Greg Hammond's Porsche 944 Turbo Page
Also known as The Great Porsche 951 Rebuild
Please Note: I sold this car in October, 2002. You are more than
welcome to write to me if you would like to know more about it, or my rebuild experience.
Page Updated February 11, 2003.
I purchased this 1987 Porsche 944 Turbo (affectionately known by it's factory designation of 951) from Priceless Auto Sales of Thomasville, Pennsylvania for $6500.00 in June, 2000. The exterior of the car was in very good condition, with only a few minor rock chips and scratches in the finish. This car was the "showroom showpiece" of a small used car lot, and the lot owner obviously took very good care of the repainted finish. Unfortunately, the previous owners did not take as good care of the interior of this car, and the usual Porsche cracked dash, broken LCD clock, and cassette storage compartment hinge were in need of repair or replacement. Also, the rear-deck carpet was completely destroyed by long-term UV solar damage and possibly a corrosive or incompatible chemical that had been spilled on the deck carpet! Oh well, nothing $500 in interior trim and carpet won't fix. *grin*
The engine was apparantly in good running condition when I picked the car up. After topping off the gas tank and driving around approximately 350-400 miles, I heard a "knocking" noise under the hood that didn't sound good at all! A quick listen by Chad Smith, my mechanic, and the cause was determined - cracked rod bearing. Now I know why the car was $6,500 and not $10,000! My mechanic and I are planning to remove the engine from the car over the next few days and determine what internal components need to be replaced/rebuilt to bring this car back to fully functional condition. With any luck, regrinding of the crank and rods, and a set of main bearings and rod bearings will be all this car needs to return to operation. While inside, we plan to replace the water pump, timing belt, balance shaft belt, replace all roller bearings, rebuild the seals in the oil pump, inspect the valves, pistons, lifters, springs, cylinder bore, injectors, and turbo for tolerances, and replace all gaskets and most of the hoses under the hood.
Once the engine is running again, an Autothority mass-flow conversion kit, adjustable fuel pressure regulator, and adjustable wastegate control will be added to the car. If the turbo is in need of a rebuild, it will likely be replaced with the larger K-27 #8 that typically accompanies the 1989 and later 944 Turbo S cars.
Edited 1/24/2001: The Turbo S came with a K-26 #8, not a K-27. The K-27 was used in the Porsche 911/930 Turbo, and the Turbo "Cup" 944/951, and is significantly larger. My turbocharger retains the K-26 compressor housing, which has been machined to fit a K-27 compressor wheel. The #6 exhaust housing has been replace with a Turbonetics housing that has approximately the same geometry as the K-27 T8.
Factory SAE horsepower for this engine should be 217 HP and 238 ft-lb TQ. Estimated SAE output of the car with the proposed enhancements will be in the neighborhood of 330 HP and 350 ft-lb TQ.
THE GREAT REBUILD:
The GREAT REBUILD became necessary only 3 days after I purchased the car in June, 2000. The entire rebuild process has taken over 8 months to complete, with no corners cut, and very few bolts left unturned. Today, only a few minor issues remain, and those could be best described as "nit picks".
Not knowing the rebuild would be such a long and arduous process, the documentation of the project did not begin until afer the initial problem diagnosis. Chad Smith, my childhood friend, now master Porsche echanic, undertook the project beginning around the first week of July. Much to my surprize, it only took two days to remove all of the parts and pieces from the engine, and remove the engine from the car. Oh, if only I had known it would take SOOOO long to get it back in! *grin*
UPDATE August 2, 2000:
Chad and I removed and disassembled the lower end to inspect the bearing damage and ascertain what is required to properly fix the car. Unfortunately, things got worse with each bolt removed, and I learned that all four cylinder bores are badly scored -- necessitating the block be sent out for repair before we can concentrate on reassembly.
The block has been delivered to Mancini Machine of Catonsville, MD for block work. They're currently waiting for me to acquire engine specifications and tolerances for them to start work. Oh boy!
Editors Note: (March 24, 2001) - Mancini Machine does excellent work, and the engine has now stood up to 1800+ miles of intense break-in. I can definitely recommend them for workmanship and quality, but you may need to stay on them to remain a high priority!
UPDATE November 12, 2000:
The block is FINALLY back from Mancini Machine. While they certainly took their sweet time doing the job, it appears to be a top-quality job and worthy of the $1600 in machine work they charged. Here's what they did:
Several more costly items needs to be repaired/replaced. Upon close inspection, the oil pump has several grooves cut into it, likely from chunks of bearing material flowing through it. In addition, we'll be replacing the clutch and several suspension components while we have the front-end disassembled. Of course, no rebuild is complete without new belts, hoses, water pump, boost control valve, and a few o-rings and seals here and there. Not to forget the exhaust system needs replacement too....
The re-assembly process will begin soon. Here is the motley mess of parts stowed in the back of the car, to be sorted, cleaned, and reattached to the now-repaired block:
UPDATE December 11, 2000:
Chad and I spent a few hours in his freezing garage last week re-attaching the head, can, cam housing, and one balance shaft back onto the block. A 150,000 BTU kerosene turbo heater can do wonders for heating a big space in a hurry!
I acquired a used 944 oil pump from eBay off of a 1984 normally aspirated car. The good news is that the pump is in excellent condition, the bad news being that the oil feed and return galleys are of incorrect size and depth, and consequently the pump cannot be used with my block. The cleaned up oil pump has been photographed and put up on eBay for sale. I shouldn't have any trouble getting my $50 back for it. The really bad news is that NEW oil pumps for a 951 run about $500, and I have to get one pronto.
The car is -finally- coming together. The following parts have been ordered:
With any luck, the next report will be soon and contain LOTS of good details to report.
UPDATE January 12, 2001:
Woo hoo! Another cold night in the garage, re-assembling the engine. The new water pump, oil pump, second balance shaft, timing/balance belt cover, oil pickup, and oil pan were reinstalled on the engine. I have to say, with the head, cam case, and oil pan back on the block - it really looks like we're making progress. It's amazing how long it takes to reassemble an engine properly in comparison to how quick you can take one apart!
The K-26 #6 standard turbocharger has been sent to Majestic Turbo of Waco, TX for rebuild, balance, and conversion to a larger K-27 compressor wheel.
This photo shows the prepared block with both balance shafts installed, before the water pump, oil pump were installed. I hope to display a nearly completed engine for the next update!
UPDATE January 23, 2001:
Upon inspection of the turbocharger, it seems that both the hot and cold sides of the turbo have been upgraded to K-27 #8 sized components. The hot side is actually a Turbonetics housing, while the cold side is a K-26 that has been machined to fit the larger compressor wheel and the intake port has been polished. The exhaust turbine has been clipped 10 degrees, and the center hub machined and polished into a shiny cone. Click on the thumbnails to view full-sized images.
Not counting an interruption from the pizza delivery man, a substantial amount of work was accomplished over about six hours. Chad believes that we may attempt putting the engine back into the car after one more night of work on the project. In this photo, Chad is preparing to install the timing belt:
The list of work done included the installation of various sensors, preparing the exhaust mainfold, installation of timing and balance shaft belts and rollers, engine mounting brackets, crankcase vapor recovery, several heat shields, and other minor assembly.
UPDATE January 29, 2001:
It had to be a balmy 45 degrees F outside when we began working on the engine for the third time this month! The goal was to finish as much as possible in preparation for our attempt at installing the motor the next time we meet, hopefully in less than a week. The turbo and related oil passages have been installed, and the exhaust manifold bolted onto the block and turbo. We were lacking the large exhaust gasket between the turbo flange and downpipe, so we made a loose fit and will install the gasket next time.
Here are a couple of photos of the turbocharger work-in-progress: Click on the thumbnails to view full-sized images.
UPDATE February 6, 2001:
The first of two nights in a row, we finally re-installed the engine into the chassis. It took a little muscle and patience to get the block and bell housing aligned, but with persistance and 40 minutes or so of wrestling, the engine was secured. I removed the CV joints and axles in preparation for a good cleaning tomorrow. Chad reattached the vital hoses and wiring. Click on the image below to view full-sized.
UPDATE February 7, 2001:
The CV joints have been cleaned and re-packed with fresh grease, new boots installed, and joints/axles reinstalled in the car. Chad installed most of the remaining heater hoses, intercooler, nose, alternator, idle air controller, and several sensors. He plans on installing the intake manifold next, and I suspect the radiator and main cooling hoses are to be installed soon thereafter. Here are a couple shots of our progress for the night.
UPDATE February 20, 2001:
Chad and I got a late start tonight, but still managed to put in a good 3.5 hours worth of work on the car. The starter and starter/alternator wiring have been installed, the clutch slave cylinder mounted, radiator installed, radiator fans attached, several more coolant hoses attached, and most of the heat shields were installed. Chad also mounted the wastegate pipe. The work isn't all that "apparant" when looking at the car from a distance, so there are no photos this time around!
UPDATE February 27, 2001:
We made a LOT of progress tonight! The intake manifold has been installed, along with the fuel rail, injectors, fuel lines, throttle, cruise control, all remaining coolant hoses, expansion tank, various heat shields, air intake boot, vacuum lines, oxygen sensor, and a few other odds and ends. All that remains is the air filter housing, the intercooler pipes, the muffler, ignition cap/rotor/wires, oil cooler lines, power steering pump, and the final nuts, bolts and adjustments for the belt-operated devices. Chad says we should be ready for ignition the next night we get together. Click on these images for full-sized photos.
UPDATE March 6, 2001:
It's Alive! It's Alive!
Chad had to acquire a Snap-on 1-1/2" 3/8" drive crowfoot to tighten the oil cooler lines. Ignition wires were ran, distributor and rotor mounted, A/C compressor and P/S pumps were mounted, belts installed, airbox installed, and the muffler attached to the car. The moment of truth had arrived, and we were ready to stand forward and be counted! After a snafu in determining which position was cylinder one on the distributor cap (the little sticker that had this information was missing) - the car started right up!
It took a while to get things bolted up, and after running the car long enough to feel confident that everything was in good working order, we closed up shop for the night. Test-drive tomorrow!
UPDATE March 7, 2001:
The car is running great! Chad and I took the car out for a brisk spin around the neighborhood to see how the engine ran under load and to make sure the turbocharger was spinning up and making boost.
Chad says the turbo has significantly less lag than he expected for the larger-than-stock unit, and everything is running very smooth. No leaks have been detected, and coolant and oil both look good on the gauges.
There are still a few minor details to take care of. We are waiting for rear control arm bushing mounts, and front swaybar bushings. The aerodynamic underbelly skirt and tray are off the car so that we have easy access to check for leaks over the next few test drives. Lastly, the car needs to pass Maryland State Inspection before it can get permanant tags, and with luck we'll have all of the minor adjustments completed next week.
Performance Notes - March 7, 2001:
The car seemed pretty "quick" before the rebuild got underway back in June, 2000. I really had no idea just how fast a properly-functioning 951 should be, and I must say that I am -very- impressed with the performance of the newly rebuilt engine! The larger K-26/27-#8 hybrid turbocharger and B&B Tri-Flo exhaust should be giving me approximately the same level of horsepower as a 1988-89 944 Turbo S even without DME/KLR chip upgrades. True performance and dyno testing will have to wait until the engine is adequately broken-in.
We are going to wait until the engine has a couple thousand miles on it before adding the Authority Mass-Flow intake. I'm having trouble envisioning how much power this car will have with 70+ additional horsepower.
UPDATE March 12, 2001:
The car was taken to the professional garage where Chad is chief mechanic so that we could get the car on a lift and finish up the final details prior to the Maryland State Inspection. We replaced the front sway bar bushings, control arm bushing/mounts, fuel filter, transmission gear oil, first 500-mile engine oil and filter change, adjusted the parking brake shoes, and installed the front air dam.
There appears to be a minor oil leak coming from the lower-left balance shaft housing seal that we cleaned up. Chad believes it may be left-over oil from the installation of the assembly, and we'll keep a close eye on the leak to see if it continues. If the leak continues, it may require re-installation of the front balance shaft seal which involves removal of the timing/balance shaft covers, belts, rollers, and balance shaft sprocket. Lets hope the leak isn't there next time we look.
Update: April 15, 2001:
What better way to celebrate tax day than to install an Autothority Mass Air kit! Actually, I installed the kit yesterday afternoon, and it took about 2.5 hours for the job from start to finish, including a couple of quick test runs, swapping of chips, and installation of the new boost enhancing banjo bolt.
The installation was fairly straight-forward, but does require a good understanding of the stock air and boost management system. The "instructions" from Autothority consist of a few poorly reproduced photocopies of a few pictures and general instructions similar to, "Remove existing intake, install MAF. Have fun!". Ok, maybe not THAT bad, but close!
A few of the hoses that came with the MAF kit needed to be cut. The kit does not provide an illustration of the provided hoses and their intended purpose, and you're left to your own devices to determine which hoses need to be trimmed, and how they get hooked up to the MAF. Fortunately, there are only a few of them to deal with, and guesswork is kept to a minimum. The only significant problem I had was the factory Bosch blow-off valve is a "very tight fit" in the limited space provided to install it with the MAF. In the photo below, you can see that the thick hose coming out of the BOV is a little cramped for space. Rotating the MAF assembly didn't make much difference. The air filter "rests" on the headlight travel stop frame, which may eventually cause a hole to be worn into the filter. I'll have to keep a close eye on that. Lastly, the red wire going to the MAF sensor itself is too short, providing no means for securing or hiding it.
Click image for more detail.
Performance impressions? WOW! The car really flies now, and makes a very cool "sucking" and "whooshing" noise corresponding to turbo boost, and the rush of air through the BOV when you let off the throttle. I don't know it the claims of 70-80 BHP increase are accurate, but you can definitely tell the car's performance has been greatly enhanced! I intend on getting the car dyno tested as soon as I come back from vacation in a couple weeks.
Speaking of dyno testing, I had a baseline 3rd-gear and 4th-gear test done at EIP Tuning yesterday morning prior to the MAF installation. The best of the two runs indicated 197 HP at the wheels, 215 foot pounds of torque. Considering a 15% driveline loss, this puts my "stock" car right at 231 BHP and 252 ft. lb. at the flywheel, right between a base 944 Turbo, and a 944 Turbo S. I was quite satisfied! I didn't expect much of an increase at all considering I was running stock chips and boost at the time.
The following vendors were extremely helpful along the way by providing either excellent parts, advice, and in most cases both! Thank you!
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