996 Reborn

Greetings all. I thought I'd introduce myself and quickly share my 996 repair project . Have to start with a huge thanks to others that have documented work on this motor -- Logray, Imo000, Dharn55 and others. Good stuff. Last summer, I picked up this 2001 996 off the local craigslist. Turns out a Rennlister had had a catastrophic failure on the local track (High Plains). He was selling as a roller with the professional diagnosis that the motor had spun a rod bearing, snapped a rod and possibly the crank. Rotating assembly/case was toast. I was in the middle of an air-cooled VW project at the time, but had been looking for a good p-car project for the side burner. I wasn't sure what the plan was for this car when my wife and I went to check it out, but I figured I would be able to rebuild a motor or devise an "relatively easy-fix" solution. So we checked it out, saw the potential, loaded her up and brought her home. The car sat in front of my house for several months while I read up on the 996/3.4 and worked on getting my VW to a good stopping point. As I researched here on Rennlist, I began to get a little nervous about this project. IMS...RMS...AOS...PMS? 996's suck? Throwing money at the problem is not an option for me unfortunately, so a 3.6 quick swap or LN build was out. Definately bought this as a DIY project, so I started considering all the options. Within a week of beginning a donor motor search, I found a 3.4 from a 99 on eBay. On a pallet, 10 miles from home... with intermix issues. Called the guy and he mentioned the motor never overheated and that milkshake was only found in the cooling system. Went down to discuss - his 99 was in immaculate shape appearing to be mostly a cruiser. Made him an offer on the motor, we found a number and I now had a core. I know I am rolling the dice on this motor, but again this is a budget build. I was hoping this 3.4 had suffered another infamous 996 disability -- the cracked head. Got the motor on a stand, tore it down and sure enough -- crack around #1. Rest of the long block appeared promising -- no scoring on piston walls, no d chunks, no red flags. Inside case looked clean looking up -- no milkshake. Cleaned it up and set it aside. Turned attention to the trashed 2001 motor - I was hoping to use the heads off that to mate with the 99 case. As advertised, A/C Compressor is a pain when pulling engine- I took off the intake plenum and unbolted from behind. I got down to the heads a few days later and they looked solid -- appeared that #2 had kissed the head, likely bending both exhaust valves. Pan suggests something less than ideal took place...

After considerable research, all roads led to Georgia. Hoffman Automotive Machine, Inc. in Athens. I spoke with Len a couple times and it became very clear very quickly that he is the guy for 3.4 heads. Sent Len the 2001 heads, he checked em out, and we started game planning... A couple noteworthy snippets from our banter: "BTW, the intake guides on your replacement heads are as badly worn as any I've ever seen on 3.4 heads. They're actually worse than the exhaust, which are pretty worn too. Not much surprises me anymore, but I have to admit these raised my eyebrows." "As for the extreme guide wear, it's likely that these heads were on an engine that saw a lot of sustained high revs. The fact that the intakes are worn worse than the exhaust supports this. The intakes being heavier they are the first valves that the springs lose control over, which induces some pretty wild spring wave action that side loads the valves. Eventually they start to wallow the guide and the wear accelerates at that point." This engine was "used"... So complete service. All new intake and exhaust guides, new springs and shims, stem seals, grind all valves + replace the two bent ex, diamond mill deck a hair, replace expansion plug that popped out.... Got the heads back -- worth every penny (price was very reasonable BTW). I put a lot of stock in heads as it relates to impact on an engine's performance -- this is where the magic happens! If the rings are still strong, these things should perform. PS-- I learned that this motor does not really lend itself to the old re-ring it approach. Not only are replacement rings astronomically priced, the cylinders allegedly wear with the rings blah blah... we'll see what we're working with. A picture's worth a thousand words...

Kevin, welcome and its great to see a DIY'er tear into one of these. Have fun and take lots of pics if you don't mind.

Thanks for posting. Keep us up to speed on this project. Best of luck!

+996. this is going to be good....Along with Dale's Pale Ale....

Excellent project. Excited to keep an eye on this. I like the Enkei NT03+M wheels on the car, too.

This is going to be an awesome project and look forward to reading this. Thank you for taking to the time to document it

Good luck with the build. I love your wheels.

I was the unfortunate previous owner, and am pretty excited to see the car again! I sure miss it, pretty car. Kevin you forgot to mention how much fun it was pushing (yes pushing) the car up onto the trailer since there was no winch...

Nice to see another project car. Hope your rebuild stays in budget and you're able to have a Porsche rebirth soon.

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Did I "forget" to mention that? Yes, I spaced on that part of the equation when we went with the trailer... but all is well that ends well? I owe you a couple beers for the effort. I'll be honest, I have spent more time spinning wrenches that taking photos... I believe there is sufficient documentation between a few key threads here and the FSM for others to DIY repairs on the motor/car. I just wanted to chronicle my experience from 30K feet to encourage others and hopefully tell a success story when it's all said and done....

Its never enough pictures, take as much as you can and post them. The more there are of these engines the better it will be for the future. Its a bit of a pain to get used to taking them but well worth it. You'll be suprised how nice it will be when time comes for assembly. I've used mi pics many times when I forgot what went where.

awesome thread in the making!

++ Keep pics coming and thread alive!

Back after it... Got the heads back on, torqued according to FSM. Was debating new lifters, but went with a refurb from Phil at Mizpah Precision in Minnesota. Phil resurfaced the lifters and added new 8lb. springs, a little bump from the 5lb. stock. This was a Len recommendation -- I guess a little stiffer spring = a little more aggressive valve action = moar power? Cams back in. New cam to cam chain, tensioner pads, and tensioner pumped full of oil. Set everything up and static timed. Did the crank bump method -- cam marks lined up perfectly after a couple crank rotations and some minor adjustments. I did have to index the cogs on the exhaust cam once--- this required me to pull off the cam cover. I'd suggest to try to adjust the cog on the chain so there is plenty of room for adjustment in either direction before installing the cam cover.

Looks great! I'm just down the road if you ever need another set of hands... Or perhaps I'll just see you at High Plains after you get it all back together! :-)

Getting this project wrapped up. Engine timed, accesories back on, tranny mated (new Motul tranny fluid). I tried to replace all questionable wear parts: new AOS, oil cooler, radiator hoses, o-rings, head bolts, other things I can't remember off the top of my head. Didn't want to throw money at it so tried to reuse the best parts between the two engines -- had a starter and alternator that tested well. Water pump cleaned up well and considering the following, had likely been replaced recently. I found quite a few pieces of water pump blades in the cooling passages including a large one in the oil cooler. Probably root cause of the intermix issue. Had left the A/C compressor connected and hanging while the engine was out. Left the intake on the side off so I could access the back bolt on the A/C. As is mentioned often, this bolt is a PITA to get to without direct access.

Excellent project... good luck on the rebuild!

Great post! I am in the same situation, My heads are currently with Len fixing a crack on # 4 cylinder. What was the results of your rebuild ? did the 8 pound springs in the lifters prevent collapsing lifter issue? Like you my cylinder walls look good but i am on the fence due to $ to do a full rebuild.

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Nice - I can't say enough good things about Len and his work. Results were great. Put quite a few miles and some good track time on the car before letting it go (back in another 996 now - don't fret!). Lifters worked great - I can't say with confidence if there was a performance improvement, but definitely no negatives. I have used them again in my current build. For me, the full rebuild did not seem worthwhile - I would however recommend doing the IMS!