4.0 Mezger 800hp.

[jimPH]

This is a long running project, should do 1200hp on the turbos I have, but my gearbox isn't straight cut and having had straight cut gears, I don't want them in a road car. I think 800 will be fine for the road too and be reliable.

Anyway, here is the build.

[jimPH]

So first up, after accumulating loads of parts, I took them all down to the engine builder. He threw most of the parts away and started again and if anyone knows Matt they will know he is a bit of a perfectionist. I just wish I went to him sooner, I would have saved a ton of money.

It's a +2mm stroker crank with billet rods and +2mm pistons giving 4.0L. I used to have billet K16's and really enjoyed their driveability, so want this to have plenty of low down torque. Peak horsepower isn't really my objective.

Bottom end in place, clearance had to be machined into oil pump:

Edited by jimPH on Sunday 16th January 06:47

[jimPH]

Next up, pistons and liners. Liners are from SRM and machined to match the pistons.

I sourced the 12mm studs cheap from ARP. If you ask them if they have a 12mm stud for a 996 turbo they will say no. but if you ask them for an M12 stud, apx 7.7" long they will give you a PN. I had Sean at SRM check them out and he's been knocking them out since at $650/set. Before that they were custom made for $2k so hopefully plenty of people in the community benefitted.

Heads were all drilled to match and timeserts fitted into the casings for increased strength.

[jimPH]

I bought some big valve heads from the states, turned out to be junk, so Matt rebuilt and ported my original set.





I'm using standard cams, i could have gone with a GT3 cam for more revs, but I'm after that midrange grunt the 911 turbo is famous for, besides, the mezger has hidden potential that you can unlock with the right ECU.

Edited by jimPH on Sunday 12th December 09:11

[jimPH]

Water hoses are welded and tested. Lots of people will say gluing and pinning is better, but if the welding is done right its a permanent fix. Bad welding will always be worse of course, so use a guy that knows what he's doing and test them.

[jimPH]

45mm large bore manifolds from TopGear, fitted perfectly. Turbos are Tial Alpha 3076 with xona cartridges. Some cars run these at 1200hp crank. They should spool well with the 4.0.



The standard turbos aren't water cooled and the tial kit comes with a Heath Robinson solution, designed to be fitted with the engine in the car. Being a scratch build, Matt can run proper welded take offs into the water lines and run the hoses with a bit of thought and planning.





All the hoses and fittings are top quality, with everything run neat and tidy. I did ask about the choice of forged over swept and the pressure drop is marginal.

[jimPH]

GT3 82mm throttlebody with a billet SRM plenum. I didn't go IPD, there must be a reason porsche doesnt use that design, so went how Porsche intended.

It came with plastic hose barbs, but Matt changed them for metal and welded a proper fitting.







All hoses and clamps are new.

Edited by jimPH on Sunday 12th December 09:36

[jimPH]

I bought SRM billet fuel rails, but they didn't fit too well on mine, fortunately another customer had some magnusson ones which fitted better and mine fitted on his so we swapped.





And thats the top end built up. Needed a new power steering pump, alternator and all the usual stuff like water pump, stat, heat shields etc..



Exhaust is a tubi that came with the car, though i think i will change it for a TopGear Switchable at some point. being a able to cruise and turn it off makes long distance driving pleasurable.

[200Plus Club]

Nice build.interested to see how it goes.

[Macron]

This looks like heaps of fun!!!

[samoht]

Always interesting to see the details of builds at this level, can imagine it'll have outrageous, useable performance.

[mwstewart]

Some great viewing there. What is the problem with the original water pipes? Are they are press-fit and eventually corrode or migrate out of the housing?

[jimPH]

mwstewart said:

Some great viewing there. What is the problem with the original water pipes? Are they are press-fit and eventually corrode or migrate out of the housing?

Porsche glue them in, so after some time they deteriorate and pop off with corresponding loss of coolant. One solution is to reglue and put a pin in so they don't pop off, which is easier to do with the engine in.

[Hoofy]

Mental. There's a short film on Amazon Prime (Superfast) that you might find interesting: https://amzn.to/3IIC7ru

They take a 997 GT2 and get it to 900bhp.

[M22s]

Following with great interest!

[jimPH]

Obviously the standard gearbox isnt up to the task. Most people fit the 997 GT2 main shaft and 1-3, then straight cut 4-6. However this doesn't solve the heat problems, so some people take oil from the diff area and dump it back over the gearset through an external cooler. 997 turbo gearboxes are out, they cant be upgraded and are known to be weaker.

I decided I'd keep my eye out for a 997 GT2 gearbox. After 18 months of searching I finally located one in Germany and got it sent over. It means i can only stay 2WD though, but then the 996 front diff is a viscous type and cant take the power anyway. Future plan will be to reconvert to AWD and fit a 997 front diff and control it through the syvecs or a DDC controller.

It didnt come with the oil pump or cooler though, so i had to buy all that.

The benefits of the G97.88 are a taller 1st, pressurised oil supply and internal lubrication, stronger main shaft and gears, plate diff (though weak and i've bought a wavetrac) and steel synchros. Im not doing the 4-6 straight cut though as i dont want the whine. It also uses a non accumulated clutch, so supposed to be a better feel. Box is like new:








Mods to fit:

New slave
New MC
New helper spring
New clutch lines
Clutch fork

I also got a billet trapdoor for extra strength, will fit that with the wavetrac later when I convert the box to AWD.

I'm not happy with the peddle fee though, its pretty stiff, so I'll be getting a bigger MC from SRM.

Edited by jimPH on Friday 21st January 14:37

[BrettMRC]

That should provide adequate performance!

Any pics of the overall package together?

[seefarr]

jimPH said:

mwstewart said:

Some great viewing there. What is the problem with the original water pipes? Are they are press-fit and eventually corrode or migrate out of the housing?

Porsche glue them in, so after some time they deteriorate and pop off with corresponding loss of coolant. One solution is to reglue and put a pin in so they don't pop off, which is easier to do with the engine in.

Hey, cut Porsche some slack - they were still experimenting with the strange new technology of "water cooling".

Great build thread too! All the little detail changes speak of a builder with experience and an eye on reliability.

[Dr G]

Oh wow, thanks for sharing in so much detail! Where do you think the torque will come in?

The switchable exhaust sounds a good plan. Is the tubi particularly noisy? Probably hilarious when you're in the mood but irritating if you simply want to go somewhere.

[Slippydiff]

seefarr said:

jimPH said:

mwstewart said:

Some great viewing there. What is the problem with the original water pipes? Are they are press-fit and eventually corrode or migrate out of the housing?

Porsche glue them in, so after some time they deteriorate and pop off with corresponding loss of coolant. One solution is to reglue and put a pin in so they don't pop off, which is easier to do with the engine in.

Hey, cut Porsche some slack - they were still experimenting with the strange new technology of "water cooling".

Hardly, they'd built plenty of the water cooled 924, 944, 968 & 928, and ceased production of them all too.

The glued in water fittings were a cost cutting exercise, nothing more, nothing less. It's led to some pretty horrendous shunts worldwide, when the fittings have come out and deposited a lethal, slippery coolant mix, either on the rear tyres of the car that had sprung a leak, or all over the track for following drivers.

Be under no illusions, this and numerous other cost cutting processes instigated at Stuttgart by the Japanese over the years, have cost many Porsche owners dearly. Profit was put before quality and safety, and continues to do so.

From this article in the NY Times in 1996 :

"Not too long ago, the production floor of Porsche's factory was not a pretty sight. Workers would storm off in a huff. Managers would fume. Voices would rise above the hum and bang of the line.

And Japanese engineers -- mostly Toyota alumni -- would wave their fingers, demand explanations, scold, lecture and browbeat, essentially telling some of Germany's finest automobile craftsmen how poorly they were doing their jobs.

Had the pride of German auto makers bowed under the dominance of the efficient Japanese? Sort of. What was in process was the salvation of Porsche A. G., Germany's ultimate symbol of racing car performance and autobahn freedom.

From the dizzying heights of the mid-1980's when American yuppies, not to mention staid German executives, had to have one, Porsche went to the brink of bankruptcy in 1992. Recession had crippled sales, and costs were out of control. Turning to the Japanese, with their "lean" manufacturing techniques, was considered its only hope of making a profitable car and avoiding the ever-rumored takeover by BMW, Mercedes-Benz or Volkswagen.

"It was the biggest shock for the company to accept that Japanese were walking around, not able to speak either the Schwabian dialect or German, and telling people what to do," said Wendelin Wiedeking, Porsche's 43-year-old chief executive. "They were tough guys. They were absolutely aggressive to the people. And we wanted it that way."

The remaking of Porsche using Japanese manufacturing techniques has a significance beyond the company. For years, German auto makers, feeling the pinch of more efficient Japanese producers, have tried to adopt elements of just-in-time lean manufacturing and to get high-paid German workers to be more flexible. But changes have been modest at best, leading many auto executives to vow they will never open a new car plant in Germany again.

Germany looked at Japan and said, 'Yes, but we can't do it here; we won't do it here,' " said Daniel T. Jones, a professor at the Cardiff Business School in Wales. "Porsche had no choice. And having done it, the argument that other auto makers ought to be following their lead becomes irresistible.

Feelings may have been hurt, but Porsche survived -- not only as a cachet name in German automobiles, but as the last remaining independent European manufacturer of sports cars. The company recently reported its first profit in four years, after $300 million in losses.

"That profit guaranteed our independence," said Michael Macht, head of Porsche Consulting, which the car maker formed to spread the Japanese manufacturing concepts it learned. "This is not a turnaround. It is a new company."

Today peace prevails on the Porsche line. The production changes imposed by the Shin-Gijutsu group, the cadre of former Toyota engineers to whom Porsche turned for advice three years ago, mean that more cars are produced faster by fewer people without losing technical sophistication and road performance.

And having put the losses behind it, the company can concentrate on developing new models and new markets. Porsche already has orders for 10,000 units of its new roadster, the Boxster, which it plans to introduce later this year as its least-expensive model. In 1997 it will roll out a new version of the famed 911. And the company is in discussions with other auto makers about possibly producing a high-performance off-road vehicle, a minivan and a small low-priced sports car.

The team of Japanese consultants now returns only about four times a year -- "to scold us," Mr. Macht said. But the innovations the Japanese initiated are being continued by the German engineers. Workers on the line submit 2,500 suggestions a month.

The factory is clean and quiet, its huge six-cylinder motors built with remarkable efficiency. Nobody stands around. No half-built engines sit to the side of the assembly line. And there are no bins of spare parts through which workers have to dig. The parts needed for assembly hang on carts that are pulled down the line with the engines, so that workers do not have to leave their work space.

Porsche management says the efficiency improvements are measured in more than just the company's return to profitability. It has reduced the assembly time for one of its speedsters from 120 hours to 72. The number of errors per car has fallen 50 percent, to an average of three. The work force has shrunk 19 percent, to about 6,800 employees from more than 8,400 in 1992. The line itself has been shortened and inventories have been cut back so much that factory space has been reduced by 30 percent. All this means Porsche is making more cars at lower cost.

Much of the credit for the remaking of Porsche is given to Mr. Wiedeking, a self-confident, direct hands-on manager who started as an engineer at Porsche in the 1980's and then left to run an automobile parts maker.

The company's family owners spent much of the 1980's warring with their appointed chief executives, eventually dismissing several. The family was often in the news and in gossip columns over their personal lives.

But no matter. The boom times early in the decade fueled sales, which soared to more than 50,000 a year.

Then the recession of the early 1990's hit. Porsche sales plummeted to 14,000 units in 1993, including a paltry 3,000 in the United States, its largest market. The family paused in its feuding to call in Mr. Wiedeking for help.

From the beginning, he says, his idea was to bring in the Japanese. First, he eliminated one-third of his managers and gave those remaining new assignments, so they would be struggling to learn new jobs -- "rather than waiting for me to make a mistake."

Next he took his management team on extensive tours of Japanese auto plants. They timed precisely how long it took Porsche to assemble body parts and engines and install carpeting and dashboards, then studied the comparable times in Japan. On most tasks, Porsche was taking almost twice as long.

"On those trips a lot of people said, 'I did 20 years of work and it's all garbage now.' " Mr. Wiedeking said. "It gave us an understanding of what had to be done."

The arrival of the Japanese in late 1992 was indeed painful. One of the engineers, Chihiro Nakao, says they were always polite to the workers but often sharp with the managers.

Porsche's assembly line, he says, looked like a dark warehouse when the Japanese arrived. On either side were shelves eight feet high with huge parts bins filled with 28 days of inventory. To get a part, workers often had to climb ladders, wasting enormous amounts of time.

First off, the shelves were cut in half and inventory reduced to seven days. Eventually the parts bins were eliminated entirely; Porsche engineers created a remarkably low-tech, but highly efficient parts supermarket in the basement of the factory. There, workers hook only the parts needed for each stage of assembly onto carts. The carts are then sent up to the line and accompany the car until they are used up, when they return to the basement to be refilled.

"Even the Japanese are interested in this system," Mr. Wiedeking said.

What is ultimately revolutionary for Porsche's auto makers is the redefinition of craftsmanship.

"The traditional craftsmanship for which Germany became famous was filing and fitting parts so that they fit perfectly," Professor Jones said. "But that was wasted time. The parts should have been made right the first time. So the new craftsmanship is the craftsmanship of thinking up clever ways of making things simpler and easier to assemble. It is the craft of creating an uninterrupted flow of manufacturing."

The company now has been able to turn its focus to product development. The 2-seat Boxster -- a roadster with Porsche's traditional flat, six-cylinder with opposing, or boxing, cylinders -- will cost about $50,000, compared with about $64,500 for a 911 coupe. Porsche hopes the Boxster will add younger professionals to its customer base of wealthy professionals and business people over 40.

Porsche still hopes to strip another 10 hours off car-assembly time, according to Mr. Wiedeking, a goal that would make the company comparable to the best Japanese auto makers. And Porsche is working with its suppliers to cut costs and improve quality and deliveries.

But the Boxster will be the true test of Porsche's campaign of self- renewal. BMW, Mercedes-Benz, Audi, Fiat and Rover have all introduced new two-seaters in recent months, or plan to soon.

"It is entering a very crowded market segment," said Steven Reitman, auto analyst for Union Bank of Switzerland in London. "The whole roadster market will be very crowded by the time Boxster hits the scene."

Mr. Wiedeking says simply: "For the others, a sports car is a marketing strategy. For us, a sports car is our life. If the customer feels he wants the real one, wait for the best."