2 stroke turbo engine (FI only)

[IG.]

I've been thinking... Tell me where I am going wrong.

You take a 4-stroke engine, and make the following changes.

o Change crank and cam ratio to 1:1 instead of 2:1, so for every revolution of the crank, the cams also turn once. Cams profiles have to be changed (new cams of course).

o Intake air is pressurized (5 - 10 psi).

o FI maps have to be re-adjusted.

o Ignition times have to be adjusted.

Here is how it "supposed" to work. Let's start from ignition at TDC, and go 360 deg till next ignition.

-30 - 0 deg: ignition (negative degree for advance)
100 deg: exhaust valve opens
140 deg: intake valve opens, compressed air purges exhaust gases
170 deg: exhaust valve closes
180 deg: intake valve closes
230 deg: fuel injected, compression continues
300 - 360 deg: next ignition

All degrees are to just illustrate the principle. Of course, extra cooling is a separate matter.

That would be a two stroke turbo. What do you think?

 

[†WÃ￾§†ëD]

huh?

 

[Mikey D]

not sure where I saw it but have recently seen a 4 stroke using premix and no crankcase oil.

A 2 stroke cycle diesel engine uses almost exactly what you have described but diesel fuel & 22:1 compression w/ no spark plug.

 

[IG.]

Thanks, Mikey,

I did a quick search on Yahoo! and found this Diesel 2 stroke engine.

It could be a cool 2 stroke gasoline engine - supercharged, or turbocharged (assuming compression ratio is reduced, and fuel injectors are added), producing like 2.5 times more power than a 4 stroke with the same size cylinders.

Don't know about emissions though.

 

[Mikey D]

Correct, I forgot to mention the 2 stroke cycle diesel uses a supercharger, no intake valve and at least one exhaust valve.

With an exhaust valve the emissions should be no problem.  Put one thgether and I'll split the proceeds with you!  



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[IG.]

Ha-ha-ha!

That would be a neat project.

But, I've never heard of modern car/motorcycle turbo/super-charged 2 strokes following this principle.

Perhaps there is no mass market for it.

I wonder if anything like this is used in racing.

 

[Noltez]

I replied in the Turbo forum in detail, you should check it out.





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