Engine Displacement and Cylinders

[GPrince]

1 your not paying for the fuel

2 the abrahams m1a1 uses turbine engine = High power dencity

[454Casull]

High power density? Wrong term.

[ivymike1031]

sounds like an appropriate term to me... what was your complaint?

[454Casull]

My mistake. I thought power density and power-to-weight ratio were different.

..mmustt... get.... of... crraa

[Gravitom]

Just a little clarification

Modern F1 cars use 3L V10s with an extremely short stroke that lets them rev to about 18,000 rpms and produce about 850hp.

Late 80's/Early 90's F1 cars used 1.5L V6 Turbos producing 1500hp. They were eventually banned because they were too fast and getting expensive. But they were wrong and modern V10s cost just as much.

[Jimbo_Jones]

heavier pistons are harder to get moving but have more weight... therefore more torque... whereas, little pistons are easier to get moving but have little weight... therefore more horsepower

[Gravitom]

Originally posted by Jimbo_Jones
heavier pistons are harder to get moving but have more weight... therefore more torque... whereas, little pistons are easier to get moving but have little weight... therefore more horsepower

Does that mean when you put in lighter forged pistons you are actually reducing your torque for more horsepower?

[texan]

Originally posted by Gravitom


Does that mean when you put in lighter forged pistons you are actually reducing your torque for more horsepower?

No, piston weight has nothing directly to do with power output.

[SaabJohan]

Originally posted by Gravitom
Just a little clarification

Modern F1 cars use 3L V10s with an extremely short stroke that lets them rev to about 18,000 rpms and produce about 850hp.

Late 80's/Early 90's F1 cars used 1.5L V6 Turbos producing 1500hp. They were eventually banned because they were too fast and getting expensive. But they were wrong and modern V10s cost just as much.

The bore is usually around 92-96 mm and the stroke 42-45 mm, and at 18000 rpm this gives forces in the 8000 G area. The old F1 turbos usually had max rpm at around 12000 and this gives forces in around 5000 G but today the parts like pistons, piston pins and connection rods are lighter. To make them light materials like metal matrix composite and titanium are used, and these materials aren't cheap..

[454Casull]

You say metal matrix composite; which part[s] use this material? And what is the metal matrix? What is the composite?

[ivymike1031]

I don't know very much about these mat'ls, so I don't have a whole lot to add to the discussion.

The whole shebang is the composite (metal and all).

Definition I looked up online: Metal Matrix Composites: Materials in which continuous carbon, silicon carbide, or ceramic fibers are embedded in a metallic matrix material.

Try this site for more info on Al-SiC MMCs: http://www.x-lite.com/materials.html#mat

I don't know for sure (and right now I don't feel like searching to find out), but I would guess that in an F1 engine, MMCs are used in the conrods and pistons, but probably not the crankshaft or piston pin. It wouldn't surprise me to find out that you can make an aluminum cylinder wall into a MMC cylinder wall through some special treatment processes. I wonder how well MMCs wear, and how well parts that run against MMCs wear.

[SaabJohan]

MMC is used in pistons, cylinderliners and possibly also in block and cylinderhead.

http://www.perfectbore.com/motorsport2.htm

Conrods are titanium and the crankshaft is made of steel.

[454Casull]

MMCC's Al/SiC MMC has a density of 2.9g/cc, while 2618 Al alloy, which is what many racing pistons use, has a density of 2.81g.

[ivymike1031]

ok... was there a point you were planning to make?

[454Casull]

No, I'm just wondering why it's used.