Trojan Boat Forum

Well, I have the engine and I am using a velvet drive 1:1 tranny, and I am also using the original Crusader tranny mounts, so the coupler lines up with the shaft very well. Now, can that inch shaft stand the 454 spinning it? And to get on plane at the lowest RPM, what RH prop do I need? 1972 F-25....Thanks!

Give me a HP at a rpm and I will see what you need
what is the shaft made of ?

Paul

The shaft is 1" stainless steel. The engine is rated at 330 hp at 4800 RPM.

dirkpitt1 You can get by with this if the shaft is aquamet 17,19 or 22
with a safety factor of 3 if its just plan old S.S. 304 or 316 it wont take it .( bet you have aquamet 17 )if fact it would not have held up to your small block . I would use what you have and prop it so it hits full rpm (4800+) (prop for less less rpm = more load)and if you have a proplem replace it with aqumet 22. ( almost a safety factor of 4)
Paul

Max HP for a 1" shaft @ 4500RPM with a 1:1 tranny & a Safety Factor of 2 is:

> SS 304 or 316 = 140 HP
> Aquamet 17 = 490HP
> Aquamet 18 = 421 HP
> Aquamet 19 = 491 HP
> Aquamet 22 = 607 HP
> Monel 400 = 280 HP
> Monel K-500 = 470 HP

A stock Mercruiser 7.4L is 330 HP - so the 1" shaft is marginal! and will break if its stainless. What engine wa sin there before?

You MUST find out what material it is!

I don't think he has a stanless 304 or 316 shaft as the lowest hp engine that boat would have had would be 188hp but more likley 225. it may be hard to find what it is for sure . The figures use by rossjo are correct
Paul

agreed - ts probably not SS 304 or 316.

I have 2 surveys on my 1974 Trojan F32, and neither states shaft material as anything other than simply "Stainless", as surveyors cannot easily determine this (or if at all without damaging the shaft?).

Does anyone know what shaft material Trojan used on various models?

I would like to know as well on my F32, as I plan to crank them up to 275-300HP each and bigger wheels, but need to know what they can take.

The last engine in that F-25 was a 305, and a 350 before that. I think that it may be a Monel shaft. Not sure. I need to check.

Maybe Bob at trojan boats would know what they used OEM if not
marine-tech should The survey on my boat (f36 )says " stanless steel reported as acumet 22 " he used to be a trojan dealer if I rember he said thats what they came with ( almost 2 years ago ) I would take that with a grain of salt I did change my old f30 from 188 hp to 255 and never had a proplem (1 inch shafts)
Paul

What shaft material did it turn our to be. or doesn anyone knwo what shaft material(s) Trojan used over the years?

I would like to know what was stock in my 1974 Trojan F32.