Originally Posted by Chris Sunkin (Post 2347370)

With many performance boaters and racers operating with huge, if not unlimited budgets and with the quality of engine builders the likes of Sterling, etc., that's not likely.

Originally Posted by DonziJapan (Post 2347934)

The same thing happens with turbos on an unloaded engine it doesn't register boost on the gauge. Load does not "make" boost. An unloaded engine is more volumetrically efficient than a loaded one. Which means the fuel and air flow through easier. The boost is the same between an loaded or unloaded engine its the difference in resistance that causes the difference in your boost pressure gauge readings. To further simplify what you're looking at consider this. A roots blower is a form of compressor. Take your garden variety shop compressor. It has a fixed output same rpm same piston. Run it with the valve open the pressure will never build. But close the valve and pressure will build. Either situation the output of the compressor is the same just the load has changed so the gage reading changes. Your "boost" gauge is nothing but a pressure gauge reading the air pressure in your intake manifold. The intake manifold is like the tank on your shop compressor and loading the engine equates to closing the valve on the tank. Hence the rise in pressure in the intake manifold. Now this is the fact the output of the roots blower is linear in regard to the engine rpms. The lobes on a roots blower displace a fixed amount of air each time they go around. The output is determined by how many times the lobes go around in a minute. Some blowers are driven at different ratios than the engine but still the output graph will be in a straight line just at a different angle. Again we're back to the illusion of boost on your pressure gauge.he blower doesn't achieve max boost at the lower RPM either the gauge has topped out or there is a relief valve that has opened at a preset level of boost and is dumping the excess. In fact the blower is putting out more boost as the rpms rise than your boost gauge is telling you. :evilb:

Originally Posted by Bigyellowcat (Post 2347593)

I have ran my turbo engines for 5 years at 1800 hp and they have the same cranks, rods, pistons, valves, blocks, ect. times 2. that they were built with. only did normal maintenance oil changes and valve springs, lifters, gaskets ect.

We are willing to build them and stand behind them like I said.

Originally Posted by Bigyellowcat (Post 2348466)

Pretty low RPM, that is one reason my engines have lasted. we usually only turn them in the 4000 rpm range but I have over 1100 hp at 4k. I run 110 octane fuel. I will admit that the 1800 hp was at around 20 lbs of boost on a 9.5-1 engine.

I tell people that my engines made 2000 hp because we ran the texoma run and the shootout at 25 lbs of boost but we never dynoed them with that high of boost. kind of scarry when all that tubing we made to dyno them kept shooting off the engine.