Posted: Mon Feb 04, 2019 9:16 am Post subject: 996.1 with 997 S 3.8 engine swap
Not sure if this was covered on our forum, I was surfing around finding some information if 3.8 from 997.2 could be installed to 996 also what work is required to do such a swap and BINGO find article exactly about it.
Page 47
spoiler alert.... it is possible, that pork end up with 400+ bhp, and just look on exhaust as this is what I was thinking about to do on mine.
digital.nexsitepublishing.com/i/1014347-august-2018/47?m4= _________________ 2003 Porsche 911 996 c4s
1988 BMW 635csi Highline - waiting for full restoration
1999 BMW e36 328i Cabrio - still not finished project.....
2011 Mercedes S350L
2004 Audi a2 1.4 tdi - I can't stress enough how good these cars are
2012 Mercedes C220 cdi Estate AMG Sport Plus Pack - wife
Alex Le Mans
Joined: 06 Mar 2014 Posts: 16529 Location: The Ribble Valley, Lancashire
Joined: 22 May 2012 Posts: 2027 Location: Buckinghamshire
Posted: Mon Feb 04, 2019 9:29 am Post subject:
Now that is a cool idea. Thing is though by the time you sourced a new lump etc could you not get a hartech / autofarm 3.9L conversion of your existing engine? _________________ 996 Turbo - Link to my 3.8L turbo build thread
2011 Cayenne
718 Cayman GTS
350Bhp astra van for work, semi-retired from daily duties
2009 Ariel Atom 3 Supercharged SOLD but never forgotten
Alex Le Mans
Joined: 06 Mar 2014 Posts: 16529 Location: The Ribble Valley, Lancashire
Not only is Hartech the most sensible option, it's also on Szymon's doorstep. What's not to like. _________________ 2000 Manual 996 C4 Arctic Silver Convertible
eabeukes Monza
Joined: 30 Jan 2018 Posts: 173 Location: Aylesbury
From the article is sounds like he would have been better to simply fit his 996 body to a 997 chassis instead - they replaced everything under the skin including the gearbox.
The 3.7/3.9 conversion sounds like a much better option, and teamed with one of Dr FrankenDammitStein's monster mod's you'll hit better performance per lb anyway using the lighter hardware already fitted.
FZP Estoril
Joined: 18 Jan 2015 Posts: 3551 Location: Cheshire
Posted: Mon Feb 04, 2019 10:34 am Post subject:
Hartech all the way. _________________ 997.2 Carrera 2S GT Silver/Cocoa.
it is not what is better but is it possible, it is nice to know that 996 owners have more options available and point to make not everyone living around Hartech
I think to visit Hartech and waste their time a bit on Saturday, have to pickup from Porsche Bolton oil filler tube...Hmmm...… or should we do another February catch up in Bolton _________________ 2003 Porsche 911 996 c4s
1988 BMW 635csi Highline - waiting for full restoration
1999 BMW e36 328i Cabrio - still not finished project.....
2011 Mercedes S350L
2004 Audi a2 1.4 tdi - I can't stress enough how good these cars are
2012 Mercedes C220 cdi Estate AMG Sport Plus Pack - wife
911tom Watkins Glen
Joined: 22 May 2012 Posts: 2027 Location: Buckinghamshire
Posted: Mon Feb 04, 2019 12:00 pm Post subject:
77szymon wrote:
are we missing the point???
it is not what is better but is it possible, it is nice to know that 996 owners have more options available and point to make not everyone living around Hartech
I think to visit Hartech and waste their time a bit on Saturday, have to pickup from Porsche Bolton oil filler tube...Hmmm...… or should we do another February catch up in Bolton
Well not exactly that. I mean anything is possible pending budget. You'd get a morris minor engine in there or a ferrari lump if you were set on the idea. You could even fit both those engines in there (one front, one back). Just more of a question of why would you. Hartech are not the only option. Autofarm have been doings these conversion for many years. No doubt so have a few others.
Depends.
If you were to go to the hassle of it, then you'd need to fit a GT3 lump. Even then for the cost just buy a GT3. Unless you were to base it on a cayman. GT3 lump in a cayman. Build a real GT4, now that would be cool. _________________ 996 Turbo - Link to my 3.8L turbo build thread
2011 Cayenne
718 Cayman GTS
350Bhp astra van for work, semi-retired from daily duties
2009 Ariel Atom 3 Supercharged SOLD but never forgotten
Dammit Watkins Glen
Joined: 23 Sep 2016 Posts: 2231
Posted: Mon Feb 04, 2019 12:21 pm Post subject:
The 3.8 is likely to score it's bores at some point, so will need a visit to either Autofarm or Hartech. At which point, if you'd taken it to Hartech, you could fit their pistons and push the capacity to 3.9 litres, and you've have the same engine that they've got in their Cayman demonstrator. _________________ My 996, AKA Project Ridiculous
Marky911 Indianapolis
Joined: 04 Jun 2009 Posts: 2457
Posted: Mon Feb 04, 2019 12:31 pm Post subject:
Can’t our 3.4s only go to 3.7 at the rebuilders Neil?
I like it. I’d rather rebuid a 3.8 than a 3.4 if getting 420hp.
Mind you that’s a big mod and the car is never going back to standard after it, so I’d probably rule it out anyway. I’d rule it out simply on efforts vs results actually, as I’d rather buy a faster car if I wanted more speed.
Interesting though. Thanks for posting Szymon.
Alex Le Mans
Joined: 06 Mar 2014 Posts: 16529 Location: The Ribble Valley, Lancashire
Yes Mark, 3.4 crankcase isn't big enough to take the larger crank the cayman takes.
I've just had an idea. Maserati 4200gt has a ferrari lump in and you can pick them up cheap as chips written off _________________ 2000 Manual 996 C4 Arctic Silver Convertible
FZP Estoril
Joined: 18 Jan 2015 Posts: 3551 Location: Cheshire
Posted: Mon Feb 04, 2019 1:16 pm Post subject:
911tom wrote:
77szymon wrote:
are we missing the point???
it is not what is better but is it possible, it is nice to know that 996 owners have more options available and point to make not everyone living around Hartech
I think to visit Hartech and waste their time a bit on Saturday, have to pickup from Porsche Bolton oil filler tube...Hmmm...… or should we do another February catch up in Bolton
Well not exactly that. I mean anything is possible pending budget. You'd get a morris minor engine in there or a ferrari lump if you were set on the idea. You could even fit both those engines in there (one front, one back). Just more of a question of why would you. Hartech are not the only option. Autofarm have been doings these conversion for many years. No doubt so have a few others.
Depends.
If you were to go to the hassle of it, then you'd need to fit a GT3 lump. Even then for the cost just buy a GT3. Unless you were to base it on a cayman. GT3 lump in a cayman. Build a real GT4, now that would be cool.
Szymon,
Dont underestimate the difficulty and effort to do what you're thinking of doing. Knowing what you have going on in the background, just getting the engine out, rebuilt and reinstalled would be a hell of a task. But i understand your point. _________________ 997.2 Carrera 2S GT Silver/Cocoa.
crash7 Hockenheim
Joined: 28 May 2011 Posts: 640
Posted: Mon Feb 04, 2019 2:27 pm Post subject:
Marky911 wrote:
Can’t our 3.4s only go to 3.7 at the rebuilders Neil?
I like it. I’d rather rebuid a 3.8 than a 3.4 if getting 420hp.
Mind you that’s a big mod and the car is never going back to standard after it, so I’d probably rule it out anyway. I’d rule it out simply on efforts vs results actually, as I’d rather buy a faster car if I wanted more speed.
Interesting though. Thanks for posting Szymon.
I spent a lot of timing looking at getting my 3.4 to a 3.9, its not possible without a LOT of additional/experimental work, which is fundamentally trial & error. - I think it would be cheaper to buy a 996 3.6 car and build to 3.9.
Contrary to popular belief it not just a case of dropping in a 3.6 crank, but once you get the crank in, with all the associated parts, you can expect a big lump of torque at the bottom end but a loss at the top due to air velocity and the fact that the heads & valves on a 3.4 cant flow enough air. - Fixing this is again experimental and again expensive.
Others are pushing the envelope on the experimental side and are far more knowledgeable than I.
What I can say is even with what is a fairly straight forward 3.7 build the slope is slippery, so with an experimental build the rabbit hole will be deep, very very deep.
I also looked at sourcing a 997S X51 and dropping it into a 996, has been done in the US, but there is little appetite and subsequently expertise in the UK for such changes, so even if you worked out the wiring and ecu issues, as Dammit points out, you could still need to rebuild the 3.8 lump to rectify the inherent issues with the bores.
Dammit Watkins Glen
Joined: 23 Sep 2016 Posts: 2231
Posted: Mon Feb 04, 2019 2:57 pm Post subject:
Marky911 wrote:
Can’t our 3.4s only go to 3.7 at the rebuilders Neil?
Trying to find the right word here, I'm going to go with "reasonably" yes, although it's more the situation that 3.4 engine cases should only go to 3.7.
We're making two engines - both based on the 3.4/for 996.1 cars, mines a 3.7 but the other is a 3.9 - that's using 3.4 heads but a 3.6 block.
The 3.4 in the Cayman is (broadly) the 3.6/3.8 M97 engine, so can go up without the issues of the 3.4 M96.
By the time I've finished with my engine it will have been cheaper and easier to put a Mezger in there*, but where's the fun in that?
*It would definitely have been cheaper to buy a GT3 than do what I'm doing, but they never made a GT3 convertible with no aero-kit, so... _________________ My 996, AKA Project Ridiculous
Slippydiff Nürburgring
Joined: 22 Nov 2007 Posts: 384
Posted: Tue Feb 05, 2019 10:40 am Post subject:
It's lovely concept. And no doubt the journey will be amazing, frustrating, expensive and educational (for us as well as you), the "holiday" may even be good at the end of the journey too.
Don't do it.
Yours, a fellow masochist
RankBajin Newbie
Joined: 21 Sep 2016 Posts: 45 Location: Edinburgh
Posted: Tue Feb 05, 2019 7:39 pm Post subject:
My 996.1 is going to Hartech for a rebuild and capacity increase this month.
I spoke with them about the possibility of going to a 3.9 but as mentioned previously there were just too many experimental type issues that I put on my sensible head and decided on the standard 3.7. I may spend some of the savings on further lightening the car (which I reckon is about 1270kg at the moment). _________________ Macan Turbo
996.1 3.7 RPM CSR
997 GTS (Now gone)
crash7 Hockenheim
Joined: 28 May 2011 Posts: 640
Posted: Tue Feb 05, 2019 8:15 pm Post subject:
RankBajin wrote:
My 996.1 is going to Hartech for a rebuild and capacity increase this month.
I spoke with them about the possibility of going to a 3.9 but as mentioned previously there were just too many experimental type issues that I put on my sensible head and decided on the standard 3.7. I may spend some of the savings on further lightening the car (which I reckon is about 1270kg at the moment).
Be interested to hear what have you done to get the weight down to 1270kg’s? - Have you had it on a scale, 1270 is very light.
RankBajin Newbie
Joined: 21 Sep 2016 Posts: 45 Location: Edinburgh
Posted: Tue Feb 05, 2019 8:29 pm Post subject:
I've not had it on the scale but using the standard weights ELA recorded on his thread it should be about that. It's a '98 C2 RPM CSR so at the lower end to start with then it's a case of the sum of a lot of small savings... the biggies are -27kgs on seats, 2-3kgs per wheel, 6kg on the flywheel, 6kg on the bootlid, 1-2kg per corner on the Ohlins, 2kgs on the rear wiper delete, 10kgs on the rear seats, 10kgs on the toolkit and spacesaver plus whatever the saving on new manifolds and 200cell cats are on OEM. _________________ Macan Turbo
996.1 3.7 RPM CSR
997 GTS (Now gone)
crash7 Hockenheim
Joined: 28 May 2011 Posts: 640
Posted: Tue Feb 05, 2019 9:11 pm Post subject:
Cheers
IMHO I think you will struggle to be below 1300Kgs.
Having done everything you mention on the same platform, plus more, giro disc, sound deadening & dash delete, cup wheel, Odessey battery, lightweight bonnet, airbag delete etc etc
I had the car corner weighted at CoG, I expected around 1280, I was nowhere near, the car came in at 1297 with no fuel.
Chris mentioned to me everyone thinks their car is lighter than it is if you can get anywhere near 1270 you will have done very well, PCGB C2 Racecars are circa 1240.
RankBajin Newbie
Joined: 21 Sep 2016 Posts: 45 Location: Edinburgh
Posted: Tue Feb 05, 2019 9:14 pm Post subject:
Really? That's disappointing.
I was thinking of the battery, dash, and bonnet next. _________________ Macan Turbo
996.1 3.7 RPM CSR
997 GTS (Now gone)
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