There has been a lot of talk here about what is better, Air Cooled or Water Cooled power trains. Let me start off by saying that there is nothing wrong with either approch and please run what ever you want to.
What is not discussed much is what it really takes to do a Water Cooled conversion in a Woods Buggy. By sharing what I have done with mine you will get a better understanding about the process. It is with out a dought a lot of work if one is to do it right! Something to keep in mind is that like most things I do, I do to Extremes and by no means is it the Intent of this artical that it must be done my way. Please use this as a guide only and use your own Judgement.
My Motor Swap selection is a 2000 Subaru 2.5 SOHC. 165 HP and 166# of Torque @ 4000 RPM in its stock format. Add A Turbo at around 6 PSI of Boost and it takes it over 200 HP. Because I allready have a lot the fixens for a Turbo setup and a Dry Sump Oil System I decided to use them in my Swap recipe. Granted I have nearly trippeled my expence and effort to achieve this goal however it is what it is. Before I removed the VW 2332 Turbo motor I spent a considerable amount of time sitting and starring at the Buggy coming up with a game plan. Like most plans they are subject to change and it did..............over and over. Taking your time in the planning stages makes the difference between a good and a bad Swap. I have learned over the years that a short cut is the longest distance between two points. There were many things to consider in the planning stages. I will cover these one at a time.
Lets start with the Chassis. My goal was to install the Subie motor with as minamal mods to the frame and Transmission mounting position and of cource that did not last long. I soon discovered the Subie motor with the Kennady adapter plate (required to mate the motor to the VW Trans)mounted would not slip into my frame with the lower studs in the plate. This is were the disadvantage of the Berrin Stalker integral lower frame section came into play. On most frames the lower frame section drops out the bottom for easy motor access. The Stalker frame requires the vertical rear section to be removed and the motor lifted out. Normally I prefer this setup for its strength however in this application its a problem because the Subaru motor is longer than the VW. I was able to at least get the motor in the frame for mock up purposes. After starring at it for awhile I discovered two major Issues. The first one was even with a shortened Subie oil pan (required for the Swap) I did not have enough clearence above the lower frame rails to Install my skid plate. I had two choises, lower the frame or raise the motor. Lowering the frame losses 2 to 3" of ground clearence so that was not the best Ideal. So option two was to raise the motor. I decided to lower the nose of the transmission to tilt the motor up to gain clearence. After the Trans was done (more on it later) I reinstalled the motor and still did not have quite enough clearence to easyly get it in. I decided that the rear stationary vertical tubes need to be removed to allow easy access to the engine bay for motor. I welded 3/8" thick Turbo Exhaust flanges to the tubes and to the frame. I did not want the tubes to move once assembled so I drilled and tapped the flanges on the frame for 7/16 20 threads. I used grade 8 Cap screws to mount them. I was able to easyly install the motor now. Shown below is the rear of the frame with the vertical tubes removed and the flanges welded on.
If you look thru the open frame in the pic below you can see the VW 2332 Turbo motor that came out of the Buggy sitting on the shelf. Its thinking what the HELL am I doing over here?
In the original build the angle of the trans did not allow me to use the 2 lower mounting bolts so I added a tab on the side of the frame horn and picked up 2 bosses on the trans. When I lowered the trans to accomadate the Subie motor I lost the ability to use the side tab without remounting it. However I was able to utilize the 2 lower trans mount bolts I wanted to use anyways so it worked out well. When I first mounted the transmission I did not use the existing mount that was for a standard nosecone however I did leave part of it on the frame and welded a piece of 1.5" tube between the tabs so I had something to bounce off the rocks with so it protected the trans better. The tube came in real handy to allow me to use the lower mounting bolts. I turned 2 sleeves up on the lathe and drilled thru the tube and welded them in for the bolts as shown below.
As I stated before I needed to change the angle of the Transmission to gain clearness for the Subie motor and Exhaust system. This also gave me a lower center of gravity for the Buggy. The problem with lowering the nose of the trans is it put it below the frame. Considering the rocky terrain I ride in I had to make a mini skid plate to protect it. I looked around and found an old angle iron battery mounting frame that was just about the right size for the project. For the actual skid plate I welded a piece of stainless steel on the bottom of it. To mount it I cut a 3/8" rod coupling to the proper size and welded them to the sided of the existing trans mount as shown in the above pic. I then drilled a2 holes in the rear of the plate and mounted it to the existing skid plte. I did not do the same on the front due to my Horizontal band saw will only cut a length of 16". Shown below are pics of the Skid plate.
Here are pics of it mounted
The dry Sump system was the next Item on the list. I decided to go this route for several reasons. First the Subaru engine has a conventional oil pan that drops down to far to be used in a Buggy as is. So they are usally cut down to approximatly 4" and a plate welded to the bottom. This method reduces the oil capacity and I did not care for that Ideal. If I went this route I would stil have clearence issues at the lower frame, so dry Sump it is.
Before making the pump mounting bracket I had to make the Crank Pully drive to be able to align the crank and oil pump pulleys. The 2000 crank pully was filled with rubber so I opted for a 2004 WRX pully that did not have the rubber. I then milled the bottom flat and made an Insert to bolt to the crank pully as shown below.
As in most of clearence issues with this project the rear winch mount had to be resolved. Gotta love them sawsalls. I cut about an inch off and welded a stop in the receiver to keep from hitting the motor when sliding the winch in.
Shown below is a pic before I cut the receiver off.
The oil pump mount would be the most time consuming part of the task. The AC compressor section of the engine was the most logical spot for it. I designed the mounting bracket so that i am able to adjust the belt.
Shown below is the completed mount. The only points of reference to get the bracket in parallel with the pully system was the top two bolt taps on the compressor mounting bracket. I turned down the ends of two bolts to a point and screwed them into the bracket to give me locations to measure from.
Here is a pic of both the pump and drive assembly
Next would be the oil pan. It just so happened that my Buddy Madmike had a nice Aluminum unit he was not using that made life much easyer. It had one Scavenge sump allready made into it however I would need one on each end of the pan for up and down grades. I made a pick up tube and had it welded to a 12AN fitting and then into the pan as shown below.
Bottom view with out the additional pickup tube Installed shown below
The additional pickup tube ready to be welded into the pan shown below.
Pickup tube inserted into 3/4" hole drilled into the pan. Note: pickup holes face down and are staggered to allow optimum oil scavenge.
The picture below shows the pan mounted. One of the major advantages with the Billet pan was the built in lower motor mounts boss. I made a motor mount out of a piece of Angle (shown on bottom of pan in pic) and welded tabs on the lower frame horns to bolt to. It tied in things nice and added a lot of strenght to the assembly
The oil pan took care of the oil system return now I needed a way to supply the engine with oil. I opted to weld a 10AN fitting on the existing threaded steel Insert that screws into the motor at the oil filter location. This required me to block off the main feed from the pick up tube to the oil filter. I had to gut the stock oil pump anyways so I decided to tap the port with a 3/8" NPT and plug while I was in there. I know your thinking what about the aluminum chips. The passage is is a direct shot to the outside of the motor (small hole next to the fitting). I allready had an external oil filter in the system so this method worked out well. Shown below is a pic of the fitting with a temperary cap too keep dirt out during the build.
I needed to modify the existing oil tank to accomadate venting etc. as shown below. Remember the Robot in "Lost in Space" , "Danger Will Robison Danger"
Shown below is the existing Oil cooler I reused in the system and the oil tank venting catch can left of the oil cooler. I had the catch can laying around so I made use of it.
I decided to add an additional oil filter to the Supply line to the motor. I did not care for the avalable mounting brackets so I made my own.
Next step was fabricating the exhaust system. Wanting to keep the Existing Turbo plumbing intact I had two options here. One was to build the system completely from scratch or modify the VW Turbo exhaust, I choose the latter. Hindsight tells me I should have fabrcated from scratch. It would have been more engineering and material however trying to modify an exhaust designed for a different motor is a challange. In any event I was still dealing with clearence issues so I had to come out of the back and over top the motor with the rear cylinders. There was not enough room to squeeze both pipes out the front like I wanted. I will lose a few ponies with the unequal pipes however the mother of nessasesity triumphs again!
I decided to make the system in five sections for easy assembly. The main section was the Turbo flange with blastgate port and the 4 stub pipes. I bought exhaust flanges from Outfront motor sports to use for the sections off the heads. I made tight radius 90s with 2 bolt flanges to bolt the exhaust too. Then I made the two pipes from the rear cylinders using 2 bolt flanges on each end. Pipes are shown below ready to paint.
Fabrication of the Exhaust system was made a lot easyer by using the Inserts avaliable thru Summit racing. They are 3/8" wide rings with a flange that fits between the two pipes being welded together. They hold the pipes together and give you a small ridge to weld too. The rings minimize the blow thru and slag on the pipes. Shown below is the system mounted.
Due to dry sump oil pump clearence I had to relocate the blast gate port to the opposite side of the header as shown below.
The Exhaust system would not be complete with out the Turbo and the Intake system. As with the Chassis and the Exhaust I wanted to keep as much of the existing design intact. The Turbo system consists of the Turbo, Blast Gate, Intake Air filter , 2.75" piping with a BOV and the Intercooler. My VW motor used 2" steel tubing for the Intake tract and was oringinally designed for a 2165 cc motor. The pressure drop was not to bad for the 2332 motor so I ran with it. I was sacrificing some top end however the smaller tubing gave me great velocity pressure at lower RPM. The Subaru 2.5 however would need more air so I opted for the 2.75" tubing. 2.5" would have been plenty however the throttle body was 2.75" so as to not have to transition I used it. I purchased a universal Intercooler tubing kit and a BOV kit off of ebay that gave me plenty material to work with. The Intercooler had 2" ports coming out of the front of it. This was not going to work for the new design. The volume of air would only be as high as the the pressure drop across the smallest openings in the system so the 2" had to go. I had to relocate the Inlet and outlets anyway so it was no big deal. Shown below are various pictures of the mock up stage of frabrication.
One of the disavantages of a Turbo system is that is creates positive crankcase pressure that needs to be controlled. The OEM PCV system will not function properly so I opted to design my own. I had purchased a box of various AN fittings off Ebay that came in real handy for this. I "T" ed the heads and crankcase together and then ran the output up the frame rail that gave the system an Inherit catch can. I used a clear braided hose so I could watch what was going on there. Later I may replace the hose with a 16 AN SS line. At the end of the hose is a Peterson crankcase pressure relief valve topped of with a filter to keep the dirt out. As with the Oil filter I decided to make my own bracket to mount the PRV. The design allows the Dry sump Oil system to maintain a vacumme and when the Turbo is on Boost and forcing combustion past the rings the PRV will relieve the Crankcase pressure and will remain closed when system is in a negative. Shown below are various pics of the system.
Note: The device to the right of the Clear hose is the relocated 2 Input fuel regulater and not part of PRV system.
The cooling system required a lot of thought in regards to radiator location. As you can see by the pics of my Buggy there is not many places to tuck a Radiator. There was no room behind the motor so that was out. I looked into putting it behind the seats however I did not like the Ideal of having a 200 degree heater behind me on a 90 degree day or scalding water down my neck or on my back and arms in case of a leak. It would also take away valuable space for my tool boxes etc. No were up front to put one so the top of the motor was the only logical place for it. The biggest hurdle was to find one with enough capacity to cool the Turbo motor and yet fit in the allacated space next to all the Turbo plumbing. After about a month I found a high dollar double pass Griffin radiator on Ebay for around a 130 bucks. They said it was a blem so I had the guy send me pics of it and the only thing was wrong with it was some fins were bent over. Im thinking Im gonna to more damage taking it in and out of the buggy than that lol. So anyways I bought it and now what to do about getting it mounted and plumbed.
I used a piece of angle iron to set the radiator on for mock up purposes.
After trying many angles I selected the best position that would not interfere with any of the other mechanics of the engine and at least allowing access to the top of the motor. I decided to make a bar that would mount between the frame rails that would bolt on and off. I welded tabs on the bottom of the frame rails. I spun Inserts on the lathe that would fit into the ends of my 1" OD tube and tapped them with a 7/16" tap. I know 7/16" was overkill for mounting a radiator however my logic was that this tube would add additional suport to the frame. I then welded on tabs to mount the 1 1/2" rubber Isolators on that the radiator would mount to.
I used some 3/4" OD tubing for the top mounts. I got to try out my new 45 ton Hydraulic/Pneumatic press on them to flatten the ends for the mounting studs. The press came in real handy for that. Way better than a hammer!
I had to offset the fan to clear the Turbo plumbing so before I final mounted the radiator I decided to build a shrould to give the system even cooling across the whole radiator. I had some .060" aluminum sheet left over from the body panel fabrication that served the purpose quite well. I made a dimentional sketch as shown below so I only had to do this once. You know measure twice cut once. Some things you just don't do on the fly. The box the fan came in work just fine lol.
Shown below are varoius shots of the completed shrould.
Now that the radiator was mounted I had to decide what to do about the plumbing. Now keep in mind I had been thinking about it all long because I dont like surprises. The stock radiator top feed comes out the front of the motor and that was just not going to work for this application. Fortunatly Outfront motor sports offers a modified water manifold that points the port out the back of the motor. I thought about modifing mine however for $80.00 and a core its not worth it. I bought that and it made the top hose routing a lot easyer and I used a length of SS hose to connect it up.
I now have a path for the top hose and need to figure out what to do with the return to the water pump. Hmmm! There is no easy way to get to the top of the motor from here. First the stock RS water pump port exits the bottom and that was not going to work, sound familiar. Fortunatly the WRX Turbo motor water pump exits out the front of the so I picked up one of those. Note: the plastic belt shrould was designed to wrap arpund the water pump and it left a gapping hole in the shrould that had to be filled, details, details! Anyways now the WRX pump is installed and I had to get from there to the Radiator. Because of the Hot exhaust I felt a hose here would not be in my best Interest. I had some left over 1 5/8" exhaust tubing and 90 degree bent so I frabricated a metal tube that would go up and around the back of the radiator. Outfront motor sports also offers a blank water pump flange just for this type of application. I welded it on at the bottom of the tube so I could bolt it on. The disadvantage of this method is it did not allow me to use a Thermosta so I opted for a restricker plate also provided by Outfront. Then I used another length of the Universal SS flex hose for the final connection to that Radiator
The pic below shows a vent I installed to get rid of air due to a high spot in the return system
All of the work up untill now is meaningless without the Electrical that makes it run. Because I am running a Turbo the stock ECU will not handle a lot of Boost and it can not retard the timing to minimize detanation. I toyed with the Ideal of a totally standalone ECM however the price tag was a bit high. By the time you added the nessasary hardware and wiring harness it was a lot cheaper to go a different route. Also the programming from scratch was somewhat of a deterant. So I opted for the Greddy Ultimate Piggy back ECU. It would allow me to use the allready programmed Crank/Cam trigger algorithem of the OEM ECU and would allow stock engine componet control all the way up to Boost level allowing open and closed loop switching. The OEM MAP sensor will only read aproximatley 2 psi above Atmosheric pressure before it needs clamped so I opted for the Greddy 3 Bar Pressure sensor. The beauty of the Greddy is that its fully programmable and its not hard to learn how to use it and comes complete with laptop software for trending, fuel and timing trims etc. Fortunaly I allready had an Inovative motorsports LM-2 AFR controller/OBT-2 Scanner that I bought to tune the VW Turbo motor. It will come in real handy during the tuning process. Tuning Turbo motors without knowing what your fuel ratios are is just asking for trouble. Becides that I like Gadgets lol. I needed a place to house the new ECU, ECM, 3 Bar sensor, relays and circuit breakers. I was allready having weight bias issues with th heavyer motor so I decided to relocate the battery to the front of the Buggy. I used a plastic watercraft Battery box up front and welded up an angle iron frame to house the Battery. I ran a "00" welding cable back to the engine compartment for +12 VDC. NO voltage drop with that. This allowed me to utilize the Aluminum Battery box allready mounted in front of the motor. It got packed pretty quickly with the componets. Shown below is the beginning of packing the box. I toyed with the Ideal of doing the OEM offroad wirng harness conversion my self however due to my time constraints and Interfacing the Gready ECM I made a deal with Enginewiring.com to do it. Even though it still left me with considerable amount of wiring, It did save me a lot of time and effort so I am ok with that.
This pic shows the Electrical box packed with the Greddy Piggyback on top. It sets in foam in the box and is not mounted so I can remove for programming as shown below. It looks like a mess here however when the Greddy is in the box it cleans up nice lol.
Well folks the Subie Swap is just about over. The motor runs and I am down to reinstalling the Turbo (had an issue with it) and will be tuning this weekend. It has been a long journey since the day I pulled a perfectly good running VW 2332 out of a brand new Buggy and did this Swap. If all goes well I will be seeing some of you at Wellsville Memorial day weekend. I hope that you have enjoyed my journey as well and feel free to comment etc.
I will add some additional completion pictures when the Turbo is on.
Here are some Pictures of the final result after a few rides. These were taken after the final season cleaning were i drop the skid plate down to clean all the caked on mud of the season.