.
These design features and a moderate increase of the injection pressure helped to significantly reduce the paniculate emission.

The modified prechamber design was first introduced in 2-valve
engines, but then carried over to 4-valve cylinder heads (see
Figure 22.5).
In addition to the 'fine tuning' of the IDI combustion systems,
the following major design features have been introduced over
the last ten years:
• Turbocharging in combination with charge air cooling
• Multivalve cylinder heads for IDI engines
• Direct fuel injection (DI) together with electronically controlled
high pressure fuel injection systems
• Turbochargers with variable turbine geometry
• Four-valve cylinder heads for DI engines
• Common rail fuel injection systems.
For many years, charge air cooling (intercooling) has been
a standard approach to increase the power output and to reduce
NOx emissions for truck and large marine diesel engines. Through
this measure, the air mass which is trapped in the cylinder at the
end of the gas exchange cycle can be significantly increased
due to higher density. The engine can burn more fuel and deliver
more power at the same boost pressure. The lower charge
temperature at the beginning of the compression stroke also
helps to reduce the thermal load of the cylinder head and the
piston which are critical components, especially in highly boosted
IDI diesel engines. In addition, lower charge air temperatures
result in reduced NOx formation during the combustion process.
For vehicle applications, this is especially true if air-to-air
intercooling is applied. Cost and packaging of the intercooler in
the vehicle have been and remain major issues regarding the
introduction of intercooling. Manufacturers have observed
significant benefits due to charge air cooling, even if the size
and/or the placement of the turbocharger in the vehicle were
less than optimal.

All this is from the Diesel Engine Reference Book, 2nd edition.

I claim no credit for any of the info presented here other than my own speculations, which are clearly delineated...

 

[L98TPI]

"At higher flow rates, nucleate boiling is suppressed. For flows
over the range 1-3 m/s (which is the range found in most thermally
critical areas), agreement between measurement and prediction
is excellent."
Indeed.
Cooling is not just about moving water in and out of the radiator. I remember reading about the GMC truck V12 gas engine, displacement around 12 liters. Yes they made one back in the 60's. It was based on the GMC truck 60 deg V6 gas engine, two of them bolted back to back, one crank though. Just like Detroit Diesels. The V12 (and the 6's) recirculated 2/3 to 3/4 of their huge coolant flow just to scrub the bubbles off the passage walls. These were tough and well thought of engines back in the day. So much so Cat put the V12 in a dozers, and many in fire trucks and the V6's found their way into all sorts of industrial applications. Efficiencies of scale killed them off, the small block was improved and the big block truck engine off the Chevy was built to replace them. And yea a 4 cycle diesel version was made also. :thumbsup:

 

[great white]

"At higher flow rates, nucleate boiling is suppressed. For flows
over the range 1-3 m/s (which is the range found in most thermally
critical areas), agreement between measurement and prediction
is excellent."
Indeed.
Cooling is not just about moving water in and out of the radiator. I remember reading about the GMC truck V12 gas engine, displacement around 12 liters. Yes they made one back in the 60's. It was based on the GMC truck 60 deg V6 gas engine, two of them bolted back to back, one crank though. Just like Detroit Diesels. The V12 (and the 6's) recirculated 2/3 to 3/4 of their huge coolant flow just to scrub the bubbles off the passage walls. These were tough and well thought of engines back in the day. So much so Cat put the V12 in a dozers, and many in fire trucks and the V6's found their way into all sorts of industrial applications. Efficiencies of scale killed them off, the small block was improved and the big block truck engine off the Chevy was built to replace them. And yea a 4 cycle diesel version was made also. :thumbsup:

This is one of the reasons I prefer the Dual thermostat housing to the single that shuts off the bypass when open....well, also that the flow rate is capable of the water pumps output....

 

[great white]

Made my first attempt at running "dynolicious" for some numbers.

First gear nets nothing but wheel spin from a dead stop like the program wants. That's with the G80 locked up and both tires fighting for traction, truck sliding sideways on a dry road. That's from dead idle, no loading up first.

No way to get on it without having to feather out right away to arrest wheel spin. To heavy back on the pedal and it just breaks loose again until you hit about 15-20 mph, then you can "mat it". 60 ft time measured out to an abysmal 3.56 secs @ 20.6 mph. Yeah, lots of tire spin, lots of frigging with the throttle looking for grip....

In all fairness, they're BFG all terrains and it's cold out. The roads aren't wet, but they're not exactly dry either.

Best I could get was 12.2 seconds to 60. Program calculates out to 208 hp (crank) at 6834lbs (scaled) and an estimated 20% drivetrain loss.

1/8 mile 12.35 @ 59.9mph.

1/4 mile 18.81 @75.4 mph.

The program also lets you take a snap shot:

So, not bad for a start. I'm not so sure I had it set up right in the truck and need to get some numbers where the run doesn't start off with wheel spin for the first ten feet....

 

[great white]

My 98 came equipped with the 10.5 corporate 14 bolt.

A pretty stout unit right from the factory.

But it does have some weaknesses.

One of them is the ujoint straps.

Unlike other u bolt equipped yokes, the 14 bolt has a strap and two bolts in the yoke to retain the bearing caps. With serious use, the straps get "loose" and need to be replaced. They also stretch out over time and should be replaced with the u joint.

Aftermarket ones usually don't fit right or are just plain wrong parts.

So I figured I'd take care of the straps in a once and for all solution:

Bearing cap girdles.

They replace the straps and are not subject to stretching. They also have full contact with the cap and give proper clamping across the whole yoke.

The manufacturer has tested their burst strength and the pinion shaft in a Dana 44 gave way before the girdles or the 1350 spicer joint:

I'm relatively confident they'll outlast the truck in my uses.

 

[DieselCash]

Were did you get these?

I am sick and tired of replacing my worthless straps.

On standard trucks the U-Joint seems to go out even faster. :agreed:

 

[great white]

Sorry, non site vendor. Can't post the link.

Also, if you don't have the FF 10.5 rear, they can't help you.

Hint:

If I were to go "extreme offroad" , it probably would be around "greatlake"......

 

[Burning oil]

Just a thought: if Im going to have a catstophic failure I would rather the strap let go than to break my axle. its like a fuse.

 

[great white]

Just a thought: if Im going to have a catstophic failure I would rather the strap let go than to break my axle. its like a fuse.

No one I've ever known of has broken a 14 bolt.

I know lots of people who have cursed the straps because they've loosened, stretched or won't clamp a new joint.

I'd rather not have anything break.

Simple enough.

 

[CtChevy427]

Were did you get these?

I am sick and tired of replacing my worthless straps.

On standard trucks the U-Joint seems to go out even faster. :agreed:

greatlakeoffroad.com/GLO-Yoke-Girdles.html

 

[great white]

That's the one.

I just didn't want to post the link because of forum rules.

But an admin has done it so all is good.

Ask for shawn when you call.

Tell him bj sent you.

 

[ak diesel driver]

if you'll notice it's not a link. you can't click on it

 

[great white]

Installing the washer heater today.

Truck is in the shop warming up as we speak.

It's only -5c here today, but no sense working on cold metal.



Time permitting, I may get to the heated washer nozzle, the bulkhead elec connector and the under hood plow valves.

I also need to re install some siding that blew off the house. Seems the cheap ass contractor didn't use the punch lock tool on the top course of siding.

I really am beginning to hate that chiseler SOB.....