My engine break in stand

[Shannon Eugene Hall]

This stand is custom made by myself time to get heat cycling!!!

 

[Timbo Whalen]

I've got a couple of dyno designs that are on the back burner, and a load stand, similar to yours,

that we're going to shaft to a ducted fan unit. It's always a better choice breaking these things

in with a load...heat cycling's the way to go and increase operating temp with each tank of

fuel. We incorporated the r/c car tire warmer wrap with a stout LiPo and a thermostatic

controller to pre-heat the Nova's, available at Hobby King... it really takes the strain off the

con rod...think we have about $45 in the whole deal. We've not had an issue with the NR46DD yet.

HOBBYKING UNIVERSAL HEATER SYSTEM

https://hobbyking.com/fr_fr/hobbyking-universal-heater-system.html

TURNIGY 5000MAH 3S 30C LIPO PACK W/XT-90

https://hobbyking.com/fr_fr/turnigy-5000mah-3s-30c-lipo-pack-xt-90.html

Thanks-

Tim

 

[Charles Perdue]

The shaft to a ducted fan unit would be a good choice. Especially if you started with a larger fan unit (say a 45 size for a 21 size engine) and installed a variable shutter to block part of the entrance to the fan. Then by blocking the inlet by different amounts you could adjust the fan to maintain different loads on the engine.

Try blocking part of the inlet to a centrifugal or blower type fan and you will see what I am talking about. The more area that is blocked, the less air that is drawn in and the lower the load.

This would make a KISS dyno or breakin stand.

Charles

Several had questions as to how this could be used for a dyno.
To expand a little on using the ducted fan setup as a dyno, a torque sensor placed between the engine and the load will give the torque reading. Using cheap a tachometer gives the engine speed (RPM). The torque readings and RPM are all that is needed to calculate the engine power.
Miniature torque sensors rated as low a 5 inch ounces and as much as 1000 inch ounces are available. They convert the torque readings to an electrical signal. They are widely used in automated equipment.

 

[XtremeRcBoats]

Tim, interesting idea using the tire warmer. I've got a mac84 with squeezed liner that is very tight and hard to start. How long do you put the tire warmer on and what temeprature does the engine get before starting?

 

[Shannon Eugene Hall]

Thanks for compliment on break in stand I agree load is good the best load is prop in water. This stand was designed only for the heat cycling method at low rpm really no load needed. I'll do a gallon this way heat cycling every tank keeping temps between 212 230 then hit the lake and start leaning more every run.