Installed SVHO cooler + Question

[Midnight2V]

@Squirrel, I'll do that as soon as I get back home in June. I should have done a better job of documenting my work, but I completely forgot to do it.

As far as exhaust, I'm not sure what we can do. I believe that the Riva Water box is a direct fit and supposedly adds 15hp on an already modified engine. There is a free flow exhaust available for skis, I'm not sure of fitment, but I'm sure something could be made to work. Here are both links at Riva to give you an idea, but I'm sure other vendors have similar items. I have no idea what gains they might provide though for our boats.

Riva Water box: https://rivaracing.com/i-17283644
Riva Free Flow Exhaust: https://rivaracing.com/i-17283621

It might even be easier to have an exhaust shop weld up a custom pipe. The exhaust is simply removing the sound suppression material, so I don't know if you want to do that given how loud our boats are to begin with. Another thing that might be possible is simply taking the exhaust pipe out and seeing if you can remove (knock out) the sound suppression material. I may have known some people to do this with catalytic converter elements that got clogged from "accidentally" running leaded fuel in unleaded exhaust systems.

One thing I can tell you, having built many supercharged engine combinations over the years, is that a supercharged engine is going to be far more sensitive to intake restrictions than to exhaust restrictions from a pure power making perspective. The two most beneficial exhaust items would be a long tube header and a performance exhaust cam profile.

A long tube header would be problematic for O2 sensor feedback, if you could even find or build one that could fit. It would probably require a custom dyno-based tune to correct readings because of heat losses before the collector cone and O2 sensor bung. Exhaust cams are available, but installation and tuning costs alone (never mind the relatively small cost of the camshaft itself) would make them not worth it for most of us.

 

[Firemedic]

Still some heat soak after svho upgrade. But it resolves faster. Drew was way helpful and honest when dealing with

 

[Midnight2V]

The dedicated cooling line will completely relieve the issue. The hi-flow jet pump strainer helps get additional water flow to the engine and the intercooler. The SVHO intercooler provides a larger heat sink and more heat dissipation potential due to the larger surface area, which is good. Unfortunately, the reality is that the intercooler in simply an interface between your charge air and the real source of cooling, which is the water body. As the water approaches the temperature of the charge air it loses it's ability to remove heat. An intercooler only increases the rate at which you can transfer heat, it does this by increasing surface area and optimizing efficiency. The most important aspect is cooling is heat capacity, which has next to nothing to do with the intercooler. To transfer heat from your charge air you need the largest temperature difference between the water, and the charge air. The faster you move the water, the cooler it stays, this allows the water to absorb more heat and to do it faster.

A dedicated cooling line is simple. The jet pump strainer cover is replaced with a unit that has a barbed hose fitting, and a hi-flow strainer can be added at the same time to increase both pressure and flow. Run the hose to the wet storage locker drain. Remove the wet storage locker drain hose and replace it with a thru-hull fitting. Seal the thru-hull fitting with silicone or similar adhesive sealant. Run a line from the thru-hull fitting to the intercooler. Block off your original cooling line because flooding is bad and your jet pump will out flow your bilge pump every day of the week and twice on Sunday.

 

[d_coyne1984]

Has anyone looked closely at how the intercooler is plumbed from the factory on the 195's? I did the upgrade to the SVHO intercooler on my 192, but am still running off the stock single cooling line. I really don't feel like adding the dedicated line with my current and future time constraints, but I am a little nervous about robbing water from the engine cooling. In the MN temps, heat soak is really only a slight problem, and even then only towards the later half of the season. If the 195 only uses the single cooling line, I'd be comfortable enough to just leave it alone. For now...

 

[Jgorm]

I've been professionally tuning and modifying cars for over a decade. I'm highly skeptical of all manufactures hp claims. I also know that reliability goes out the window when you start heavily modifying and tuning. I applaud your efforts and wish you guys the best of luck. If i want a faster boat I'll get a big block Berkeley pump boat that will throw a 100' roost. Then I'll have the Yamaha for when I'm working in the other boat. First i need to get the Yamaha working!

 

[Midnight2V]

The dedicated line doesn't take any cooling away from the other cooled components. It is a completely parallel line to the original auxiliary cooling port coming off the jet housing. Whether used in conjunction with the hi-flow strainer or not, it results in an increase in cooling flow to all cooled components. You give the intercooler a dedicated line that receives full supply pressure which greatly improves it's flow. Also, original line which was supplying 4 loads at the same flow as before is now supplying only 3. It's simple fluid dynamics. The only possible thing it could affect is a very slight drop in auxiliary port pressure due to reduction in auxiliary line backpressure, which would have a negligible affect on cooling flow.

The hi-flow strainer adds additional pressure to both cooling lines by being less of a restriction between the nozzle discharge and auxiliary port. You will definitely end up with higher line pressure and flow in all situations using the strainer. When I added my $50 strainer and nothing else, which was a five minute job involving a crescent wrench and 4 bolts, my original SHO intercooler heat soaked engine speed went up by 300RPM and 4-5 MPH.

Don't get me wrong, the SVHO intercooler will flow more water than the SHO will at the same line pressure when using 2 discharge lines. It also has more flow channels in the cooler itself, thus provide more cooling flow capacity through the intercooler than the SHO. However, that flow increase WILL result in lower cooling flow to other cooled components because the flow limiting component is the 4-way main line coming off of the jet pump auxiliary port through the pump housing. More flow to the intercooler will result in less flow to the other branches. It may not have any impact overall if those components are not near a limit.

Furthermore, when simply swapping the SVHO cooler swap onto an SHO platform it will not normally reach the same levels of performance as it would on the SVHO platform. The SVHO platform provides higher line pressure than the SHO due to the more aggressive pitch on the SVHO impeller and the overall impeller size, resulting in higher discharge pressures - which leads to higher auxiliary line pressure, which results in more coolant flow to all water cooled heat loads on a SVHO propelled system. Although it is a different method, the end result is more cooling water flow, which is exactly what a dedicated line modifications does.

Rest assured that a dedicated line doesn't adversely affect the flow through the original auxiliary port in any meaningful way. Deleting the intercooler from that line is a thereby a two-fold benefit when you account for the intercooler performance increase and the additional flow to the other heat loads.

 

[d_coyne1984]

The dedicated line doesn't take any cooling away from the other cooled components. It is a completely parallel line to the original auxiliary cooling port coming off the jet housing. Whether used in conjunction with the hi-flow strainer or not, it results in an increase in cooling flow to all cooled components. You give the intercooler a dedicated line that receives full supply pressure which greatly improves it's flow. Also, original line which was supplying 4 loads at the same flow as before is now supplying only 3. It's simple fluid dynamics. The only possible thing it could affect is a very slight drop in auxiliary port pressure due to reduction in auxiliary line backpressure, which would have a negligible affect on cooling flow.

The hi-flow strainer adds additional pressure to both cooling lines by being less of a restriction between the nozzle discharge and auxiliary port. You will definitely end up with higher line pressure and flow in all situations using the strainer. When I added my $50 strainer and nothing else, which was a five minute job involving a crescent wrench and 4 bolts, my original SHO intercooler heat soaked engine speed went up by 300RPM and 4-5 MPH.

Don't get me wrong, the SVHO intercooler will flow more water than the SHO will at the same line pressure when using 2 discharge lines. It also has more flow channels in the cooler itself, thus provide more cooling flow capacity through the intercooler than the SHO. However, that flow increase WILL result in lower cooling flow to other cooled components because the flow limiting component is the 4-way main line coming off of the jet pump auxiliary port through the pump housing. More flow to the intercooler will result in less flow to the other branches. It may not have any impact overall if those components are not near a limit.

Furthermore, when simply swapping the SVHO cooler swap onto an SHO platform it will not normally reach the same levels of performance as it would on the SVHO platform. The SVHO platform provides higher line pressure than the SHO due to the more aggressive pitch on the SVHO impeller and the overall impeller size, resulting in higher discharge pressures - which leads to higher auxiliary line pressure, which results in more coolant flow to all water cooled heat loads on a SVHO propelled system. Although it is a different method, the end result is more cooling water flow, which is exactly what a dedicated line modifications does.

Rest assured that a dedicated line doesn't adversely affect the flow through the original auxiliary port in any meaningful way. Deleting the intercooler from that line is a thereby a two-fold benefit when you account for the intercooler performance increase and the additional flow to the other heat loads.

I am looking at it the other way around. I am more concerned that not adding the dedicated line will cause issues with the engine cooling, but either way, you provided me with the info that I need to know to make a decision so thank you for the detailed response.

 

[Midnight2V]

Happy to help in any way I can.

I added the cooling line for the same reason, engine longevity. I tend to boat in very warm water, with very high ambient air temps, either at or very near my maximum load conditions for gear/people. I wanted to improve my margin to any temperature limits. Curing the heat soak was a nice benefit.

Before long I will be splitting the intercooler line to added a water-cooled supercharger housing. From what has been explained to me, cooling the supercharger housing can greatly increase the longevity of the supercharger clutch in addition to providing another heat transfer point for the charge air temperature.