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Re: Can you swap in a bigger motor? (archive)

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Posted by Allan Lueb on November 07, 2000 at 14:12:06:

In Reply to: Re: Can you swap in a bigger motor? posted by FWK-Z3 on November 06, 2000 at 21:40:03:


Depends how scared you get in the middle of things. Stuff that is not part of an average toolkit that you wuill need to do it are:

11 mm 1/4" drive socket (most socket sets have 10 and 12 but not 11 mm)

A torque wrench capable of measuring 11 ft-lb. (on the 11mm nuts).

A 14" drive universal

Fortunately, Downing Atlanta gives you very clear instructions. There are lots of pictures and you are talked through in detail. The tow traits I would really stress are cleanliness (you are have to takwe the injectors out and the fuel rail off) and thoroughness -- ask yourself if you really thingk the way you put it together wil last 10, 20 or 100K miles.

What you will be doing is taking the intake manifold off and replacing it with another one. you will have to pull the throttle body off (and keep tha vacuuum hoses and cables straight) then taking the intake manifold apart and removing it. You also have to remove an electrical junctioon box and create a new wiring harness by wrapping existing wiring in (supplied) electrical tape.

The main points to watch out for are:

1. When you make the wiring harness, be sure to leave the maximum length for the wires going to the fuel injectors. Fold them in a group towards the back of the car and wrap the other wires from the front, wrapping inmto the fuel injection wires. Wrap the other wires only up to where the fuel injector wires come out of the main bundle, the wrap the fuel injector wires separately as a bundle.

2. I replaced the hex head bolts that hold the supercharger on with metric cap screws (the kind you use an Allen wrench to tighten). Otherwisw, they are too close to the manifold to get a socket on so you can torque them.

3. When you take the old manifold off, stuff some paper into the intake ports so nothing drops into the engine - remember ONE OF THE INTAKE VALVES IS OPEN! If something goes down the open hole, yiou have just made a MUCH BIGGER job for yourself.

4. When you are putting the new manifold on, REMOVE THE PAPER FROM THE INTAKE PORTS and TAPE OVER THE FUEL INJECTOR HOLES. You don't want a wad of paper sucked through your engine, and the 11mm nuts from the intake manifold will go right down the fuekl injector hole. Also, try to keep the tape off themating surfaces of the intake manifold -- duct tape makes a lousy gasket.

5. The fuel injectors are tough to get in the holes. I took them off the fuel rail and inserted each one individually (also , if you have the air injectors off to the side of the injecotrs, be very careful taking each of the rubber hoses off of the plastic manifold -- it breaks easily and a new one is fairly expensive (besides, (1) you will have to wait to try out your handiwork until the dealer gets a new one fo ryou and (2) enough of us have put superchargers on that your dealer will likely guess what you are up to when you go in looking for a new one of these). Line up the injecors so that the rectangular plastic boss is pointuing away from the engine. Gently push the fuel trail over the injectors (one at a time) then install the clips. They go on wiht the straight sid eof the forks down and these go through grooves cut in the injectors. When everything is lined up, the clip should align the injecotr to the rail by engaging the boss on the injector with thelower part of the backside of the clip and the metal tab on the rail with the top of the backside of the clip.

Other than that, just make sure that everything is tight (and that you have replaced the tiny o-ring on the feed fitting to the fuel rail - the one that you tighten with a 12mm wrench).

I also took the precaution of turning the engine through by hand a couple of time, just in case somethng fell in unnoticed. Better to have it make a soft clunk and stop turning over when you are doing it by hand, than a louder and infinitely more expensive clunk when you fire it off and it tries to compress a nut with a piston. Also, its really hard to breeze into your dealer to buy a new piston without provoking a whole bunch of questions you would rather not answer.

There is a 90% probability that the first time you get everything together and turn the key that the engine will not fire. Let it crank a few seconds, release the key and try it again. Some of the fuel has drained from the lines while you have been working on it -- cranking and stoopping will replenish the fuel.

As its running, check for leaks and also checkl to make sure that there is a little slack in the throttle and cruise cables.

Paln on spending a weekend on it, and at 4PM on Saturday -- STOP! Anything you do after that ypu will end up redoing on Sunday.

If you live within a 1000 miles of Atlanta the trip would be worth it to have D/a install for $400.00



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