3.8L MIVEC Swap - Not for the faint of heart!
I've got this posted on multiple forums so it's going to be hard to keep everything up to date. I'm also cut and pasting from previous posts so don't mind if it's disjointed.
Something got delivered today.
http://ucsperformance.com/album/6G75/IMG_0643.JPG
:)
I'm going to discuss some of my findings and why this swap would be a major pain in the ass.
First, some pics of the engine. I'm really happy w/ how this engine was pulled. Harnesses are intact and I got most of the accessories, even the cats! Motor is CLEAN.
http://ucsperformance.com/album/6G75/IMG_0638.JPG
http://ucsperformance.com/album/6G75/IMG_0639.JPG
Notice the motor mount bracket doesn't have provisions for our type of alternator.
http://ucsperformance.com/album/6G75/IMG_0640.JPG
http://ucsperformance.com/album/6G75/IMG_0641.JPG
Note the clutch is a push style, not a pull style like the 3G.
http://ucsperformance.com/album/6G75/IMG_0644.JPG
http://ucsperformance.com/album/6G75/IMG_0647.JPG
New type of flywheel bolt.
http://ucsperformance.com/album/6G75/IMG_0648.JPG
Flywheel is like nothing I've ever seen. The flywheel itself acts like a sprung hub. The friction surface can actually rotate from the part that bolts to the crank.
http://ucsperformance.com/album/6G75/IMG_0651.JPG
What do you see there? The 4G uses a returnless fuel system.
http://ucsperformance.com/album/6G75/injector.JPG
305cc injectors.
http://ucsperformance.com/album/6G75/IMG_0659.JPG
Nice rear harness.
http://ucsperformance.com/album/6G75/IMG_0660.JPG
Stock 3G heads.
http://ucsperformance.com/album/6G75/IMG_0661.JPG
4G heads.
http://ucsperformance.com/album/6G75/IMG_0662.JPG
http://ucsperformance.com/album/6G75/IMG_0664.JPG
http://ucsperformance.com/album/6G75/IMG_0665.JPG
http://ucsperformance.com/album/6G75/IMG_0666.JPG
http://ucsperformance.com/album/6G75/IMG_0667.JPG
http://ucsperformance.com/album/6G75/IMG_0668.JPG
Head differences.
Lower intake manifolds are not swappable due to port differences. Hell the 75 lower intake manifold DWARFS the 74 and it dwarfs the 72. It's a good inch longer in width from runner 1 to 6. This also means you can't swap on any 72 or 74 intake manifold.
The MIVEC version of the 75 is an entirely new beast. The block is not the same casting and neither are the heads. All hardware has been upgraded in every sense, even down to the bolts and washers used.
Problems? They are many. First and foremost is the fact that anyone running a stock computer CANNOT drive the ignition system. Even if you jerry rigged wiring to the cam, the computer wouldn't recognize the trigger pattern of the cam sensor as it's radically different in output signal. Crank sensor is identical.
Next up is the fact that there is no provision for the through bolt of the alternator. You would have to use a 4G alternator as well or come up w/ an ingenious solution as I already have to use the 3G alternator instead. Hint, it's all about the right parts combination from 3 different engines. ;)
Now lets tackle the drive by wire system. There is ZERO provision for a throttle cable on this manifold. The TB is dbw afterall. Swapping over to a different throttle body is possible but you must fabricate a way to use your throttle cable and from the looks of it, it's going to be one tight ass fit.
I have a feeling a 3G flywheel might not fit. The crank is definitely machined differently than a 3G crank. Will test later.
Fuel system is returnless. You would think that you could swap on a different fuel rail. Nope, they took that away too. The angle of the arms that the rail is bolted to is about 40 degrees off. The stock rail for the 75 is a non returnless system. So your options are to modify the rail to make it a return system or convert your fuel system to a returnless system. Or, there's a 3rd way I came up with. It involves machining but will allow me to retain my current fuel setup on my car.
Next, you need an exhaust system. I'm going to build a set of headers for myself. Most people can't do that. Maybe RPW's might fit. I actually think they might.
Your biggest problem is still a computer. I don't have that. I have a stand alone. I can even drive MIVEC. I'm ditching the DBW even if I have to seriously modify the intake manifold so that I can use a throttle cable PROPERLY w/ the setup. Oh yeah, wiring would be a bitch too. You have to run new wires from the ECU to connectors on the engine. Good thing I'm pretty good at that. ;)
http://ucsperformance.com/album/6G75/IMG_0754.JPG
http://ucsperformance.com/album/6G75/IMG_0755.JPG
http://ucsperformance.com/album/6G75/IMG_0756.JPG
http://ucsperformance.com/album/6G75/IMG_0757.JPG
Completed downpipe. I like. It's sexay.
http://ucsperformance.com/album/6G75/IMG_0758.JPG
http://ucsperformance.com/album/6G75/IMG_0759.JPG
http://ucsperformance.com/album/6G75/IMG_0760.JPG
http://ucsperformance.com/album/6G75/IMG_0761.JPG
The hell I'm dealing w/ now. I've got it mostly figured out but I'm not going to have a tach signal to my cluster. Good thing the AEM has a nice dashboard display I'll be running on a netbook in the center console!