In the background, an engine is technology to make the industrial basics traditionally, and it is clear worldwide and supposes that it was big Hino challenge to establish technology of Hino Motors themselves. The GR100 engine became a new design of Hino Motors. Many experiments were repeated. In September, 1964 before 40 years, GR100 just came out to a market. However, it was a life very short fatally afterwards.
When we consider the history of many engines, they take dozens of years, and the aging is formed. As a representative example, the engine of Austin of 1950's was succeeded to an A-type engine of Nissan Motor. A V8 engine of existing Land Rover dates back to Buick of 1962. An engine of Renault which Contessa 900 was copied from is succeeded to ranges and Renault R5 of 80's afterwards. As for them, 30-40 years all and life are long.
Why did I say such a thing? It was GR100 which new technology was included in various ways. However, excepting early stage of trouble with a design change, GR100 cannot take in the aging by practice in a market and had to leave a market. If there is some progress, it is degree to be seen in a G-type engine (basically, GR100) which put on Toyota BRISKA pickup truck. GR100 is the engine which disappeared soon getting evaluation in a market. In addition, GR100 is extremely few if I watch it about volume of production to be said to have been useful for the world worldwide. And I suppose that it was a large amount of development costs for a block other than Contessa 1300 if, as a result, I watch a cost price as business.
In fact, there are a lot of cars is running on a high way without overhaul cheerfully even if exceed present, 200,000km after 40 years. As a result, how should we evaluate it? Was GR100 a perfect engine? Or was it merely lucky?
Now, here is the main subject. I like simulation software of engine tuning on a PC of an engine tuner shop of American Drag Race and I play now. I would try to test "validation of GR100" with using the computer technology and this simulation software.
<Validation 1>
At first simulation tries to assume normal coupe specifications it for trial (refer standard specifications). It shows about 70HP /5000-5500rpm(SAE) so that a list shows it. 65HP of catalogue notation are DIN. I think that it was 68HP by SAE notation in those days. This simulation is a great thing. A peak of torque accords with 3000-3500rpm, too. The time did not have simulation whether it was before 45 years by a design. It is a PC. However, it is very much impressed to give the output that the latest software simulation is equal instantly.
<Validation 2>
If sports kit was put on, how will be normal GR100? It is Solex-Carb and a cam of some high turns type, the compression ratio that it raised to 9.3, a boa of 72.2mm and exhaust system of public road specifications near straight. Unofficial data of those days become 78HP (DIN) of about 13HP up with a simple kit. Simulation is equality in a little over 80HP/SAE! In addition, porting is not included in here about high tuning.
<Validation 3>
In this way, as for this simple software, trust stops in amateurish estimation remarkably. Therefore here is to inspect 75mm boa up of the prohibited tactics that a speed guy and legendary winning all the time Contessa Dune Buggy tried secretly of much Contessa from those days (see boa up (75mm)). It is quite horsepower up of approximately 10% by torque up to 5000rpm. It is not the effect that I thought of if I think about reliability. However, a horsepower will appear to many 75mm piston users more because they perform improvement intake & exhaust at the same time.
<Validation 4>
Next is a stroker engine made by BRE for trial (see stroker engine). It produces 98HP (DIN) in 5500rpm at a bench of Hino Motors of those days and, as for it, lower than 4000rpm are unstable, and it is written that it is not a thing to be able to use. Be elaborate, and a result of the street is given to simulation again. The maximum output in simulation is about 120HP (SAE) in 7000rpm. 5500rpm is the best turn experiment measured value of Hino Motors. More than it does not seem to have turned this in piston speed and other conditions as experience of a GR100 developer of those days. It is an engine of 120HP if I think about a cam put on. However, I suppose that there were various problems to get it to there.
<Validation 5>
Here is a goal of this theme. It is GR100 which a market did not have for only two years. When It became a more powerful engine when it was longevity life, I want to yearn. Fortunately, we think that there is it, and we practice even today that we passed through from development for 40 several years. In such a thought, here is to test a piston of generally possible 72.2mm, intake valve diameter up, a cam (about 280 degrees), improvement such as an intake & exhaust system, and the result that there is in "possibility". It produces a little over 120HP (SAE) in 7500rpm without sacrificing low speed torque like normal GR100. We want such an engine. It may be a similar with Donington Mini of those days and a Goldini engine of Renault.
We have still various problems in GR100, but we can make the world beyond a life of about 2 a real thing if we make an effort like other OHV engines. There was not it by time limitation as Hino Motors. This engine simulation tells us that it is possible now.
An outsider writes a selfish opinion and thinks that I am sorry. However, I would hear comment of Dr. Suzuki of a GR100 designer by all means and consider it to be it. In addition, the YE47 & YE57 engine that Hino tried a new design after GR100 wants to try to do simulation if there is an opportunity.
<Engine Simulation : HP>
