Small engine dyno ideas

Jesse Nordlander /
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Bought this at an auction for $5 6 years ago. Everyone was downtalking it, i just smiled. Its finally time to put it to use.

It is an old go-power water brake. Im thinking to run 2 driven rollers to the input? Any ideas?

Re: Small engine dyno ideas

Holy crap that's awesome

Re: Small engine dyno ideas

Jesse Nordlander /

certaintly useful, hp is hp regardless of a fancy printout. will probably be handy for checking tuning progress. probably wouldnt be perfectly accurate

Re: Small engine dyno ideas

Any updates on this?

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Beach Club Nick /

I'm also interested as to whether this went anywhere. My new year's resolution was to put together a dyno this year

Re: Small engine dyno ideas

I am not electrically inclined but I just had a thought that the indoor bike trainers could be adapted to measure hp at the wheels. They also have resistance settings to maybe simulate going up a hill, if going up a hill is a thing people measure.

Re: Small engine dyno ideas

Pushrod Fifty /

That looks cool. No joke. Most of the factories I have worked in used test instruments to this degree on a regular basis.

Re: Small engine dyno ideas

I've been working on this off and on for a couple years now. It's the second version of an engine Dyno mostly set up for 1 speed.

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My original plan was to use the power steering pump shown in the pic but a couple weeks ago I bailed on that and bought a proper hydraulic pump.

It should be good for 15-20 HP with the new pump. I still have Lot of work to do on it and progress is real slow since it's way off on the back burner.

Re: Small engine dyno ideas

Jesse Nordlander /

So I was slightly discouraged from this due to gopower recommending only using Dow Corning 200 silicone fluid, which equals $$. Does anyone recommend an alternative? They specifically say not to use atf. If I could source new seals I would try it, but parts are NLA.

I did get 4 pillow block bearings, and shafts. Just need to mount all that, some rubber to go over the shafts for traction. Then some gearing and chain for the drive.

Re: Small engine dyno ideas

Ehhh yeah silicone is is own deal, once the bearings have it impregnated into them, they will not absorb mineral oil and they will run dry and seize up even in an oil bath. It's the craziest thing, even a teaspoon of silicone in a hydraulic circuit can wreak havoc.

The Dow 200 shouldn't be too stupid expensive especially for the qty you need. Look for an industrial lubricant supplier in your area, or try Benz oil in Milwaukee, a quart shouldn't be more than $20 unless the world has completely lost its damn mind with covid.

Re: Small engine dyno ideas

So what are the values of the pounds guage? Hundreds???

Re: Small engine dyno ideas

Jesse Nordlander /

So the pump must have separate chambers, one for water, which is plumbed to a tank. The silicone must be just filled into the unit from a separate port. I need to get it out and investigate

Re: Small engine dyno ideas

Jesse Nordlander /

Not sure on the pounds, as far as hydraulics go it should be hundreds. There is a full manual on gopower site I haven't yet read in depth

Re: Small engine dyno ideas

It's not psi, it's actual lbF force on the reaction arm, then they have you do a manual calc.

We had a Froude Dyno a lot like this at college we used with the high mileage car. You load the brake at individual setpoints and measure lbF then do the calc.

If you want a Dyno curve, you start the engine and warm it up, then you slowly open the throttle and the water valve at the same time to hold a steady RPM say 3000 maybe.

Then you read the force, and write that down for 3000

Then you go in 500 or 1000 rpm increments closing the water valve to hold steady RPM, reading the lbs.

As the engine comes on the power band, you have to dick with the water valve to hold the load. At like 6000 when it starts jamming you'll actually have to open the valve or it will run away on you.

If you watch those guys like Steve brule on engine Masters that are like hella pro Dyno operators, they are constantly fiddling the water supply to give a nice linear 'curve' .... Doing it manually like this (no computer data acq) takes a little more dickin around but you get the hang of it pretty quick.

If you decide to bail on the project I'd pay some good money for that unit, let me know. I've been looking for one for years they are hard to find.

Re: Small engine dyno ideas

One of the times I got to researching small dynos I ran across one some folks had built based around just a water pump. In addition to using the pressure readings as measurement they had the water outlet pointed up next to a post or tree with markings up the side so you got a run visual of how much power it was making.

I think it’d be fun to build a simple wheel dyno of sorts like that to take to rallys.

Re: Small engine dyno ideas

Not that you need this but someone else may be wanting to do the same thing (or it could maybe help with ideas) but I saw this on marketplace:

Bike Dyno on Marketplace $350

Looks pretty nice Idea how functional it is

Also yourdyno.com may somehow help you too

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