merc 888 (or general engine question)

[mrdjflores]

question....
why are most of the ford, chevy based I/O setups use a manual flywheel??
i know for the ford engines, it can't be for the engine weight balance...the early engines were externally balanced (28 oz) and they have manual and automatic flywheels that are 28 oz balanced...

someone asked me this and it has be puzzled....

anyone know of a good reason why manual flywheels?

 

[achris]

Re: merc 888 (or general engine question)

The clue is in the name, 'flywheel'. An engine will not run well without one. A flywheel is not there just to balance the engine, it helps the engine run smoothly. Cars with slushboxes have a drive plate bolted to the crankshaft, not a flywheel, the slushbox torque converter is bolted to the drive plate, and that has sufficient mass to act as the flywheel.

Chris......

 

[mrdjflores]

Re: merc 888 (or general engine question)

thats the best explanation i have heard....but it seams that the mass and torgue of the drive spinning in the water would provide enough mass to compensate

 

[Don S]

Re: merc 888 (or general engine question)

The water works at trying to stop the prop from moving. If you was not moving and the drive was in gear and the prop was spinning, almost immediately on putting the drive in neutral the prop will stop moving.
With all the gear changes of direction, bearing preloads and friction in the drive, there is no mass to act as a flywheel.
Everthing from the crankshaft to the crank attempts to stop the engine. Except the mass of the flywheel.

I would bet that without the flywheel, the engine would probably die when first put into gear.

 

[RogersJetboat454]

Re: merc 888 (or general engine question)

thats the best explanation i have heard....but it seams that the mass and torgue of the drive spinning in the water would provide enough mass to compensate

I'm guessing you meant to say prop?

By that logic, a car with a manual transmission shouldn't need a heavy flywheel because the wheel's have enough mass to keep the engine spinning. Problems with that logic; What happens when you put it in neutral? What happens when you put it in gear? How much more likely is the engine going to stall when the interrupter switch bumps the ignition off for a moment? Your engine needs it's flywheel to maintain a good idle, and help it through the initial bump of a load, or momentary loss of ignition.

 

[achris]

Re: merc 888 (or general engine question)

thats the best explanation i have heard....but it seams that the mass and torgue of the drive spinning in the water would provide enough mass to compensate

The prop spinning in the water is a load, not a mass..

A load is trying to stop the engine, a mass is trying to keep it running.

 

[stackz]

Re: merc 888 (or general engine question)

pretty much what everyone else says but you also need something for the starter to engage unless you want to try to pull start the engine which would suck unless you're hercules

 

[mrdjflores]

Re: merc 888 (or general engine question)

on an interesting note....my engine specs:
block is a 69
heads are 70 (1970 351W to be precise - 60cc chamber, 1.85 int valves, 1.54 ext)
manual flywheel is stamped C6ZE (66 mustang)
bought a regular 73 truck manual flywheel for $25 and sold my mustang one for $249...hahaha