76 CCDRW...Cummins noises

[Hogback Fabrication]

Agreed Kert, especially when towing...the BBC ran great at 75 w/ no load, but mileage suffered for it...I believe Eric figured it to be about 3500rpm at that speed....running a Cummins at 16-1800 @ 70 should be a sweet spot!

Unloaded, that kind of RPM probably works great. Towing, not so much.

My setup (12V, 4.10's and 37's) actually tows better at 70 mph (~2000 RPM) than it does at 60 mph (~17xx). It's not that it doesn't have the power at the lower RPM, but the slower engine speed means less air being pumped throught the motor so the EGT's are hotter and I've found I have to get out of the throttle on big hills at the slower speed to keep EGT's happy.

When I first put it together I thought about switching to 3.73's, I don't feel that way any more.

 

[76zimmer]

Does turbo size and exhaust piping size make a diff in egt's?

 

[Smokinthehippies]

Does turbo size and exhaust piping size make a diff in egt's?

oh yeah.

 

[jekquistk5]

oh yeah.

Yup going full 4" turbo back will help out a bunch.

 

[jekquistk5]

Yup going full 4" turbo back will help out a bunch.

Also make sure you add an egt probe and gauge right away.

 

[Deuling]

I'm loving the snowball here

 

[Hogback Fabrication]

Does turbo size and exhaust piping size make a diff in egt's?

It definitely does, but one thing to keep in mind is how modified the motor will be. When mine ('93, VE pump) was stock, I couldn't break 1000* pre-turbo pretty much no matter what. I actually thought the gauge might not be working right

FWIW, I do have a full 4" exhaust and a good turbo (HE351CW from an '05), but I have mine pretty much turned up as much as you can with a VE pump so lots of extra fuel over stock.

 

[76zimmer]

School is in session....help a brother out!

More fuel+4" exhaust=more power=better mileage=higher EGT's?

Where to put the EGT probe?

 

[rompinstompinmudmonkey]

The egt probe goes in the exhaust manifold right before the turbo. All you have to do is drill and tap an 1/8" npt hole for the probe to mount in. This is very important to have if you do any fueling mods. Max temp for these motors is 1250° sustained or 1300° intermittently. Any more than that and you risk serious damage. With more fuel it isn't hard to get to those temps, especially when towing.

I agree with Chris. My truck tows better at 70 than it does at 60. 1900-2200 rpm is really the sweet spot.

 

[jekquistk5]

The egt probe goes in the exhaust manifold right before the turbo. All you have to do is drill and tap an 1/8" npt hole for the probe to mount in. This is very important to have if you do any fueling mods. Max temp for these motors is 1250° sustained or 1300° intermittently. Any more than that and you risk serious damage. With more fuel it isn't hard to get to those temps, especially when towing.

I agree with Chris. My truck tows better at 70 than it does at 60. 1900-2200 rpm is really the sweet spot.

Same with my dmax, right around 2k is where its happy. Plenty of power to pull up hills, and egts are alright. If i'm at 1500 rpm rolling into a hill I'll hit 1250-1300 easy. Up the rpm and it settles down to about 1050-1100.

 

[76zimmer]

So if your on A long Climb like say coming out of rifle Colorado and making that long climb when you don't have momentum to begin with you just keep the RPM's up to keep the EGT's down?

 

[jt512]

another question or two...

1) the fuel pin....explaination of exactly what it does and what it takes to make the mod..
In my mind I assume it controls the amount of fuel through the pump?


2) the governor spring...Is this in the injector pump...if so I've read not to mess with an injector pump unless you have the right tools and know how to do it....I have neither! Where is this spring and what does the mod involve?

3) #10 plate...same questions as previously mentioned.

Since this kind of got skipped....
1) I think I remember you saying it was a 98, if so no fuel pin. That is a VE pump thing 89-93
2) Also refered to as a GSK (gov spring kit) not that bad to do especially since youll have the engine out. There are lots of good articles and some youtube vids on it . Located on the side of the injection pump (assuming P pump 94-98).
3) The fuel plate controls how much fuel can be delivered. Just by sliding your stock plate forward along with the AFC cover and a quick adjustment of the starwheel and pre boost screw approx 50 more rwhp is possible . We did this to my brothers old 96 along with a 3000 gov spring, 4" turbo back exhaut and it was like a whole new truck.


On the gear /rpm debate , my old 00 cummins had 3.55's and I ran 285/75's (~32.5") and honestly it was perfect. 70mph was the sweet spot loaded or unloaded and it regularly pulled 20-22mpg unloaded on the highway and 15-16 pulling 8-9k.

 

[Hogback Fabrication]

So if your on A long Climb like say coming out of rifle Colorado and making that long climb when you don't have momentum to begin with you just keep the RPM's up to keep the EGT's down?

I generally tow at 70 mph whether the speed limit is 65 or 75, if someone slows down to 60 mph or so in front of me on a significant hill, it will start to run hot in OD (mines a 5 speed btw) if you lay into it. At 70 mph i can pretty much pull as hard as I want while towing ~14K GCWR total other than Vail/Eisenhower pass (the two very steep, ~12,000 ft passes on I70 in CO for those that don't know). If I'm forced to slow to 60 on a decent hill, that's pretty much 4th gear territory.

More fuel = more power but it also means higher EGT's. To lower EGT's, you need more air flow via better exhaust flow and/or better turbo. When the mixture gets rich with too much fuel, that's when you see black smoke and EGT's rise very quickly, and of course poor economy with it.

I've never dealt with a p-pump motor myself before but people sure talk like the injection pump can more than overwhelm the stock turbo. My suggestion would be to just do the minor stuff, turn things up just a little. Do the free/cheap/easy mods (and research of course), but those don't generally get you into any trouble. Built autos behind diesels get CRAZY expensive, that would be my biggest fear of turning stuff up a lot.


Also, I don't know if anyone mentioned it, but the intercooler from your '98 donor fits well around the GM radiators if you mount them upside down.

Lots to learn, I know I still am and I have mine running 2+ years. You'll love it

 

[DEMON44]

Ya 2000 rpm is the bread basket.

Slide the stock plate forward. Adjust star wheel to set your taste for low boost defueling. That's it for you. For fuel I'd say.

Install 4000 rom governor springs. Do it from the top. Do one at a time. Set each one the same.

Set injection pump timing to 16* btdc. Use the plunger lift measurement. Nothing else is accurate enough.

I would seriously recommend installing an adjustable pump gear. Even of you stay close to stock power. Slipped timing happens ALL the time and is a huge cause for low power and loss of MPG. It'll run you about $300-350 for an adjustable gear. It is worth it. It turns the shaft into a keyed application from the stock taper press fit. It will never slip again.

 

[DEMON44]

If your auto is still in good shape. Now would be the time to put a billet converter and valve body in it. That will make it last for you. Keeping the bands adjusted is a huge key to making those babys live on as well. Gorend Bros. makes the best dodge auto parts IMO.

Crazy expensive is a matter of perspective when it comes to autos. And generally you get what you pay for with them.

 

[DEMON44]

The egt probe goes in the exhaust manifold right before the turbo. All you have to do is drill and tap an 1/8" npt hole for the probe to mount in. This is very important to have if you do any fueling mods. Max temp for these motors is 1250° sustained or 1300° intermittently. Any more than that and you risk serious damage. With more fuel it isn't hard to get to those temps, especially when towing.

I agree with Chris. My truck tows better at 70 than it does at 60. 1900-2200 rpm is really the sweet spot.

You want it in the manifold between #5 and #6. Last hole is always the hottest. By design of coolant flow and Charge air flow patterns.

The cast manifolds are very soft, drilling and tapping a 1/8th NPT is like a 60 second process. theres a nice flat spot back there to put it in the top.

1250-1300 sustained is pretty tops. But intermittent is more a function of time, than temperature. They are far more robust than you give it credit for. I've pinned a 2000* guage for short periods of time. and pulled the head later on and seen inside, I've never had an issue.

High sustained temps are far more damgerous to the engines than short peaks of extreme EGT temps.

 

[76zimmer]

Since this kind of got skipped....
1) I think I remember you saying it was a 98, if so no fuel pin. That is a VE pump thing 89-93
2) Also refered to as a GSK (gov spring kit) not that bad to do especially since youll have the engine out. There are lots of good articles and some youtube vids on it . Located on the side of the injection pump (assuming P pump 94-98).
3) The fuel plate controls how much fuel can be delivered. Just by sliding your stock plate forward along with the AFC cover and a quick adjustment of the starwheel and pre boost screw approx 50 more rwhp is possible . We did this to my brothers old 96 along with a 3000 gov spring, 4" turbo back exhaut and it was like a whole new truck.


On the gear /rpm debate , my old 00 cummins had 3.55's and I ran 285/75's (~32.5") and honestly it was perfect. 70mph was the sweet spot loaded or unloaded and it regularly pulled 20-22mpg unloaded on the highway and 15-16 pulling 8-9k.

My Duratracs are about 31.5 tall right now, hopefully the Dodge has a D70 3.55 that will swap into my D70HD in the CC, so I should be pretty close to your setup. I guestimate my GCWR to be in the 16K-18K range.

I generally tow at 70 mph whether the speed limit is 65 or 75, if someone slows down to 60 mph or so in front of me on a significant hill, it will start to run hot in OD (mines a 5 speed btw) if you lay into it. At 70 mph i can pretty much pull as hard as I want while towing ~14K GCWR total other than Vail/Eisenhower pass (the two very steep, ~12,000 ft passes on I70 in CO for those that don't know). If I'm forced to slow to 60 on a decent hill, that's pretty much 4th gear territory.

More fuel = more power but it also means higher EGT's. To lower EGT's, you need more air flow via better exhaust flow and/or better turbo. When the mixture gets rich with too much fuel, that's when you see black smoke and EGT's rise very quickly, and of course poor economy with it.

I've never dealt with a p-pump motor myself before but people sure talk like the injection pump can more than overwhelm the stock turbo. My suggestion would be to just do the minor stuff, turn things up just a little. Do the free/cheap/easy mods (and research of course), but those don't generally get you into any trouble. Built autos behind diesels get CRAZY expensive, that would be my biggest fear of turning stuff up a lot.


Also, I don't know if anyone mentioned it, but the intercooler from your '98 donor fits well around the GM radiators if you mount them upside down.

Lots to learn, I know I still am and I have mine running 2+ years. You'll love it

Thanks for the Scenario Chris, and good tip to know on the intercooler! Should be fun trying to package everything up front inside the stock grille!

Ya 2000 rpm is the bread basket.

Slide the stock plate forward. Adjust star wheel to set your taste for low boost defueling. That's it for you. For fuel I'd say.

Install 4000 rom governor springs. Do it from the top. Do one at a time. Set each one the same.

Set injection pump timing to 16* btdc. Use the plunger lift measurement. Nothing else is accurate enough.

I would seriously recommend installing an adjustable pump gear. Even of you stay close to stock power. Slipped timing happens ALL the time and is a huge cause for low power and loss of MPG. It'll run you about $300-350 for an adjustable gear. It is worth it. It turns the shaft into a keyed application from the stock taper press fit. It will never slip again.

If your auto is still in good shape. Now would be the time to put a billet converter and valve body in it. That will make it last for you. Keeping the bands adjusted is a huge key to making those babys live on as well. Gorend Bros. makes the best dodge auto parts IMO.

Crazy expensive is a matter of perspective when it comes to autos. And generally you get what you pay for with them.

You want it in the manifold between #5 and #6. Last hole is always the hottest. By design of coolant flow and Charge air flow patterns.

The cast manifolds are very soft, drilling and tapping a 1/8th NPT is like a 60 second process. theres a nice flat spot back there to put it in the top.

1250-1300 sustained is pretty tops. But intermittent is more a function of time, than temperature. They are far more robust than you give it credit for. I've pinned a 2000* guage for short periods of time. and pulled the head later on and seen inside, I've never had an issue.

High sustained temps are far more damgerous to the engines than short peaks of extreme EGT temps.

OK, I need to learn what each of these pieces are and what they do...need to do some schooling on this oilburner...unlike you guys, I've never worked on one!

Thinking I might get the thing installed and running (as it is stock now and sounds real good) before I start modding stuff...One change at a time to know what each change does for the package.

From what I'm reading....high EGT's will be alleviated by more airflow through the engine, which means more rpm, but how do you get the airflow without additional fuel too?

What would be a good choice for intake/turbo/exhaust sizing to accomdate the stock engine as well as future mods discussed to get to 600ft/lbs?

 

[76zimmer]

something else I read about is the amount of smoke produced by unburnt fuel....I'm not big on the black smoke out the pipe look, so keeping it relatively clean would be desirable as well.
Is this a by product of more power or just bad tuning and poor parts compatibility?

 

[Hogback Fabrication]

something else I read about is the amount of smoke produced by unburnt fuel....I'm not big on the black smoke out the pipe look, so keeping it relatively clean would be desirable as well.
Is this a by product of more power or just bad tuning and poor parts compatibility?

Stock, it's hard to get them hot ever. An EGT gauge is still pretty much necessary but it's unlikely you'd have problems at a stock setting. Stock trucks barely smoke at all.

Getting more fuel in the engine can spool the turbo more, which means more air, and with more air and more fuel, you have more power. That's only true to a point, eventually the turbo can't deliver any more air for all that fuel and you get black smoke. And with black smoke comes high EGT's.

For guys that drag race and guys that run on the dyno, they usually (not always) run WAY rich. I guess it makes sure that there's enough fuel to use up all the air available. See the mention above about short spikes of EGT's being ok, but not long ones.

For towing, when you have to be hard into the throttle for more than 10-15 seconds, you generally don't want smoke. Plus smoke is wasted fuel.

So, really, the black smoke is from guys trying to make as much power as they can. The fix is a bigger turbo, or more turbos (or nitrous).

IMO, you have the plan right. Get her in there and run it as is. I ran mine stock for a while, they're no slouch, especially at altitude with the advantage of a turbo. But the 12 valves leave a LOT of power on the table and it's easy to get bit by the power bug

 

[jt512]

600 ftlbs is pretty acheiveable with no more then an exhaust and a big air filter (as far as parts to change). Dave do a search on diesel power magazines site for project triple threat, look for the article about 96hp for free. That is a good read to show you what no money can do on a 12v and it also shows some good pics of some basics like the fuel plate, afc, and starwheel on the pump. If nothing else, I would definetly do the gov spring while the engine is out along with checking the KDP, if you dont feel.comfortable doing the timing bump (I recommend bumping it) take the engine while out to a good shop and have it done, lots cheaper out of a rig.