Project = Boxster engine into a 996

This thread has been split out from my 2001 project car thread, as although it is all part of the same grand plan in terms of engine development, it isn't really anything to do with that particular project. This part of the project involves buying in a full Boxster 3.2l engine, seeing which ancillaries are the same as the 3.4l M96.01 engine so that I can use those for checking clearances, and then have the rest of the engine rebuilt as a 3.7l engine for my C2. The thinking behind this is as follows: 1/ The overall project aim is to develop 3 sets of camshafts for different engine specs, so it makes sense to build up three engines. We already have two lined up, so this one will be the most 'base' spec of the three. 2/ A 3.2l Boxster engine can be had MUCH more cheaply than a good 3.4l 996 engine. It produces less torque and power so is less likely to have internal wear issues, and it shares the same block, heads, crankshaft and camshafts, which will all be used. 3/ As the block is being bored out anyway, the fact that the Boxster runs smaller pistons is of no consequence.[/list] I heard the engine running before it was pulled so hopefully no bad suprises in store. MC

The standard engine from my C4 has been taken off the stand... The Boxster 3.2l engine I have has gone on the stand. I now need to see which components from this: Are the same as the components on this: And put any ones which are the same on to this: The rest of the engine will then be stripped down so that the bottom end can be converted to 3.7l and the heads can go off for porting. MC

I have started to dismantle the engine by removing the wiring loom and the intake manifold. The manifold appears to be slightly lower than the 996 one and definitely thinner, it does look like it isn't likely to flow as well, which makes some sense. I never cease to be amazed at the packaging on these cars. The way the wiring and pipes loop around each other but are still easy to remove, with connectors which just fit through the spaces required. With the wiring and the intake removed it looks very much like the power steering, air con and alternator, and associated brackets, are exactly the same between the two cars, so they can all be moved across. The AOS is different, but I already have a scrap one of those on the spare engine. MC

Air con compressor, alternator, power steering pump, alternator, and a few sensor moved across from the boxster engine to the 3.4l scrap engine. The 3.2l is getting to the stage where it can be dismantled now. It looks like one of the AOS bolts might be a little challenging. I will have to note the differences in the drilled and tapped holes on the 3.2l and 3.4l head so that the additional required holes can be added at the machining stage. MC

Almost two hours in the garage this morning, making some progress on stripping the engine down. The rounded off bolt on the AOS was removed by slotting it with an angle grinder and using an impact screwdriver. The manifold bolts looked a bit crusty, all but one came out with a single hex 13mm socket. One was beyond it and will need a lot more work, an 11mm single hex will fit on it which shows the corrosion. I think I'll attack that when the head is off the engine. Water pump removed, oil pump cover bolts all removed and bagged up, then the engine was locked at TDC First camshaft cover removed. To my relief the camshaft journals look really clean. Next up is to remove the camshafts, tappet chest, and the head. MC

Now I finally understand how you get so much done... posting an update at 7:41am after almost 2 hours... you do it instead of sleeping! Fair play - I couldn't get up that early and if I did, the kids would get up too and then I wouldn't get anything done. Loving the engine strip. Did you ever consider one of the bolt induction heating tools considering the amount of work you are doing on rusty bolts? Or are do you choose the patience approach?

Those manifold bolts look brand new compared to mine.

I don't do all that much work on rusty bolts, but if I do more I might look at them, I do like a good gadget. Up at 4:20 this morning, out of the house by 4:45, in the garage at 5:15, start work at 7:15. MC

Yes I guess it could be cut off, I didn't want to do that as without having it near the car I wasn't sure if it was required. The clip isn't needed in my case anyway. I haven't looked at the gearbox end yet, but will do soon. Heads are off the engine. Bores look nice and clean. MC

Oil pump, water pump housing, sump, and IMS cover all removed. No obvious play in the IMS bearing, but I will remove the cover to take a look at what it is like inside. There were some small plastic particles in the sump, no idea where they are from, could be from something a long time ago. All of the guides are intact, and although there is some wear on them, they don't look terrible. With all the talk of bearing wear, bore wear, IMS bearing failure, I am genuinely interested to see what the bearings look like on this engine when I get to them. This is from an engine on 147k miles. MC

Bores look very good indeed. whats the mileage? MC what are you doing with the car again engine wise? taking it out to 3.7?

The current plan is.... The 3.4l engine has been removed from the C4 The prototype tappet chest and dual chamber scavenge pump will be fitted to this engine and it will go back in the car for testing. Whilst that is being tested in the car, a new engine, based on a 3.6l bottom end which is being bored out to 3.9l with an EN40B crank a bunch of custom stuff is being put together. That will run with the 3.4l heads with slightly larger valves That will all be fitted at a later date, when hopefully the rest of the car is pretty much done. The engine I am stripping down now, the 3.2l Boxster engine, will also be bored out to make it a 3.7l and will have the ported heads, new tappet chest, camshafts, intake system etc. and will end up in my C2. MC

Block halves seperated. I have removed pistons 1-3, the worst wear is on piston 3 as shown below. Big ends on the crank look lovely MC

Now i am really confused! I didn't know you had a C2 too! To clarify - C4 engine will go back in for testing. Then a modified 3.6 based engine will go in. Is that the C2 engine? Ex Boxster engine will go into the C2 What will happen to the C4 3.4? Or have I missed something? Still loving this thread. :thumbs:

The 3.6l engine is based on a new block with a pair of 3.4l heads I already have. So the plan is. 3.2l boxster engine becomes a 3.7l for the C2 3.6l new block becomes a 3.9l for the C4 I then have the 3.4l engines from both the C2 and C4 as spares, along with another 3.4l engine in parts which needs a crank. I have written a fair few threads on my C2, nothing recent as I am not doing much other than driving it. 1998 C2 on about 61k. MC