Thread: Cooling SHO with RXP pump
06-23-2012, 01:53 PM #1
Cooling SHO with RXP pump
I'm having an issue keeping the temps of my SHO down. Running a RXP pump(Philip's conversion), with stock SHO lines. I'm thinking the RXP pump is not flowing enough water to keep it cool(engine mods in sig). What options do I have, and what have others done to keep their ski's cool?
06-23-2012, 04:17 PM #2
remove you siphon hose and tap the pump housing somewhere. run a line to you siphon fitting outside ski and run the inside siphone hose to the intercooler. now you will have a seperate line to cool engine and intercooler.
06-23-2012, 05:51 PM #3
I already have a 1/2" line direct to the IC.
06-23-2012, 07:21 PM #4
- Join Date
- May 2007
- Auckland, New Zealand, New Zealand
The Seadoo pump can flow more than enough water to provide cooling. Its how you get it from the pump to the engine that is the trick. The yamaha transom plate inlet hole is too restrictive and that is why many run more than one pick up from the pump and supply water to each requirement. With my conversion I designed a complete replacement transom plate utilising the standard water-in from the seadoo pump and I can meter it just as Seadoo would. It supplies more than enough water, that then can be split up and used as required.
06-23-2012, 09:06 PM #5
I doubt the problem is from the pump not feeding enough water. The stock cooling just needs to be opened up a little to handle the extra heat. Pull out the tee fitting under the header, & you'll see the barb that points forward to feed the block & oil cooler has a tiny ID...similar to the fitting for the stock intercooler. Either drill it open larger or replace it with a 3/8, 1/2, 1/2 fitting. This is what Riva does with their engine cooling kit, but it's kind of a lot of money for 2 aluminum fittings & a few lengths of hose. You can take it a step further to fully replicate their routing, but the next step will require removing the waterbox & header/manifold & buying a replacment manifold gasket. Downstream of the 3-barb tee, there is a 4-barb Y fitting. Instead of running the 3/8 hose to the y-fitting, run it directly to the fitting on the block. This way the block & oil cooler no longer share that feed. Then replace the stock y-fitting with a 1/2, 3/8, 3/8 Y. This gets fed from a 1/2 hose teed off your dedicated IC line. You can see a diagram if you look up Riva's online instructions for their kit(the one for use with the Riva IC). Also, if you look at my "SHO Rebuild" thread in the Yami projects section, I think there are a few pics of this setup in the last few pages of the thread.
It's an easy way to get lots more flow without drilling additional holes in the hull for extra thru-hulls(like the R&D kit requires). I was concerned tee-ing the oil cooler line off the IC hose would affect IC performance, but it didn't. I was seeing the same IAT #'s with the new routing.
06-24-2012, 06:25 AM #6
Awesome info! I'll have to go get a manifold gasket. I might as well go all the way, and get it right!
07-01-2012, 06:19 AM #7
Tried a quick fix of putting a T in the IC line and running that over to the stock 4 way splitter, but it didn't seem to accomplish anything, as it still overheated. So I think I'm going to block off the port in the adapter plate, and run a thru hull fitting(might drill out the bilge hole and use that).
07-01-2012, 10:50 AM #8
Don't forget to add more pissers out, the OEM pissers have a small diameter so they are restrictive in themselves, the OEM pissers are great, their diameter is just too small so more of them are required.
The other thing to look at is the thermastat, I like the idea of having a thermastat (especially for people in the north) but it can be very restrictive. The R&D kit to add a 2nd thermastat is a good idea if the motor is out. In my case I use a single thermastat and I opened up the holes in it.
For the IC feed I use the bilge siphon thru hull fitting. I replace the pump side of this fitting to match inner hull size. This then feeds lots of water to the IC line.
07-01-2012, 10:54 AM #9
as I think about it, until you get a chance to do some of the other suggestions, if the thermastat is still installed a quick fix might be to remove it
07-01-2012, 02:24 PM #10
I drilled and tapped another hole in the stator housing for a 2nd water feed to the engine. It just doesn't seem like there's quite enough water feed. The stream coming out of the pissers is pretty weak. I'll test this out tommorow and see whats up.
For the IC line, I installed a -8 bulkhead fitting, and it flows more than enough water for the IC. My IAT's are basically river temp.
Also, what temp does the thermostat open?
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