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the 997 snorkel requires the use of the mating fitting that snaps into the deck lid but this requires no modification to switch.
I heard that too, and ordered the 997 deck lid piece. But the 996 "bellows" slides right over the top of the 997 snorkel, so I left the 996 piece in place.
996 bellows work just fine -- this is a shot with the spoiler up, shooting under it to show the parts with the engine lid closed
Thank again for the thoughtful replies, everyone. Good call on pinning the IMS; spoke with Jud today and I'm going to have it sent to LN with the block when it goes for the machining/Nickies and I'll have them do the job and install the Solution at the same time.
I also appreciate the thoughtful replies - thanks guys. Good food for thought for when/if I ever do an engine out on my 986 S. I see reasons to just run the motor and maintain it and reasons to reach for a little more performance if I'm already doing big mainentance.
I just drove my 3.4 to 3.8 first time yesterday. LN Nickies. Carillo rods, LN deluxe kit. (there is no Porsche supply chain in Australia), Standard heads. Standard intake/induction. Nothing to see, except cleanliness. Pinned IMS, IMS Solution, UAOS thanks Skip. Old tech deep LN Sump. Top Gear mild exhaust headers, X pipe, cats. Calculator shows 11.7% displacement increase. Hartechs post for their 3.4 to 3.7 is that max hp approaches the displacement increase. Torque under the curve from idle is close to double the displacement increase. Mine sound and drove responsively, with a noticeable wall of torque, as the difference. A very satisfying result.
Alright, teardown complete and it appears the carnage was limited to that one piston and valve and some bore scoring.
Block and IMS arrived at LN yesterday and I’ll be having them install the Solution bearing and pin the IMS as well.
Heads were shipped to Hoffman yesterday. Gotta say that Scott at Auto Associates, Len Hoffman, and Jud at LN have been exceptionally generous with their time and patient with my questions. Their explanations haven’t just helped to demystify the M96 and rebuild process, but honestly made me feel quite a bit better about the costs involved. It’s absurd dough for me, but I’m confident the car I’m getting back is truly going to be my optimized and bulletproofed NA 996.
My new thing is considering installing an LSD while it’s in surgery. It’s a non-PSM and non-LSD car, but it felt pretty planted in the rain a few days before it went grenade mode. I’m a confident driver, but haven’t had wheel time with 3.8 996 build.
Thanks again to everyone for their advice and stories. I’ll keep updating this thread as things move along.
Alright, teardown complete and it appears the carnage was limited to that one piston and valve and some bore scoring.
Block and IMS arrived at LN yesterday and I’ll be having them install the Solution bearing and pin the IMS as well.
Heads were shipped to Hoffman yesterday. Gotta say that Scott at Auto Associates, Len Hoffman, and Jud at LN have been exceptionally generous with their time and patient with my questions. Their explanations haven’t just helped to demystify the M96 and rebuild process, but honestly made me feel quite a bit better about the costs involved. It’s absurd dough for me, but I’m confident the car I’m getting back is truly going to be my optimized and bulletproofed NA 996.
My new thing is considering installing an LSD while it’s in surgery. It’s a non-PSM and non-LSD car, but it felt pretty planted in the rain a few days before it went grenade mode. I’m a confident driver, but haven’t had wheel time with 3.8 996 build.
Thanks again to everyone for their advice and stories. I’ll keep updating this thread as things move along.
Awesome! You are working with the right people. Good people. They can hook you up with a how-to on engine assembly as well. These engines ain't exactly normal when it comes to that.
Awesome! You are working with the right people. Good people. They can hook you up with a how-to on engine assembly as well. These engines ain't exactly normal when it comes to that.
Thanks! Scott at Auto Associates is the one building it.
Be sure to check the scavenge pump on bank 1 carefully during assessment. With a bent valve means the cam timing became un-timed and is caused by the timing chain breaking/jumping a tooth or the scavenge pump locking up and causing excess stress on the chain..
Scavenge pumps are very tight tolerances and it only takes a small bit of metal to lock it up and chain re-actions take over to form serious or catastrophic events.
You would be surprised at how many catastrophic events start with just a failed $2 part ( clip , O-ring, ect.) or a small bit of metal getting in just the wrong place...
Be sure to check the scavenge pump on bank 1 carefully during assessment. With a bent valve means the cam timing became un-timed and is caused by the timing chain breaking/jumping a tooth or the scavenge pump locking up and causing excess stress on the chain..
Scavenge pumps are very tight tolerances and it only takes a small bit of metal to lock it up and chain re-actions take over to form serious or catastrophic events.
You would be surprised at how many catastrophic events start with just a failed $2 part ( clip , O-ring, ect.) or a small bit of metal getting in just the wrong place...
Right on. The heads are being gone through/refreshed and given a few performance and reliability upgrades by Len Hoffman, so I’m trusting he’s got his eyes on that.
Len Hoffman is done with my heads and they’ve been shipped back to Auto Associates. All good news; no additional damage found besides the one bent valve and the typical corroded exhaust flanges.
Heads got Len’s base service with seat and guide work and we also did Stage 1 porting, replaced the freeze plugs with threaded brass ones to further bulletproof the heads, and I upgraded to high performance valve springs. The list of work done in Len’s base service is pretty extensive and he was super communicative throughout the job, happy to educate without trying to upsell me on unnecessary work or parts, and the turnaround was much quicker than initially quoted. Obviously people on this forum know his work is the best, but I’d like to echo that he has been a great guy to deal with throughout.
The block and IMS are still at LN and in the queue for the 3.8 bore machining job/Nickies install/IMS pinning service, but Scott at Auto Associates did say there was actually no bore scoring present at all when he split the cases, which contradicts what the first Porsche indy that diagnosed the kissed piston saw on their sump-routed bore scope. I’d have gone the Nickies route while the engine was split for peace of mind either way, so no sleep lost, but interesting news.
And we’re now in the assembly phase. Scott at Automobile Associates sent some shots of my parts coming together. Carillo rods, forged Mahle 101s, IMS Solution and LN pinned the IMS assembly while it was there with the block getting machined and the 3.8 Nickies installed, and some of Len Hoffman’s handiwork on display with the heads.
Curious. We see a large power bump with 4.0 Vs. 3.8 - what led you down the 3.8 path ?
I understand you started with a 3.4 and am wondering if that played a part ?
I was told going from a 3.4 to 4.0 requires the crankshaft and carrier from a 3.6 and some modifications on top of that. I honestly liked the car a lot with a stock 3.4, so the extra power I should net from a 3.8 and Len’s head work should be gravy for me. My failure was a low RPM timing issue that luckily only destroyed a single piston and valve, so the crank was fine.
09-25-2023, 11:19 AM
