turbo charged
 

My friend is building an ex Navy Seal HSB and this is what he is using for power. What do you think?

the exhaust is designed to go out of the bottom of the boat

from what I see its a draw through the carb set up wouldnt touch it with a 10' pole. No matter what you do the seals in the compressor end will allow oil and fuel to mix into the engine and turbo causing damage. If those turbos have no seals big trouble. No seal can withstand the RPMs a turbo runs at. Go blow through or injection and it will live for years providing boost is not higher than the engine components can handle.

I have wondered about the pros and cons to a draw thru system. I had a blow thru system a few years ago. It ran well but was difficult to prop for getting on plane with very little boost, then having the prop want to blowout once boost came on.

Depends on how much the compression is lowered. Low compressionn with serious boost and a boat might never get on plane. In this situation a 2 sp transmission helps, a low gear to reach planing speed and turbo spool up hit second and your gone. Low boost aplications the compresion can be left high enough the engine will have enough power to plane the boat before boost cuts in.
Makes it sound easy but its not turbos produce tork lots of it or high HP also depending on sizing ... intent. I did a 460 goal was same HP as stock 375. 10 lbs of boost c/r around 7.5 pulled 375 HP and 800 lbs of tork. An indy engine the old turbo Cosworth Fords were more HP didnt have any power untill 4000 RPM from there the graph was almost a vertical line. Most aplications in the performance world start out with too much power then they are detuned so they can hook up to whats avilable gearing, tire sizes, prop size, etc.

I like for it to look as good as it runs. These set ups just look like they belong in a 1972 jet boat. Even that new 1200 that chief did still has the same goofy looking log exhaust....he tried to dress it up but I still think it looks dated. I understand this is a navy boat....I hope it works out. All I have heard is horror stories. I have personally had two experiences with twin turbo's......my first and last! The motor blew apart so severely that we had to repaint the bilge!! That was years ago and I am sure technology has come along way.

Footnote.......we also had no idea what we were doing......but Gale banks built the motor.......and I will have to say, the banks motor blew up bigger than anything else I have ever seen......so in that respect it was truly high performance.

Had a Gale Banks Twin turbo setup like that for about 20 years. Tore up a few motors but was running the motors on the edge. I had added waste gates with a dial on the dash. I could adjust the boost from 5lbs to 15 just by turning the dial. With the waste gates the motor would build 5 llbs of boost just off idle.

Good to see the old girl being refitted for civilian life. Having spent a lot of time on these boats when I was in the Teams, I can say he'll be very happy with the ride once she's back on the water. What manufacturer made the hull? Two companies come to mind. Just remind you buddy, these are HEAVY hulls, that were ment to work,and take a LOT of abuse. It takes some hp to make them run.




Darrell.

I love the look!

Have the engines been on a dyno? That would be a good place to get a feel for the torque curve of this combination. I currently have two Gale Banks Twin Turbo sets similar to those in the pics and am trying to decide if I want to try then on a pair of 502 MPIs. It sounds like a fun project but I am not sure about a reliable calibration with with the processors I have or MEFI 4s. Keep us up to date on this project.
Thanks.

Same experience as Turbojack - run them on the edge and watch em go. Just go with the basics of any blown motor - good valves, low compression, moderate boost and they will live a long life.

4 to 6 lbs of boost and they increase power by about 40%. With the right prop up to 25% fuel economy increase at your current cruse speeds. MMoree poer than a blower because there is no drive loss. Engine ssould do well for yeas if you dont push it to far all the time

It is possible to run very low compression and high boost. My static compression ratio is under 7:1 and I'm running over 20# of boost. Engine starts making boost at 1500 rpm's so getting on plane is not a problem. I'm using efi and not a blow through or draw through set up.

Check300 - how bout posting a pic!

Not real pretty but It's all home built.

Check300, are details of your engine project available? It looks like there is no intercooler and it is not a Merc EFI system... How fast will it push the boat? I am considering a similar project on a 283 W/ twins but packaging it may be a challenge.

The intercooler is the round piece on top of the engine. The efi is Big Stuff3. The boat runs in the triple digits. With twins you could use smaller turbos but packaging would still not be easy.

EFI twin turbo 2 sets
 

I have two sets of Multiport EFI turbos willing to sell. They come with injectors, fuel rails, computers, 4 turbos using mercruiser exhaust...riser is bolted to the turbo. Intercooled with Paxton fuel pumps and regulators. Only thing missing is edelbrock intakes and some of the wiring was hacked by the previous owner. I'm building a different setup and have decided not to install them. These will fit in twin engine setups, but narrow engine spacing will required an adapter between the inboard turbos to kick them into the center of the motors. Neat setup and would hate to sell them...but no need for them to collect dust. Also come with tall valve covers. This is a PFM setup using shielded garret turbos.

Tom
561-676-8624

Check 300 has an awesome ride, very effective set-up.



Jon

another pic

one more

This is the boat that these engines are going into.

The boat and trailer weighted 10,200 lbs without engines or drives. The four 100 gallon bladders have been replaced with one 200 gallon center line tank. During this process they lighted the boat by about 1,500 lbs. The hall is made of Kevlar with re-enforced area's made of carbon fiber. Engines get installed next week.

How much power is he looking to make per engine with the turbo's?

Is he going to dyno them?

Jon

The part of this package that is going to hold the HP back is the log manifolds. Back when Richard Lee was working with this package after he changed to a different exhaust manifolds (Started with the Drakes) he started making bigger HP.

The Gale Banks setup on a 454 made 850HP. Today with the better heads, better exhaust, whipple, vortec or procharger you can make the same HP with a lot less boost. The Turbo do have a different sound and the exhaust is a lot quiter.

I don't think your going to see 850hp with those little Rajay's...

This boat will be especially quiet since the exhaust comes out under water.

Those little rajays can make 15-18 lbs of boost on a 454

Tom, send me some pics of your turbo set-ups.

Sure they can make boost, and heat, but how about Flow?Even a boosted engine is nothing but an airpump so flow is all that counts.

hey wrap the chain in a rag:p


cool looking set up:D

Amount of heat for boost is less then a roots blower and somewhere around a screw blower or centrifical blower. As I stated above the exhaust is what is limitiing the HP this set up can make, the turbos can make all the boost the motor needs. This setup was state of the art back in the 70's. I had 2 friends both with same boat and only difference was one had the turbo setup and other had a roots blower. After a while the roots blower guy changed to a turbocharged setup.

[QUOTE=Strip Poker 388;2262396]hey wrap the chain in a rag:p


what do you mean?

[QUOTE=mcraymond3;2264011]The lift chain is just laid ontop of the airintake by the carb scratching the polished intake.Im a little anal:drink: :drink:

oh, I gotcha. I had no idea what you were talking about?

MCRAYMOND3,
What year is your hull? Looks like ya got a very cool project there. You'll really love the way the boat rides.Solid, dry, and work great in BIG water. Trust me those hulls can take some serious abuse. I spent a lot of time in different "HSB's" over the years. We went through a number of different iterations when I was in the TEAMS.




Darrell.

thanks for the info... I´m going the turbo route myself on several projects as we speak.
Plus improving one...
On a boat there´s not much rpms so apparently small turbos by a pair will live with a bigblock and not heat things too much.

its ocd i guess:sport009:

Darrell Moore,
The ID plate was removed before I picked it up. This was a newer design because the exhaust was channeled to an exhaust can at the bottom of the hall. The engine compartment was lined with sound absorbing/insulating material all around engine compartment to reduced the IR signature of the boat. Do you have any HSB pictures?

Heres my twin turbo EFI set up. Worked for two years making intercoolers, watercooled pipes, watercool the John Deere tractor turbos. Thier were 100s of things that had to be made to get everything working right and running. Did this in 1993. Motors have 1000s of hours on them. Turbos are the way to go if you can stand a little lag.