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Hello,

Nice forum you've got here! I've got a 1997 Chevy P-30 Bluebird School Bus that I have converted into an RV. This has been an ongoing project for me over five years and I love working on it. I've put about 50K miles on it so far driving up and down Oregon Cascades and across the high desert, and over all that time i can tell you my one major complain is the lack of power. The non-turbo 6.5 is about as gutless as its 6.2 cousin in my 89 diesel burb and the bus weighs about 3x as much (currently riding about 14000lbs).

About two years ago I blew a head and had the engine rebuilt, that was a saga all in itself that is a story for another time. I removed and reinstalled the engine myself so I can turn a wrench. I can tell you that this is a weird, weird engine that seems to have some 6.2 parts on it and some 6.5. For example, it's got a mechanical DB2 pump, no PMD or any electronics at all, but the crankshaft as a reluctor wheel on it for the crank position sensor that doesn't exist and for which there is no hole in the timing cover. The water pump pully is driven by a serp belt, but the fan bolt holes are drilled to the 6.2 fan pattern and the fan is from a 6.2 (good times when I ordered my fan upgrade to find out it didn't fit!).

I'd like to turbocharge the bus in the next couple weeks but as the long time owner of a 6.2 and this NA 6.5, I've never actually seen the turbo setup for this engine with my eyes. The internet isn't much help, so I'm appealing to the experts here to see if there's anything I'm missing and hopefully to answer a few of my questions.

I've ordered the exhaust manifolds from the local salvage CO and the flowmaster crossover/downpipe combo. I'm going to go with the KBDP N/A intake plenum and intake coupler kit they sell here:


I've looked at a few turbos, I haven't made up my mind yet, the prices vary wildly from $300-$1000. The Stigan turbo sold on Amazon looks interesting. Any opinions on turbos would be greatly appreciated. I could get a used one from the salvage for $200, but I think for a bit more I should just go new.

Ok, the questions I have are some of the details I'm not finding a lot of info on:

- What kind of coupler joins the turbo exhaust outlet to the downpipe? It doesn't look like its bolts on, that there might be some kind of coupler or band? Anyone know where I can get it?

- I see -10AN turbo oil drain adapters for the mechanical fuel pump which is fine with me, I've already went electric FP when I did the rebuild. That end looks doable to me, what I don't know about is the oil feed side of the turbo. I see lines like this:


But I'm not sure if that's the right size or length, I'm not even sure where I'm supposed to tap in. I know there's a couple of oil ports under the lower intake manifold between the pump and filter, one of them currently hosts the oil pressure sensor. I can imagine a short line going from the other port to the turbo but I'm not exactly sure what I'm looking for. Any help on the oil feed line matter would be greatly appreciated!

Ok and last, the NA exhaust crosses over to the drivers side and runs down over the axle and back behind the real driver's wheels. The turbo downpipe clearly comes down the passenger side from what I can tell. So from there I have to cross over and hook up to my existing pipe or my other option is to run something new down the passenger side. Any thoughts on the relative difficulties or advantages?

Thanks again, sorry for all the off the wall questions!

-Mike
 

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Welcome to DieselPlace
Without some pics, I'm not sure if the square nose of the bluebird will allow room for a side mount turbo.
You could get away cheaply with a GM8 Turbo install if you have the room. You would need the 6.5L Turbo manifolds to reroute the exhaust the correct way.
The N/A Motor is equipped with the Economy Injectors and Precups. You would need to change out the Injectors for the Turbo Injectors
Oil feed can be installed where the old mechanical fuel pump mounts using an adapter plate
 

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Discussion Starter #3
Welcome to DieselPlace
Without some pics, I'm not sure if the square nose of the bluebird will allow room for a side mount turbo.
You could get away cheaply with a GM8 Turbo install if you have the room. You would need the 6.5L Turbo manifolds to reroute the exhaust the correct way.
The N/A Motor is equipped with the Economy Injectors and Precups. You would need to change out the Injectors for the Turbo Injectors
Oil feed can be installed where the old mechanical fuel pump mounts using an adapter plate
I've attached a couple of pics with a measurement of the passenger gap. There's about 11 inches to the wheel well, and maybe 8-9 to the bottom corner of the doghouse well. I'm not sure if there is room, but if not I'm happy to cut into the well a bit to open it up.

I've already substituted in turbo injectors when I did the rebuild but thanks for pointing that out!

As for oil, I've seen the mechanical pump plate used as a drain, but also as a feed? I don't see where there would be a pressurized oil port. I was considering teeing off the oil cooler return line, but not sure that's legit or not.

635903


-Mike
 

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That's cutting it awful close for the measurements. I don't think there will be enough room.
You could go with a center mount turbo but would run into a problem with the heads/exhaust mounts I believe the angles are different and you may have to modify the firewall.

Others may chime in on the oil feed line and offer other suggestions
(y)
 

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The oil feed port is on the front passenger side of the block. I'll find a photo.
The turbo return oil goes to where the mechanical fuel pump would be, that's OEM for a 6.5td.
The turbo to downpipe is a special clamp, mainly for turbos, GM 15671559.
The oil feed hose is GM 10183962 or 12562378. A hydraulic shop could fab one up if NA.
If you ever have the timing cover off be sure to replace it with one that has a hole for the CPS.
Do you have an auto tranny?
 
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Turbo oil feed line.
635906
 
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