Anatomy of an M96 Engine Rennsport Kansas City

Took some time today to tear down this M96 motor to show you the internals of the 996/Boxster Engine:

On the stand ready for dis assembly.

First thing we do is pop the cam plugs out of the end of the cam housings so we can see the orientation of the camshafts. Starting with bank 1, the intake camshaft notch should be pointed outward when the crank is at TDC. If it is not, rotation 360 degrees and it should be there.

Install a TDC pin to keep the crank locked.

Remove the Bank 1 cam tensioner.

And install your cam lock. You can use either the factory cam lock tool, or use the camshaft alignment tool. Either one works fine. This is the alignment tool locked into the cams.

Then remove the front oil pump.

You can skip the step and remove with the cam cover, but I thought I would show removing the spark plug tubes from the engine if you ever need to do that due to leaking o rings. Special tool KEW4852.1bV2 pops them right out.

Once that is done, you can remove the cam cover bolts and pull the camshaft cover off. Once off, install the camshaft bearing bridges to hold the camshafts to the heads. The cam cover normally holds the cams in place, and uneven pressure can cause them to break, thus bearing bridges are installed while we remove the other bearing caps.

Removing the front chain sprocket, a few bolts holding the camshaft tensioner, remaining two bearing caps, then the alignment tool and the cams can be removed from the engine.

The cams with the tensioners removed from the engine. If you are doing top end work, at minimum the followers and cam tensioner pads should be replaced. While you are in there, it is a good idea to replace the tensioners as well, though they are not cheap. At this point, disassembly of this assembly is not really any different than a 968.

At this point, we have the hydraulic cam followers to remove, along with the camshaft follower plate assembly.

Followers removed from their bores. If you are in here, replace them all.

And the follower plate removed.

What it looks like off the engine.

Next the oil shield comes off (only on bank 1 side)

And a few small allens on the head to case junction.

At that point, you can remove the head studs, and pull the head off.

One side of the engine broken down.

And the bare cylinder head on the table ready for cleaning.

This is a little shot in at the coolant passage. Notice the black piece in there? That is a piece of a broken waterpump impeller that got sucked into the system after a waterpump failure at some point in it’s life. Blocking the coolant passage in the cylinder head. Not good.

At this point, we remove the TDC pin and rotate the crank 360 degrees to put the bank 2 camshaft mark pointing outward, and reinstall the pin.

Repeating the same procedure, that side of the engine is broken down and the result is this. The oil mess isn’t too bad yet.

Removing the front crank pull and IMS bearing flange assembly.

And the front coolant port and oil pump drive assembly.

Flipping the engine over to remove the oil pan. This is where the oil slick mess starts. Since everything is getting cleaned in the big washer, I dropped floor dry on the ground to soak it up. Unless you have a huge parts washer, only use pans and rags to collect the oil. Floor dry is dusty, and motors don’t like that dust in them. Make sure that after parts are cleaned, the motor is assembled in a clean room.

And the oil pickup tube assembly can be removed.

Once that is done, rotate the engine 90 degrees with bank 2 up, and the case half bolts can be removed. 2 on bank 1 and one on bank 2. Torx bits.

After removing all the case bolts, the right side can be lifted from the motor, leaving the pistons and rods exposed on that side.

A good shot of the intermediate shaft and the chains that are driven off it.

Where the infamous IMS bearing sits in the end of the IMS.

At this point, bank 2 wrist pin clips are removed and the pistons are separated from the rods. Note: Wear safety glasses, these clips will come flying out.

With the pistons removed, the crankshaft carrier assembly can be raised out of the left side engine half.

And the crankshaft carrier. Pretty interesting design vs a traditional engine.

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2 Comments

Leave a comment
lin

November 3, 2012 at 7:38 AM

“Took some time today to tear down this M96 motor … ”

Nice! Obviously a two Mountain Dew morning.

lin

    porschedoc

    November 3, 2012 at 9:21 AM

    Nope, it was a zero mt dew day. I have given up what I love the most.

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