The April 2009 issue of Racing On Motorsport Magazine (No. 437)(Japanese Language)
The deciphering of this was done some time ago, but I never took the time to smooth it out in English.
This article seems to confirm some of the apparent motives and patterns of action of Isuzu. After the early 1970's, they don't seem to hold as much value in maintaining a constant participation in motorsports as either advertising or proof of credibility. The three generations of Geminis were supported in rally and touring car racing in Japan, and the trucks always run Dakar, but there is not a whole lot in international competition. And it appears that they decide they want to prove something, throw their whole weight behind the effort, succeed, then conclude that they have proven their point, pack up their toys, and go home.
The Conventional Wisdom of the F1 World is Overturned; The Excellent Nature of the Isuzu Made V12F1 Engine Quietly Tested
April 1, 2009
In the summer of 1991, a Japanese made F1 engine was quietly tested in a Lotus chassis at Silverstone. It performed perfectly without even minor trouble, and people were impressed. Even though there was no trouble at that first test, the V12 engine disappeared.
At the beginning of August, 1991, there was a private test at England’s Silverstone Circuit with three F1 teams: McLaren with Ayrton Senna, Leyton House with Maurício Gugelmin, and Lotus with Johnny Herbert.Lotus’ Motivation Was Different From The Other Teams
At that time, McLaren was aiming for the title with a Honda 3.5 liter V12 engine. This was the third season of a four season sweep for McLaren. But Williams, using the Renault 3.5 liter V10, was threatening that sweep.
Leyton House was using the Ilmor 3.5 liter V10 engine, which had reliability problems which had caused them to retire from numerous races. So this private test was the last chance for them to sort things out for the last half of the season.
On the other hand, Team Lotus had financial problems. In the third race of the season, the San Marino Grand Prix, Mika Hakkinen had finished fifth and Julian Bailey had finished 6th. So a total of 3 points were earned. How could they survive this situation? So Team Lotus’ purpose for joining the test was different from the other two teams.
A new engine was installed in the previous season’s 102 chassis.
So, for this test, Lotus did not use the Judd 3.5 liter V8 engine. Was it a Lamborghini 3.5 liter V12? No, not that either. In fact, they brought an Isuzu engine, from a company known for truck and diesel engines.
Isuzu started developing the 3.5 liter engine for F1 in January of 1990. Only four people were involved in the project. This is because Isuzu never intended to provide the engine for F1 competition. So, when I interviewed the engineers involved in the P799WE project in 1997, one of them told me:
“They wanted to test the level of their gasoline engine design and engineering. Not only for F1, but at the time, the 3.5 liter naturally aspirated engine was the standard. We wanted to see our level compared to the other companies. So the project is over if we achieve a sufficient level of power and reliability. At that time, not only Isuzu, but the other engine makers were doing the same thing.”
Probably, this statement is accurate.
Some of them were involved in only the design, while others were involved only in the building. Some were used in the F1 project, but the project was secret. Even the media did not know anything about it.Engine Builders Admire V12
For a 3.5 liter naturally aspirated engine, the engineers decided that a V12 was the best bet at the time. They did not separate test and production. This configuration was used not only in F1 Grand Prix cars, but also in Group C Sports Cars. From the beginning, they used the maximum level of technology in the effort.
For parts, the parts were built in-house. They ordered metal from Kobe Seko Sho (Kobe Steel, Ltd.) and other companies. For pistons, they went to the famous German company “Murray/Mare”(?). By December of 1990, all of the parts were in hand. They had enough parts to build ten of the P799WE engines. On December 24th, 1990, the first engine was built. In February of 1991, the first engine was started and the first bench test produced 646 PS at 12,000 RPM (637 HP at 12,000 RPM) and 41 kg-m at 10,000 RPM (296 lb-ft at 10,000 RPM). This was more than they expected out of the first engine, and was comparable to the magazine published performance figures for the other manufacturer’s 3.5 liter naturally aspirated engines of the same time.
They improved the design a little and got the numbers up to 765 PS at 13,500 RPM (755 HP at 13,500 RPM) and 42.5 kg-m at 11,500 RPM (307 lb-ft at 11,500 RPM).
So, according to the engineer’s statement, these results should have brought a successful end to the project. But they wanted to put the engine into a car, and see what it could do.
Their wish came true fairly quickly. They had a business relationship with Lotus in the 1980’s and 1990’s through the Gemini and Piazza cars. In addition, there was some connection through Komatsu and Tamiya, who were sponsors of Team Lotus and had ongoing business relationships with Isuzu Motors. This made for a very smooth connection between Lotus and Isuzu.
In May of 1991, after Golden Week, Peter Collins, Lotus Managing Director, and Peter Wright, Lotus Racing Car Designer, came to Japan. Isuzu introduced the P799WE engine via a third party (shokai), and Lotus showed interest in the proposition. They started to prepare for testing at Silverstone.Everything Went Unexpectedly Well
The 102B Chassis, which Lotus had developed for 1991, had the Judd EV V8 engine. The car had been built for the V8 engine. The Isuzu V12 seemed an impossible fit. It was expected to be a difficult installation. The original 102 Chassis had been designed for the use of a Lamborghini 3512 3.5 liter V12 engine. The 102B had been adapted from this chassis, and perhaps taking a step backward toward the original 102 would solve the problem. Adapting the 102B Chassis to accept the Isuzu V12 engine involved adapting the engine mounts, building a new bellhousing, rebuilding the engine cowl, and setting a larger radiator. Even though they had only three months time, Lotus and Isuzu had the car fully prepared by July 31st. On August 2nd, they finished the shakedown test including the system check, on Lotus’ test course.
On August 6th, they transported the newly finished “Lotus 102C Isuzu” car to the South course of Silverstone. On August 7th, they ran this unique F1 machine about 150 km on the Silverstone track. On that day, they ran the car for 15 laps non-stop and trouble free.
Isuzu’s engineer, who came to Silverstone with a camera, said he looked like a tourist. Talking about the test, he commented:
“The car didn’t have an alternator, so they switched out several batteries. Because of this, the car could not run long, continuous lengths of time. When the car started running, I was really impressed. Because the sound that I heard with the engine on the test bench was totally different than the sound it made when installed in the chassis. The staff of Lotus praised us about the speed and acceleration, better than the Leyton House Ilmor, and compared to the McLaren Honda, it was only a few KPH slower.”
“By the way, the Lotus 102C Isuzu’s best lap time was 1:30. The same day, Senna in the McLaren Honda ran a 1:24.7 second lap and Maurício Gugelmin in the Leyton House car ran a 1:25.4 second lap. You see, the Lotus time was not the best, but Maurício Gugelmin had the first heat tires and both McLaren and Leyton House were running F1 racing gasoline. Some of the time difference is accounted for by the difference in tires and fuel. But this was the first dress rehearsal for the Isuzu, which was also carrying 80 kilograms of extra weight in batteries, because the car did not have an alternator. The setting was not perfect.”
This gives some context to evaluate the Lotus 102C’s lap time.
About a month later, Collins from Lotus returned to Japan for a press conference concerning a cooperative business venture between Lotus and Komatsu. Collins commented about the test at Silverstone:
“I can not tell you which company the engine was from for the test. But this is my first experience that a racing engine started on the first try. Time was OK. But we could fulfill the number of laps without any trouble. Not only the engine, but the other Japanese items worked wonderfully. I believe it could be possible to team up for a F1 racing effort.”
We don’t know if Collins consciously made the comment, or if it was lip service. Because Lotus had no budget for a racing program at the time, and everyone expected the comments were like grasping at straws toward a racing effort.
The comments by Collins lead the media to believe that there was a possibility, maybe even a probability, that Isuzu would be starting an F1 program.The Plan Was Until Test
Again, the engineer that developed the P799WE said:
“Isuzu didn’t have any intention to provide engines for F1 racing, spending further money developing the engine, or spending money sponsoring or supporting racing teams. We planned to build the engine and learn at the bench. That was the end of the project. The Silverstone test was paid for out of the money originally allotted to pay for the bench testing. Just set the engine in the chassis, that was the original plan.”
Looking back, one of the engineers said:
“If I have a chance, I would like to run that engine again.”
So, Isuzu’s 3.5 liter V12 engine was run on the circuit only once, the Summer of 1991. Almost 20 years later, we interviewed Isuzu about the P799WE, but Isuzu declined to comment, saying that it had been so long since they had ceased sedan/passenger car production.
In 1997, there were 7 engines, and enough spare parts to assemble two additional engines. Maybe the engines are in the corner of the Fujisawa factory. Or, maybe they were destroyed.
In 2009, there is one P799WE engine at Tamiya Headquarters, and the writer said he received a piston from one of the engineers he interviewed. That is all that can be confirmed to exist: one engine and one piston.
But one of the engineers involved in developing the P799WE is still working as an engine engineer for one (unnamed) F1 team.