ElTorrente

No, I'm not making a thread about 996 engine problems - just curious if anyone has had their engine rebuilt and maybe converted/modified to 3.6 or 3.8stroker or anything like that?

I have 115k on my engine and it runs clean and strong, and no issues at all - but I was thinking that in another 15k or so I might look into having the engine rebuilt to give it a new lease on life- and perhaps modifying it up to 3.6.

"GT Performance" is close to my house and it says on their website that they do engine rebuilds, so I was thinking that would be a nice route for me. My car is currently there getting an oil change and to clear a windshield wiper warning light that came on out of the blue, so when I go pick it up I was going to ask them about costs, procedures, options etc.

Has anyone done anything like this? What are your thoughts about doing something like this?

Chads996

There are groups out there getting ready to offer this. A couple have contacted me about my sleeving ideas. I'll see what I can dig up for you.

C.

smshirk

I thought Porsche didn't sell engine parts for the new motors, read water cooled. Have they changed that policy? I've been told a factory rebuilt replacement with core was the only option. The cost is fairly reasonable compared to rebuilding an air cooled engine. At least thats what I've been led to believe

jcb-memphis

British mags had sleeve offers up to 4.0L..... Total 911 I think had the ads....fyi.

Ray S

It is my understanding that internals are now available.

Wellardmac

I had also heard the same thing.

Chads996

I can confirm this is correct for the Boxster motors, unsure on the 996's.

C.

Wellardmac

I've heard of it locally on a 996.

htny

the aftermarket isn't mature yet for this, so much of your success is going to rely on the patience and experience of the engine builder. Factory internals are seemingly available for the 3.4L motor, but if you're doing a simple bore job then you can source aftermarket pistons, rings, pins, etc., assuming you can retain the factory valvetrain.

the UK based company offering the turnkey 3.7 (for 3.4L motors) and 4.0 (for 3.6L motors) is Autofarm. With the exchange rate today it's cost prohibitive, and you're better of supercharging (although perhaps not in your case with that much mileage, opinions vary). These are bored over retaining factory spec crank.

I'm not sure how cars with modern crank and cam position sensors respond to swapping to longer stroke shafts, but as far as I know th factory 3.6 is a stroker retaining same or similar bore to 3.4L

LN Engineering in the US offers pistons and liners for overbore applications for the 996 as well. Contact Charles Navarro on this board (that's his username, and he is the man at LN Engineering). He's very friendly and accessible.

I would definitely run the economics of doing this against trading in and buying a 996TT especially given the additional headroom in tuning the TT.

smshirk

This is really really good news. Not that I have anything wrong, but with depreciation as it is, I've always thought I was pretty much stuck unless I just give it away. The ability to rebuild the engine will open up a lot of possibilities over time as the tuners think of new products to offer. These are way better cars in most every way than the older versions. Porsche just made too many and was still able to get premium prices. This gives us long term options.

htny

Let's remember that it's always been frighteningly expensive to rebuild the top end of a german motor, porsche, mercedes etc.

I don't think the cost of a rebuild will ever be cheaper than porsche's artificially low price for a replacement motor, but as the price for a factory replacement increases (already more expensive than it used to be) and more groups begin rebuilding motors for core exchange, theoretically it might become economically viable. I just don't think it's likely, there just isn't enough cash money demand yet, and there won't be so long as Porsche continues to subsidize the cost of a replacement.

It would be cheaper today to get a replacement motor from Porsche and supercharge it than to buy an autofarm 4.0L, import, and install.

Tippy

Ok guys, I have the tools to do the M96.

I have bailing wire, Vise-Grips, large screwdriver, and the ever important BFH! (big f@#$in' hammer)

htny is right, the labor hours and cost of parts probably would exceed the cost of a replacement engine from Porsche.

Hell, it took 99firehawk around 40 hours (times that by ~$100 shop hour rate) just to install FVD cams! That is just the top end!

Not to crush anyones hopes or dreams, but I am a little pessimistic about this happening anytime soon, but I could very well be wrong.

Macster

Have not come across anyone who's rebuilt one... There are companies -- in the UK at least -- that have delved into rebuilding these engines not only for increases in HP but reliabilty (for competition). One even goes so far as to afix an 'external' main bearing at flywheel end of crankshaft to help control crankshaft whip.

Others (AutoFarm comes to mind) offer 'big bore' kits (sleeves) and coupled with a stroker crankshaft can up displacement to 4.0l.

If you just want to rebuild your car's engine to rejuvenate it you first need to know you can buy the necessary wear items: gasket, seals, oil pumps, pistons, rings, main/rod bearings, thrust bearings (pads), valves, valve guides, lifters, possibly new camshafts, chains, chain guides and tensioners, case studs, main and rod bolts, and other fasteners that should never be reused.

'course, I've not come across any written info on guidelines on rebuilding the Porsche engines so I'm not sure what critical fasteners are reusable and which are not.

There is the question of how to recondition the cylinders if necessary because of wear or surface conditions. What kind of finish is necessary to ensure if used new pistons/rings will seat properly.

If you rebuild the heads you need a head shop that knows how to ensure the valve seats are done properly and the valve lifter and camshaft lobe contacts remain in spec. (Recutting/grinding valve seats and maybe touching up the valve head faces will cause the valves to seat lower in valve seat and thus the valve stem will be longer (effectively) and this could be enough to cause some binding at the lifter/camshaft lobe interace.)

Also, you need details on how to set up camshaft timing and other low level assembly tricks.

For the engines I worked on this info was available and had been debugged and idiot proofed long before I get involved so by simply following the instructions/guidelines all engine rebuilt were successful.

You need to locate this info for the Porsche engines and of course study it and digest it and try to get confirmation the info' accurate and be prepared to research for the info you need.

Sincerely,

Macster.

ElTorrente

Well I talked to GT Performance (I wish I could remember his name), and they are a GREAT Indy to take my car to - very impressed.

He took me back to look at their race cars and to show me a couple engine rebuilds in-process. I asked him about rebuilding my engine sometime in the future, and he said that while he would like to make money off of me, that there is no reason to think about it right now. He had driven my car and said that it felt great and he felt it wasn't down on power or that anything was wrong with it, so i shouldn't worry about it - basically cross the bridge when/if I get to it. I told him since I had high mileage that I was worried that someday I may end up with coolant in my oil or some catastrphic event, and he said not to worry about it, that my engine would likely last for a very long time as long as I keep it maintained as I have been.

He said that if I end up rebuilding it, that he could add performance parts to it (cams/pistons/etc..) and make it faster and better, but advised against going to 3.6 or higher, since that would incur fairly significant higher costs and complexity to the rebuild.

I felt a lot better after talking to him and seeing what they are doing in the shop, and the fact that they are running race cars and rebuilding engines on a regular basis, so I'll go with his advice. I guess it makes sense to not spend 10grand when I may not need to, and if something DOES go wrong, that I have an experienced mechanic that can completely rebuild it and I'd know that it would be high quality- and a bit faster than it was before.

It was also comforting somehow to have a mechanic with a German accent.