Got a question for all you gear heads. Scary thing but I was thinking and wondered why a normally aspirated diesel enging makes so little power and is so slow. When things like high compression are present and diesel being far more energy producing than gas yet a non turbo engine is gutless. I understand theory of forcing air/fuel for power and the reason for power gains but?? without= nada.

 

Because the diesel is a air limited engine. It can only draw in so much air per stroke. This is where turbocharging comes in. For every 1psi of boost is equal to about 10hp.

MikeyB

 

I have a 4600 series International with a Re-man International non-turbo charged motor. It's an outright DOG, it's geared so low that it can haul fairly heavy, but it has a top speed of 61 MPH empty & on flat ground.

Since it only gets run twice a week for a total of about 50-75 miles I don't complain much, but I know better than to pull out in front of anyone.....

 

Low rpm compared to a gas engine and typically a longer stroke/bigger flywheel for slower revving ? I'll guess that a similar dog would be a gas engine limited with similar bore and stroke limited to the same rpm range.

 

Look at it this way.....When you have a N/A engine you are severly limited as to the amount of fuel you can put in without a severe smoke problem. With a turbo forcing more air into the cylinders there is a lot more oxygen available meaning more fuel without the smoke. Smoke basically equates to a rich fuel condition where all the fuel does not get burned. Unburned fuel going through the exhaust equals no power. Try pulling the boot off your turbo and you will really see what I mean.
Tom

 

You can turn the fuel up on a NA diesel and it'll run like a scalded dog and smoke like a tire fire (for a little while - until something melts). The real problem from the manufacturer's point of view is smoke, though. There's just not enough air available to burn the fuel cleanly without a turbo, so the fuel settings need to be conservative to keep the engine running clean.

 

I wasent the results of overfueling a N/A diesel would result in anything but massive smoke. I guess I would like to compare a identical pair of engines, stroke/bore/flywheel/valve size all that stuff and see how they compare. Although the compression ratio wouldent be close to run different fuels. Makes me rethink my old post on military rigs that are dual fuel. how do it know?? Actually much of this was brought on after driving a 6.9 Ferd. Although it had a Banks kit on it made me laugh. I think my old 240 D benz would have whopped it ****.

 

Build a pair of 350 Oldsmobiles.

 

I think the turbo makes up for the diesels inability to rev up past 3000 rpms.

 

Them Oldsmobibbles were cool as well the Chebbys. I drove a PU completly under water once, hit the what we thought was a puddle at 50 mph it still ran after yankin the glow plugs. Nothin like a engine flush to revitalize things.