11-12-2009, 09:52 AM #1
Single cooling vs Dual cooling? You thoughts please
Starting this here as to not clutter up MP's thread.
Ok, how about these questions...anyone who knows can answer. Thanks
Lets keep this about twin cylinders, as that is what we are talking about now.
Seeing how the cooling line that is already there in the pump supplies LOTS of volume, do you feel that installing a "Y" or "T" fitting in the engine compartment and then using that for "dual cooling" is effective enough?
If yes, why don't more people do it this way? (Have seen it done and have done it this way in the past myself)
If no, does the new fitting you install really supply that much more volume?
Is this "extra" volume really needed?
I feel and have had no problems in the past, using a single line split off into 2 lines. Now this has only been on my past boats, all either 650 or 701 derivative Yammy twins.
I feel that it is better to control the location of the water flow, than to just "throw it" everywhere and let it cool as it "chooses".
One line from the pump does flow a hell of a lot of water, and this split off to where it is needed has always worked for me.
Now I am not saying to route the water to certain places and not others, only that with it routed from one line, with different size lines, flow restricters, etc., one feed can supply more than enough to cool the engine and exhaust.
If I am off on anything, please explain. I am always willing to learn. How else would I be a "vault of useless information" as I am known.
11-12-2009, 01:19 PM #2
Dual cooling...and my 49 cents.
Stock cooling line is ample on the boats however....a stock 701 engine makes anywhere from 63hp on a blaster to 80hp on a Raider. This works out ok...however a ski like a blaster that will see the pump unhooked quite often and usually rode hard on the course I don't feel it's enough. A stock 93-95 blaster makes 63hp and when you dump in extra compression, a pipe, porting etc...you can easily at another 30-50Hp or even greater if you jump onto a stroker, flat top etc. I have found over the last 10 years of blaster riding that once I installed a Factory pipe and increased compression, I get the engine hot enough that I can get into detno issues from the extra heat the higher HP produces. As far as the "T" line, it's always a great idea because it balances the water going into the hottest part of the engine "ehxhuast manifold" and will help prevent once cylinder from running much hotter then the other.
I have a thought that if someone was just idleing around and then jumping a wave....idleing around etc...yeah they can likely get through with single line cooling. I on the other hand who can ride almost non-stop WOT on the lakes always get into heating issues....then into detno.
If I was to ride your blaster around the way I ride, I would bet you that I could overheat the engine if you have a mod/limited pipe on it. It's all in how you ride IMO and personally I would never run a factory pipe without dual cooling ever. Take another thought....run a tripple piped ski...look at the cooling going to it.....I can't say I've ever seen a stock cooling line run. TJ for example told me to run dual cooling on my single pipe raider to help prevent any issue if I'm running it hard.
It helps with heat soak...helps prevent detno ..and keep the engine cool. I tap the exhuast mani on the other cylinder and run a line for each side. Another though of dual cooling is a redundency for cooling also.
I just don't believe a stock single line cooling the engine that's making 30-40% or greater power is enough.... and prior to running dual cooling on my 95 blaster in my video, it would overheat after about 15-20 minutes of riding.....installed dual cooling the following weekend and I could ride that red ski non stop tank after tank without a single issue.
Lastly volume...yes it does add extra...watch your pisser on a single line vs a dual line...both pissers are completely full of water spraying out at an amazing volume....
11-12-2009, 01:35 PM #3
Btw...just read your post again.
A "T" or "Y" really does not add extra volume so really the only effective thing it does to is balance out the water coming from the sinlge line cooling better in the cylinder. It does help prevent one from being excessive different in terms of opeating temps
I was digging for some old info about my 95 on a single cooling line ...I could get outlet temperatures in the 235-240F range on a single line cooling, 185 PSI, Factory MOD piped ski running a 13/17 Solas Concord prop on my 95 blaster with an aftermarket F/A prior to dual cooling. This is well above desired ranges and cleraly is beyond what an alum cylinder/head would like to be and Im sure had I continued to run it that hard, it would have lead to an early death.
11-12-2009, 01:51 PM #4
not familiar with the 701 or the 760 for that matter with heat related issues ( soon to be.. so thats why my question on where MP's drilling)...
The 500 twin on the other hand ,IMO, runs too hot when flogged non-stop..water out of the pisser then is too hot to run thru your fingers let alone touching various parts of the block..
dual feed or at minimum, split feeding cool water to both ends of the block is the wise move..
the piped 500 with upped compression has the o/e single feed split to cool the front cylinder via a nipple in the 'thermostadt' cover.
I will watch this thread with interest to see where the masses stand with another line or just a split!!!
11-12-2009, 03:00 PM #5
Split equals good balanced cooling but not more volume to supplment the increased HP. Big gains are made with factory pipes....porting, reeds etc. I was very nervious running my Riva pipe blaster this summer because it ran very warm ....ok hot....to the point it had insane condensation on the roof unless you opened it up to allow it to vent from the heat.
Dual cooling on modded skis when experiencing big gains in power!!
11-12-2009, 03:22 PM #6
Good discussion, keep it coming.
I will try and "attack" one thing at a time.
Let s look at how I have my one Blaster.
Single feed line, split into a "Y" in the engine bay, then each line to side of the exhaust mani. Just like Mike said, each cyl. get its own line.
I see more than enough volume this way to keep it cool. Now if I am running too cool, I will add restrictors to slow down the flow (In the lines coming out of the head). This will allow the water to better absorb the heat.
If I am running too hot, I will open up the flow. This can be done in many way. Larger lines, larger pissers, more pissers, etc.
Relieving the pressure and allowing more flow this way will help cooling while still being within the range of having enough volume.
(Take the feed line off of the pump and run the boat on the trailer in the water. See just how much water come out of that single line)
This is why " think" a single line will flow enough volume.
Mike mentioned being out of the water and no flow, unhooking the pump if you will. No matter how many lines you have, it will still "dry out" some while unhooked. Here is where the line volume matters. Not how many. 4 small ones may not be equal to 1 large one. Size matters. Out of the water = no water, period.
BTW, my "MOD" Blaster has 3 pissers. All 3 have a steady flow of water out of them. I try and have even flow between the exhaust mani. and then out the head so each cylinder will be cooled as close to equal as possible.
Disclaimer: I may be running all my boats on borrowed time like this, but I have yet to have any failures. Heat related or not.
Again, just me shooting the sheet here and seeing what all we come up with.
So to sum up my babble, I feel a single line will supply enough volume to properly cool if that water is distributed correctly.
11-12-2009, 03:26 PM #7
Sounds like the water was in the engine too long and you needed extra volume. Extra pissers here could have helped, among other things.
11-12-2009, 04:27 PM #8
Volume ..your correct ...no water not cooling however, with the extra volume you get from "dual" cooling, it helps quicky cool the engine back down to the the extra volume is what I was referencing...just typing on an I-Phone is not quite the best.
In terms of water from the extra pisser...you get double double the volume from the pump but, not a 100% gain in overall water volume as the engine itself can only handle so much flow through the channels etc. I think however that your providing the most possible cooling "chance" per say other the restricting the line using this also. Sure you can restrict the line to increase the volume inside the engine however if it's producing a ton of heat..the water most flow to the point it doe carry away the heat with it.
Think of a 350 small block...guys run higher volume oil pumps for a reason...sure the stock pump works fine..but when they mod them why would they run 60-80 pounds of oil pressure vs the stock? The pure volume of the extra oil helps lubricate the parts because they are generating more heat.
I would still be a few starbucks that if you came and rode with us...I can overheat your single cooled factory mod pipe boat. If you ride it hard enough for a long enough period...with a single cooling line...I can overheat it IMO. You can adjust flows...restricters ..etc....I will ride it hard enough to overheat it IMO.
My 95 blaster had a bone stock 701 with "2" pissers with the Riva head at 185PSI, Factory mod pipe and ran hot and o rings etc were all brand new mint....and even the other older 93, 94's I had...overheated without dual cooling.
11-12-2009, 04:35 PM #9
aww my previous babies...sniff sniff
11-12-2009, 04:40 PM #10
ahh my little troops..I miss them =0(
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