Looking at a boat with 370 TRS engines (1986), in the future if I wanted to upgrade to a fuel injected engine and keep the TRS drives and BW trannies. What are the options?

Options are endless... Same as with Bravo drives, just different flywheels, and possibly different exhaust locations (I say possibly because my boat has a weird set-up that uses a drop down pipe... I can use bravo exh. on my boat if I keep that goofy piece in there).

You can also add EFI to your old motors, but you should probably consider rebuilding them in the process.

You can bolt up any BB chevy to those B-W's. To change to FI you will have to change some wiring,add computer and sensors, fuel lines and go to electric fuel pump. The 370 is a good base engine to work with as it has forged crank, pistons and rods. Rectangular port heads with an aluminum high rise intake and roller rockers. 8.8:1 compression. It was considered a mercury production performance engine.

you could always go to a konrad drive if your in love w/the boat.in what i mean by that is the cost of the conversion,comparried to how much the boat is worth.i just bought a 10meter fountain.it has the same set-up.one of the motors was blown up when i bought it.i figured i could salvage some of the motor,,,,,,,wrong,it was blown the pluck up bad.so now i am doing 496,s out of some 2bolt main blocks that i had laying around.i will say this,the trs set-up is a heavey duty set-up,,,,,,,,,and real heavy comparried to a bravo set-up.

I see some 496 HO take outs that seem reasonably priced. What is the opinion on these motors?

A lot of people run them without much problem, but if I'm swapping out motors and selecting motors from scratch, I'd buy something with forged internals. Basic 502 or 502 MPI/EFI, IMO, is the way to go.

I have a pair of 500 EFI intakes if you need them.
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If installing fuel injection, I suggest staying with the Mark IV engines (with the mechanical fuel pumps). There is nothing better than using a mechanical fuel pump, mounted on the engine, to pull the fuel from the gas tank to supply the high pressure electric EFI pump.
Electric EFI pumps don't suck fuel very well, they only push.
Install the water/fuel filter between the gas tank and the mechanical fuel pump.
Install the high pressure EFI electric pump in the fuel line between the mechanical fuel pump and the fuel rail.

Mercruiser really made fools of themselves by using VST tanks and the "Cool Fool" nonsense, all in an attempt to satisfy the boat builders. The boat builders were simply too lazy to provide a return line to the fuel tank (like in an automotive/truck application).
You should make the effort to run a return line to the boats gas tank. The constant supply of fresh fuel circulated through the fuel rail will remain very cool and the engine will never vapor lock. Fuel return lines routed to the fuel fill hose work well.

Of course the best solution would be an in-the-tank electric EFI fuel pump BUT that would require pressurizing the water/fuel filter with 30-40 PSI of fuel pressure!

When installing a high pressure electric pump make sure you install an inline pump that has the fuel passing through the pumps armature. These pumps run very cool and last ten times longer than an air cooled electric pump (and they are less noisy).

Keep in mind that aftermarket EFI systems will work better with an O2 sensor. There are O2 sensor plates available that mount between a Mercruiser manifold and the Mercruiser riser.

Good Luck
Dennis Moore

Dennis,
Are you the guy that wrote the 454 marine book? Its been some time since I looked through it but, very good for a beginner to get there bearings straight!
Jr.

If you do purchase this boat there are many options. I have some new Konrad 540 with gimbals & pumps still in original crates. A pair of new 572 short blocks or we can complete it with Canfield 350 alum heads, that includes, valves springs, ti retainers, Jesel Pro Series rocker arms. Have 2 trans, Huber upgraded have to check series. I can offer you a sweet deal as a package. Mark