Project 3.6 coming together

[Bfan]

My 3.6 project is hopefully coming to an end. I have spent most of my spare time since January on a “big engine” project. There is nothing wrong with my 3.2 engine. It has gone about 70 K miles and is still running strong. But as they say; “There is no replacement for displacement.”
Knowing that the M96 engine is not the simplest of task to take on, but being a good “googler” and generally interested mechanical things I decided to give it my best try. And I figured that as the new engine will be pumping more air than the old, I should try to upgrade both intake and exhaust. I was tempted to stroke the engine at the same time so I would end with 3.8 as I figured I might want to get new and stronger rods anyway, so I might as well have them made in the correct length for bigger crank, but found out that it was not worth the extra cost, which is at least $ 4.000+ if you are lucky to find a good cheap crankshaft from a 3.6. So I ended with OM rods but new ARP rod bolts.

With the help from ByProdriver I got a second hand 3.2 engine that went to LN Engineering for 3.6 bore and sleeves before it was shipped overseas to me with some LN goods (thanks again Pro). I then gathered together other necessary things for the project, mostly from Pelican but some from eBay. I spent a lot of time, studying the task at hand, searching the net for info on M96 assembling, head porting, component balancing, M96 tool building and more. Found lots of information in the Boxster Workshop Manual which my quest on the net led me to.
I did things like cooking the lifters in Jo Gibbs oil in my kitchen for several hours until my eyes hurt, I think my downstairs neighbors have jet to forgive me as the whole building smelled for days. (Yes Jake, I probably had the oil to warm). I spent days weighing and balancing components, used weeks or months on studying and performing head porting. I tried to do it all “by the book”, although the book does not exist jet. I thought about taking pictures and documenting the whole process, but there is already a thread on Rennlist which does that very well.

And few weeks ago after months of head scratching, rereading, reopening and redoing things, the engine was ready to go into the car, which is a 01 S. I followed Wayne Dempsey’s advice on engine removal and installation (He is right; it is 20+ hours for only the removal, first time around). I even managed to get my hand on “Jo Gibbs run in oil” for the startup, the only jars that were to be found in my country. It has been an interesting and enlightening journey which I have enjoyed a lot. And if it all still goes wrong I have my old, double row, 70 mile engine to fall back on.

Specifications of the build:
LN 3.2 to 3.6 sleeves and JE pistons
LN triple row ceramic IMS bearing, called „The IMS upgrade“
LN 0.5 Quarts deep sump kit
LN chromoly oil pump drive
LN spin on oil filter adapter
LN billet chain tensioner paddle
ARP rod bolts
ARP crank carrier bolts
160 deg. thermostat
997 intake manifold
83 mm Porsche 996 GT3 throttle body
987 Cayman air box
997 plenum, ported to take 83 mm throttle body
Heads flow optimized
Aftermarket headers

In the near future I plan to:
Install Cayman 3.5” MAF housing and remap the ECU with Euro 996 tune which is compatible with the 3.5” MAF housing and does away with the two downstream O2 sensors that keep throwing CEL after header installation.


Old and new engine side by side, the old one proved to be double row
against all odds as it was listed as single row after the IMS settlement.
Next task was to move most of the externals over……


3.6 engine in the car, dropped about ½ an inch to make space for the 997 manifold


Engine with custom painted 997 manifolds behind a homemade, clear engine cover, made
from double layer of Lexan, bent with heat gun. I want everyone to see my 3.6

[jimk04]

awesome.....are you soon having it mapped/dyno tuned?

[iaincamp]

OK...I know the clear plastic cover was probably the easiest part, but I love it!

[Jamesp]

Excellent. Great work, way to go! Keep us informed on how it performs!

[BYprodriver]

Good work Bfan, I was wondering recently how the project was coming. Intake manifold & clear cover looks good!

[silver-S]

I am very impressed with your work, and in awe of anyone who would undertake such a conversion.

Would you like to do mine next? We have a spare bedroom and our winters are sunny and mild.

[trimer]

you want to make some extra money to pay for all this...you should product that plastic engine cover and sell them. Great idea. Wondering what it does to heat in the cabin, but I like the idea of going to a cars show and being able to actually see the motor.

[woodsman]

Massive project- congrats on getting it done! Let us know how she runs.

[pjq]

wow, ......what a project! Congrats. Have you turned the key yet?
What was the ordering time for parts to Iceland? What about missing bolts or screws were you able to get those locally?

[Bfan]

Hi and thanks to everybody for the kind words.
Very funny silver_S, I might take U on your word and move in on U, but then again, I might not, as I am an avid X-country skier, so I look forward to the snow season that is coming up over here.
And yes PJG, missing bolts and screws were one of my big headache´s, causing a few delays, but I ordered some extra's with my many orders (about 3 weeks from P...lican) and got some locally, and it all came together with a few to spare in the end :-)

trimer, the plastic cower is not my idea (I which), it is known on the Cayman´s, just check Planet-9. But I don’t know anyone else to do it DIY, they are about $ 1000, but mine came to about $ 500 in materials (plastic and edge-liners)…..I used double layer lexan with different layer thickness (4 and 5 mm) for sound isolation (that is my idea), known method in sound glass in houses. The engine is not to loud, although I would change to the original and original “blanket” on top, before traveling long distance with DQ in the car. And I don’t think it will be legal for racing….but it surely is a head turner, much more than all my efforts on the rest and almost takes the car into super sports car league…

To make a long story short, I have now ridden the engine though the first oil change, but not without issues. As much as I wish I could tell you that starting up was all “hunky dory”, it was not the case.
After turning the engine around for a while without the fuel pump rely in place to make sure the heads were primed and oil was flowing, it started with a blinking CEL. I almost shi*** in my pants and turned it off and I can tell U my gut hurt more then when I broke a window in my youth. I read the codes on my Durametric and it proved that somehow, one of the O2 sensor was not plugged in properly. On second attempt it came on alright without issues.

But then after a while, I got real low (-0.75) Rkat-readings on one bank and high Rkat´s (+0,20) on the other, so I assumed that I had somehow screwed up moving the externals over and gotten a vacuum leak. After a few attempt´s and a lot of head scratching, I found a plastic tube at the very bottom of everything that was broken. It connects to the change-over valve and I probably broke it when I was fighting to get the shifting cables in place, under the intake manifold. It was an old post by Bar10dah on this Forum that got me on the right track for this one……...This Forum and all the old posts on here prove to be invaluable again and again……The car is running fine now and I am using dry warm days to run it in, always with a BIG smile on my face. I even ride with the top down some of the time, you just need a few degrees over zero celsius to ride topless if U turn on the heat and were a cap…..
I still want to get all the injector balanced/cleaned, I somehow did not find time to do that in the process, as stupid as that might be. But I will probably have to send them to RC-eng in the US for that.
To be honest, I can’t really feel the difference in power so far. But now I have an engine with some of the 21(or is it 23) failure mods addressed and I will get it dyno'd when it is ready. I did the 997 plenum, desnorkel, 74 mm TB and headers on the old engine and think it was about 285 HP (it did 0-62 in 5,2 sec) but I have not really been pressing the new engine so far……First I have a ski season to enjoy, but U guys will be the first to hear of my 0-62´s when the car is ready and there is a good day with hot enough tarmac over here for a decent “go for it”…..

[woodsman]

You mean were going to have to wait all winter for a 0-60 time???

[Kenny Boxster]

I'm glad to hear the results. Man, more power is certainly going to put a grin on your face!

[Cloudsurfer]

If you can't feel the difference in power, me thinks something isn't quite right. My LN based 3.8 in my Boxster S was faster than SH$T.

I'd def consider a RoW flash to get rid of all the secondary air injection guts, and also avoid the CELs from the post-cat O2 sensors.

[jaykay]

What went in to your decision to install 997 plenums?

Are they perhaps more geared to the 997 3.8 heads?

Nice work by the way....keep it going!

[Crono0001]

I want that engine cover

[Bfan]

I have simply not had the opportunity test the car yet, been to busy worrying about and "fighting" the vacuum leak. And I am taking it a little easy as I am still running it in. But I am sure I will get the opportunity sooner than later.
Jaykay, regarding the 997 intake manifold (plenums?), I read somewhere of a guy using it on an 986S engine with the help of an adapter plate. It has some of the bolt holes in the wrong place as the 997 heads are different from the 986S/996 heads as I assume you know. But the intake ports are in exactly the right place. Out of the six bolt holes on each side, two did fit perfectly, I drilled the manifold for two, and made an adapter plate fastened to the top of the manifold to take the remaining two. And I guess I went for it as it is geared to the bigger engines and also, not that it is a big issue, it looks dam good under the clear engine cower, in my opinion.
I now have "problems" with the blue air intake boot at the throttle body that contrasts the red PORSCHE letters on the manifold. As the boot was real hard to find, I should maybe change the letters to blue for better "harmony"??....... so many details to worry about......
but in the meantime I continue to ride with a big smile at every opportunity.

[Bfan]

Drove the car yesterday in just below freezing temperatures, but dry roads. Took couple of spirited runs, as I now have about 500 mi on the rebuild. Man, it felt good and it is like a new car. The engine is running smother and smother and feels better and better. Maybe I was a little over concerned in the beginning, sort of half scared that something would breakdown, caused by me and my build. The car will spin on take off if I'm not careful and just like a good track car should, it feels like it now has torque enough to steer by throttle in the turns. But I will wait till after the next oil change to really drive it like the doctor intended. I hope do do a lot of that in the future.

[rp17]

Good job on this project. Keep us updated. I think rebuilds should be done in pairs!

[Bfan]

Originally Posted by rp17

Good job on this project. Keep us updated. I think rebuilds should be done in pairs!

Thanks for that, I am taking it "slow" in many ways until spring. Regarding rebuilding in pairs I must say that one engine was a handful for both me and my pocketbook. But talking of pairs, I still have the old working 60K miles double row 3.2 engine in the garage. I had planed to sell it to recover some of my cost.

[Brad Roberts]

Good job!!

Yes, 3+ years ago we built a 3.6 LN engine with a 987 CaymanS intake (easier to fit under a 987 engine cover) which is a direct fit for the 986.