outdrive showers =cavatation
 

I installed wicked marine outdrive showers on the boat,now I have a bad cavatation if I take off more then 1/4 throtle,I removed the outdrive showers and the cavatation is gone,reinstalled the outdrive showers and adjusted the tubes as high as I can on the cavatation plates ,it might of helped a little but still cavatating,is there any fix for this? or do I just remove the outdrive showers and live with the holes on my outdrives.
Do outdrive showers really do anything other then keep the top of the outdrive looking clean???

Experienced the same proble as you.....finally swithed to a clamshell type pick up from rex and it helped ....but was still there....Finally went to an Imco Extreme Sc upper and it is run off the intake for the water pick up ending the problem...so to answer you question it is up to you, but trust me you are not a lone in the problem and it really is a hit or miss thing on what people experience it and those who dont

Tex

These are the ones that I used, that didn't require drilling holes. The drives definitely don't have the white chalky build up on there upper half anymore, and I never noticed any change in speed or cavitation since they have been installed. It's possible this style might be less likely to cause cavitation because the pick up tubes are spread farther away from the prop.





http://www.driveshowers.com/

Rigging a forward facing pick up with the bottem blocked off, keeping it as close to the cavitation plate as possibe is best. Sometimes you can notch the pick up and fold the rear piece of metal forward to shield it from the prop. Ugly but it will work in a pinch.

If I am reading this right, it sounds like the drive shower tube flows in reverse at low speed, and turns into a ventilating tube causing cavitation. They use similar tubes, albeit smaller, on some surface drives to purposely cavitate them, so they engine can get its rpm up into the torque band.

I would be interested in hearing answer to the original poster's question, about what, if any, drive temperature drop people have measured.

Michael

I installed them on my Top Gun with Bravo drives . They do spin a little just getting up on plane but hook up once the boat gets going . Not a problem for me .

http://www.driveshowers.com/

There are test results on this site.
Just the fact there is no longer white chalky mineral deposits on your drive (from water boiling off) shows they drop temps. Cheap insurance. They won't make your drive stronger, but it may last longer.

I don't think it really proves it drops drive temps. Take the situation where you are boiling water on a stove. When you put the cold water in the pan, it's tap temperature. On the other side is a 1500 degree flame. If you keep changing the water, the temperature never gets very warm, yet the flame is still 1500 degrees. It all has to do with how much heat transfer there is from the inside to the outside of the pan or in this case the drive. The only true way to measure the performance of the shower is to measure the oil temperature itself (Livorsi has a guage for this).

As far as keeping the mineral deposits down, that seems like a nice benefit in itself.

Michael

I did a test on my boat with a drive oil temp. Ran the boat without, and then with the drive shower (simrex), no difference. Buy one to keep the drive clean, thats it !

Well that's discouraging.

This letter is in response to your inquiry regarding the performance of the drive showers which my agency purchased for performance testing.
The shower was installed on a 42' Fountain Lightning with 502 EFI engines and Bravo 1 outdrives. Only one shower was installed on one outdrive and both outdrives were equipped with temperature gauges, with sensors in the oil filler holes.
After approximately five minutes of operation at 4500 RPMs, the outdrive without shower registered 190 degrees. The drive with the shower failed to record the minimum gauge temperature of 140 degrees. The gauges were reversed to make sure that there was not a gauge failure. The same results was obtained.
Based on this single test, I found that the use of the shower results in a sensor reading indicating a reduced oil temperature of at least 40 degrees and possibly more. How this finding will effect the life of the outdrive unit is difficult to determine. However, I do know that the enemy of moving parts is heat and I have every reason to believe that the shower significantly reduces this problem. It therefore stands to reason that we can expect a proportional increased life expectancy for our outdrive units.
I hope that this letter answers your questions. If I can be of further service, please contact me at your leisure.

(signature removed for security purposes)

Benjamin A. Rich, Special Agent
Program Manager

The most recent testing was done by Jim Wilkes for Hot Boat Magazine, and published in the April 2000 issue. Dockside magazine also tested the Summit Design and found a 50 degree drop in drive operating temperature and published their findings in the August 1999 issue. They also did a side by side comparison between the Summit Design and the Halo Design and found the Halo to cool the drive by an additional 8 to 10 degrees. Testing was also performed by the United States Customs Service. They found a 50 degree Fahrenheit drop in temperature.

Gene Weeks of Team Lazar did a side by side comparison between an Imco Power Shower and a Summit Multiport Drive Shower®, and found the Multiport system to cool the drive by an additional 15-20 degrees over the Power Shower.

As everyone says, its worth it just for not having to clean the drive very often. I do think they drop the oil temp though.

We installed a Simrek drive shower in 1999 while racing APBA Factory 1.
F1-51 ONE VISION Racing.
We lost no measurable speed
We never lost a drive.
I still run the same drive with the same Simrek drive shower
Mike "Gordo" Gordon

I'm still trying to understand how these drive showers can cause prop cavitation. Over the winter I intalled the Latham showers on my outdrives. Haven't run them yet, but now I am wondering about cavitation. The Latham shower has one intake mounted through a 3/8" hole drilled on the port side of the cavitation plate with the right hand swinging prop. It is a couple inches behind the prop and about one inch from the back of the cavitation plate. Can this cause cavitation and, if so, how?:confused:

There is a low pressure area on the bottom of the cavitation plate during startup, and it just sucks air down the tube. There must be some backflow along the surface of the cavitation plate toward the inducer side of the prop to draw air forward.

Michael

Michael1 above is correct. There is a low pressure region being created by the prop, predominantly on the face or forward side of the propeller.

To go a little further-
Cavitation is an inverse function of fluid density (among other things, but density is what we're concerned with here). Increase in density, decrease in cavitation. Decrease in density, increase in cavitation.

As air is sucked down the drive shower by the low pressure region created by the propeller, it mixes with the water around the propeller, creating a water/air suspension mix that is less dense than water. This decrease in density increases the likelihood of cavitation. In your case this is what is happening. The prop spins faster than it should if it were in "solid" water.

Others that do not have this cavitation issue with a drive shower still may have this decrease in density, though some of the "other" factors are coming into play that prevent it.

Wow...I'm actually using this education.

Brad Holbrook.

Thanks Mike and Brad for the explanations. Don't know if that will be a problem for me as I haven't run the boat yet with the showers. Attached is a pic of the shower and another picture showing a similar shower installed (to show location mine is installed). The Latham unit barely protrudes below the cavitation plate surface (not like the shower shown in the pic).

I assume the pressure at that location eventually increases to start flowing water up the tube. Latham installation instructions stated to put it on the side of the upward rotation of the prop. Just curious, anyone out there running the Latham shower having problems with cavitation? I will find out myself pretty soon once the river drops.

I dont really know if it matters how far down or up the tube is past the cavatation plate,mine is adjustable and I tried with it up,down,half way up,still cavitates

If you don't have any luck with it they should let you return it.

Isn't the shower you have the type with 2 inlets, one on each side of the cavitation plate? I seems to me with a right hand prop (turning clockwise) you would only have a low pressure region on the starboard side of the cavitation plate. This is the side of the 'downward' sweep of the prop and may be pulling the air down that tube. Latham instruction were specific and stated to install the pick-up on the 'upward' sweep side. I would try plugging the one inlet and see if that helps.

Makes sence,I will try it and let you guys know

Where do showers go on here? :D

:d

c.p performance has a very good unit. no speed loss , no cavitating. and without a doubt there is a difference between no shower and shower.
ever see a blue case?
and this proven on c.c, cruisers, and speed.
everything leaves with showers.

Love this site
 

I love this site!!! It's been 15 years since I've had outdrives and have never even heard of Drive Showers. What a neat idea. I've already asked my dealer to install them for me.

Thanks guys :ernaehrung004:

I have the Latham drive showers on my 30 Baja with Bravo outdrives and haven't had any problems. However I did have problems with my 275 Baja after I installed a drive shower. Fixed the problem by cutting the pickup tube shorter.(different type drive shower)
Jay

Thanks Jay, glad to hear that!:D

I have 1 extra one if you need a spare:D
Jay

Picking this thread back up, Im considering latham drive showers given I have the latham plate top of drive with the threaded hole ready for the NPT elbow. I dont boat long distances (fairly small like for my Baja 35 Outlaw), and just researching all I can before deciding. Not even sure what I am asking in specifics, rather are folks for or against, hows the experience been, etc. I have twin 525efis, Bravo 1 XR Sportmasters. Thanks!

https://www.driveshowers.com/

get the simreks, best bang for the buck and are removable, no drilling.

If you go a head and buy them just be careful of the placement of the pickup in the cavi plate, Ive seen them cause aeration issues with the props

Ya, thats what I've heard for some. Besides the template, one really doesnt get a second chance on the placement after drilling a hole. I know no drilling with some, but Id only go with Latham if I did it...

spinning in or out also comes into the equation for placement