kompressor one zylinder

[Heiko]

sombody know, what is happened to the bike wich has an hatz 1b30 with kompressor supercharger.?

one foto i find.

runs good with that kompressor or not.?

i try now the same because turbo was not so positive!



its an beginning.
now i have 0,3 bar in 4000ump.

was the best meeting between loss powerr from charger and bring power to engine to the 3 zylinder lombardini.
now we have so much snow that i cant try it. its the china diesel 418ccm.
what do you mean.
heiko

[Sphere]

Actually, I would have thought you would have better luck with the 3-cylinder. It seems to work pretty well for the Daihatsu engines? From what smart people have told me, a turbo on a single cylinder is useless, because there is too much time between the turbo spinning up and actually pushing air in the cylinder.

Also, if you add more air, you need to add more fuel. But I guess a seasoned mechanic like yourself knows this already.

[Sphere]

I have received word that the above reaction makes no sense at all when talking about blowers. Sorry for the misinformation.

[oilburner]

Sphere wrote on Sat Feb 21, 2009 7:55 pm:

Actually, I would have thought you would have better luck with the 3-cylinder. It seems to work pretty well for the Daihatsu engines? From what smart people have told me, a turbo on a single cylinder is useless, because there is too much time between the turbo spinning up and actually pushing air in the cylinder.

I think Sphere's comments are possibly on the right track:

According to Hugh MacInnes in his book Turbochargers, a small engine usually requires a plenum (airbox) at the intake because the airflow slows between intake strokes. Here's a quote from Hugh's book, in which he is discussing a two cylinder engine compared to a four cylinder:

Air between the compressor discharge and the intake ports is stagnant half the time. During this time, it's possible for the compressor to go into surge.

When the intake valve opens at high rpm, the instantaneous engine demand can exceed the flow of the turbocharger.Intake manifold pressure will drop off even though the average flow is far below the capacity of the compressor.

The author he is discussing gasoline engines, but I expect a similar problem could show up on the slower revving diesels, perhaps to a lesser extent , and it would occur with superchargers as well as turbos. Paraphrasing the quote, what he's saying is there is still positive pressaure in the intake manifold but the air stops flowing because the intake valves are all closed. When an intake valve then opens, the air rushes so quickly into the cylinder that the intake manifold pressure drops off rapidly, adversely affecting the compressor. The plenum provides additional air capacity to minimize this problem. I suspect a single cylinder engine would make the problem worse. I guess only a sensitive recording pressure indicator would confirm this.

With respect to the efficiency of the supercharger, the engine first has to produce additional power to make up for the mechanical losses of the supercharger, and then make even more horsepower to realize any performance improvement. My instinct tells me there might be some performance improvement, but this would be offset by high fuel consumption. With no mechanical losses a turbo is definitely the way to go. I'd go for a small turbo that spins up quickly, coming in at low rpm, with a wastegate, and a plenum integrated into the inake manifold.

Hugh says you can successfully turbocharge any engine.

Back to the drawing board

[Nanko]

Heiko uses a belt driven compressor , not an exhaustgas driven turbo charger.
Especially with single cilinder engines the compressor is IMO the best solution to increase intake pressure.

It would be interesting to measure the pressure with a fast response pressure gauge , the 0.3 Bar is the average pressure with the intake valve closed for > 75 % of the time.
With a wrong compressor gearing ,pressure easy goes negative when intake valve is open

[Diesel Dave]

Regardless of which method is used to provide the compressed air you need somewhere to store the charge whilst waiting for the inlet valve to open. Both Superchargers and turbo's will provide a steady stream of compressed air whilst the motor will only open it's intake for a limited duration every second crank revolution.

The alternative is to compress the air a lot higher into a smaller space but this is innefecient and in the case of petrol motors very dangerous - imagine the results of the pressure keeping the inlet valve open when the plug fires......

There are 2 areas of experience applicable:

1) Big Diesel Loco's
2) Drag bikes

Big diesel locomotive trains can have a single turbo for each cylinder, back in the 1970's such loco's would sit outside Liverpool Street station in London and rev up to full rpm's to spin up the turbochargers, drop the rev's momentarily and engauge the drive whilst the turbo's were still spinning at high speed. Without this little dodge they didn't have the power to pull up the incline to Bethnal Green at a decent speed.

Drag bikes like the 'Mighty Mouse', used Shorrock vane superchargers on single cylinder 500cc Vincent Comet motors to very good effect. These are extreme engineering examples but it had two huge pipes from the blower to the intake ports to store compressed air. Petrol motors also benefit from an additional butterfly throttle plate just before the intake but luckily diesels don't need this.

Anecdotal evidence suggests you need a plenum chamber volume of 3x cylinder capacity and you need to be cautious of water gathering inside as is common on vertically mounted intercoolers.

For a 400cc single your going to need an intake pipe about 3" (7cm) diameter and a foot long (30cm).

In order to get a reasonable boost (under 4psi) in the cylinder your going to need a plenum chamber pressure of nearly 9psi to allow for the drop in pressure when the intake opens - it will get much worse if there is a valve overlap as your precious charged air whistles straight out of the exhaust.

So the bigger the plenum chamber the less power will be absorbed by the charger but the slower the throttle response will be to changing rpm's.

[oldbmw]

Once again Dave has explained it well. I have to confess I do look out for his posts as they are nearly always informative.

This business of air chanmbers is often misunderstood. For ablower or turbo, you need a reservoir of air between the output of the blower and the inlet tract.
What is not so often realised is for a carburetter bike a big air chamber after the fiter helps breathing a lot by allowing the filter extra time to allow the air to flow so reducing inlet drag. This is why tiny filters stuck directly onto carburettors mouths are usually inefficient. The less cylinders you have the greater effect airbox size has.

[Heiko]

i know that i need more fuel for more air but that is no problem buy china diesel.
with chamber between charger and valve i will try different sizes.
today i begin to make me an test stand for messure the power off the engine on the backwheel. because than i can try every change i make.
than if i know more i will hold you informed off the more power off charger.
heiko

[Heiko]

i know that i need more fuel for more air but that is no problem by that china diesel.
with chamber between charger and valve i will try different sizes. thanks for informing me.
today i began to make me an test stand for messure the power off the engine on the backwheel. because than i can try every change i make.
than if i know more i will hold you informed off the more power off charger.
heiko