V8 Engine - Maximum RPM

[Paul B Technic]

I was thinking last night about how strong Lego is and what sort of loads (physical and rotational) something like a Lego Technic engine could handle. For something like the standard engine below what sort of RPM's do you think it could handle and what parts would break first?

I might build up one and run something like an electric drill just to see, has anybody done this before?

Paul

[LEGO Guy Bri]

Very interesting question. Since the technic motor isn't actually producing power, I don't think there would really be any load. Its free spinning, so attaching a drill to the crank shouldn't damage anything. Honestly, I don't think a drill will spin fast enough. The average drill's max RPM is around 400, I think.Some thing like a Dremel, that can spin up to 12,000RPM or as low a 1000RPM might give a better result as to what it can handle. If you feel froggy, gradually crank it up til something comes loose. I have a feeling the g-force on the piston would cause it to pop out. Or worst case scenario a a connecting rod jams and cracks. I would like to know instead of speculation on this

[Sariel]

I ran the Lego V8 at 2000 RPM and everything was fine. It sounded cool too.

[Paul B Technic]

Thank you for the replies, I might build it up over the weekend to test. I will post my results.

Paul

[Ape Fight]

Thank you for the replies, I might build it up over the weekend to test. I will post my results.

Paul

My guess is a fair bit of heat at high rpms

[martinnygaard]

In my Case IH' Combine Harvester, the V8 engine also run around 1000 to 1500 RPM. and a spinning with the same speed - very cool sound ..

[Blakbird]

I was thinking last night about how strong Lego is and what sort of loads (physical and rotational) something like a Lego Technic engine could handle. For something like the standard engine below what sort of RPM's do you think it could handle and what parts would break first?

Real engine speed is limited by heat, but more importantly but the forces and stresses generated by accelerating the mass of the pistons and connecting rods. The LEGO pistons are very light, so they do not have much inertia. I have connected a V6 to an old 9V motor which turns about 4000 rpm with no problems. It is fun to watch.

[LEGO Guy Bri]

Could anyone provide a sound clip or video? I'd love to here one

[allanp]

They do sound really cool. I connected a v8 to two old style, ungeared 9v motors with a 3:1 upgearing. That went soooooo fast! I always like to spin the engines fast in MOCs because it's more realisic, however in my latest jeep hurricane MOC (just got the bodywork to finish), so much mechanical power is required to turn it on the spot that there isn't much left to power the two v8s at a very high speed, so they run a little slower than my usual.

Edited May 7, 2011 by allanp