I'm running 6 lbs of boost according to the boost gauge and to the installer. I am wondering if the 4 loose valve seats could have been a factor and also if the blown head gasket occured prior to making itself known. Could I have been down in power due to those things? I'll let you know Wednesday.
Thanks for the interest.

Tom

It could definitely have been down on power due to those problems. But it could also have been down on power due to the thing that caused those problems. Is there a knock sensor in the system and could it have been pulling out timing? Detonation is not good, but retarded timing will reduce power and increase heat.

How did the boat run before? Did you have great midrange, then flatten out? Did the last 1/4 throttle do anything? What RPM were you getting to?

The reason I am asking is we are fine tuning the Fountain now. It idles and shifts well, although one engine needs a little more air at idle; it stalls sometimes going into gear. I was worried about getting on plane. When the shop delivered the boat to the customer, they filled the fuel tanks to the top, put 5 big guys on the boat and expected to go 100 mph. Amazingly the boat still jumped onto plane with no blowout at any point. This is with the 1.26 ratio in the 2" shorter XRs. That was a relief.

Midrange acceleration was great with WOT applied. Then when they got to 4500 RPM it stopped accelerating. The throttle went "soggy" and when you backed off to about 3/4 throttle it would accelerate again but only to about 4600-4700 RPM. At this RPM the boat was going 90 mph on GPS. We get exactly this sensation on carb systems when the secondary jetting is too rich. After leaning the secondaries we get better midrange and all the throttle with no stumbling or sogginess.

I suspect that the computer was set up to be safely over rich; I know that's what I would do if I was Arizona Speed & Marine. I told them that I expected the supercooler to deliver more boost than the stock Vortech system. The other possibility is that the knock sensor is pulling timing out. The heads were milled on these engines to get a true 9:1 C.R. and there was some old gas in the tanks. Fuel pressure was right were Vortech says to run it: 50 psi.

I will be calling Vortech and AZS&M on Monday, then going back to the boat on Tuesday or Wednesday with the shop owner. They didn't have any boost gauges yesterday and didn't take the scanner.

Good luck with your testing. We will compare notes on Wednesday!

hotlavey, you need to run the boat with a scanner hooked up to it. That's the only way you're going to see if everything is ok. With the scanner you can see if you're getting any knock, which would be pulling timing which would greatly effect performance. Actually excessive knock would have caused your blown head gasket. Any merc mechanic who is capable of working on efi engines will have one...if not, find another mechanic.

Please put an O2 sensor on one of those engines. Without one you have no idea where you are, and where you're going.

Chase,

After the Whipple was installed we put the boat in the water with the scanner hooked up. We ran it for about an hour; slow, mid, and WOT. Bernie(installer) made a few minor adjustments and we were good to go. I am very sure everything was adjusted and checked that could have been. I don't believe the loose valve seats were caused by the Whippple or by any misadjustments. The problem is that there are so many variables here that it is hard to pinpoint the problem. Water pressure(too little or too much?)is one. Now I have a pressure gauge. There is a knock sensor in the system so??? Could have been a weak gasket from the get go- who knows? I'll know a little more after Wednesday.

TC,

Ran the boat today. We could only pull 5K with a stock 30 Bravo 1. Water pressure was way low at 10 lbs and we should have 20-30 lbs. 8 of the 16 side inlets are plugged so we have to experiment with both removing some or adding some more. I was told to consider enlarging the nose holes a bit to allow more water. May do that after trying the side inlet plugs. Engine water temp stayed right around 120-130 but the engine builder says I must have more flow. Speed was only 81GPS and the water was oily smooth(bad). Air temp in the 80's. We were on a small lake so we did not even have chop.

You should just add an offshore pickup and be done. Dustin had told me in the past that only the Merc low water Bravo drive, the Performance Bravo 1, would have enough water flow, otherwise install an offshore water pickup. Without enough water pressure, flow through the intercooler, you're not getting the cooling of the intake charge which will result in greater chance for knock, which the engine will then start pulling timing...(which you will see in a performance loss)...to protect itself from destruction. This could be seen with the scanner hooked up and set to view knock. That's what you should be looking at while running. For tuning, the only thing you can do and use the scanner for is setting idle, by viewing the tps voltage, and setting the base timing. BTW, your suppose to check water pressure first before install to make sure its ok.
Again, everything is ok when you can run WOT with NO KNOCK registering on the scanner....don't go by feel or speedo/tach....hook up the scanner.
I'm convinced excessive knock caused your head gasket problem, especially now that we know you have inadequate water pressure.

Chase910: Thanks for the advice on the use of the scanner. I also understand that if pulling timing doesn't stop the knocking, the ECU starts dumping in more fuel.

It is a good question "How much water flow do you need through your intercooler and what pressure do you need to get it?" When we tested the supercooler (for carbs) on the dyno I measured just over 5 usgpm with an inlet pressure of 10 psi. Vortech says that their intercooler needs 5 usgpm. Since we use a Vortech intercooler water tee is installed just after the sea water pump. I figure there is much more than 10 psi there.

The Fountain goes back in the water tomorrow. Didn't go today because the boost gauges arrived and were being installed.

Yes, tomcat I believe that is correct, if timing pull doesn't stop it tries more fuel. The scanner can view knock and timing and you will see timing being pulled as knock increases.

With the water pressure, I only checked at the block, but Whippled needed more than 10 at WOT measured at the block, heck 10psi was at idle. The question is, What flow through the intercooler is needed to keep the intake charge temp low enough to prevent knock at WOT, with pump gas, and normal summer lake temps.? So, if you're saying you only need 5 usgpm flow through your intercooler to keep temps down and increasing the flow doesn't lower the intake charge temps, then you're ok at 10 psi.

I’m also curious how your getting 10 lbs of water at idle.
I use a 5 lb check valve on the outlet of my IC just to keep pressure around 3 lbs at idle???

Hey HotLavey,
My water pressure problem cost me dearly last season over heating and destroying the back four pistons and some chambers. I was using a transom mount water pick up for the engine and the standard outdrive pick up for the IC. The stepped hull gave me fits using the transom mount and when she burnt down I had 3-5 lbs of water pressure. I had fought this all year. Pressure would change with weight load, attitude, etc… I should have seen it coming.
My flow out the IC was marginal at best using the outdrive. I could see this by looking at my dump out the starboard side when up and running.
A couple of things; the dual pick up drives are not suited well if your X dimension is high at all. If you lower your drive when on the trailer, look and see where your upper intakes are in relation to the bottom of the V (hull). All my holes were above this imaginary line. All this does is allow water to be pounded into the nose and right out the upper holes; whatever’s left, your motor and IC can have There is a Merc bulletin regarding this problem.
I have done away with the transom mount pickup completely. I plugged all of my upper holes and enlarged the lower nose holes to 5/16” which equals the one 5/8 hole found in the nose of IMCOs and such. I also added a sea strainer. I plumbed my IC in right after the sea pump with 5/8” barb fittings. First time out I could bury the pressure gauge at 50+ lbs at only 4000 rpm. That was easy to fix with a Merc relief valve and one inch hose that dumps on top of my outdrive. My pressure now stay perfectly steady at 25lbs at WOT. I didn’t have good pressure at idle so I added a 5 lb check valve to the outlet of my IC. This in turn kept my pressure at 3+ lbs at idle and allows no flow thru the IC at idle.
In my case the now low water pick up supplies more than enough water for the motor and IC with 5/8” hose..
You may not need a pressure relief if you don’t run a thermostat. I have to run a 120 deg thermo for our icy cold spring waters, but that’s a whole different story. Whipple and GT Marine suggest a 5/8-3/4 restrictor in place of the thermo in non-thermostat applications to keep pressure up but that again will depend on your source of water ingestion.
Bottom line is, there’s plenty of water to be had and controlled. This is just how I did mine after a very costly experience.
My temps hold steady at 120 deg and pressure at 25 lbs when running hard with this thermostatically controlled setup. All systems go!
Fix the problem before your right back where you started.
Hope that helps.
Sorry Tom, kind of got off subject a bit…
Dave