Highly boosted engine - University Project

[diesel des]

You can't compare any high boosted diesel- with a gasoline engine.
The combustion of those engines is very different, especially you haven`t any knock problem with diesel.
Basically leads a high turbine upstream pressure to a high level of knocking on gasoline engines.
Knocking is different from engine to engine. -> You need a very good combustion model from the engine including a knock controller.

I think in the first step, you should set up a few limitations:
-turbo speed
-compressor outlet temperature
-temperature intake manifold
-cylinder peak pressure
-pressure turbine upstream / peak pressure at the exhaust ports
-temperature turbine upstream


In GT-Power you could easily scale the turbo-maps up and down. Play with this function learning by doing

Generally I agree but it depends on fuel. Lpg propane or e85 work great with high boost numbers. High boost numbers work great with Turbos in series. A vnt small turbo feeding a large free floating turbine work great in that application. Even model lean burn with Lpg and lots of boost to keep efficiency up.

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[hunker7]

Does anyone know TDC Clearance Height for AAN engine? Can't find it anywhere.

[diesel des]

Not sure what stock is but I am for 1mm

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[hunker7]

Not sure what stock is but I am for 1mm

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I used 1mm and it says valves are hitting pistons basically. I guess it's down to design of the combustion chamber and piston, so I'll just increase TDC clearance height slighty till I am in the safe.

[newsh]

Or change valve timing?

Clearance will affect compression ratio and squish

[hunker7]

Or change valve timing?

Clearance will affect compression ratio and squish

I'll look into it, it's just they've done it so I am learning software as I go along, and I am starting to run out of time, so might need to take "shortcuts"

But then again you specify compression ratio separately, so it's possible that within software it doesn't affect CR.

[diesel des]

The pistons have cutouts for the valves. Is it that clearance your after?

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[hunker7]

The pistons have cutouts for the valves. Is it that clearance your after?

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Those cut-outs are not considered in the software as far as I know, and therefore 1mm isn't enough of clearance.

[Thuppu]

Valve to piston clearance should be more than 1mm for safety, way more. Squish then less, if I remember right stock is something like 0.8mm.