Rebuilding a 964 3.3 turbo

[staffanbe]

Originally Posted by sand_man

I'm glad you're getting it back together. I'm also sorry for your troubles with the B&Bs! I really think something has changed with regard to the techniques used by B&B to assemble (weld) these pipes. I know of a few people that have had the same set of B&B headers for damn near ten years with no issues. Some might blame incorrect AFR tuning for causing a lean and thus excessive heat situation; my AFRs, however, were checked regularly and were good. Plus most of the failures I've heard about lately have been in the heater-box to primary pipe interface. Nope, I think something is not right at Billy Boat (B&B)! These things cost far too much money not to stand up to the challenge!

Maybe it will take some poor fool to obtain a hefty dose of carbon monoxide poisoning one winter, from running the heat, before something is done!

I'm a little bit lean have to admit that, about 12.5 at full boost, would like to be closer to 12.0 if not 11.5. I will probably go EFI sometime in the future, but I don't have the budget for it at this time, so an adjustable WUR together with a rpm switch to tamper with the control pressure will be the short term solution.

Still, the welds holding the heat exchanger to the headers seems to be a weak spot. Hope this will hold up to the task, there is a great weight advantage running this setup.

[WERK I]

Originally Posted by staffanbe

I'm a little bit lean have to admit that, about 12.5 at full boost, would like to be closer to 12.0 if not 11.5. I will probably go EFI sometime in the future, but I don't have the budget for it at this time, so an adjustable WUR together with a rpm switch to tamper with the control pressure will be the short term solution.

Still, the welds holding the heat exchanger to the headers seems to be a weak spot. Hope this will hold up to the task, there is a great weight advantage running this setup.

I think the welds broke because of the lean conditions causing some serious expansion/contraction issues in relation to the heater boxes.

[staffanbe]

Originally Posted by WERK-I

I think the welds broke because of the lean conditions causing some serious expansion/contraction issues in relation to the heater boxes.

Yeah, that do make sense, at least for two of the holes.

The welder claims that one of the holes (don't ask me how he "concluded" that) is due to a weld going all the way "through" the header metal (not sure I'm explaining the way he explained it to me and what implications this has). He says in general the welds are good, more of a quality control issue, oh well.

My AFR is a bit lean I give em that and I don't want to be reborn as a header on a car running the long uphill straights at the Nürburgring, the conditions doesn't get much worse...

Hope to have my car running tonight, with a bit of luck I will spend the weekend on the race track

[sand_man]

Originally Posted by staffanbe

Yeah, that do make sense, at least for two of the holes.

The welder claims that one of the holes (don't ask me how he "concluded" that) is due to a weld going all the way "through" the header metal (not sure I'm explaining the way he explained it to me and what implications this has). He says in general the welds are good, more of a quality control issue, oh well.

This is my point. I understand how sensitive these turbo engines are to proper tuning...no excuse for that. But when I look inside the remainder of my B&B primary pipes, where the heater boxes are tacked, I can clearly see where these welds have just about burned through the pipe. In other words, if I kept my B&Bs and only had the one crack/hole fixed, soon the other five would have developed the same problem. This is what I think has changed between older iterations and the latest offerings from Billy.

[staffanbe]

Got to love this sticker.


Got everything together and started up the car.
Engine sound is 100% and the car is as fast as ever


A strange thing though, the car seems to pull as hard as ever and spool up is fast, still the boost pressure is lower than before using the same boost control setting and the boost pressure isn't going crazy at 2nd and 3rd gear as it did before. Looking at the picture above, this is the pressure hose between manifold and my boost control, it was dented at one place but most probably not leaking.


I fixed the dented pressure hose with a 2 way connection (see picture above).
Why is my boost pressure lower now with the same boost control setting.
Would a dented hose show a higher boost pressure, wouldn't it be the other way around, could I have a leak now?

Anyway, the car is as fast as ever, engine sound perfect.
Will check the rocker arm shafts for movemnt tomorrow.

[staffanbe]

Just got back from a track weekend, the engine sounds and runs really well.
No mechanical sound, just pure deep exhaust sound.
Checked the upper rocker arm shafts before leaving, they where fine.


The welds and header gaskets seems to have stood up to the task.
Thanks everyone for helping me out!

Since my engine seems fine I have developed a gear box sound, a mechanic that has driven the car says he is pretty much convinced it's a bearing in the gearbox going bad. Any hints on good resources for a gearbox rebuild ?

[cuongnet]

Go for it! The Cayenne S is really a great vehicle.

[staffanbe]

Originally Posted by cuongnet

Go for it! The Cayenne S is really a great vehicle.

I bet it is...

[WERK I]

Originally Posted by cuongnet

Go for it! The Cayenne S is really a great vehicle.
My site: www.findlowestprices.net

This guy is such a scumbag. He posts with Porsche related comment that has nothing to do with the topic, then conveniently lists his link to his latest scam.
Back to our regularly scheduled programming......