Well, this is probably not good...

[getz]

Went out for a spirited drive today and ran the rpms up to around 6.5 grand and suddenly billowing smoke out of the exhaust, and the oil gauge bouncing all around. Oil pressure didn't appear to be affected, and the car seems to run okay. Any thoughts as to how much I broke her? On the upside I have been saving to send her out to Turbokraft.

Info: Modified 88 930 with EFI. I bought her from an old fella in Florida and she has driven well for the past 2 years. I don't know much about the components, but apparently increased displacement, new pistons, and a bigger turbo.

[Oheggem]

I`m very far from an expert but this sounds exactly like what i had happen. I ended up looking inside the exhaust outlets after removing the headers. Then i saw the oil spill and sot on one cylinder. Changed the valve seal on that cylinder and patched it up again. Ran perfect after that.

Others will probably help diagnose

[gsxrken]

Assuming your oil pressure never wavered, and not knowing exactly how much smoke let loose, you may have blown your turbo seals.
Keep us posted on what you find. You could always tell your wife it’s unsafe to drive like this and MUST get to TurboKraft. Think of the children...

[getz]

Thanks fellas, and I especially appreciate the advice on how to pitch Turbokraft to the wife.

[pu911]

I had a 79 that did exact same thing - blown turbo seal, not a big deal

[mark houghton]

Agreed on probably the
turbo seal, but this comment "and the oil gauge bouncing all around" has me scratching my head. Why would a blown turbo seal cause the oil tank level gauge to fluctuate as apparently it did?

[02fly]

Oil level gauge may have bounced around because of the scaveng pump, just a thought

[full quack]

W.A.G.
If the seals failed and it pressurized the turbo oil return line, could have pressurized the oil tank as well, making the sender float move around????

Mark

[TurboKraft]

Originally Posted by getz

Went out for a spirited drive today and ran the rpms up to around 6.5 grand and suddenly billowing smoke out of the exhaust, and the oil gauge bouncing all around. Oil pressure didn't appear to be affected, and the car seems to run okay. Any thoughts as to how much I broke her? On the upside I have been saving to send her out to Turbokraft.

Info: Modified 88 930 with EFI. I bought her from an old fella in Florida and she has driven well for the past 2 years. I don't know much about the components, but apparently increased displacement, new pistons, and a bigger turbo.

The bouncing oil gauge is the mystery -- for sure the level gauge, correct? You say that pressure didn't appear to be affected.

Oil still blowing out the exhaust? Is she still running okay?

A cold, dry cylinder leakdown test will tell you a lot about the internal condition of the engine.

These scenarios are another reason we advocate for a -0.5 -- 1.5bar 935-style boost gauge: you get a sense of what "normal" vacuum for your engine is at idle, A/C off.
If you mechanically hurt the engine, either break a ring or blow a seal, you typically lose some vacuum and it registers on the gauge. If you're drawing the same vacuum as always, it's more likely everything is fine mechanically (no blown out o-rings or top rings) and it's something else (turbo seal failure, etc.)

FWIW: stock cams are usually done by 5,500rpm, and most factory sport cams (SC, 964) peak by 5,800-6,200rpm. Once the cams peak, there's really no sense in revving it higher.

[getz]

Originally Posted by TurboKraft

The bouncing oil gauge is the mystery -- for sure the level gauge, correct? You say that pressure didn't appear to be affected.

Oil still blowing out the exhaust? Is she still running okay?

A cold, dry cylinder leakdown test will tell you a lot about the internal condition of the engine.

These scenarios are another reason we advocate for a -0.5 -- 1.5bar 935-style boost gauge: you get a sense of what "normal" vacuum for your engine is at idle, A/C off.
If you mechanically hurt the engine, either break a ring or blow a seal, you typically lose some vacuum and it registers on the gauge. If you're drawing the same vacuum as always, it's more likely everything is fine mechanically (no blown out o-rings or top rings) and it's something else (turbo seal failure, etc.)

FWIW: stock cams are usually done by 5,500rpm, and most factory sport cams (SC, 964) peak by 5,800-6,200rpm. Once the cams peak, there's really no sense in revving it higher.

Thanks for the great insight Chris (I need to reach out to you and get more information about getting her out to AZ to get her sorted out). In regards to the car, it seemed to drive okay, I really babied on the way home. Just lots of white smoke from the exhaust. The car has 964 cams, not sure the type (the seller was a pretty wealthy open check book guy when he had the car built). Looks like I was wrong, she is on stock pistons. It does have a 935 boost gauge, but unfortuanetly doesn't work

This was the description I got when communicating during purchase:

"The sequence of events on this 34,000 mile car are as follows:

A decision was made to remove the stock low horsepower engine in 2005-2006 at about 26,000 miles. He had owned the car for 15 years by this time. He wanted the car to keep up with, or beat new Turbos. He enlisted the professional help of Joe Rodriguez (JROD) owner of FAST FORWARD, a premier Porsche speedshop based in Ft. Lauderdale. Joe consulted Joe Eassa, a local fabrication expert as he had a working relationship with the legendary Dave Jarvis Racing Co. Jarvis built the engine and Joe Eassa fabricated the headers, Turbo (precision) and intercooler (Griffin core). The engine was installed, tuned and tested by Fast Forward. As the warranty had expired after the first year, it's now had trouble-free operation for the last 12 years. Being that Jarvis had retired and Fast Forward was sold 10 years ago, the record keeping on various projects has long been discarded. Knowing this, Jim had asked Joe Rodriguez to inspect and scope the engine recently. What Joe found was an engine that showed virtually no signs of wear (7,500 miles) and noticed some minor seepage that was quickly rectified. What we do know is that the engine is capable of 620 hp. What we also know is that its currently tuned at about 400 rwh. However this engine is made for boost. It starts and runs strong and smooth, very streetable in its current tune. Any minor issue that would arise over the years identified and corrected by local Porsche techs, including JROD. As a multiple Porsche owner myself I can tell you that the car has been well sorted and has been a joy to drive.

If you need any further clarification on engine components or
tune, I can put you in touch with JROD. As he is a full-time Senior Captain who flys 747's for a national airline, he is frequently out of the country but can be reached by email, text or a call from time to time. We know from his memory and recent scoping that it has 964 cams, stock Porsche pistons and rods, ARP rod bolts, ARP head studs, brand new Turbo seals, Electromotive dual plug head setup and EFI. 3.3 liter. Injectors, other ignition and fuel management questions can be addressed by Joe.

[getz]

Hi all. Quick update, looks like on scope I scorched a piston. Car will be off to Chris at Turbokraft. This should be fun!

[getz]

Just an update, she is safely in the capable hands of TurboKraft. I'll do my best to keep you guys updated regarding her progress!

[JacobS911]

Originally Posted by getz

Just an update, she is safely in the capable hands of TurboKraft. I'll do my best to keep you guys updated regarding her progress!

Lucky lil turbo! What's the plan for the build?

[getz]

I'm thinking upgrade the EFI, bigger pistons, and new turbo. It has a good sized intercooler already, but waiting to hear recommendations from the guru. My only requirement is that it is fast and shoots flames!

[b5aar]

Per Chris comments...bought an auto meter based kit off eBay...decent...had to add add a few fittings Ran Poly through the transmission tunnel...kit had a rubberish sleeve around the gauge that fit well within the clock hole

[b5aar]

And adapter bezel

[getz]

Update:

Spoke with Chris at TurboKraft and hopeful to have the car finished in the next month or so. Complete engine rebuild shooting for 500+ to the wheels and new coilover suspension. Should be fun!

[voitureltd]

Yours should be great after TurboKraft does his thing. I have currently 2 motors by Jarvis, first photo motor was built in 2002 and the other one was built long before that . No scorched pistons yet. The motor in the first photo usually runs 18psi on around 100 octane and 21psi on 112 and has around 8K miles since built 19 years ago.



The second motor photo was just rebuilt and upgraded after bending a rod ( stock rods with ARP bolts ) on the break in dyno tune about 14 years ago and now has Carrillo billet rods, 8.0 compression 3.4 liter pistons & liners and EVO 2 webcams otherwise left as built by Jarvis Tech with 993 TT exhaust and his custom intake etc. Recent break in dyno is 370 WHP at 11psi so should be lots more @ 16 or so psi and race fuel.
Does your intercooler and his fab work look like the photos of this early Jarvis one?

[voitureltd]

Current break in wheel HP Dyno sheet @ 11psi for the early Jarvis motor. Too bad about your piston and with mine bending a rod. I hope both yours and mine will be good for a long time. I suspect with mine a tuning mishap, maybe a previous tuning may have been your cause also. Hope you post your results. Is TurboKraft doing more head porting etc, from original Jarvis build ?

[slow&rusty]

2 years at TurboKraft?