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YOUR RESEARCHMy Slakker / Hartech Journey
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Performed · outcome unconfirmed · Original poster
My understanding is the heads are checked for cracks, cleaned, re-finished to meet the new, closed deck cylinders.
Leading evidence: 'Check cracks' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'hydrolock event' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check but rather oil temps' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
My understanding is the heads are checked for cracks, cleaned, re-finished to meet the new, closed deck cylinders.
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Performed · outcome unconfirmed · Original poster
The AC leak turned out not to be a leak but rather simply not enough coolant filled into the reservoir.
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Performed · outcome unconfirmed · Original poster
All of this filled me (and my wallet) with sadness and anxiety.
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Performed · outcome unconfirmed · Original poster
- I think as long as you're getting your oil inspected every change and doing preventative stuff like looking after your AOS, etc, you'll be alright.
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Suggestion
After saving money for a while, and checking my options (not as extensive of some here), to either sold as is (I won�t be able to buy another Porsche) or buying a used engine (with all the factory weakness and unknown history of the used engine) and never considering an LS or a K swap, I decided to go with the rebuild options.
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Suggestion · Original poster
The good news is all of that is hopefully getting fixed and checked today and I'm hoping to get an update at the end of the day about the latest test drives!
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I decided to document this whole process mostly for two reasons: 1. Because I wish I would have come across a post like this when I was trying to figure out what my options are. And therefore, hopefully, this might help someone in the future, who will undoubtably go through the same experience. 2. For my own personal joy. The experience of getting small nuggets of updates from Brandon about how it�s going is part of this whole crazy obsession so many of us share about these amazing cars.
Background
My car�s a very early build (�98 build date) example with the original IMS, RMS and AOS. That�s a lot of acronyms. If you�re reading this, you already know what they mean, or you�re about to. So let�s move forward. I had spent the last year diligently taking care of the car, doing the oil changes myself, getting oil readings and attempting to meticulously document what I could. What was wonderful was that the car had seemingly very little mechanical issues. This was backed up by the original PPI that was performed when I purchased it.
After about a year of ownership, I got in one day to start the car to find the engine shaking upon start. The entire car had a noticeable vibration as a result. Subsequent starts resulted in the engine firing up and immediately dying. White smoke poured out of the exhausts and fault codes for Cylinder #4 fired away.
After an anxious tow to my shop, I was greeted by a phone call from my tech who informed me that they had in fact removed a cylinder�s worth of coolant from the very one that was firing codes. Cylinder #4. What was more troubling was the fact that, having cleaned and dried the cylinder, they attempted to refill the coolant reservoir, only to find the coolant dripping back into the cylinder without even pressurization. �Sorry man, I�m pretty sure you got a crack in the cylinder wall� informed my tech.
The sad news was that I had basically 3 options: 1) Sell the car as is. 2) Buy a used engine 3) Get mine rebuilt / get a new one built. All of this filled me (and my wallet) with sadness and anxiety. Selling the car was something I genuinely considered. But unfortunately I had developed a deep emotional connection to the thing.
I spent the next two weeks scouring the internet for used engines. I spoke to probably 80% of the people selling a used M96. There were Ebay listings, dismantlers, chop shops, private sellers with a �spare engine in my garage,� etc. All of it came down to a pretty clear price range: $8-$10k. The thought that I kept coming back to was that I was about to spend a bunch of money on an engine I knew nothing about. I worried about being in a similar boat, or worse in a year�s time.
Finally I considered option #3. I reached out to Jake Raby at Flat Six Innovations and Brandon at Slakker Racing. I have to say, that both men were extremely thoughtful and took their time to talk to me. Going back and forth over many days to educate me and provide some options. They were both sympathetic to my situation, as clearly, it wasn�t their first such discussion.
The options were pretty clear. 1) Purchase a new engine from Jake for around $30k built by him personally or 2) Have Brandon�s team rebuild my engine from the ground up with all new Hartech bits inside for around $24k. More internet research and reviews ensued. Videos, feedback, past customers, etc.
At the end of the day I decided to go with Slakker, because I wanted to retain the car�s original block and attempt to save at least a little bit of money on this already pricey endeavor.
March 3
Samm at Slakker arranged to get my car picked up from my shop, and at 9am I got a call that the driver was on his way to load the car up on the truck for the trip out to Oklahoma.
3 days later, she was safe and sound at Slakker HQ.
March 12th
The folks at Slakker had disassembled the engine, cleaned it, and given it a temporary home as they prepared to get new bits from Hartech.
March 26th
Brandon and I discussed a few options for exhaust, and after much deliberation, I decided to order a set of Fister replacement mufflers.
April 3rd
The replacement cylinders, pistons, etc had arrived from Hartech and Andrew sent me a few lovely shots of the shiny new cylinders having been fitted into the block. Joy of joys, it was coming together.
Next step, hoping to get everything assembled in the next few weeks!
Interesting to see the difference in the Nickasil liners in the block compared to LN/FSI.
Can you post a picture from the other side(outside the case) as well?
Here you go:
Differences I see are in the support between cylinders and the fact that Hartech uses the same liners for 1-2-3 as they do for 4-5-6.
I assume this is done by Hartech as a cost cutting measure.
The case half above is obviously bank 1. (1-2-3)
Looking forward to seeing more assembly pictures.
Thank you for sharing your experience. We all benefit when owners, like yourself, share their own project with the rest of us.
As a long term 996 owner (over 20 years), I have researched all of the different options for what to do, if I ever experience an engine failure. I have looked at the top engine rebuilders, like you did. I have researched the different engine transplant options..... from doing a wrecked 996 GT3 or turbo drivetrain etc swap, to an LS transplant. We have two members here that documented GT3 swaps. The first was before the GT3 ever came to the US. He bought a wrecked mk1 996 GT3 from Europe and had a shop in the Portland or Seattle area do the swap. We have a member in Europe who documented a turbo swap, and several members who have documented LS swaps.
I'm sorry that this happened to you. I hope you end up with a car that you enjoy for many years to come. I will look forward to following your journey.
Thanks
@Mfletch
- interestingly enough one of the options my shop initially came up with was an LS Swap, but I quickly realized that it wasn�t the right solution for me.
My understanding is the heads are checked for cracks, cleaned, re-finished to meet the new, closed deck cylinders.
I probably should have clarified that the displacement is going from 3.4 to 3.7
Great thread, You are going to love having an engine that you Can. Just. Drive. And not worry about all the M9x gotchas.
It appears to me that each cylinder insert is identical to the others.
It's good to see some people enjoy spending $$ on upgraded engine hardware, So many people love spending $$$ on wheels and dress up items, but regret any $$ spent on engine hardware..
Seems like they can justify it on SHOW but not on GO...
Subscribed and thank you for sharing.
Had some questions about the closed deck design. From my understanding the trade off from having a more robust block is potential overheating.
What measures are best at mitigation this?
Low-temp thermostat?
Third radiator (not sure if this is an option exclusive to C4S)?
Any other I can�t think of?
That may be true for others, but Hartech addressed this in their original design by increasing the cooling surface area on the cylinders and machining larger coolant channels into the block to improve flow.
We do install a low-temp thermostat on every build�though its benefit is minimal beyond simply being a new thermostat. Adding a third radiator, however, is a great upgrade for any car that will be driven aggressively for extended periods.
Thank you for the clarification, that�s great to hear. I�m hoping to stretch my engines life as much as possible but this has become my favourite option if ever I need a rebuild.
Yep, its all pointing to a crack in the cylinder wall on #4.
Interesting side note, while I was doing my research and diving deep into others who've had an engine failure, I kept coming across Cylinder #4 as the most common culprit. I wonder if there's something about the layout of the engine that makes this particular cylinder fail most. This sometimes resulted not in a crack to the wall, but simply an issue with the piston, or a combonation of both (bore scoring), however, it seems to me that this is by far the most common cylinder to be reported as problematic.
Thanks for creating this thread! Recently found out about Slakker in OKC and their Hartech program. I've got an 02 C4S that I'd love to eventually do a 4.1 conversion. Looking forward to seeing your build progress!
When I took the M9x 101 rebuild class from The Knowledge Gruppe, Jake went over the water flow and oil flow of the M9x engine.
If I recall correctly (which definitely may not be the case since that was 7 years ago) the water flows to Bank 2 first from the water pump.
It would make sense that broken impeller pieces would end up in the Bank 2 cylinder head and block before Bank 1.
I wish I had the actual route water and oil take memorized.
"You might be way ahead selling the C4S and buying this"
Thats an understatement for sure.
Nice TT...
I just missed getting a nice yellow one that sold for 60K on Bat.
Did you have a previous "extreme smoking event" ?
Anytime I see a crack in #4 cylinder I suspect a Hydrolock event...
Yes the layout of the flat six intake when you have an AOS overload from a high-g turn or a failing AOS, the oil pools in the intake and will spill out into #4 cylinder the worst/most......It always effects #4 the worst/most but can also be enough to get others at the same time.... like #4 and #6 ...then #3 and #1 ..rarely ever #2 or #5..
The combustion chamber is about 60cc on M97/7 engines so 60cc of oil at one time can hydrolock or nearly hydrolock the cylinder and cause extreme force on the cylinder and cause it to fracture, or bend a rod.......
There has been many a rod found bent slightly during a rebuild that no one can explain, but I can explain it........They don't just bend for no reason and don't come pre-bent .............
As a young M E student, remember studying volumetric efficiency and fluid mechanics . A discussion on VE drifted to hydraulic cylinder lock. After some debate/experiments in the lab we determined only a small amount of liquid, maybe 10% of of chamber volume is needed to cause major damage in light weight high output designs. The full chamber volume was not needed to cause extreme pressure spikes. Catastrophic damage can occur without full hydrostatic lock up or hydraulic lock.
iirr, cylinder pressure reached unbearable high spikes from just a little liquid, damage to cylinder walls/ head/rod/ piston were common. We also found detonation from high cyl pressure spikes was a possible factor adding to the damage
Its all about cylinder pressure & cylinder structure....
The longer I'm on this forum the more I see the importance of a good AOS for our cars. A faulty or over worked AOS might be the cause for many of our engine sudden failures.
jmo
I'd never had a previous smoking event, nor any other issues with the engine, BUT! I washed the car 3 days prior to this happening. Started her up and put her in the driveway for the night. Came back 3 days later, turned it on and the problems began. Therefore I assumed a possible hydrolock as well.
Latest Update
After going back and forth on exhaust options, it sounds like everything is in good working order, so all I'm really looking for is a bit more sound to bring the new 3.7 to life. Therefore, spoke to Darin over at Fister today and ordered a set of his mufflers. Brandon and his crew are shipping out mine to Darin. Sounds like it should be a 4-5 day turnaround once he gets them.
In other news, I decided to get the clutch and flywheel replaced while the motor's out since both were original and the car's nearing 80k miles.
Getting excited as things get closer to completion!
Thank you for sharing your journey with us! My 2004 C2 has a little bore scoring detected in a PPI, and I'm doing everything I can to keep it from worsening. If/when the day comes that I will have to face a similar situation to yours, I'll be grateful to be able to draw from your experience. My last car was a Corvette with the LS engine, so I may be more inclined to give a serious look at that swap. Still, I like the idea of keeping the Porsche 100% Porsche!
Great to hear
@Modern356
- I think as long as you're getting your oil inspected every change and doing preventative stuff like looking after your AOS, etc, you'll be alright. I considered the LS swap for about 5 seconds but just couldn't do it. To each his own. Afterwards I spoke to a friend who's a race mechanic and works on 996s. One piece of feedback he gave me is that over the long term, there are issues that they see with those swapped out installs.
Latest update from Brandon and the crew at Slakker. Motor is back together after its rebuild and mufflers have been shipped off to Fister.
Next steps are dyno testing, new clutch/flywheeel and updated mufflers back from Fister hopefully next week.
I�m glad I ran across this thread. My 2002 C4S had catastrophic engine failure due to IMS failure 2 weeks ago. I�ve been in contact with Brandon at Slakker for a 3.6 to 4.1L rebuild. The car should be headed there in 2 weeks or so. FD Motorsport will be sending my Fister mufflers there to go in with the new engine. Excited watching this build!
Hey all,
Latest update is that Darin over at Fister has completed work on the mufflers and they’re currently on their way to Slakker. Latest word from Brandon is that the motor is scheduled to get dyno’d this coming week and broken in. I’m assuming new clutch and flywheel will be added shortly after along with Fister mufflers.
Hoping to get some good numbers from the dyno and can’t wait to see my car back together soon!
Thanks for sharing this with all of us. I know that price, time, expectations are always three things that everyone wants to ask. You're answering them and I think its great!
Look forward to seeing how it all turns out.
Wow. Im on the same journey.
https://rennlist.com/forums/996-foru...s-toast-2.html
Have a call w flat6innovations Monday and because of your thread and feedback from other members im looking into slacker now too.
Hey hey! Welcome to the journey man haha. Send me a PM if you want to chat some more. I also went back and forth with Jake from Flat 6. He�s really a legend.
This is a big update folks. She�s alive!! First Dyno video from Brandon and the crew!
Pushing out
331 horsepower
294 torque
We�re really close folks!!
60 more HP/TQ from a 3.6 rebuild get you to GT3 numbers.
100 more HP/TQ from a 3.6 rebuild gets you all the power you need on the track to be competitive with the new models. For sure, LSD, suspension, brakes, tire enhancements and driving lessons will be needed to manage all that power.
100 HP/TQ seem to be pretty doable with today's rebuilds.
Very respectable #'s... Is that with a upgraded tune..?
The extra 36 tq is where it will really shine seat of the pants feel/response/power...
331 CHP is 35 chp above a stock 296 chp 3.4.
294 tq is
36 ft/lb more
than oem 258 tq
imho, the power is nice but secondary to the re-engineering of the engines many problem areas the m96 has, that Hartech addresses nicely...
Yeah it is. Add in enhanced headwork, cats and headers, plenum, TB for more flow and he is pushing additional power gains. For sure, power can be very expensive.
Congrats on the build.
Update
Another milestone reached today. New clutch, flywheel + Fister mufflers all mated together to the motor. Seeing this get hoisted back into place makes my week. Thank you Brandon
Quick Update
Hey all, was traveling last week and didn�t get a chance to drop an update here.
The car is back together and the Slakker crew have been doing test drives. Sounds like things are going well except for a slow AC leak and some noise from the transmission. Once they can sort that out, she should be heading home.
I gotta say, I�m glad I decided to ship the whole car out rather than the engine alone, as this would be getting done by my local shop and I feel a lot better knowing Brandon and his crew are taking care of it.
Other small note of appreciation is actually the transparency they�ve provided about chasing down these gremlins. Hoping to find out this week if she can come home 🤞🏻🤞🏻
Minor Update
Hey all, heard back from Slakker this morning. The AC leak turned out not to be a leak but rather simply not enough coolant filled into the reservoir.
As for the noise from the transmission, sounds like its the new lightweight flywheel that's slightly thinner than the OEM spec. Slakker's ordered a replacement, which should arrive tomorrow for a swap. The crew has also noticed a few
small oil leaks from the cylinder head freeze caps so they'll be replacing those as well.
Gotta say, I continue to appreciate the attention to detail and thoroughness of the team's work.
Amazing topic!
My engine just went Kaboom in Sonoma Raceway, so I am headed to a similar journey.
My shop has not finished the diagnosis yet, but at least it is nice to see real life reports on some options I will have ahead of me.
You Tube
For those interested in how Hartech came to be and the origin story of the parts and their general philosophy, this interview is fantastic. You get a really good understanding of how they�ve made the decisions they have.
While 3.4 to 3.9 has always been possible via a long stroke crank, crank carrier, correct rods and pistons. I've never seen one on the net and the Hartech reason has been the low head flow of the 5 chain M96. USA has Hoffman heads, but has any one done a 5 chain 3.4 to 3.9 Hartech Nickies or 3.4 to 4.0 LN Nickies? My focus is just the 20 mph to 80 mph legal limits response, torque and 3.4 to 3.8 (LN Nckies) does the job.
@FlattestSix
I might have seen your car last April. I picked my car at Slakker on the 21st to drive her home to Los Angeles. I have a 2003 C4S that suffered an unusual drop valve seat. When I asked my mechanic what to do, he said considering the car already have a 130K, it is good idea to do a complete rebuild because just doing the top end now, I would need to do the bottom end very soon afterwards due to mileage. That happened early 2024. After saving money for a while, and checking my options (not as extensive of some here), to either sold as is (I won�t be able to buy another Porsche) or buying a used engine (with all the factory weakness and unknown history of the used engine) and never considering an LS or a K swap, I decided to go with the rebuild options. I can that do locally (various cost and qualities), FSI or Slakker. I decided to go with Slakker for their Hartech conversion as I have heard nothing but good things about the Hartech conversion in all the British Porsche magazines. Besides that overall cost will be lower than going via the FSI route. I got the 4.1L Hartech conversion, polished ports, polished intake manifolds
I sent my car in November 2024 and picked it up on the 3rd week of April 2025. I told Brandon to take his time, just rebuild it correctly. He has been very transparent, and helpful. It has been a very positive experience. Looking forward for many miles to come. As a bonus he did a driving video of my car
You Tube
Yep, I dropped a few updates above.
I asked Slakker to also replace the clutch and flywheel. The first flywheel they installed ended up being a bit too thin for the application and turned out to not be the right one. They also found a few small oil leaks during initial test drives.
The good news is all of that is hopefully getting fixed and checked today and I'm hoping to get an update at the end of the day about the latest test drives!
Does a 2000 996.1 3.4L - 4.2L conversion count? Here's a pic of the 5-chain head with 997 exhaust valves and custom 40.2mm intake valves. It took some work but we were able to get it within a few CFM of our ported 997.1S flow numbers. The dyno video should be released within the next week...
With just a little more bore size increase you get to 3.9. Probably not a lot more cash to get their. Might be good to have it done even if the head porting can't be done yet and full potential can't be seen quite yet...
Always can port heads (+30%flow Slakker port job) later, like next time(year or 2-3..?) the engine/tranny is out for a clutch/repair/whatever. The lower end (rings) will probably just be seated fully and ready to make full power.
Its not outrageous to consider taking off the heads and sending them out for a port job/refresh to finally take full advantage of the 3.9/4.0/4.1 upgrade. Its not like you'll have to disturb a mint 3.9 nik'd bottom end at all.
Most engine builders know real crisp throttle response and full power potential of an engine is in the heads ports and valve sealing...
Seems Hartech/Slakker, and HammerHeads Len Hoffman do nice head/port work on the m96. IIRR Slakker just posted a 30% increase in flow on their port jobs...
jmo
It's great to see the 5 chain 3.4 get more love than the Hartech 3.7 or LN 3.8. Despite my current satisfaction with my 3.8. I will be keeping an eye out for the 4.2 5 chain dyno. Can you just clarify which I think, whether a displacment of 3.9 or 4.2 requires a crankshaft and carrier? Thanks.
Hopefully Slackker will chime in and confirm.
IIRR, 3.4 bore increased to 103mm will increase displacement to 3.9. To get anther 200cc the 'oem stroked' 3.6 crank and rods must be fitted along with case/carrier machining to clear the crank/rods. Thats how 4.1 is achieved on the 3.4 is my understanding. A great balance job is also required.
3.4-> 3.7 100mm bore
3.4-> 3.9 102.7mm bore (gt3 size)
3.4-> 4.1 102.7mm, 3.6L crank and crank carrier
3.4-> 4.2 102.7mm, 3.6L crank with offset grind 82.8 to 85mm stroke
A 997 Turbo was my first Porsche—but the 996.1 was the first one I fell in love with. It still has that quirky, nimble feel that made the 993 so popular, but with a modernized cooling system and a better ECU starting in 2000.
Because the 996.1 made up such a small percentage of our builds (we didn’t have a single .1 rebuild in 2024), I had to prioritize development for the 996.2 and 9X7.1 platforms first. But as soon as I had the opportunity, I wanted to backdate everything we’d learned to the 996.1—out of loyalty as much as anything.
The 3.4L is still a great engine, especially paired with the lighter chassis (I still run a 3.4L in my ‘00 SP996 race car). And the 3.7L upgrade adds just enough extra oomph to make a real difference. Now, with our latest larger-displacement builds and ongoing cylinder head development, we’re putting the 996.1 on the same playing field as a 997.1 GT3.
And being able to do that for what many considered the “black sheep” of the 911 lineup? That’s honestly a dream come true.
Every one of these posts makes me that much more eager to get my car back and finally take her for a drive!
I asked Slakker to go with a dual mass flywheel as the lighter Aasco was creating some cabin noise. Sounds like the work is gonna get done this coming week and hopefully she�ll be on her way home!
Just getting back to the shop after being out for nearly two weeks, so I haven�t had a chance to hear the noise in question yet. Out of two dozen LWFW installs, this is the first we have switched back. That said, the primary reason Porsche uses a dual-mass flywheel (DMFW) is to smooth out torsional inputs to the transmission. So it's possible the DMFW is masking some "looseness" in the transmission that is only present at idle when the engine is not under load. We saw this on our engine dyno before we refreshed the gears on it.
On another note, we�ve added a new master technician to the team�bringing us to 13 members total. He starts Tuesday and will help us work through the current bottleneck with in-house cars. Our engine only to car ratio has shifted significantly since we started, and the number of �while we�re at it� upgrades has grown as well. So hopefully, this addition helps bring us back into balance�at least for a few more years.
Quick Update
Spoke to Brandon today and fresh off his honeymoon trip, he did a few test drives and sounds like the motor's running strong. According to Brandon, the flywheel noise is very faint and at this point I have come to trust the man at his word. He's not let me down thus far.
Sounds like all that's left is for the freeze caps to get re-tested for oil leaks there and hopefully she'll be heading home this week!
Stay tuned!
Great news to end the week: heard from Will at Slakker this evening that the car is officially ready to go home!
Hopefully there�s a ride home waiting for her early next week!!
Also would be interested in specs for the 3.4 expansion. Just purchased a higher mileage 99 and assume I will have to/ want to do something there in the near future. Not looking to change the character too much, but 25 year old high mileage engines do start to feel their age.
Porsche horsepower always had a premium and always cost money. Always did and always will. Sure, labor costs have gone up and you can't logically expect to have the same costs in 2025 that you might have had in 2020, 2015, 2010 etc. Talk to the air-cooled crowd and ask how much it costs to just reseal a leaking engine. It probably has low miles too but that's the reason why it is leaking. No performance mods of any kind too. It starts to make the M96 rebuilds a really good deal. Air-cooled HP is even more expensive.
Don't rebuild until you have to and when you do have a plan in place on how you plan to use the car. Nothing sadder than seeing many 4.0L rebuilds that end up sitting and accumulating just a few miles every year. I completed by rebuild a year and 20 days ago (as of today) and have accumulated 11k miles in that time. Money well spent in my case and getting more and more value out of it as the miles tick away.
Quick Update
The car's getting picked up at Slakker tomorrow and finally heading home. She should be here Sunday! I'll drop photos of her arrival as soon as she gets here. Obviously that will be followed by first impressions of finally getting to drive the final product!
She�s home!!
After what�s seemed like an eternity (but really was only 4 months) she�s back home!
I will do a much more in-depth write up, but wanted to drop just a quick first impression after getting her unloaded.
I hopped in and went for a quick 25 min drive. Damn! I immediately remembered why I love this car! All of the pieces have come together better than I could have imagined. Between the motor, new clutch, flywheel and Fister Exhausts, the whole is much greater than the sum of the parts.
The sound of that 3.7 mated to that fister exhaust is absolutely intoxicating. Exactly what I was hoping for. The shifts with the new clutch + flywheel feel so clean. Touch the throttle and you�ve jumped 10mph.
More photos and updates to come. But for now. A massive thank you to Brandon and the entire Slakker crew!
Congrats on getting the car back! I think you'll discover some more new things as you continue to drive.... Outside of power, looks for how effortless and efficient the new motor will feel and the best part is that this will evolve as you drive. I'm at over 11k miles on mine and are still noticing improvements. Really quite amazing. There's always the old tale of cheap, fast, well done - pick two. Keeping in mind all the work that is put into these motors it's quite amazing that they are able to turn in around so quickly!
Thanks guys, a video is a good idea, I�ll try to record something today for you guys.
Absolutely
@plpete84
- I went for a drive this morning to drop my daughter off at school. On the way home, it occurred to me that I was accelerating with the gas pedal pushed only half way down. When I stepped it the rest of the way, the motor came alive and I was suddenly going 75 without realizing. Joy of joys.
First small thing I�m noticing is the exhaust note is wonderful at cruising speeds. It�s when you put your foot down that it rumbles to life.
That�s awesome�so glad you love it!
It was a pleasure to work with you on your build and a huge thank you from the team for being a great partner throughout the process.
I love the picture. It is ubiquitous. Everyone that has sent their car away has a picture like this of it coming back. Brings back all the memories of mine making a similar trip.
The car sounds great. I can see you smiling from here!
That's awesome! When are you guys coming down? I've actually been thinking about taking some of the fabrication classes over there. Would love to meet up.
4 years in August. I'm at 25k miles. it's a 3.8L S1 from FSI. It has so much more power in the mid-range and it revs so fast. Just try to not smile. I have to believe yours does the same thing.
It's my daily driver. Zero concerns about the engine. Gas and go. Change oil every 6 months. People at work think I'm nuts driving a 23 year old car to work. The car is nothing special, except the engine. '02 C2 6mt cab. If someone runs into me and kills the car, I'll just move the engine to the next one. Suspension is dialed in with Ohlin's at X74 height. 235/40F 295/30R on GT3 wheels. PS4S tires. Fast and glued to the road. Crazy fun.
Im currently floating around the Indian Ocean until maybe Oct so I�m thinking in the fall. Been wanting to go to Revs for a while now and seeing your car would be an added benefit of visiting Naples.
Here is a 3.4 to 3.8 built exactly 10 years tomorrow...It has 50K hard miles on it with lots of Track Time....Has Carrillo Rods, JE Pistons.. Nicky Cylinders...HamHead port Job ect.....I didn't build it, I just supervised it to make sure he didn't make any mistakes...
.I made him do all the work..lol..of course it also has the.UAOS/UIDS as they were developed using a lot of Data from this car....
OOps, looks like Facebook Video's will not post to Rennlist.....hmm
https://www.facebook.com/randy.remington.5/videos/823091291115179/
Hey all, its been a few weeks and I wanted to drop a quick update and impressions now that I've gotten around 250 miles on the motor.
I know I've said it before, but the sound of this engine coming to life first thing in the morning is one of my favorite things. Pulling out onto my street and opening the windows as the engine is warming up, and slowly pulling away from my house has become just such a lovely routine.
The weather here in SW Florida is hitting in the low 90s so the new AC compressor has been getting its workout and I've been diligently watching the engine temp and keep an eye on the oil level. Both are sitting steady and I'll continue to monitor them. First oil change will be coming up around 750-1000 miles. I'll be picking up some DI50.
The final thing, and probably what everyone wants to know is,
how does it feel?
The first thing you just notice consistently is the power and response. Even at low RPMs, the engine just pulls at what seems like completely effortlessly. This causes you to shift at higher RPMs to enjoy the lovely run up the Tach 😁. I won't mention top speeds on local roads, but I will just say, its very easy to hit the speed limit, as the car just wants to go.
If there's anything I'm left wanting, its twistier roads around here to really get the best out of this engine. But for now, the transformation continues to put smiles on my face and just make me chuckle at random moments
Yep sure is !!! Tina has about 175K miles on her now ... 50K on her rebuilt 3.8 liter....( She only had a hair-line crack in Bank 1 head that prompted the rebuild at 125K,..not WP related)
Thanks for reminding me to do an update. Perfect timing!
I just did the first oil change on her this morning at right around 850 miles on the rebuild. The car has been absolutely fantastic and the motor has been singing. I drive it almost every day to drop off kids, run to the store, etc. And with the summer temps in FL I have been watching the temp gauge. I�m happy to say, the AC is blowing cold and the engine stays at a solid temp once it heats up.
One random note is the new lightened flywheel. I was worried about the extra noise coming through the cabin and to a slight degree this is noticeable. The one thing about it though is that it kind of mixes together with the sound of the exhaust and the whole thing just rumbles together. At this point, I�ve really gotten used to it and it�s only something you notice with your windows closed.
I dropped in 9 quarts of Driven DI50 this morning and sent a sample to Speed Diagnostix as per Slakker�s guidance.
What I will say is that the more I think about this improvement, the more it makes me recognize how much a 996 is a hidden gem. All things considered, once a few of these improvements are made, suddenly, you�re not worried about the IMS or the AOS going bad. You�re not worried about whether there�s bore scoring. You�re just driving. And that�s why I bought this car. Yes, this was much more money than I planned on spending. And that�s a really
important consideration for anyone who undertakes this endeavor. But I will say that the result is fantastic. It�s the equivalent of a 996 restomod for much less than you would ever spend on any other 911.
Low temperature thermostat.
Personally I wouldn't recommend the third radiator unless you're in the deep south of the country or if you plan weekend races.
I can tell you from personal experience that the larger displacement motors make more heat and could benefit from the third radiator for enthusiastic road use.
I�m in North Carolina, not exactly the Deep South, but my 4.0 liter C4S doesn�t have the third radiator.
Never had an issue with the engine temperature creeping up; new water pump and low temp thermostat.
You're lucky, your C4S has the massive Turbo side radiators, although is does not get the 3rd center radiator like the TT gets.
Regular C2 Tiptroniuc. all come with the center radiator, come to think of it,,,, not sure if the C4S tip also does..?
My C4S was originally a tiptronic before I converted it to a 6 speed but never had the 3rd radiator. I thought all tiptronic C4S�s came with the third radiator as well. Apparently not!
You're right. I forgot what the thread was on. I'm going with a low temp on my stock 3.4l currently but plan a larger rebuild (4.0l) next year. I'll rely on the builder for recommendations. I have a Tip, so I'm not sure how it may be effected with another radiator in place. I'll just have to see.
As noted in my sig, I'm still making my way
Third radiators are not so much as needed for maintaining engine temps in check but rather oil temps. I'm in DC and sitting in some traffic in the city will heat soak your motor pretty well and in turn cause your oil temps to go up by about 10F or more. It's nice to have the extra cooling capacity for those situations.
I�ve got a third radiator and recently had my passenger side radiator fan go out. Car started overheat sitting still in 90F Florida heat. While I was moving the center radiator picked up the slack and kept me in temperature.
The center radiator doesn�t have a fan so is really only working while moving.
If you upgrade to a center radiator, get a CSF radiator. They are all Al instead=ad of plastic tanks and have more cooling capacity. I have upgraded all my cars with three CSF radiators.
Good luck with your project!
Mark
The csf radiators do nothing better than stock for engine temp as tested by Slakker:
https://rennlist.com/forums/997-foru...t#post19367396
Go for them if you want to get rid of the crimped plastic tanks on the stock ones, though reports on here regarding quality of the welds are not always positive.
While I generally adhere/agree with Slakker/Brandon as a source of reliable knowledge, I�ll go against him here. There are two models of CSF side rad, and there is a perhaps a 50% premium for the performance model. The base unit can be found on RockAuto near stock price, is single pass, and basically a shoe in for the OE in size and config but with welded end tanks. I would be surprised if there was any performance difference (other than durability).
The premium CSF rads are two pass with alternate fins and channel geometry to push the efficiency higher and lower return water temps. These are real differences in configuration that will physically improve performance.
Note that they won�t return water any cooler than the thermostat demands, so they only provide any benefit once the cooling system is overloaded and the thermostat is full open at return temp.
We hope to have an opportunity to perform our own comparative testing between CSF and OEM in the near future.
The linked checklist items above are still our current recommendations for cooling. One note however is that a GT3 water pump has the same size impeller with a smaller pulley. We recommend these for use with underdrive crank pulleys.
Good info. Did not know. Do you happen to have the CSF part numbers for the performance radiators for the 996?
There was a time that the factory 996 radiators were cheaper than the CSF and the argument to replace with OEM was a good one. Factory radiators are now just as expensive if not more.
https://www.fcpeuro.com/products/por...iator-csf-7044
And center
https://www.fcpeuro.com/products/por...iator-csf-7057
Got a pin hole in the center at the track and used the warrentee.
I certainly appreciate the insight and time taken with the checklist! The note on the GT3 water pump is very interesting too, I�m surprised there is commonality between the Mezger and M96, but I suppose a waterpump isn�t that unique� just the packaging lining up is interesting.
I only raised the point as I recently got a set of these rads and waded through the details to compare the �cheap� and �not cheap� CSF options. The graphics below are pretty clear� the performance core is ~30% thicker (42mm vs 32mm� ahem, 1-5/8 vs 1-1/4) in addition to better finning, another pass, and special tube geometry. RockAuto has Mahle in their lineup and you can compare core geometry, I�m confident OE are 34mm or 1-1/4 nominal.
The blurb here notes the 7044 rads are 20% more efficient (they probably flow more air, to be honest, in addition to 2-pass making them counter flow for lower return temps):
https://www.amtuning.ca/products/csf...id7L8As8F1ImuX
Hi performance rad 7044
OE replacement 3564
In the middle of this thread there was reference of development of a 3.4 to 4.2L 5-chain. I follow slacker on YT/ IG and the latest build posted is a 3.9 making impressive power. Is this the same build that was considered for a 4.2 increase? I�m curious because this post promised Dyno results and then went silent.
My C4S Tip does not have 3rd radiator. It has the larger turbo rads. These rads are mounted differently than the smaller ones and a total PITA to get it apart enough to clean the rads. Or, at least that is what I thought about it from my experience.
Engine will be 4.1 L, so bigger rads are probably better than smaller rads, luck of turbo parts on C4S.
I would like to get the back bumper that has the horizonal rectangle holes in it for cooling engine air area (I guess?). What bumper is that one? Comments.?
YMMV
Your C4S already has the Turbo rear bumper with a filler plate covering the intercooler exhaust opening. Turbo has intercoolers where the Carerra has mufflers. As noted those exhaust vents in the Turbo are not connected to the engine bay. Intercooler air goes into the side scoops and out those exhaust vents.
Thanks for looking. Yes, that was it. I just did not know what car it was on or where to find it, would it fit, does it help lower engine compartment temp, and so on.
Just thinking about stuff. At the time I "found" that bumper I didn't have much knowledge about various flavors of 996/997s . I was thinking "heat is the enemy" logic.
YMMV
That also won't lower engine compartment temps.
Look at what sits behind the bumper cover and notice that is all separate from the engine compartment.
Lowering temps in it is done by the small extraction fan that sits in the rear deck lid.
This is a source reference. Confirm exact model applicability in the original material.
