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996.1 with 997 S 3.8 engine swap

77szymon

Well-known member
Joined
14 Mar 2018
Messages
346
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=
 
:popcorn: Subscribed.
 
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?
 
Not only is Hartech the most sensible option, it's also on Szymon's doorstep. What's not to like. :thumbs:
 
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.
 
Hartech all the way.
 
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
:D

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 :lol:
 
77szymon said:
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
:D

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 :lol:

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.
 
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.
 
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. :wink:

Interesting though. Thanks for posting Szymon. :thumb:
 
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 :grin:
 
911tom said:
77szymon said:
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
:D

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 :lol:

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.
 
Marky911 said:
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. :wink:

Interesting though. Thanks for posting Szymon. :thumb:

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.
 
Marky911 said:
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...
 
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 :wink:
 

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