Part Two: Turbocharger Selection.

I spent a lot of time carefully selecting the turbo for my project. The turbo is the heart of the build and all other systems will be secondary to it. With that in mind I grabbed the very first free turbocharger I found. It came from a Saab, early 90's I think. The Saab had 180,000+ miles and a blown motor. I took everything, turbo, hunk of the exhaust, inter cooler and piping, everything. It is important for you to get as much of the extraneous piping and fittings as you can, especially the oil lines as they can be very special fittings.

Once cleaned up it became apparent the turbo is worn out. Lots of shaft play, signs that the seals might be leaking and it spun a little stiff. After blowing a little lacquer thinner through the oil journals she started to free up but the shaft play got worse. One of the fins on the exhaust side had lost just the tiniest bit of the outside corner. (I think I might have done that when I took it apart, my bad) I "fixed" the problem by taking the same amount of a fin on the opposite side. A real custom balance job. As it doesn't hit the housing I am going to run it anyway. I figure if the project is a success then it will be worth rebuilding it, a failure well then I am not out any money, God tends to favor the ambitious and impatient. The unit I scored is going to work out nicely. I will need to rotate the center section to position the oil drain properly but other than that it fits the space I want great.



What I found is a Garet low pressure T25/T25 with water cooling and the mechanical waste-gate. In my mind the smaller T25/T25 is better for my application than the T3/T4 as I am not a dumb high school kid hell bent on blowing the motor. I want a very moderate power boost and reliability. The mechanical integrated waste-gate requires no external fittings or plumbing so less work for me. I had not given any thought to water cooling but if the application is a success the extra effort to hook up the water system will pay for itself in longevity.

Part One: Scope of the project.

I foresee the following 'stages' on the project:

1. Connecting the unit to the current exhaust manifold.
-Building a nearly 160 degree u-bend with proper flanges on either end.
-Needs a good seal and be strong enough to help support the turbocharger's weight.
-Plan to use 1 7/8 pipe to help keep the velocity up.

2. Piping the exhaust from the turbo back down to the muffler.
-Pipe I have from the Saab makes an immediate 90 so I will have to cut and modify.
-Should not be difficult but it is a short, twisty run.

3. Connecting the oil and water lines
-Special banjo fittings on all but the oil drain. Plan to use auto tranny pressure line.
-Oil drain must be gravity and big, 1/2 or larger big. I plan to attach to the fuel pump blockout plate.
-Oil pressure is always an issue on the F head. Can I just tap the output of my remote oil filter and not return it to the top of the timing gears? I seem to remember they also get oil from inside.
-What kind of oil delay will I get out of the filter? Will it keep draining (and cooling) after shut down?
-Will the turbo live on such a miserly amount of oil (3-5 psi at hot idle) if it is also water cooled?
-Is my piss-poor oil pressure due to a worn pump or worn motor? Will I need a new or remote oil pump to keep the block happy?
-Will I need an oil cooler? I have the one from the Saab but it is big. Turbo's foam the oil they use, is the Jeep's smallish 4 quart oil pan big enough to let the foam settle or will I pump oil foam to the rest of the motor?

4. Carburetor: blow or suck?
-I plan to suck (lol) for reasons I will discuss later.

5. Pressure piping to intake.
-Need to copy carb base for a flange. Shorter is better but the hood must close. If I use metal pipe it will be heavy and have vibration issues, if rubber it has to survive gasoline. Can I build it all out of hard pipe or do I need rubber to isolate it? Can I built a hard pipe to enough tolerance to get a good seal?
-How big should the pipe be? Volume, velocity or convenience?

6. Vacuum piping to air filter.
-The suck side. This is the most cramped component. Shorter pipe is better but it might have to be on the other side of the engine bay. Also as a suck system I need to avoid fuel pooling.

7. Building brackets to support everything to the motor so the whole mess doesn't rip off.
-Attaching the turbo will be easy with a nice tab all set for attachment at the top and a firm attachment to the manifold at the bottom. I worry about having the suction side hanging off the unit. Can I mount the carb to the fender or will body movement pull it apart? What if I stick it farther off the intake manifold so all I have to do is extend the current throttle linkage? That sets up some long and complicated piping. Figure I need to place the turbo first and work around it to see what is best.

8. Replace motor with a small V6 after blowing it up.
-Lets hope I can skip this one.

The journy begins.

I rebuilt my 134ci F Head Jeep motor about two years ago. It only had 60,000 miles on it but as the poor thing sat for a decade the rings were stuck. At the time I debated with my father about forgetting the little F Head and putting in a small V6 from a Bronco II we had sitting around. Dad's vote was the Bronco, mine was the F Head. Call it nostalgia or being in too much of a hurry but the little 134 came out one weekend and was back in the next.

I should have gone for the V6.

The 134 is fun, makes a great noise but... There is a lot of good info about hopping up a 134 on a CJ3 page but rather than bothering with that I am putting in the turbo. Many have looked into it, and on youtube there is one a guy did running propane. Seems to be a crowd online that just pounce on anyone who broaches the subject. I suppose it might be because they have some new guy on the forum every month or so who wants his F head to turn 12 second quarters with no effort or money. I am not that person. I am doing this because I want a little more reliable power at the high altitudes I run. I want to see faces turn in confusion when people hear a 4cyl jeep 'spool up'. I want a cool project for the winter and I don't want to be like everyone else. I will put it all on here, good and bad, success and failure. I have a 1yo son so don't expect this to be instantaneous but it will be accomplished over the winter of 2010-11 one way or the other. Thanks for coming along for the ride.