BigMike's Forum

Automotive and Theory => Engine Theory => Topic started by: Sirdeuce on April 17, 2010, 08:19:58 PM

Title: Lightening rotating assembly
Post by: Sirdeuce on April 17, 2010, 08:19:58 PM
Better to lighten flywheel or engine internals? Light weight crank, rods, pistons, with standard weight flywheel. or just removing half the flywheel mass with standard weight internals?
Title: Re: Lightening rotating assembly
Post by: BigMike on April 17, 2010, 11:28:13 PM
The flywheel has the largest diameter and thus the largest moment of inertia. Any change to it will make a greater difference than changes made to internal components.

If we can only do one and not both, then I say standard internals with a light weight flywheel. Also we'll retain the durability of the stronger engine internals.
Title: Re: Lightening rotating assembly
Post by: Sirdeuce on April 17, 2010, 11:52:58 PM
How 'bout the case of a torquer? 22R in a 4X4 truck. Lighten internals, but use a heavy flywheel.
Title: Re: Lightening rotating assembly
Post by: BigMike on April 18, 2010, 01:47:49 PM
Reciprocating mass is as reciprocating mass does. The case for a truck would be to build up inertia so that slight inclines in the road has less affect on the vehicles velocity, and also when rock crawling, so that a sudden drivetrain impulse doesn't overpower the idle speed torque output of the engine.
Title: Re: Lightening rotating assembly
Post by: Sirdeuce on April 18, 2010, 06:04:13 PM
Just trying to find a way to reduce overall mass while keeping enough energy stored to lug those low rpm loads. I guess I was thinking it would be better to have all the weight in the flywheel instead of spread throughout the engine.
Title: Re: Lightening rotating assembly
Post by: BigMike on April 18, 2010, 10:43:58 PM
I guess I was thinking it would be better to have all the weight in the flywheel instead of spread throughout the engine.


I think we should do both: light internals and light flywheel. What flywheel are we going to use? We could use my 9-pounder if yours is crazy light.
Title: Re: Lightening rotating assembly
Post by: Sirdeuce on April 19, 2010, 11:53:54 AM
My flywheel is 9lbs, 200mm. Yours may be better if it's a 212mm.
Title: Re: Lightening rotating assembly
Post by: BigMike on April 19, 2010, 06:36:59 PM
Pictures taken from my SUPER old page located here: http://bigmike.marlincrawler.com/stage1/running_gear/toda_trd/index.html


My TODA wheel, 9.5 lbs:
(http://bigmike.marlincrawler.com/stage1/running_gear/toda_trd/toda_9_5.jpg)