paulywood1

I have Enforcer Magnum 57, Motor ported by Butch the boat man, .005 base gasket, lighten piston, low drag seals, big bore carb, 2" band pipe, clutch, etc...
44 mph loose, 41 mph solid. Still working on correct lenght for band pipe & header.

Will a stock lenght Stuffed Crank help out in power on top or just low & mid?
Is it worth the money?
Will I have to change pipe lenght also?

Thanks, Paul.

Justaddwata

My Feedback: (3)

Hi Paul,

Welcome to the forum.

Personally I would not mess with the motor without checking with Butch. I have a butch motor and believe it is one of my best motors. Impessive power. If there were benifits to the stuffed crank I would think butch and other high end modders would use them more. But ask Butch his thoughts - he did the work and should have an answer for you on any true pros and cons for any additional tweaks.

benckie

the stuffed crank is a round crank difrent to zenoah cranksand its my understaning that a zen water coolled engine needs to be moded to fit the sikk/cy stuffed crank, i belive oneail brothers sell moded zenoah crank cases that have been moded to fit a stuffed crank, you might find it will not fit you cank case with out it being changed or moded to fit, it would not behard mod to do.

the idea of the stuffed crank is to increase secondary compresion/charge of the motor and all that jazz.... the idea is there, butfrom persoal expernce i have not noticed any improments using stuffed crank on stock or modded motors, some say yeah there is a improvment i have personaly not see it in my motors and the zenoah cranks seam to waer better.

i realy dont think it will give you any extra power it will not give any extra mph or make your boat more stable at speed, and like just water says speak to the engine maker and see what he things about it, i asume if butch thought they where any good the motor would have one in it.

i know some engine builders dont like them cause of the stuffed bit is actually plastic to fill in the gaps of the crank to make it round, these can come off and get cuaght in the motor causing it to jam or spin a bearing causing damage

jacob711

it is said that a stuffed/full circle crank will give slightly more torque, but the stuffing bits tend to fly out at high rpm and wreck motors, better off with a plain full circle crank which is basically the same but without stuffing bits, but you will need a custom adapter to fit one on a marine engine

or even better yet a 1mm stroker full circle crank, you will also need an adapter for this one

but with that said it still may not give a huge increase in power

Scott Schneider

Made numerous Zenoah 231/260's using them. If running a stock engine don't waste your time and effort.
But if willing to tweak the internal setup there is a gain to be found, but doing so is more than just simply screwing parts together.
See: http://www.modelgasboats.com/option,...id,14/id,1668/

Many who RACE, no longer do this because of the rules being tightened up on what CAN or CANNOT be modified and still be legal.

The link listed actually shows an engine that Set and broke the NAMBA G-1 sport hydro 6 lap National record twice !!
It does work, and quite well if executed correctly.

paulywood1

Scott, read many of your articles, thanks for all the info.
I notice your in Placerville and I'm in Rancho Cordova, maybe we can meet out at folsom lake or somewhere and run some boats.
If your into it, I'd like to get another 5 mph out my magnum 57, see if your doing any mods for money.
Thanks, Paul
916-955-8213

glennb2006

Paul,

just re -read the posts on this one, the boat is not going all that quick, that is, not for the motor package etc that it has in it, it might be that the key to finding more speed that you need does not lie within the engine.

Maybe the boat set up will deliver more impressive results for you.

Glenn

Tahoe1970

I agree , full circle not worth the effort...............You would get better results changing your set/up