29Firefox

480? kinda just out of reach. The 6LY2 series is a 2 valve engine. 440 is the max your gonna get out of it without major. modifications. Now the next generation 6LY engine the 6LY3 which has the same displacement but is 4 valve engine. The 6LY3 will do 480 hp in stock configuration. Plus the 6LY2 is famous for nasty emissions the 6LY3 is a lot cleaner burning.

Jassman

Correct me if Im wrong..The newer one (480 Hp) is elec injection vs the 440 which is mechanical injection. Do they by chance have a program out yet to raise the hp on the 480hp Yanmar. Thanks Jeff

29Firefox

Don't know of any program templates available. But the real problem is the Yanmar doesn't have the mechanical reliability to handle the extra horsepower. Someone is bound to find a way to turn it up but the crank, rods and pistons just can't handle it. Compared to Cummins Yanmar turns their engines up close to the max in stock configuration. If Cummins did the same thing they would be selling a stock 700 hp QSB 5.9

29Firefox

When you bump the TST does the RPM climb a little before the popping starts? Does the popping show up at peak RPM and power falls off? Sounds like the edges of your turbine blades are going supersonic.

stirling

The popping start when max torque start ,lets say from 1700- 2700 I ,m draining the rail and the engine starts to pop.

Higher in the powerband ,from 2700-3500 ,I don,t have the popping ,and reach 52 psi max in overdrive lock up.

Funny that some tell the Yanmar 440 can do an easy 480 -500 hp , I guess we,ll see what happens on the dyno,with an EGT gauge in the exh manifold ( pre turbo )

29Firefox

As long as "easy" includes serious pump modifications, a bigger turbo, a bigger raw water pump and a bigger aftercooler

E Colby

The endurance run was "sanctioned" by SBI.

mthill

As stated by 29Firefox, The CP3 is capable of well over your 550 hp number. Period. You have some other limitation that is preventing it from working as well as it could/should.

What is your fuel supply pressure (to the CP3). To get into the 700s, you may need 70-80psi. You need enough pressure to keep it full of fuel. Running it at these levels will degrade the life of the pump. But, you can buy several pumps to replace a single stock unit for the price of the dual kit (~$3000 USD). Redundancy of course has some value, so it's not for nothing.

The 735hp QSB that Banks did was back in '02. It was done on a single CP3. I don't think dual pump kits weren't even being considered back then. Another version of this engine was built for boats. "At the request of the United States Navy, Banks' Cummins turbodiesel engine developed for Sidewinder Dakota is redesigned and "marinized" for use by Navy SEALs for military application" from http://bankspower.com/timeline.cfm. A 700hp marine QSB is possible, but to make it live, a substantial number of changes should be made.

The intake manifold isn't necessarily a limiting factor, but the intake and exhaust ports are. Substantial gains can be had with some mill work, a bit more with a lot of work. Intake port flow at 28"H2O can be readily increased 25% or more. This is very beneficial to overall performance and efficiency.

The "Brazil" head 29Firefox mentioned still has room for improvement. More importantly, it's cast from a better alloy. He can certainly give you a lot more detail than I can. For 700hp, the stock head, ported, will get you there for awhile. I agree with Firefox that studs aren't necessarily the right solution. Bottom tapping for additional thread engagement is probably of little use, but it can't hurt.

52 psi of boost is more than enough to make 700hp if you can get the mass flow up by improving flow t the cylinder and out of the exhaust. Any restrictions result in an lower mass flow for a given boost pressure. Fix the restrictions instead of trying to force the air in with more pressure. This isn't rocket science, it's an air pump.

Think of it like this: sitting on your couch, watching TV, you could probably breath comfortably through a drinking straw. No go out for a run, trying to breath through the same straw and see how far you get. Replace the straw with one the size of a garden hose and things get better. Adding a turbo (or a bigger one) to the engine doesn't change the fact that the QSB intake port is a straw.

29Firefox

Your not making sense. The rules are simple. To get more horsepower you need to burn more fuel. If your were draining pressure in the fuel rail it would get worse as your horsepower out put went up. In fact it would prevent you from climbing any higher in the power band period. The fact that you get past a certain point and things sort themselves out debunks the lost fuel pressure theory. If you can put your truck on a dyno. Take off the duct from the inlet side of your compressor and use a strobe tachometer to measure your turbine speed. Engine load factors, rpm, manifold pressures, and a whole slew of factors determine turbine rpm. I think your going to see that your turbine compared across the engine powerband is spinning fastest just before the "popping" occurs. If so take the max rpm and outside diameter of your compressor turbine and figure out how fast the outer tips of the compressor turbine are moving. Sounds like your tips are hitting Mach 1.

stirling

At maximum torque the engine has the longest injector duration pulse width (max duty cycle) and when the engine is not turning that fast the cp3 pump isn,t pumping at its max speed too,thats why the draining starts lower in the powerband.
the injector duty cycle is where the injector gives the most fuel in comparing with engine speed /revs..watch the injector time /duty cycle time in a 2 d field at max torque.