During the winter months in IL we have very limited access, if any to launch ramps. This has posed a challenge for us in the past, however our in house prop dyno opens the door for us. Running a boat on the prop dyno can offer a hp output number, as well as load testing. Load testing an engine is great for diagnosing leaks / engine problems that may only occur under way or after a certain run time. This video demonstartes load testing used for engine break in & checking fresh rigging for leaks. The test engine is a NEW Mercury Racing 565!

** We did not run this engine for a HP reading, this was a load test / rigging check**

Thank You,

Alan Gordon
Service Manager - Pier 57
847-336-9037
[email protected]

I have had many requests / questions on how we supply sufficent water to run a boat on our dyno. When we started looking for a new facility last year, one of the more important items was water supply / pressure. Adequate water pressure is a 'must' for any modern day EFI engine. Without proper water supply or flow these engines put themselves into 'Guardian' and fall on thier face. While running on the dyno, engines are directly fed through a sea strainer by (2) 3/4" high pressure water feeds. On boats without a strainer setup the water is forced in through the main water intake hose to the impeller housing. The dyno itself runs off a 55 gallon contained supply.

Alan Gordon
Service Manager - Pier 57
847-336-9037
[email protected]

This is only a question regarding hp dyno runs. Do you run the risk of blowing an out drive putting so much load from the dyno? Not meant to be a smart ass question. Just curious how much load is actually applied? When I bought my chassis dyno years ago I saw a prop dyno in the company's catalog and was curious how that worked. I see a lot of boats on this site that are in excess of there out drives hp ratings. (Mine included)

I see where it could be a big help with checking for leaks and engine break ins like you mentioned.

That is a great question. You honestly run the same risk of running the boat on the lake with big power. While testing an engine as you described ( engine hp that exceeds drive rating ) extreme caution is taken. The load applied is controlled by the operator and can be removed instantly upon turning a valve. To test a high hp engine or load it would only be done in the higher rpm range. Example: Applying a load off 2-3k rpm range on a blower motor would risk having the torque destroy the drive.

Alan Gordon
Service Manager - Pier 57
847-336-9037
[email protected]

Alan, Can you post the clip on YouTube....

I've dyno'd 800 HP blower motor, Bravo drive on our L&S prop shaft dyno. Like Alan said you just don't load them at low rpm. If you think about it the dyno is a smooth load letting it accelerate thru the power band. No blades pounding or jumping out of the water. I've never broken a drive with it. It sure can identify a lot of proplems when boats don't perform to their expected level. You can quickly determine if it's a power problem or setup problem.

+1 for you tube. My phone won't let me see this style video

I guess my main conern would be the drive heating up over time. Do you have an external water source to cool the drives as well?

Does the 565 have the same intake as the 525 just with twin TBs on top instead of one on the front?

you should get a hold of the 7 marine outboard and see how much power is really getting to the prop through all those gears and turns.