You have to decide two things. What do you want to achieve and how much do you want to spend.
Turbocharging the Ford six is a popular choice but it would take me all night to list out the considerations. he is what I reckon is a good bang for your buck package
Lets say 300 - 400 rw hp setup. There is not much point aiming for less as the Ford Six eats 300 rw hp without trying. You'll can get this by using the following setup
- Turbo - TO4 preferably, 1.05 or 1.15 split pulse turbine housing, P-trim turbine wheel, V2 or 60mm compressor wheel (60mm is good for 450 rw hp)
- External wastegate 32mm is okay but 45mm is better to suit upgrades later. Cheap trust and Tial rip off versions work fine.
-Exhaust manifold - old cast garrett is fine if you can get one, custom is better if designed properly. Manifold design really effect spool up time and top end power.
-custom 3" (minimum) exhaust system
-Rebuilt engine with duralite 27.9cc pistons to drop the compression to 8:1, careful assembly and good tolerances etc but nothing super special is required.
-Standard rods, shot peened for added strength, ARP rod bolts
- O-ring the head or block and use the ACL race series head gasket with stainless steel bore binders if you want more than 400 rwhp.
-Try to use only 20 thou oversize pistons to keep the cylinder walls thick, have the block ultrsoniclally tested for thin walls as they tend to have then standard due to the cores moving around during casting.
- Use alloy head with EFI sized valves. Port work is preferable but not totally necessary. be careful which chambers you use, the late XF heads have a very closed chamber which will increase the compression too much.
- Camshaft is very important, Sure cam do a great Mild turbo cam which is around 230 degrees duration @ 50 thou on 114 lobe centres.
- Note: Don't try to make a standard cam work with a small turbo or you are just asking for high backpressures in the exhaust and pinging anywhere near about about 7 psi boost.
- 550 cc injectors are a good size allowing for up to around 450 - 500 rw hp later if you get hungry for more power.
- Bosch 984 or 044 pump (plenty in reserve for when you upgrade as seems to be common with turbo ford six engine owners, I am on my third turbo/ injector / fuel pump combination now)
-XF banana tube Inlet manifold is okay for upto around 350 rwhp or so but huge gains can be made by custom plenums with shorter larger diameter runners in combination with a ported head.
- Engine management, you will need a microtech, Haltech, Autronic,
Motec etc to do this properly and keep it all together. Any comprimises in the tunability of the engine generally results in pinging and destruction of engines. I managed to detonate one engine to death even with an autronic ignition.
Electrics- in addition to the ECU you need, MAP sensor, ingnition module, injector plugs, coolant temp sensors, etc etc. This stuff all adds up at the end of the day as does heat shrink and connectors etc for finishing the loom.
- Distributor - Generally the sequential igntion ECU's. Motec and Autronic will require mods to your distributor as they need a top dead centre reference. This can be a a real pain to do. microtech and Haltech are easier in this sense.
- Ignition. I suggest a good electronic ignition triggered by the ECU as a minimum. I got away with a Bosch electronic ignition coil and Camira style ignition module upto 400 rw hp where it started to put out the spark. A Mallory Digital Hyfire VI is the best by far. Better than any of this MSD crap. The ECU will trigger this happily.
- Spark Plugs. BP7ES NGK plugs work a treat. Don't use the projected tip ones. The 7 heat range is about two heat ranges colder than standard plugs (5's). I had 13 degrees total timing with 9 psi boost with the projected tip 5's and heard pinging. I ended up running 19 psi with 17 degrees total timing when I changed the plugs.
- Intercooler as with the engine management this is highly recomended if you want to keep it together and stop pinging. Go as big as you can fit in the car. The size of the cooler wont cause too much lag with these big 4L engines. Water methanol is an option but it is the 21st century now and every second place around is selling intercoolers for good prices so it is not worth messing about with.
- Cooling- cortinas are harder to keep cool than falcons. Thermo fans don't seem to keep them cool I know that much. Stick with the clutched engine fan because once you stick a big 3" thick intercooler in front of your radiator thermo fans just wont pull air through it. Read the davies Craig catalogue and it rates the CFM free flow, dig a bit depper and see how much they flow through 6" of finned core, not a lot! Ally radiator is the way to go especially in Cortinas as they are thinner and give you more room for the intercooler with less cutting needed.
- Alternator- once you add EFI and a CDI and a fuel pump and a bunch of other things you will need a 80A alternator. 55A just won't cut it. Leaving Thermo fans out of the equation goes a long way towards helping your alternator charge your battery
- Starter Motor. Standard is fine but use the Early type which have the solenoid on top of the motor instead of out the side. This gives more room for you dump pipe. Use a heat shield over this also or it will cook.
- Clutch If going manual then modify the flywheel to accept a clutch of the later 4.0L engines which are six bolt dwelled types then have that modded upto around 2800 lb clamping pressure. This will hold 450 rw hp without slipping
- Auto is the way to go. A strong C4 is just fine
- Diff Standard XF LSD wil be okay as long as you don;t put slciks on it and take it out to the drags. 9" or Borg Warner four pinion LSD with 28 spline axles is better.
- Tune up If you get this far then don't skimp now. Spend some time on the dyno and get it right because messing about on the street dialing in crazy amounts of boost etc is a good way for all your hard work to be ruined. To make 300 rwhp around 12 psi will be needed depending on a lot of variables particularly turbo size.
- Don't be scared to go a bit bigger on the turbo first time round they will happily spool up a T66 / P-trim combo with 1.32 A/R turbine housing. Going too small is worse than too big. Too small means you have full boost by 2500 rpm then the car stops pulling hard after that, backpressures get high which starts cooking turbos and makes the engine want to ping more etc.
This will set you back $10,000 in parts alone but most of the money is tied up in all the bolt on bits which really makes this exercise no different to modifying an SR20 or 1JZGTE or 2JZGTE engine. The actually long motor it is all haging off should cost less than $2000 to build if you assemble it yourself.
