flyinb44

Im currently running a stock 3.3 turbo 965 and its about time to get things rebuilt. Its fair to say that reliability is out the window at this point and unfortunately the car spends more down time than on the road.



I was curious to see what routes other people have taken with this service. Bottom end components, over sized cylinders/pistons, wastegate/bov etc. Im already running a B&B exhaust and headers.



I was also toying around with the idea of doing an EFI conversion. I found the EFI injector blocks that Turbo Kraft offers and will allow me to use the original cylinder heads, intake manifold and intercooler. Has anyone used this component with any success? Would you recommend using motronic off of a 3.2 or another ecu setup?





If i decide to stay with the cis, obviously the fpr and the wur need to be rebuilt. Does anyone have any suggestions for anything else that needs to be done with this system? Any particular reason to keep it over the EFI?



These are the major things I've been pondering over. I'll thank you in advance for your time and advice.



Brian

pcar964

Just curious, what kind of reliability issues have you had with the car? I'm considering going the EFI route with Turbo Kraft's injector block also, as it seems a more natural (and much cheaper) way to go EFI than the traditional Carrera manifold conversion. Will this be a DIY or do you have a shop doing the work?

Big Jock

Can I ask the mileage and symptoms and why you think your motor needs rebuilt?These engines are bulletproof apart from oil leaks but they can be fixed.

flyinb44

The engine has approx 114k on it. It has been re-ringed once. The crankcase has never been split while I have owned the car and there has been a tick that has developed. I was told at one point this could be the shaft bearings. The headers have a broken stud in the front that needs to be repaired which is going to require dropping the exhaust. There are leaks on the front and rear side of the motor which need to be repaired and I was told the engine would need to come out of the vehicle. Taking preventative measures while the motor is out seems prudent at this mileage so it doesnt end up grenading on me. At one point I think I got a bad tank of gas which obviously caused running issues. At the current time when any water goes down the vents in the rear spoiler the motor falls on its face and doesnt want to start again. Im tracing electrical issues in the engine compartment as well. Its really just alot of little things that are annoying me and I have some money to throw at them for the moment. So this was a worst case scenario, if i had to dig deeper what would be my plan of action. To answer the first question a friend of mine who works for a porsche tuner is going to be doing the work.

flyinb44

On another note, if I'm going to spend the money I would like some tunability and the EFI systems seems to be the way to go and still have the reliability.

Metal Guru

I don't think I'd rebuild an engine and hang EFI on it all at the same time. However, having the engine apart is a great time to add a trigger wheel to the crankshaft pulley.
I would say that the bottom ends of these engines are relatively "bulletproof" but I've heard a lot about worn valve guides and broken rings on engines that have a lot fewer miles on them than yours. A rebuild certainly won't hurt.
What you change during the rebuild would be a function of your budget and performance objectives.
I put together an Excel file of all the parts required for a rebuild. Email me if you want it (pbreweris@comcast.net).

Big Jock

If youve got an exhaust issue at the head then thats almost certainly what the 'tick' is.A shaft bearing noise would make you want to switch the motor off.But I understand,'the sum of the faults and all that'.

flyinb44

Right now I am looking more for reliability than anything else. If I got 350whp out of this build I would be happy at this point. However, I can picture having the urge in the future to want to be able to tune for 400+ so that was my reasoning for wanting to go efi. I know there was another person on this threat that was interested in taking advantage of the turbokraft efi kit. Does anyone know of a successful endeavor? Also, any cam recommendations would be appreciated along with ecu's.

kleinbbc2

I'm running EFI and headers with bigger turbo etc... If I had to do it all over I would have went with a 993TT motor and called it a day. You will be at 400hp and would not need to dyno tune. I have spent alot more in EFI stuff then my engine rebuild.

flyinb44

I appreciate the list and words of wisdom metal guru. My mechanic has been trying to talk me into keeping the cis. If I had the money to drop on a 993tt motor I'd probably just buy the whole car haha. There are too many choices.

Metal Guru

I think that we all daydream about building monster EFI engines but if one does not plan on taking his 964T to the grave with him, EFI will limit the target audience when it's time to sell.
If someone can integrate EFI himself, great. If someone has to rely on a tuner, chances are that if something goes wrong the car will have to be shipped back to the tuner for resolution.
For me, the 997 Turbo holds great appeal since a chip and aftermarket exhaust will yield really good hp gains without big changes to engine management. Problem is I have to wait for used 997 Turbo prices to become more reasonable.
In the meantime, I'll continue to tweak up my CIS. There's still some headroom with it.