Dyno?

metalmagic

New member
Anyone know where to get the water break part to build a dyno? I need to hold about 60hp but I really want to build it myself
 

JLSRacing

Member
I have a older Stuska Dyno. I should hold 100hp +. Can send pictures if interested. The frame will run both 2 and 4 cycle motors with kart frame mounts.
 

alvin l nunley

Site Supporter
I built one back in 1985. I used a GoPower water break. The only thing included was the strain gauge.
It’s a lot easier now days.
I was working part time in a welding shop so in my off hours I could build the frame and motor mounts. I hope you have lots of money.
Comments, compliments, criticisms and questions always welcome.
 

curtracer

New member
Why lots of momey ???? .measure acveleration of a known mass while monitoring an unknown prime mover . Anyone can rush out and buy one if they want it bad enough im with metal majic lets build our own get it improvised keep it secret ( not for profit).use it ruthlesslly for morning of tuning and diagnostic while giving those guys who rain money on tje speedway .just kidding .but i want one myself leaning twds inertia.
 
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metalmagic

New member
Could u not just use a big brake rotary and caliper to create drag and use a old style torque wrench to measure the torque?
 

laser3kw

Member
Hey metalmagic
I Agree about tuning. Somethings are better on a water brake, some on the inertia. I have both.
I have a 15 year old Stutska model 90/ It was set up with a self contained water system. That way you don't have to run your garden hose all day and flush the water down the drain. It has the original load gauge but also has a Davenport data logger for computer logging.
I tried to find "Cambletown, In." on google but no luck. You may not be that far away.
if you are interested let me know. I would like to see someone get it that will use it.
 

alvin l nunley

Site Supporter
I wish I could find a big enough water pump t hold 70 ft/lb of torque then I could figure the rest out

Why would you need that much capacity? I can’t imagine a kart engine that could generate even half that. My KT would make about 10ft lbs. at max. torque. And the faster you spin a water brake, the more it can hold. Torque X RPM / 5252.1 = HP
Comments, compliments, criticisms and questions always welcome.
 

alvin l nunley

Site Supporter
I have a 15 year old Stutska model 90/ It was set up with a self contained water system. That way you don't have to run your garden hose all day and flush the water down the drain.
That’s true, but with a fresh water supply you don’t have to worry about the water getting hot and changing your readings.
Comments, compliments, criticisms and questions always welcome.
 

metalmagic

New member
Lol I don't want to build it twice and I guess u could say I have aspirations lol and im working on 50hp now so I hope a v twin is in my future lol

Why would you need that much capacity? I can’t imagine a kart engine that could generate even half that. My KT would make about 10ft lbs. at max. torque. And the faster you spin a water brake, the more it can hold. Torque X RPM / 5252.1 = HP
Comments, compliments, criticisms and questions always welcome.
 

Outrider

Member
Why would you need that much capacity? I can’t imagine a kart engine that could generate even half that. My KT would make about 10ft lbs. at max. torque. And the faster you spin a water brake, the more it can hold. Torque X RPM / 5252.1 = HP
Comments, compliments, criticisms and questions always welcome.
Al, not everyone dyno's normal kart engines - I have a friend who built his own kart frame (think slightly stretched flat kart with twin tube roll bar) to make the engine installation a bit easier - the last time I saw the engine on a dyno, it made 117hp and about 46lbft of torque. That was two iterations back, and I suspect it makes a bit more torque and a little over 120 hp now.

It's water cooled, has 4 cylinders, and displaces 600cc......... :) there is a class for it in SCCA autocross.
 

alvin l nunley

Site Supporter
It's water cooled, has 4 cylinders, and displaces 600cc......... :) there is a class for it in SCCA autocross.

This is a kart forum so I “assumed” that’s what we were talking about.
I hope in the future people remember that, or at least mention the application. Not that I would have any rules against regular car engines being talked about, but I’m sure you know what I mean.
Comments, compliments, criticisms and questions always welcome.
 

metalmagic

New member
Anyone built there own inertia dyno? Hard/easy cheap/expensive? What about using car brake pads and caliper for resistance instead of water or oil?
 

DynoDon

Moderator
Back when I was researching my broken water braKE, I remember finding stuska ( spelling) and go power. Both had a line of large water brakes. Just Google "waterbrake"
 

SHAVED APE

New member
Land and sea also have the kit to build a water brake . I have a Stuska water brake w/ Depac for the big stuff and and a hydraulic for the kart stuff .Just bought another hydraulic with a strain gauge that i have to fix up . I like the brake over the inertia just because of the ability to back off throttle make a change and throttle back to the same rpm and see if you screwed up or became superman . :)
 

kingtut

Member
Hey metalmagic
I Agree about tuning. Somethings are better on a water brake, some on the inertia. I have both.
I have a 15 year old Stutska model 90/ It was set up with a self contained water system. That way you don't have to run your garden hose all day and flush the water down the drain. It has the original load gauge but also has a Davenport data logger for computer logging.
I tried to find "Cambletown, In." on google but no luck. You may not be that far away.
if you are interested let me know. I would like to see someone get it that will use it.

From the sounds of it many like myself have both types of Dyno's. I have the Stuska Model 90. Have had it for over 30 years. Have an Inertia dyno for the last 6 years.
They both have the place and advantages and disadvantages. For the Briggs and Clones I prefer the Inertia dyno. If I'm having Carb problems (Cracks or air leaks) with briggs or Clones love the water brake for quick repeating loads. My Stuska is manual, but after 30 Plus years I'm pretty good at it.
It depends on what your going to do with the Dyno. Now with the Briggs and the clones I like my interta dyno better. If I were still doing open 2 strokes then my Water Brake dyno.
 

alvin l nunley

Site Supporter
So y r some direct drive and some geared.... Seems like gearing would change hp?
Not really. You measure the torque at a given RPM, if you change the gear, yes, the torque changes, but so does the RPM. Torque X RPM / 5252.1 = HP
Geared and direct drive, I think, are the same thing. It’s the difference between having a clutch on the engine, or not. Some use a clutch. Sneeks for instance. Other than making it easier to start, I have no clue why.
One problem with inertia dyno’s is most have no peak load device and the wheel feeds power back into the engine. Some use an engine clutch to prevent this but then you have the power loss in the clutch. And you still get some feedback, I think.
Look at the dyno curves of inertial dynos compared to water breaks; you will always see more HP at the high end with the inertial dyno.
The first inertial dyno I heard of, one that Pete Muller was involved with, they had a 471 blower attached to simulate an ultimate load. They would vary the air intake on the blower to produce enough load to hold the engine at a peak RPM. An RPM that they might see on an Enduro track. They would hit the gas and, using a stop watch, clock the time it took to get to a certain RPM. If they made a change in the engine setup, they would just look for quicker times. This was in the seventies and data acquisition was expensive and hard to come by.
Comments, compliments, criticisms and questions always welcome.
 
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