Turbo Charging Gas Engines ?

The point of the original quote is missed ...in an auto the power required in most situations is small so a small engine can provide the power with high economy ..but for those situation that require extra power then the turbo can come in ....if you boost 15psi you in effect double the capacity of the engine....hence small engine economy off boost and big engine power on boost .... 1.2 litre at cruise 2.4 litre for acceleration ...This is not the marine situation where the load at a given speed is constant ..no hills ....

 

As long as the wastegate and overall setup is tailored to the engine there should be no major problems. There are turbocharged engines from the 60s and 70s probably still running around like the old Datsun Z cars for instance. Of course, the higher the compression of an engine, the higher quality of fuel required. There is information out there on what must be done if adding aftermarket turbocharging to a naturally aspirated engine. Go with better plugs to ensure ignition at higher pressure. There are other less expensive undertakings which can probably add comparable power to an engine, but turbo is the best option for power along with better fuel economy. Some people online even claimed to have gotten over 150 BHP from a home-brewed turbocharged 50 cc two stroke from a scooter.

 

Thats 3000 HP per litre I think not .....

 

And just try boosting some 'stock, non-turbo' designed engines with a steady diet of 15 psi and watch them come apart in short order.

 

my boat is powered by 2 inline GM 250 6 clyinder engines. I purchased M&W turbo kits that used RAYJAY turbos. to keep the boost low, under 6 pounds, they took a B comperssor housing and put in a smaller E wheel. It did nothing for the bottom end which was ok, but above 2500 rpm's it really came on strong. At 5200 rpm's it was singing along. With propeller, carb, distributer and exhaust modifications, I picked up about 10 MPH. It was supposed to be up 20-25% in horsepower.

 

Those GM 6 cyl inline engines were good old tough engines. They were built to put out and handle torque. Your boost pressure of 6 lbs is very reasonable, compared to 15 !

Exhaust turbos are notorious for their lack of low end response, and one of the reasons some car manufacturers went back to belt driven superchargers. Boaters on the other hand don't need that low end 'jump-off-the -line' response, so turbos are the better option.

BTW, did you realize that the inherently best naturally balance cylinder configuration is the in-line six arrangement, not 4, not V-8, not V-6. BMW was one car manufacturer that stuck with that arrangement for years. Ford and GM should consider looking back at their good old solid performers as well. Cutting 2 cylinders out of their engines could save manufacturing cost and give them better fuel economy.

 

Cutting 2 cylinders out of their engines could save manufacturing cost and give them better fuel economy.

Could be fairly EZ to build an I-6 for the coming tiny death reap econoboxes , and a V 12 for the cars that weigh over 1500lbs using all the same components , except the block..

FF

 

I think GM did that during the 30's. Somewhere I remember Dad telling me about the V-12 that used the Pistons, rods, etc of the Six.
There were lots of strange things done under the hood's of those early cars.

 

Why do you think the Chrysler 'Slant 6' exists? It was supposed to be a V-12 for luxury and muscle cars, but the recession of ~1960 put a halt to that plan. So the slant 6 was born instead. As an interesting side note, for technical/logistical reasons, namely, the main and cam bearing oil galleries were on one side of the V-12 block, that is the 'side' of the engine that became the slant 6. Trouble is, that side of the block did not contain an oil gallery for the tappets, so hydraulic tappets were out of the question. So the slant 6 got solid tappets at a time when the whole (American) industry had already made a switch to hydraulic tappets.

Jimbo

 

I've often thought Chev could keep its great Suburban vehicle while giving it 25-30 percent better fuel economy....just cut two cylinders out of that big V-8, and put an extra gear or two in the transmission....wala 25-30% better fuel econ.

Then cut out the um-teen different models they have of the same vehicle and save some more manufacturing cost...doesn't take a rocket scientist to figure that out, but certainly appears a lot of highly paid car executives couldn't

 

Jumbo, I wonder if the Volvo slant six diesel started its life as a V-12?

I considered grafting one of them into my Ford pickup till I drove one. It might as well have been a Slant 3!

 

Turbo and compressors are just as old as racing car
MG and others used this much before war
The main problem is that the dynamic volumetric ratio is very wide on a charged engine, turbo or compressor
This will be the origin of the stress as it will make the mixture set up much more difficult as it will depend on variable pressure

The other much more interesting thing is that a turbo is rising efficiency of an engine... I insist on efficiency, not just the power, but the power per litre of fuel is increased
Strange isn't it ?
The 2 LT is not respected as energy to run the turbo is only coming from the engine, so efficiency should go down as power is lost in turbine friction, and a lot, as friction is not linear but exponential with rotation speed.
But no ...efficiency goes up !
This is the important point about the turbo effect...it is always so fun that such an anomaly is accepted without any interrogation !
Maybe it is because turbo are now common item, so it is too late to hide them, but their true real effect is ignored.
Same mistake is not done on much more sensible subject, not spread yet, such as cold fusion, violently rejected.

 

The Exhaust driven Turbo was best used in WWII on the Hi-altitude Re-cip's of the Bombers and Fighter escorts, to provide Combustion Air in the thin air.

Turbos are really better suited to stable Rpm engines. The expanding gasses do provide enough energy to run a pump which provides a little more air than atmospheric pressure.

All those variables you mentioned can be handled with Electronic Fuel injection and all the sensors EFI uses. The SAE are pretty good at getting a lot more out of a Turbo engine without killing the engine.

When you try to get a lot more Rpm out of an older, normally asperated engine, without an Engineers help, is when you start killing good engines.

 

Of course, cause that's the dummy way of turboing an engine.
If someone wants to push anything higher than 7 or 8 psi(general rule of thumb) there is more involved than just slapping a turbo charger and some pipes. But generaly 7 or 8 psi of boost will greatly improve performance on stock internals. For anything higher, forged internal are recommanded and usually the way to go. But again, 7 or 8 pounds of boost is usually plenty to have fun on a stock NA engine. That much boost can usually improve performance by has much as 75% with crappy tunning. So a motor doing 100hp will usually do easily 175hp on stock internals if you give it enough fuel.

Turbocharging an engine is a science. You can do it right, or you can do it twice.

 

Turbo's

I turbo'ed a 1.6L, 1972, stock, rebuilt Datsun 510 4-cyl engine with a Rayjay

turbo which had a "B" housing on it using a 1 1/4 SU carburator many years

ago. I ran a 1 1/2 straight exhaust out the back. It was noisey at idle, but

once the turbine spooled up it was almost quiet. I ran 100/130 av-gas and

reached 14 PSI on a regular basis using a two stage water injection system.

My point is, I was 19 years old and just winging it and it ran for years.

I raced the car and did quite well until we flew off the side of a mountain.

I agree that marine applications are too demanding for "high" pressure

boosting.