James Bailey

The wing helps keep the transom down for more traction

DR

Technically that is true... in this case "traction" = less cavitation (or sucking air in the case of a jet).

Props sound funny spinning in the air, BTDT

Jim, BTW, this is probably more our speed these days...

DR

I agree about the power and speed, BUT since it was supposedly made from Kevlar..the weight could make a big difference. If not I have something that could fix that S4 Motor to give it more speed. Boats love Twin Screws.....especially in multiples (see pic :-)

BTW, the Winged Boat was made by Tempest Marine 20 years or so ago?. At first glance the drives look like Bravos, but the silver color ?????

docmirror

I just found this thread and have a few things to add having built some jet boats in the past. First, you'll need to get a new impeller with less bite. The one on the 850HP boat had a much taller pitch than you can push with a 928Euro.

Next, the CIS is sort of ideally suited to a boat since the boat engine runs at 40-75% rated power much more often than a car, and the CIS has an enrichment for higher throttle operation. The mixture pin is calibrated so that the mixture gets richer with more throttle. Also, besides being counterweighted the air metering plate is damped by the action of the metering pin in the fuel.

You will need to use the right temp thermostat and insure that the temp of the WUR is sensed right so that the WUR provides the right fuel pressure to the CIS head. It's common on boats to use a 160-175F thermo and that will not let the engine warm enough to get the WUR at the right setpoint for the FI. Of course, you'll be doing some tuning with the CIS mixture screw to compensate but I would stick with the 192F(I think) thermo for the boat.

You may also need to investigate a pre-heater from the exhaust system for the water entering the cooling jacket of the engine. The 928 uses a bypass circulate system with the cooling jacket rather than the blocked system of the US big blocks. Something to investigate before you either can't get it warm or can't get it cool while out on the water.

Lastly, because you don't have to support the big electric loads of the 928 chassis, you might consider going to a small Geo Metro alternator or similar. It will release some HP by smaller mechanical loads, and also will weigh far less than the stock 928 alt.

DR

Dave,

Not sure if you can find him, but Mike Nicholson who worked at Tempest in Miami in the 80s/90s supposedly design/rigged that winged boat (and one other) AND one of the single jet "Kineo" versions. All accounts is he likes talking about those projects... Facebook search??

I finally found the post from 2006 in a boat forum that put me down the path of finding more info on the Porsche boats where he was mentioned...

"I spoke to Mike a couple years ago about the Porsche Kineo 27'. He said they (F.A. Porsche) built 10 boats, all silver, at Marine Concepts in Cape Coral, FL. They built both singles and twins with various propulsion systems: alphas, jets, arnesons. He specifically told me about the amount of time he personally worked with the jet drive manufacturer to get the single jet boat to run properly. So, I am thinking this could be one of the 10 original boats. All of the ten Porsche boats had 928 motors marinized by Wiseman (sp?) in Austria. He said they could go 2-3000 hrs between rebuilds, but had low hp ratings. 5 stayed in the states and 5 went to europe. Tempest built two more after the project was scrapped by F.A Porsche (note from DR: think these were the Winged Tempest Super Sports with S4 engines). Over the years, I have seen a couple for sale. Usually with rediculous prices...."

Might be a fountain of info for you....or not. :-)

Cheers,

James Bailey

Are you planning to run an oil cooler/heat exchanger ?? Like one of the NASCAR style liquid to liquid.

mallman

If you need more power ,have this taking up room in garage, would trade for 928 STUFF

Tass 928

Doc, thanks for the insight You bring up a lot of good points to consider.
The PO's big block was running 6-6.5K rpm max so I figure I'll be close to that range. My plan was to start out with the impeller thats in there and see what I get for performance. I am guessing decent top end but a crappy holeshot.

Cooling wise, the jet provides pressurized cooling water that I will regulate on the output side of the engine. I'm questioning if I need a water pump at all? Leave it in place or pull the impeller and just use the "pump" as an idler pulley ?

In an effort to keep the front of the exposed engine free from moving parts, I was going to try and drive the alternator from the rear of the engine. My plan was to sandwhich the stock alt pulley somewhere in my driveshaft coupling and mount the alt up high, out of the bilge area (and related fumes). I agree, some smalller aftermarket alternator is probably in my plan.

This is meant to be an impractical toy so I'm hoping to keep it as simple as possible. I'm going to drop in the stock engine, no oil cooler or custom oil pan and see what it does. I'll watch it carefully for temps and pressures and solve problems when they come up.

Tass 928

If I went that route I would surely get stupid with it and kill myself.

Tass 928

I read another add for the single engine /jet and they are claiming 68 knots...
isn't that about 78mph ????? I guess thats why its' so expensive .......even so, I would sure like to own it.

DanielD

Here's an engine already built...

DR

Hey Dave,

You may want to hold up on the build.... Looky what is for sale on Ebay ...LOL









http://cgi.ebay.com/ebaymotors/MISS-...item1c1d2f4688

Nicole

There is our (almost) flush center console that we have been waiting for...

123quattro

Oh come on...if you are going to go, go big. Turbos are even better! 1350hp.
http://www.mercuryracing.com/sterndrives/hp1350.php

docmirror

You don't have enough torque to turn that impeller. It'll dog out around 3500 or so. It may not even get on step

The water volume from the pump is plenty to cool the engine. I just wonder about pre-heating for the 928 engine. Most big blocks don't use a water pump, they just take the draw from the jet pump and pre-heat it through the aluminum exhausts. They're called water logs, and there are several makers, but none for the 928. It's possible to re-rig the cooling system so that it's a blocked style like a Chebby, so check into that, rather than a full bypass setup like a 928 car.

You have to have a damper on the front of the crank, so there's no way to avoid spinny things on the front of the engine. Just mount the alt up front where the old one was, and drive it with one of the v belt pulleys already provided. Put a chrome cover on it if you are concerned about toes. I just usually put up a small wood wall around the front of the engine that comes up easily. It keeps feet out of there, and it tends to block the view of the dirty bilge bay. They can lift right out for service.