Need More Boost in Big Yellow Power Wagon
Need More Boost in Big Yellow Power Wagon
I finally got the power wagon on the road. We just got back from a 2,800 mile trip to Montana in it. I bought the '93 Cummins from a wrecking yard so I don't know the history. But the intake and exhaust manifolds were drilled and tapped to indicate it had some work done. It rolls the smoke out too.
At 75mph is 1,800 rpm and it only boosts to about 14psi. Rev it up to 2,200 and it will reach about 20 psi of boost. Revved up the smoke ain't bad but rolling across Utah at 75mph it smokes and smokes. I want to get the boost up, nothing crazy.
I've read that the '04.5 - '07 works good on these engines. So I got a few ????
1. Will the turbo bolt right up to the exhaust manifold?
2. How much boost increase might I see with the newer turbo?
3. Any engine mods needed for the additional boost?
4. What about the wires running to it? No computer on this old truck.
5. Any other turbo might be better for my application?
Thanks for the help.
At 75mph is 1,800 rpm and it only boosts to about 14psi. Rev it up to 2,200 and it will reach about 20 psi of boost. Revved up the smoke ain't bad but rolling across Utah at 75mph it smokes and smokes. I want to get the boost up, nothing crazy.
I've read that the '04.5 - '07 works good on these engines. So I got a few ????
1. Will the turbo bolt right up to the exhaust manifold?
2. How much boost increase might I see with the newer turbo?
3. Any engine mods needed for the additional boost?
4. What about the wires running to it? No computer on this old truck.
5. Any other turbo might be better for my application?
Thanks for the help.
With a truck that big, and a motor that sounds like it has a tuned VE pump, I would install an EGT probe in that manifold.
If you already have one, what temps are you running?
My truck made those boost levels totally stock, and with a turn and a half on the fuel screw jumped to 32 PSI.
Sounds like you are getting plenty of fuel, so I am surprised your boost is not higher.
Could be it is losing boost as well, from a loose clamp, bad intake / grid heater gasket...
If you already have one, what temps are you running?
My truck made those boost levels totally stock, and with a turn and a half on the fuel screw jumped to 32 PSI.
Sounds like you are getting plenty of fuel, so I am surprised your boost is not higher.
Could be it is losing boost as well, from a loose clamp, bad intake / grid heater gasket...
The 351cw will bolt up to the manifold with a quick run of a drill bit.
The compressor outlet to the Intercooler or engine is different though and will need a custom tube. Also need a different flange for the exhaust downpipe.
The solenoid for the wastegate can be left in if you get one with it. If i recall it will open at 20psi with no power and 40psi with 12vdc to it.
I run 40psi with stock injectors on mine (pump turned up), wastegate is tack welded shut but i would recommend building a spring wastegate.
If you search "My project" and my forum name you will find install info.
The compressor outlet to the Intercooler or engine is different though and will need a custom tube. Also need a different flange for the exhaust downpipe.
The solenoid for the wastegate can be left in if you get one with it. If i recall it will open at 20psi with no power and 40psi with 12vdc to it.
I run 40psi with stock injectors on mine (pump turned up), wastegate is tack welded shut but i would recommend building a spring wastegate.
If you search "My project" and my forum name you will find install info.
I think it is worth taking a look to see what is actually installed on your truck, and doing a quick check for possible boost leaks (as mentioned above).
The 351's are probably better turbos, but you might be very happy with a wastegated 12 cm, or a non wg 14cm housing on your current turbo, or an hx35 turbo. hx35 w/12cm housing was stock on second gen trucks.
If you have the stock turbo, it should be an H1C with an 18cm exhaust housing, if I recall correctly. That exhaust housing is too big for the mass air flow at lower engine rpms. The 21cm housing used on the first intercooled trucks was even worse. If that's what you have, it would explain the smoke at 75.
The 351's are probably better turbos, but you might be very happy with a wastegated 12 cm, or a non wg 14cm housing on your current turbo, or an hx35 turbo. hx35 w/12cm housing was stock on second gen trucks.
If you have the stock turbo, it should be an H1C with an 18cm exhaust housing, if I recall correctly. That exhaust housing is too big for the mass air flow at lower engine rpms. The 21cm housing used on the first intercooled trucks was even worse. If that's what you have, it would explain the smoke at 75.
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Being a 93 it should have the 18cm2 exhaust housing as mentioned above. Mine had the 21cm2 stock and i made 12psi with stock fueling.
You really need to get an EGT gauge if you dont have one. At 40psi and stock injectors i can still hit 1350F if i am towing.
You really need to get an EGT gauge if you dont have one. At 40psi and stock injectors i can still hit 1350F if i am towing.
The last '93 I had would hit 30psi with minor tweaks to the fuel pump while still on stock injectors and stock turbo. Really sounds to me like you've got an intercooler pipe leaking. It would lead to all the symptoms of tons of smoke with less boost than you should be seeing.
Track down the boots and clamps from the turbo all the way through the intake and/or pressurize and check for leaks on the charge side yet?
Track down the boots and clamps from the turbo all the way through the intake and/or pressurize and check for leaks on the charge side yet?
Yes the '68 power wagon has a pyrometer. No matter what I do I can't get it over 12K.
With it idling I found a few leaks spraying starting fluid around all the inter cooler connections. Engine even revved when I sprayed around the little intake 90deg manifold. I pulled apart all the connections and put on a thin layer of form a gasket material. It's sitting over night now and tomorrow I'll test it out.
The truck progress has been posted on here before. But here's a quick review. I modified the truck as a regular cab but there was no room for everything. So we extended the cab two feet. It did have a 10 speed with a divorced transfer case and a low-direct-high Brownie Box. Every time the Mrs. drove the truck we got into a fight
. Out with the 10 speed and now it has a 47RH that is controlled by two toggle switches. One for the lock up and one for the overdrive. The Brownie is still there.
The back half frame is '01 F350 with 5.38 gears. '78 GM Dana 60 up front. All 4 wheel disc brakes with the Ferd hydro booster. Cross over steering was installed to eliminate bump steer. The cab sits on its own air ride frame to keep her happy along with air bags on all 4 corners. It has nice truck air ride seats too
With it idling I found a few leaks spraying starting fluid around all the inter cooler connections. Engine even revved when I sprayed around the little intake 90deg manifold. I pulled apart all the connections and put on a thin layer of form a gasket material. It's sitting over night now and tomorrow I'll test it out.
The truck progress has been posted on here before. But here's a quick review. I modified the truck as a regular cab but there was no room for everything. So we extended the cab two feet. It did have a 10 speed with a divorced transfer case and a low-direct-high Brownie Box. Every time the Mrs. drove the truck we got into a fight
. Out with the 10 speed and now it has a 47RH that is controlled by two toggle switches. One for the lock up and one for the overdrive. The Brownie is still there. The back half frame is '01 F350 with 5.38 gears. '78 GM Dana 60 up front. All 4 wheel disc brakes with the Ferd hydro booster. Cross over steering was installed to eliminate bump steer. The cab sits on its own air ride frame to keep her happy along with air bags on all 4 corners. It has nice truck air ride seats too
[QUOTE=Mike Mc;3244169]Yes the '68 power wagon has a pyrometer. No matter what I do I can't get it over 12K.
With it idling I found a few leaks spraying starting fluid around all the inter cooler connections. Engine even revved when I sprayed around the little intake 90deg manifold. I pulled apart all the connections and put on a thin layer of form a gasket material. It's sitting over night now.
I figured you where losing boost PSI somewhere.
That should help with some of the black smoke under load.
12K is a nice safe temp, you might have room to add some more fuel when you get your boost pressure dailed in.
Great looking Power Wagon!
With it idling I found a few leaks spraying starting fluid around all the inter cooler connections. Engine even revved when I sprayed around the little intake 90deg manifold. I pulled apart all the connections and put on a thin layer of form a gasket material. It's sitting over night now.
I figured you where losing boost PSI somewhere.
That should help with some of the black smoke under load.
12K is a nice safe temp, you might have room to add some more fuel when you get your boost pressure dailed in.
Great looking Power Wagon!
Should be a workable list.
Here you are, It is alot of info but i think the turbo stuff is aroung pg 5 & 11.
https://www.dieseltruckresource.com/...hlight=project
https://www.dieseltruckresource.com/...hlight=project








