preston_brown

Here's a page describing the dealership and racing operation in Halsbach:

http://www.halsbach.de/index.php?opt...d=112&catid=40

Car Obermaier

Obermaier - Automobile

At the village square 6 × 84 553 Halsenbach
Tel: 08 623 223 ˇ Fax: 08 623 1823 ˇ E-mail: johann.obermaier AT t-online.de

1933 began. Hans Obermaier left the "Barthen-yard" in Hofschalling his brother George, the old school house was bought in Halsenbach and took over by Alois Spielhofer the bike shop.

Centrifuges, straw presses, sewing machines - everything has been repaired. It has built engines for mowers and thus had the first vehicles without horses - the forerunner of the tractor - was developed.

About 1,000 tractors were sold after the war and maintained. A huge potential.

Hans Jr. Obermaier., Recognized the recession in the agricultural sector in time and looked for alternatives for his business. Cars were repaired. At Porsche, he rose to become the world's best specialists. The racing team won titles and cups all over the world.

The experience gained from racing us in good stead today. The truck repairs are going very well. This could be compensated fully by the end of the racing activities of the sales and earnings declines.

Whether ASU, catalyst, SP (security check), error memory, OBD, on-board computer - all buzzwords of the new age that does not scare us. Our time in the motor sport experience and knotted compounds, we are also familiar with the most complicated technology.

We focus on our core business: cars, agricultural machinery, truck service.

Picture: Obermaier Motorsports Porsche Team World Champion 2000, Michael Fitzgerald (USA)

mobius911

Nice find! Interesting mix of activities, but they have managed to pull off some wins so good for them. Based on the contact email I'm guessing a son is running it now.

Geoffrey

I used Getty Design 964 Turbo parts on mine and it worked out very well. I'd recommend them.

Laker

after reading this entire thread, I have absolutely no need to watch "Chasing Classic Cars"
Thanks for sharing!

preston_brown

No problem guys. Getting this car on the road is going to be fun.

Went out to work on the car again today. Its at a nearby shop at the moment where the owner is letting me use a lift. I have rebuilt several motors in my own garage and have plenty of tools but a lift is something I haven't let myself get yet. Maybe one of these days...

So to summarize, I went in today to try to diagnose the condition of the motor a bit more. First, I pulled off the rear bumper. To do this it is best to take off the rear flares first, they come of in about 30 seconds each after the DZUS fasteners are undone. Then the rear bumper is held in by two special pins that are passed through holes drilled in the hollowed out bumper shock tubes. Pretty much a piece of cake. Clearly meant to be removed in a hurry.

My rear reflectors are all in sorry shape due to heat from the motor, cracking due to racing "incidents," and the inevitable sun damage these all face. Not sure whether I'll bother to replace them or not yet.







The "muffler" on this car pretty sweet. Built by Bischoff, Porsche part number. Pretty sure there's nothing inside though...pretty loud.

The heat shielding inside the rear bumper also has a Porsche 996 part number. I'm assuming it was added / replaced later. In any case, it is not in good shape, and I really could use some replacement material, same part or different / improved. The heat that comes off the muffler without the bumper in place is IMPRESSIVE when the car is running.

After that was done I pulled the filters off the intakes and observed the carbon fiber stacks in all their glory:



Beautiful. Individual throttle bodies all tied together with a common shaft and there is the linkage rod running out from the center of the motor behind the fan.

Here's a picture of the oil overflow catch can and fuel filter:



Neat how they reused a washer fluid bottle as the catch can. Sticking to factory parts...

OK after this bit of disassembly we made sure all the intakes looked fine (they do); made sure the butterflies opened simultaneously (yes); and put a flow meter on the stacks to see if they are balanced (very close). At this point we can fire up the car and it sounds pretty good, but it will not idle. it will run for a few seconds and then die. If I keep the throttle in so as to keep the RPMs up above 1200-1500, then the car will keep running but it is popping and spitting back through the intakes especially on the right side.

We decided to check valve gaps and plug condition next. Pulled rocker covers and got to work. All gaps are fine. Cams look good. Plugs all look good too, not white like we are running too lean. Exhaust tailpipes are a light gray color on the inside however.

We decide to check leakdown and compression.

Leakdown test:

#1: 2%
#2: 5%
#3: 9%
#4: 30% (ohh..)
#5: 35% (ohhhhhh...)
#6: 8%

We have something not quite the same as the others on two cylinders.

Compression test agrees. We have about 190 psi on the good cylinders, but 160 or so on the two bad ones.

The leakdown test made it sound like most of the leakage was past the rings. I could hear much more from the oil return tubes than I could hear from the exhaust or intake. So we tested that theory on #5 by adding a few squirts of oil into the lower spark plug hole and re-testing leakdown. Result: leakdown went from 35% to 20%. So the rings, I hope just from sitting all these years, aren't sealing perfectly on those two cylinders. I hope running the motor for a bit could re-seal these but a little bit more testing will tell.

We also installed a manual pressure gauge in the sending unit location to confirm oil pressure. The pressure gauge has been going off the scale (5+ bar) when we are running the car. The manual gauge confirmed we have 80 PSI oil pressure at 1.5-2k RPMs. Sounds high to me but I'm coming from a street car world. We have Brad Penn 15W40 in the car at the moment.

I am planning on taking off the chain covers next to look for sprocket damage. We still need to try to assess where/what the metal particles on the drain plug originated from. That may happen tomorrow.

Anyone else have any ideas on how to proceed with the motor? Wideband O2 sensor to check how we are running? Other instruments?

KiwiSean

The grayish color inside the pipes looks like it has been running av-gas or some other leaded race fuel, not running lean.

Sounds like it's definitely a timing issue based on what you describe, I'd spend some time on the ignition side of things if you haven't already. I'm not sure what ignition it's running but everything ok with the distributors and coils?

preston_brown

We are running very hi test 110 octane leaded. And I was told that was what was in there before.

We checked the distributor rotors and both are spot-on. Neither is cracked. Haven't looked at spark yet but don't have a real reason to believe it isn't getting good spark. Or do I?

I'll get a sound recording tomorrow.

KiwiSean

Well the popping and spitting at revs with a rough idle would make me want to look at timing of the spark more than if it's sparking.

What ECU are you running?

PS- yup that's why your pipes are gray.

preston_brown

If there is a timing problem, it has to be with the cams... the distributor rotors are happily pointing at the little "pip" indicating TDC on #1 when the crank pulley is at OT. Unless you are suggesting that the DME is not interpreting signals from the distributors properly...

It's a 993 DME on the outside, but we haven't opened it up to see what sort of markings might be on the chip inside.

Bill Verburg

The muffler is not really a muffler, that's a 993 Bischof cat case, probably gutted as that was a common practice, most likely the headers are a stripped 993 set

KiwiSean

hmmmm, I guess you could check the cam timing and maybe throw a timing light on it just to see what it's doing, without knowing the map on that chip you're flying a little blind. Perhaps get a scan of the chip so you know what it's doing from a timing point of view? I don't know who could do this in your area but I'm sure there's others that could chime in on that.

My understanding is that if there was something wrong with the speed sensor on the flywheel (the primary input the DME uses to set timing) then you'd have no spark at all rather than an inconsistent or erratic one. Others care to comment on this?

If you have ITB and stacks what is the DME using for measuring the air coming in?

preston_brown

Good question, I've wondered that myself.

Jacke2c

Throttle Position Sensor.... gives the position of the throttle body. This is used by the ECU to calculate the amount of fuel injected...

KiwiSean

While I know Motec and other aftermarket ECUs will run without a MAF because they use a Throttle Position Sensor and Manifold Air Pressure sensor I didn't think the stock DME could determine load and therefore fuel and timing without it? Otherwise, why not just ditch it all together?

Sorry we're going around in circles here Preston. I'm not sure where you are at on your process of elimination but if you've got fuel, compression and spark, timing is good I would start checking or replacing sensors like the TPS and perhaps the Flywheel speed sensor and work through a process of elimination on inputs for the DME.

I know this doesn't help but if it was my car I would also consider putting a Motec or similar (no affiliation) on it and start again. Given how much work has been done to this engine on the inlet and heads I'd say this is the best way to get the most out of it anyway.

In the meantime I'll keep trying to help, I do wonder where the forum wizards are at the moment though?!

preston_brown

Here's my update on this Friday's work on the car.

I got the muffler and rear tray off so I could start inspecting the timing chain, gears, and sprockets. The muffler is completely hollow, as I suspected. I will also be welding on another bung for a wideband O2 sensor. I got an AEM X-WIFI kit, which puts out your AFR reading via WiFi and can be read on any device. Of course it has output for engine management systems and data loggers as well. This seemed more appealing to me than putting an AFR gauge in the dash.



This is what the inside of the headers look like. I assume the white color is the leaded gas that has / is being run in the car:



And here she is with the rear tray removed, the muffler off, and the timing chain covers removed:



Good news is inspection of the timing chains showed nothing is screwed up. Here's a shot of the left side:



The gear and chain look almost brand new; they were definitely replaced as part of the engine overhaul. We turned the engine over 360 degrees a couple of times and thoroughly inspected the gear, the sprocket behind it, and the gear on the inside of the case (with a nifty Snap-On boroscope) and couldn't find any evidence of damage.

On the right side, we also could not find damage, but the gear does look like it is wearing a bit faster than the left side. Possibly it isn't perfectly parallel?



Here's a detail shot. The one other "weird" thing is that someone has marked / punched two little dots on the gear, and then a corresponding dot is visible on the sprocket through the hole right between them. Must be something to do with timing. But I wonder why... thoughts?



Not finding anything wrong here was a relief. So I buttoned it back up.

I wanted to investigate the DME unit a bit more, so I unplugged it from the harness and opened it up. Here's a picture of the box:



And here's the chip inside:



I read:

SC950007
[some german I don't understand and can't quite make out]
3.9L 18.2.97

So clearly there's a custom map chip in here for the motor. I never suspected anything different but here we have confirmation. I put the DME back together and reinstalled.

I then pulled all the injectors, as I'm going to send them off to WitchHunter for rebuilds. I've used them before and they are pretty cheap and very fast. Good insurance as we sort this puppy out. While doing that I noticed a really weird and jerry-rigged throttle return spring arrangement. The return spring is double-zip-tied to the left side fuel rail. This has got to change. Thoughts on where I could anchor the return spring to instead?





That's it for now, but decent progress. Looking forward to getting some AFR readings, hopefully next week.