V6 Transplant - Will it fit?
General sizeDuring my lengthy research period into this engine, I came across some sectional drawings of the V6 which I scaled some rough dimensions off. It seemed like it would fit ok. The good thing about the Baja is you don't really have any space restrictions. Since then I ordered an SAE paper on the engine so I could try to learn some more about it before I started pulling it apart. The SAE paper had a good cross-sectional drawing of the V6 so I tried overlaying it on a VW motor cross-sectional drawing to see how big it will be in comparison. I scaled both engines drawings such that 1 pixel = 1 mm.
This is the two motors overlayed on each other. The KL sump is currently
Another thing I haven't shown on the overlay is my current twin 44IDF webers. They made the vw engine even wider. So the V6 will be a lot smaller width wise than my current twin webered 1915 set-up. I want to try to run twin exhausts on this engine, so the room on either side should allow me to do that. I'll try to run custom headers, twin cat's (might be too expensive), and twin turbo mufflers then get them ceramic coated so they look good and last a long time.
The V6 is also longer, but I currently have exhaust behind my engine, which the V6 won't have. My Baja exhaust has a gap after the pulley, two rows of header pipes, then a turbo muffler, then the engine cage. The V6 is a lot shorter than all of that so it should fit in the engine cage easily. I think the engine should look good in the Baja engine bay. It should fill the space out nicely.
Any cutting required?The only problem with this engine is it's from a front wheel drive. So it is designed such that the intake manifold and distributor hang over the gearbox (the distributor actually comes out of the rear of the head). So I will have to a bit of cutting and reshaping of my firewall to make it fit. I am going to make a removable reshaped section of firewall which will make getting access to the engine easier. My engineer said it is ok to have it removable, as long as it has a gas tight seal to prevent exhaust gases entering the cabin.
In order to figure out what I will have to cut and where, I am making a jig to transplant the engine into first. The jig consists of a rear half of a IRS beetle. I am going to install a 2inch wood lift kit in the jig, and an old broken type 2 gearbox so that it is identical to the back of the Baja. That way I can make the adaptor kit and removable firewall section in the jig without having to take the Baja off the road.
What about the radiator?
Option 1 - My original plan.I plan on running a radiator at the front of the car. I think I should be able to mount one in the nose cone without too much trouble. I will mount it so it draws air under the bullbar and through the radiator, then out over the front suspension. I should be able to do this in a way that you won't really be able to notice it's there.
What about the water pipes? - I thought about a few places. I can't run them under the car because they will get damaged offroad. I could've run them under the running boards, but it would be difficult to make all the turns required work. But I have decided to run them under a false floor on the passengers side. I have a 2 inch body lift kit, so raising the floor 2 inches to run pipes through will just put the floor back where it was anyway. The false floor will protect the pipes from damage and the weather. It will also give me room to run any other pipes (air-con / heating / fuel), wires or cables.
Option 2 - A new possibility
After sitting down and looking at the Baja for a while, I realised I could probably run the radiator above the gearbox. Since I have a 2 inch body lift, I have more room than normal under there. I am also going to cut the firewall already to clear the throttle body and distributor, so I might as well cut a bit more and fit the radiator there as well. This will also give me back a little luggage space at the front, and keep some more weight over the drive wheels.
Being above the gearbox will also be a lot more protected offroad. My worry about putting it at the front was hitting it on something. No chance of that above the gearbox. The only worry is will it be cool enough above the gearbox? Well the radiator has two large thermo fans which should keep it cool. At the moment my VW motor gets it's hottest during slow heavy off-roading, where the radiator wouldn't get any more air flow whether it was at the front or the back of the car anyway. So I think it'll be OK. The VW is lighter and will be less work to move around than the MX6 it came from anyway.
What about the wiring / computer?The reason I bought a half cut and not an engine is that the half cut has the factory computer / air flow meter / sensors / etc. So if I have everything running in the half cut I should be able to transfer it all over to the Baja if I take my time and mark all the wires. Another thing the EFI requires is a very high fuel delivery pressure of around 90psi from the tank, so I will have to get a factory fuel pump and modify a VW tank to accept it.
What about adaptor plates?The adaptor plates will be one of the trickier parts. I could order them from KEP in the US. I emailed them and asked how much their adaptors cost. Here is their response;
"Our #7900 kit, Mazda 2.5 to 200mm flywheel Cost $440.
If you using the 9", 228mm set-up the cost is $550.
Kit includes: Adapter plate, flywheel, pilot bearing and bolts."
I guess those prices are US, so in order to save myself some money I am going to try to make my own adaptors. I will draw the various VW bell housings and the Mazda engine mating surface in AutoCAD, and then figure out how hard they will be to mate together. I should then be able to draw up the adaptor and send it to a laser cutter to have made. The flywheel and pressure plate shouldn't be too much trouble, but I'll wait until I see what the Mazda stuff looks like.
Update - Cad Files
For those that are interested, you can find all my Cad files here - Cad/index.htm