11-17-2007, 03:31 PM #1
Overheat, low speed, etc ... IC blocked!
Wow, I just learned something today ... my mods are in my signature and I should have been running 78+ all year last summer ... instead I had exhaust overheats and had to block off my flush fitting (to the right of the pump) to force enough water in the exhaust to avoid the exhaust overheat warning. That stopped my overheats, but all summer my ski would not run over 77.5 mph, and the mods I had added should have pushed me up to 78.5 and match my friend Dan's speeds ... but I never could all summer. I DID backflush my intercooler a number of times too, and the water seemed to flow well enough ...
I bought an intercooler off Ebay since I suspected my Riva intercooler's water flow was partially blocked after three seasons. Wow I drained and blew out the Riva intercooler today and compared it to the Ebay IC ... I blew compressed air into the water passages of both, and the difference was amazing ... the Riva IC flowed almost NO AIR thru the water passages, while the new IC felt wide open. To give you an idea and a test you can try, with both cores completely dry and open, I could not draw a breath through the Riva IC, while I could easily breathe forever by inhaling thru the new IC's water passages.
Honestly I am shocked my ski still ran as well as it did last year!! The only reason it did is due to the high water pressure forcing its way thru the intercooler.
SO, if your ski has an aftermarket intercooler with a couple years on it, and your performance is off a little, you get exhaust overheat warnings, or you have had to block off your flush outlet to keep the overheats from stopping, pull your IC, blow out the passages and try to inhale thru them. My guess is you will find that over time sediment has eventually blocked the small passages, as it did in mine.
I can't wait to run my ski with the new IC next year (which fits the Riva bracket and the IC to TB Riva tubing, and only requires a small change on the SC to IC connection). Trick is I will have a LOT more mods as well, but I think the combo of blocked IC, excessive water dumping into the waterbox, poor boost cooling, etc, set me back about 1 to 1.5 mph this past summer. This is not a knock on any IC, it just reflects the super fine sediment present in our lake that accumulated in my IC over 3 summers of use ... I ran a Groco strainer all last summer, but I believe it was too little, too late, the damage was already done. I am also not sure IF the Groco could stop this 100% ... we have super fine sediment that I think goes thru the Groco filter, altho it DOES work great, and I will NOT run without it.
Last edited by Vern; 11-17-2007 at 03:34 PM. Reason: added
11-17-2007, 03:58 PM #2
Filters will still pass contaminants small than the filter material.
The lithography tracks I work on have .5 micron filters between the pumps and supply tanks. that doesnt mean a particle of .45 microns will be stopped.
so the Graco will stop most but definitely not all. Regular flushing wouldn't a bad idea.
11-17-2007, 04:40 PM #3
You might have mineral formation in there too. Try filling it up with some 50/50 vinegar and purified water and let it sit for a day.
11-17-2007, 09:18 PM #4
that sound like a good idea.. is lime away to strong??? is it possible to do it without removing the intercooler ... how would you get it in???
11-17-2007, 10:08 PM #5
Remove intercooler. Only use a product that wouldn't attack aluminum. Being a Riva intercooler, I'd junk it since they are notorious for leaking.
11-17-2007, 10:14 PM #6
personally, i've just found that the ebay ICs downright just flow more water, simple as that.
I thought there was something strange about the water flow thru an IC that i had so hooked it up to the garden hose full blast and let it squirt out... did this with 3 ICs... ebay, riva, and RR... the ebay IC must have larger passages in the core bc it BLEW AWAY the water flow of the other intercoolers by a long shot. the hose ran thru that IC like there wasn't even anything there.
but i suppose yours could be considerably worse than they typically are with some use... it'll be interesting to see if your speeds come back from this or not.
11-18-2007, 03:51 AM #7
Maybe that is why some of us have excellent results, and some don't. Water flow.
11-18-2007, 05:45 AM #8
my ebay intercooler works fine so far
11-18-2007, 05:00 PM #9
Mark, thanks, I will try the vinegar/water and see if it changes anything. Either way, I am swapping since the passages seem so blocked ... Now I am curious how a brand new Riva, Piranha, and XS-type would flow (cfm) by testing the water passages. Danny??? I would donate my Riva for forensics, but it is already mostly blocked ...
Shibby, I believe it, the ebay IC has no restriction at all when I try to breathe through the water passages ... which is good I think. Unfortunately my ski is stored for the winter, I won't be able to back-to-back test since I am upgrading quite a few things this winter. Tell you what tho, no question that this was my overheat problem and I will be able to open up my flush connection now.
By the way, I think I found the enemy ... and it is me ... I used to lower my ski into the water then fire it and let it warm up a few minutes on the lift. Unfortunately I think it sucked bottom sediment from doing this and over time I plugged my intercooler. I need to rethink this for next year ...
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