OT latest update on 4000 HP natural gas engine

Well, it is still not running correctly.

The original turbo was re-installed after the re-designed turbo was found to be too large, turns out the old turbo is too large in cold weather, they are upsizing the waste gate, as I suggested 4 months ago, to accommodate the bigger turbo under "all" circumstances. The leaner burning engine is producing a lot more exhaust gas than the engine did before, and looking from an exhaust volume perspective a lot like a Diesel. I think they will install the new waste gate in the upcoming month. The old waste gate was 4", the new one will be 5" and the piping is being upsized.

They installed a pre-chamber to make it burn leaner. They found out the pre-chamber was too long and there were rich pockets inside it causing detonation. They shortened the pre-chamber and that seemed to get rid of the detonation issue. They also changed the position of the pre-chamber, it was mounted horizontal, the new mounting is at a 45 degree pointing down. These two changes made the flame front appear to be about 2 degrees under no load and 4 degrees quicker than the old one, thus the engine started pre-igniting. They have now retarded the fuel timing and it is not not pre-igniting.

More testing will be done once the new waste gate and corrected turbo are installed.

This was a 2 million dollar fixed bid conversion, I think they are about a million over, glad I did not bid that.

I think you lost me after the first sentence, but am sure you know what your doing. Good luck and keep on trying. Ron MN

In a sense, this sort of brings to mind the mistaken theory that you can increase the horsepower of your Farmall M simply by installing a bigger carburetor. That doesn't work either.

Thanks for the update. Was wondering what was the outcome on this engine the other day.

On this conversion what is pushing this, EPA requirements or fuel gas savings or a lot of both?

Our Company while I was working in my factory job, had a big engine like that. Not sure of the size, it looked like a V 8. Pistons looked to be 10 inches dia. It was in another dept. I never got involved. It was always being worked on.They were going to produce their own power, and sell some back to the electric co. It never worked out. It was finally removed, and a large Cat. engine generator was installed for emergency power. Stan

that much HP & my imagination as to engine size, makes 5'' wastegate seem still small.

Would it help to put a swirl plate in the air flow. Keep pockets of air and fuel coalescing?

Always interesting to hear what is going on with your project. Don't understand all of it, but seems awfully complicated. Is this such an unusual case? Hasn't someone already gone thru a project like it?

If the piping were 50 feet going from 4" to 5" would make a big difference. The short distance for a waste gate, I don't see that it will make much difference in flow.

Worked for a Fiat-Allis dealer back in the 80's. The 8205 engine was a sweet package in a 150 hp dozer till they started
playing the horsepower game to keep up with Cat. Yea, more fuel= more hp right? Started getting field service calls about
oil shooting straight out the exhaust. Found holes the size of a dime in the tops of melted pistons.

Their answer to the problem was to add a turbocharger which seemed to help. Kind of hard to explain to customers why after
only 300 operating hours, their new dozer needed a turbo installed!!

Beagle

Project was to reduce NOx, should also see a 5% fuel savings.

Field engineering by trial and error.

Whew!

The buyer should have had a deliver or pay contract, liquidated damages. I bet the loss to the buyer of the use of this engine has far surpassed the contract cost of the engine, unless there are spares taking the load.

David;
The thought that occurs to me is the possibility of using a blower/supercharger approach with a VFD driving it?? Just rambling thoughts.

I think your engineers need to go back to school and learn some basic principles, otherwise it's going to take a few more wasted millions of dollars to make that engine run. I tried to tell you once before that a lean mixture is one cause of detonation.
But they are on the right track with a larger waste gate that lowers the boost which Richens the fuel to air mixture.
The size of a turbo is very important also. They have to be sized just right. When I first started hot rodding engines I thought I knew everything, ha ha. We had a Oliver 1955T and we thought let's put a larger turbo on it and add more fuel. Well that was a waste of time and work. It made quite a bit LESS power!
When you build a race engine with a power adder like a turbo,blower or nitrous you have to start with a rich mixture when you first fire up the motor then you can read the plugs and lean it down gradually, otherwise if you start too lean it can detonate and blow up the engine. I have seen pictures of blowers that blew up because of a lean mixture. They have learned to wrap the blowers nowadays to keep from killing someone.

Whoever wrote the job specifications will be responsible for the cost overage. If the owner or owner's representative wrote the spec, then the owner better be looking for his check book.

I think this is the norm when dealing with these big engines. The engineering will show what will work but don't bank on it. The co. did a lean burn on an engine in Birmingham Al. and it took some extra work.

What is the top speed on this engine, 250 rpm?