flywheel question
 

the way i have been told boats use a flywheel as in the type used for a manual trans car. what would happen if you used a lightwieght aluminum flywhel or a SFI approved flexplate as with an automatic. i know there is a thickness issue whick is no biggie, but sems if you could knock off that much rotating mass if would free up alot of horsepower. just a thought.

I run an aluminum flywheel on a 632 Merlin. I'm not sure how much power you gain from going with aluminum, but I do know this "big inch" motor will rev like a Honda. :cool:

MXZ< it is my opinion and belief that you won't gain HP because once it is turning the weight is a non issue. I have a heavy flywheel instead of a light one which was on the boat in the begining because the weight helps in shifting the OD from neutral
into gear with out stalling. I have a lot of canshaft so it lopes heavy, with the heavy flywheel it smooths it out some. Hope this helps some. GEO

I would think with a lightweight flywheel it would over rev quick when you exit the water and upon re-enty it would bog down do to light mass of flywheel.
Just a guess :)

these are somethings i didnt consider but should. was hoping someone had already tried this swap (ie. guinea pig:eek: ) and could tell me the pros and cons of it thanks for the info. any other thoughts. jdnca1 do you have problems with motor shifting? i realize you have a touch:rolleyes: more horsepower than my 7.4 efi mag does.

In years past, the rule of thumb on flywheels was -light weight vehicle alumimun flywheel; heavy weight vehicle, heavy wheel. The wheel stores kinetic energy, if the boat is light no problem with the aluminum wheel. Engine will rev faster, but when a load (like boat reentering the water) is on the engine, rpm will drop like a rock.

Flexplate with an HP500 EFI
 

My two cents,

I am running a standard GM 502 automatic transmission flexplate in the Camaro behind my HP500 EFI and I can tell you from experience that the engine rev's a "whole lot" faster than it did in the boat. I would think that most people would find it too fast in rough water. I can zing it from 2800 RPM to the rev limiter in less time than it takes to shift into second. :) Another consideration with the EFI motor is that it almost rev's too fast for the stock merc programming.

Again, just me two bits.


Adivanman

http://www.adivanman.homestead.com