Rebuilding a 964 3.3 turbo - Page 2

staffanbe · 09-06-2007, 02:18 PM

Quote:

Originally Posted by sand_man

Those look like B&B headers...I'd check them!!! Especially where the heater boxes attach to the pipes. My B&Bs cracked only after a short while! I thought I had a broken head-stud on my 930 when I developed that "PHAT PHAT PHAT" SOUND. I was pulling a low mileage engine, anyway, to perform a rebuild to fix an endless array of oil leaks, and just got carried away with "while you're in there". However, I didn't think to investigate the headers since they were almost brand new. When my rebuild was complete, I also ran an open "zork" straight pipe on the turbo. The exhaust sound was soooo loud, I never realized that I still had a header leak. It took me installing my current Borla muffler (quieter) to realize that I had a problem.

When I pulled my B&B headers, I shined a light into them and the cracks where VERY apparent! Unfortunately I was just outside of B&B's warranty and ended up running a new set of OBX headers (no heat). I'm amazed at how smooth my engine sounds and runs!

Thanks, yeah those are B&B, not completly happy with them.
Can't run with a silencer after the wastegate because it creates to much back pressure, the exhausts won't evacuate through the wastegate properly on 2nd and 3rd gear, so the turbo pressure goes too high. So I am running with a dump pipe pointing into the ground, it's crazy loud, have to use ear plugs and I love sound.

staffanbe · 09-06-2007, 02:27 PM

Quote:

Originally Posted by sand_man

Also, are you sure your rocker shafts are still properly installed in the cam housing? They have a tendency to "walk" if they aren't properly aligned and torqued. Mine did this....was the only gotcha I had with my engine rebuild. I made the mistake of installing them with assembly lube and they kept moving about after the engine had run. I finally had to pull them, insure that their place in the cam housing was totally clean and free of oil, install them dry and then oil them once torqued.

Thanks, yeah I should check this.
What was the "tell" for you, oil leak or sound?

sand_man · 09-06-2007, 02:52 PM

Quote:

Originally Posted by staffanbe

Thanks, yeah I should check this.
What was the "tell" for you, oil leak or sound?

Actually, a little bit of both. I had installed the RSR seals on my rocker shafts and that probably helped a tad with slowing the oil leak...I just thought the sound was a little loud.

As for checking them, make sure whichever cylinder you happen to be working on, that you've turned the engine as such that the valves are closed for that cylinder...so that the rocker is loose (clearance between the rocker and valve stem). Sometimes the force of the valve spring will give the impression that the rocker is still tight.

staffanbe · 09-07-2007, 04:47 AM

Quote:

Originally Posted by sand_man

Actually, a little bit of both. I had installed the RSR seals on my rocker shafts and that probably helped a tad with slowing the oil leak...I just thought the sound was a little loud.

As for checking them, make sure whichever cylinder you happen to be working on, that you've turned the engine as such that the valves are closed for that cylinder...so that the rocker is loose (clearance between the rocker and valve stem). Sometimes the force of the valve spring will give the impression that the rocker is still tight.

Got it, thanks!

staffanbe · 01:24 AM

I located the sound to the servo pump, removed the toothed wheel and found it to be damaged. It must have tilted while I was tightening it. It has been grinding the servo house cover.

The camshaft looked and felt okey, put everthing back (making sure the toothed wheel had contact with the camshaft during tightening) and started the engine. The "hard" sound is gone, but I still have a "lawn mover" sound which very well could be an exhaust leak. It's really hard to tell lying underneath the car, I will hopefully get a second oppionon later today.

Took the car out for a drive, the turbo pressure builds fast and the car has lots of power, feels as strong as ever. Have a hard time accepting that my allmost brand new B&B could be broken.

sand_man · 05:29 AM

Glad you found the source of the sound!

As for the B&Bs, I refused to believe that they could have been cracked. In fact it was pretty damn well hidden. I discovered it because I pulled them thinking that I had a burned exhaust port gasket. When I got them off, I could see that the heater box tube that runs to the front of the car (connects to the cockpit heater hoses) was full of carbon and soot!!!!!!!!!! I shined my shop light into them and could clearly see that on the number three primary pipe, right as it enters the top of the heater box, had a crack!!! I checked the other primaries and could see the beginnings of more cracks/holes.

I think the issue was a manufacturing defect in the way the actual boxes were tack welded to the primaries. It must have weakened the metal.

Keep in mind that this whole internet diagnosis thing can be scary at best...so take all suggestions with a helping of spices. I'd hate to think of you pulling the headers off, only to find that they were fine! Maybe figure out another way of detecting the leak. In my case...I just couldn't pin-point it without removing the headers...YOUR MILEAGE MAY VARY!

staffanbe · 09-07-2007, 10:12 AM

Quote:

Originally Posted by sand_man

Glad you found the source of the sound!

As for the B&Bs, I refused to believe that they could have been cracked. In fact it was pretty damn well hidden. I discovered it because I pulled them thinking that I had a burned exhaust port gasket. When I got them off, I could see that the heater box tube that runs to the front of the car (connects to the cockpit heater hoses) was full of carbon and soot!!!!!!!!!! I shined my shop light into them and could clearly see that on the number three primary pipe, right as it enters the top of the heater box, had a crack!!! I checked the other primaries and could see the beginnings of more cracks/holes.

I think the issue was a manufacturing defect in the way the actual boxes were tack welded to the primaries. It must have weakened the metal.

Keep in mind that this whole internet diagnosis thing can be scary at best...so take all suggestions with a helping of spices. I'd hate to think of you pulling the headers off, only to find that they were fine! Maybe figure out another way of detecting the leak. In my case...I just couldn't pin-point it without removing the headers...YOUR MILEAGE MAY VARY!

Don't worry, I know how hard it is to diagnose these things remote.
Anyway, you and Dave seems to be spot on!

I took the car to a shop today, they spend some time underneath the car with a stethoscope. The verdict is a probable leak (inside the heat exchangers) at #4 and #1 (I think). I was pretty sure about #4 myself.

So, if I get the time tomorrow I will remove my B&B and install the stock headers to check if the "lawn mover" sound disapperes.

staffanbe · 11:44 PM

Jacked the car up and for the first time in years the right side was "dryish", perhaps the work I did with the rocker arms has paid off, a little bit to early to tell though (I will still check for rocker shafts walking).

Removed the headers and found that the gasket for cylinder 4 was damaged.
Not hard to tell that a lot of exhaust has used an alternate route..

[#4 gasket] My guess is that a nut started to come loose and then the gasket got blown to pieces. The #1 cylinder had some damage to it's gasket as well, but I can't conclude it has been leaking.

Next step is to examine the headers, my plan is to follow the advise I got here and drop a LED-ligh into the headers, might remove the heat exchangers alltogther since I'm not using them.

WERK I · WERK I's Garage

staffanbe,
The news keeps getting better and better all the time! It's great to hear there's nothing seriously wrong with the engine. The header gasket pictured is the factory OEM gasket. The B&B's were solid cooper. You might try to find a set of copper from any Porsche header manufacturer. The B&B header gaskets I got looked like they were cut by a first timer with a gas torch. Had to mill them flat to insure they would seal properly.

sand_man · 09-10-2007, 07:49 AM

Yep...I'm running metal gaskets in between my headers and exhaust ports. I bought them from our host.

sand_man · 09-10-2007, 07:52 AM

Quote:

Originally Posted by sand_man

Yep...I'm running metal gaskets in between my headers and exhaust ports. I bought them from our host.

Part number:
930-111-191-12-M17

staffanbe · 09-12-2007, 01:03 PM

Thanks, ordered a set of durable gaskets!

Started to examine my B&B headers.

Didn't need to do much cutting before I found a hole in the cyl #1 header.
It's right where the heat exchanger is welded to the header, you guys where spot on!

Looks much better this way and it's a bit lighter too.
1 done 1 to go
Starting to think that I might need to change the title on this thread, but I won't until I'm sure I found all the problems.

sand_man · 09-12-2007, 01:45 PM

ABSOLUTELY UNBELIEVABLE!!!!!! I'm soooo disappointed with B&B!!!!

sand_man · 09-12-2007, 01:47 PM

Those folkers at B&B wanted to charge me $300 plus shipping both ways to fix their bull*****!!!! I threw the gawd damn headers accross my garage, I was so pissed!

sand_man · 02:21 PM

here's my thread on it:
B&B Headers - got a god d@mn hole!
Pictures on page 3

staffanbe · 09-13-2007, 04:09 AM

Quote:

Originally Posted by sand_man

here's my thread on it:
B&B Headers - got a god d@mn hole!
Pictures on page 3

Thanks, interesting reading!
My story:

After installation I found that my turbo pressure went to high on 2nd and 3rd gear. It doesn't evacuate enough exhaust to the wastegate. Removed the muffler on the wastegate (to reduce back pressure), still more turbo pressure than I want, but I decidede to live with that and a sound level that makes it impossible to drive on most tracks.

I believe the header must have cracked after about 6-7 hours of track driving, that was when I got this exhaust sound. My turbo started to smoke, could be (but I'm not sure), from pieces of the weld going into the turbo. So I had to have the turbo removed/installed, oil change etc. $500 usd the turbo renovation was another $500 usd.

The sound led me to believe that my engine was going downhill, after a while the sound got worse (probably when the gasket was blown), moments later I lost most of the power (probably because of the spark plug coming loose). Had the car transported from Nürburgring back to Sweden.

It's been "that" kind of season....

WERK I · WERK I's Garage

Quote:

Originally Posted by staffanbe

Thanks, interesting reading!
My story:

..............Had the car transported from Nürburgring back to Sweden.

It's been "that" kind of season....

Nurburgring??!! You lucky, lucky guy!

staffanbe · 09-13-2007, 06:07 AM

Quote:

Originally Posted by WERK-I

Nurburgring??!! You lucky, lucky guy!

Oh man, this season has been so much fun but my wallet keept shouting "eject, eject, eject"...

staffanbe · 02:35 PM

Removed the other heat exchanger and found another hole in the cyl 1 header, same spot where the heat exchanger is welded to the header (sorry for the bad picture quality). Just got the headers back from a welder, he found another hole in them, so a total of 3 holes after less thena 10 hours of driving.

Installed a fiber glass hood while I was waiting for the headers to get welded.

This time the headers will be installed with good quality gaskets.

Well, I think 3 holes in the headers, 1 blown header gasket, one loose spark plug and a powersteering pump wheel grinding on a aluminium cover probably will cover most of the bad sounds I heard...

Hope to be able to start the engine in a couple of days, keep your fingers crossed

sand_man · 09-25-2007, 03:30 PM

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!