Trojan Boat Forum

OK! i not sure if i fell off the deep end.. my boat is a "88" Trojan 10 meter. this boat ran ok this year 33 mph on gps witch feels great in this size boat. i need to rebuild the motors so i feel like doing a stroked 454. now i thought i would get some info from others here. anybody do anything like this to a cruiser. this thing is around 16,000 pounds

also i have built many motors and now the importance of great machining.
the plans are

496 stroke kit all forged internals 9.5-1 comp. heads are 308cc intake runner with a 119cc combustion chamber, a 2.250 intake valve and a 1.880 exhaust valve , performer RPM air gap duel plan intake manifold, and a 950cfm carb or dominator, Hyd.Roller, Revolution marine exhaust manifolds.... now i have left the cam open? this is where i need some help. i want it to be reliable not building it on the edge but i feel that 575-600 HP should be doable. my drives are velvet drives not v-drives. also i know that the reverse rotation motors crank needs to be cross drilled and reverse polised any other information would be great.

Big Big mistake leave it stock . You need the low end of a stock engine to get it on top. The over lap of a H.O. cam cause issues with sucking water back in causeing stuck valves . The cooling system will need to be changed to handle the extra heat . The Velet drives will need to beefed up . larger shafts ?

This is not a speed boat , its a good crusing boat but it won't be if you try to hot rod it .

Maybe you can mount a few new 100 gal fuel tanks on the bow
But seriously.... what do plan on using the boat for??

Ron

prowlersfish wrote:Big Big mistake leave it stock . You need the low end of a stock engine to get it on top. The over lap of a H.O. cam cause issues with sucking water back in causeing stuck valves . The cooling system will need to be changed to handle the extra heat . The Velet drives will need to beefed up . larger shafts ?

This is not a speed boat , its a good crusing boat but it won't be if you try to hot rod it .

no disrespect but this is not a hot rod build just makes sense. the motors need rebuilt and by stroking them i will receive over 100 more foot pounds of torque in the same RPM range with a mild cam with 110-114 lsa . and should have no reversion. i have been doing a lot of study just thought i would see what everyone feels. not looking for a race boat just a little extra when i want it. the drives say they can handle around 500hp on them stock, cooling is fine i am a closed coolant with six set of ducts running for air inlet to the motors, shaft claim their ok as well, but will absolutly be reproping

rbcool wrote:Maybe you can mount a few new 100 gal fuel tanks on the bow
But seriously.... what do plan on using the boat for??

Ron

i am on lake ERIE and i have 2 125 gal fuel tanks i can go any where with that much. but really i usually cruse around 26 mph on gps and this year i pushed the motor at the end of season just to see what i could do and the boat feels great over 30 almost like it gets up on plane again. and smooth as silk, so i thought more power, torque, and props should be great.... it just seems like the boat wants to go faster; my wife even said the boat felt like it was smoother from 29-33 mph area.

Well your name says it all. Good luck with it. I guess there's no reason you shouldn't do it. We do it with cars all the time. I had joked with Tony about putting 502s in my Tri-Cabin, but anything is possible.
Post some pics when you get her done.


Ron

I agree with Prowlerfish. Leave it stock! I did what your talking about on another boat, one big headache! Putting that one back stock, and never doing it again! Change the spec's just a little thats all I did, boat didn't want to plane out, took forever than a day. Not worth it in my opinion.

go diesel. screw the gas engines in a skiff that big. twin 1200 hp man diesels should do the trick!
a friend of mine stroked two 454's, knocked 'em out 30 over (mistake), high perf ignition, roller interior, blah,blah,blah and dropped them in a f36 trojan...he eventually got sick of the headaches and dumped it. sure, it went like a bat outta hell but between cooling issues, ignition issues, spun a few drive couplers, steering issues (yes, steering) etc,etc it just wasn't worth it.

Whatever you do - post some pics for us. I am not knowledgeable enough to recommend anything to you but good luck with whatever you decide.

It's your boat - make it the way YOU want it

How can the cooling system be just fine when it was made for a lot less HP ??

What model Velet drives ?

even when you start jucing up a car engine it has cooling issues... if you leave the cooling system stock.

The first question I would ask is : If it ran well and you can get 33 out of it (pretty good for that model I think), why do you think you need to rebuild? With that kind of performance, the engines don't sound tired to me.

I used to drag race cars! i currently have a 7 second 1/4 mile 4cyl.
cooling isues in cars come from lack of air / shrouds and poor water circulation.

Why is it if someone rebuild a motor over stock it is all of a sudden the reason why it breaks! instead if the builder builds it to handle more than it is used for as stock ones are built. than it might last.

now I know that a factory produced boat has a formula that makes it work the way it does.... so I need to find a formula that does it for me. thats the R&D. The engines are stroked and bored out to 496cid. roughly around 600 ft. pounds of torque @ 5k and 575 horse. now i have to figure props and couplings? i will also be proping it for 4500. not to mension the engines are capable of spinning around 7k safely 3k less than they will see.

Prowlerfish...i will check monday which drives when i get to the shop.

atleast i hope most of the horror storys are from poor builds. but i will upload photos as it moves along. i would like to talk to the guy that did it to a F series boat.

captainmaniac wrote:The first question I would ask is : If it ran well and you can get 33 out of it (pretty good for that model I think), why do you think you need to rebuild? With that kind of performance, the engines don't sound tired to me.

the old owner lacks the skills to put gaskets on and the engines seen a lot of time with low oil....I am a very picky about how a motor works and i am in ohio and winter is the best time. this way i am asured they are strong enough for my family to go where ever we want

A race car that runs the 1/4 mile has nothing to do with a boat engine the runs under high load for hours . Air flow and shroud's have nothing to do with cooling a boat engine . the size of the heat exchanger is the key ( and a water pump to match . yours is made for a stock engine . won't cut it on a built engine.


I seen this time and time again , you'll spend more time fixing it then using it . The people I have seen go this road end up going back to stock or just let it sit . Most the folks have done well doing cars but do not understand boats are a different ball game ..


BTW Those big carburetors are marine right ?

also The reverse rotation motor will need a custom camshaft