Prevost engine swap possible?
I'm looking at a used Prevost that's a beautiful unit in nice condition, but it's got the old DD 8v92 motor, which I'm really leery of. It's got a rep as a dripper and fuel guzzler. What are the chan...
Forum Discussion
Greyhound ran the 8V71 and 8V 92 in many applications from coast to coast, for many years, until enviromental regulations made a cleaner engine a requirement.
The 8V92 is 92 cubic inches per cylinder and there are 8 of them! IT is also supercharged and two stroke, so it makes power on each stroke. It is a little more fuel costly than a 4 stroke, but if you get a quote of $25,000 to install a rebuilt inline 6 and adapt to your transaxle, you will be lucky.
The inline 6 will be about 8 feet long, while the V8 is a compact 5 feet long. You might not have enough space. You will never save $25,000 on fuel. You might get 7-8 MPG with the most fuel efficient engine and transaxle, while this one has a lot more slippage than a modern transmission, but still was built with fuel efficiency in mind.
The 8V92 can be turned up to about 500HP. The 8V71 mentioned above is much smaller - giving up 168 cubic inches with smaller cylinders. They also came in 6V71, 6V92 and inline versions. I worked on a 16V92 generator, rated at 1500 HP and 750KW power output! It turned 1800 RPM and roared! The most that many road engines are allowed to run at is 1700 or 1800 RPM, before the governor kicks in.
The advantages of a 2 stroke engine over the 4 stroke is more compact size, lighter weight per HP, and less internal friction per HP rating. The disadvantage is a little more fuel consumption. It will use about 20% more fuel than a 4 stroke engine. But they are fun to drive! My buddy has one, and he said he took it in for a check up - they hooked it up to the computer. Said it was rated at 450 HP and they could turn it up to 500, but he said no, it is fast enough. They stated the maximum road speed was 87 MPH. I suggested that his poor little Honda was hanging on for dear life to the back of the RV!
Good luck with your decision! I think you will end up liking the 8V92. Drive it hard, the engine can stand to be wound up to it's max RPM rating. At slow engine speeds, it will not put out the HP that you will need for getting over a mountain, but it will cruise along with no problems.
Another friend had a 8V71 in a 18 wheel tractor. He ran coast to coast with it but had poor performance in the mountains. He ended up turbocharging it, and installing fuel injectors from a 92 cubic inch engine. Then it would make lots of power, got 10 mpg empty and 6 full. Just check the fuel and fill it with oil. Because it is two stroke, the air is blown into the engine, then into the slots in the cylinders. IT can take in oil and burn it with the diesel fuel. So it can burn a lot of oil at higher RPM range.
The generator that I took care of had a specific over RPM shut off, that closed off air to the supercharger in the event that the engine started to burn it's oil, and not slow down. In come cases, they would shut off the diesel fuel, but if overfilled with oil, and over the rated RPM, it would splash enough oil into the cylinders to keep running at the higher RPM. It was a sort of panic switch to close off air to the engine on the generators.
Good luck, happy camping!
Fred.
The 8V92 is 92 cubic inches per cylinder and there are 8 of them! IT is also supercharged and two stroke, so it makes power on each stroke. It is a little more fuel costly than a 4 stroke, but if you get a quote of $25,000 to install a rebuilt inline 6 and adapt to your transaxle, you will be lucky.
The inline 6 will be about 8 feet long, while the V8 is a compact 5 feet long. You might not have enough space. You will never save $25,000 on fuel. You might get 7-8 MPG with the most fuel efficient engine and transaxle, while this one has a lot more slippage than a modern transmission, but still was built with fuel efficiency in mind.
The 8V92 can be turned up to about 500HP. The 8V71 mentioned above is much smaller - giving up 168 cubic inches with smaller cylinders. They also came in 6V71, 6V92 and inline versions. I worked on a 16V92 generator, rated at 1500 HP and 750KW power output! It turned 1800 RPM and roared! The most that many road engines are allowed to run at is 1700 or 1800 RPM, before the governor kicks in.
The advantages of a 2 stroke engine over the 4 stroke is more compact size, lighter weight per HP, and less internal friction per HP rating. The disadvantage is a little more fuel consumption. It will use about 20% more fuel than a 4 stroke engine. But they are fun to drive! My buddy has one, and he said he took it in for a check up - they hooked it up to the computer. Said it was rated at 450 HP and they could turn it up to 500, but he said no, it is fast enough. They stated the maximum road speed was 87 MPH. I suggested that his poor little Honda was hanging on for dear life to the back of the RV!
Good luck with your decision! I think you will end up liking the 8V92. Drive it hard, the engine can stand to be wound up to it's max RPM rating. At slow engine speeds, it will not put out the HP that you will need for getting over a mountain, but it will cruise along with no problems.
Another friend had a 8V71 in a 18 wheel tractor. He ran coast to coast with it but had poor performance in the mountains. He ended up turbocharging it, and installing fuel injectors from a 92 cubic inch engine. Then it would make lots of power, got 10 mpg empty and 6 full. Just check the fuel and fill it with oil. Because it is two stroke, the air is blown into the engine, then into the slots in the cylinders. IT can take in oil and burn it with the diesel fuel. So it can burn a lot of oil at higher RPM range.
The generator that I took care of had a specific over RPM shut off, that closed off air to the supercharger in the event that the engine started to burn it's oil, and not slow down. In come cases, they would shut off the diesel fuel, but if overfilled with oil, and over the rated RPM, it would splash enough oil into the cylinders to keep running at the higher RPM. It was a sort of panic switch to close off air to the engine on the generators.
Good luck, happy camping!
Fred.
