Really wish I had a v-8!

[Ole Sarge]

Hi, new to your forum. I just purchased a 97 Maxum 1900 SR. It is in beautiful shape, 1 owner, stored indoors since new, less than 200 hours. 1 problem, it's a 4.3L v-6. I was really hoping to find a V-8 boat. I build hot rods for a hobby, so making it a v-8 shouldn't be too much of a problem, but have some questions. Read somewhere that hulls were rated for the power they can handle. Can anyone direct me to a source of information on what engines were offered in this model? I'm pretty sure you could get up to 5.7 w/ maybe 260 horse, but not positive. I also understand that you need an outdrive rated for the engine you put in front (kind of like putting a TH200 behind a big block would be a bad idea). Any information or knowledge on this subject would be much apprechiated. I am kind of expecting to purchase a second parts boat with v-8 to use for parts.

Attached is a pic of the boat

Thanks

Chris

[seapuppy]

Welcome to the zoo Chris...I'm a bit of a motor head myself....used to build up engines for people many yrs ago....
as for the boat...we tested a bunch of boats last yr...everything from an 18ft to a 41ft maxum...had a great time and the boat your on is rated up to about 300 hp...with that your gonna need either a Bravo 2 or B3 drive...with that ...300hp would make that boat scream.....260 hp on a b3 drive would make that a 60mph boat easily.......you'd be able to yank the socks right off of a skier........

as for looking for options..just go to the maxum.com boat site and you can go back a few yrs with engine/drive options on thier web pages.....

keep posting and if you do change the engine out...post pic's ....we'd love to follow your progress....


SP :hello:

[Gazjen]

I was going to do the same, I brought a 1996 SR with a seized engine.

I found a 350 Mag 5.7 to put in it, but I was going to use the standard Alpha 1 I researched that they are ok up to about 300 hp

It looked a fairly simple swap but the sale fell though on the engine so I rebuilt the 4.3 in the end, still goes well with that in though

[Ole Sarge]

Yeah, I was looking at mebbe a 260 horse 5.7. I read that the Alpha 1 gen 2 is rated to 300hp. I was gonna keep cost down initially by keeping the outdrive, then maybe upgrade later. I also read that I have to have a 1.48 or 1.50:1 shaft. I'm at 6000 ft, what ratio do you recommend?

Talking engines, some guy tried to tell me that marine motors have larger water jackets, and different bearings, so they could run at 4-5000 rpm all day?!?! I can't see GM casting different blocks for boats, or that standard Clevite bearings wouldn't be up to the demand of recreational boating. It is my understanding that some may have reverse rotation, buy my 4.3 on my last boat looked like it rotated Clockwise. So, I have to wonder, other than the manifolds and cooling system, what difference is there, really? Is this just another idiot trying to sound like he knows WTF he is talking about?

BTW, I am in Afganistan right now, and haven't even seen my boat yet. Get home for leave in two weeks, plan on enjoying the hell out of it! :mrgreen:

[TonyA]

Yee I tend to agree in what you are saying the motors are just GMs with the exception of the marine bolt on stuff,
I noticed that the water pump on my spare 5.0L has a SS backing plate and a bronze impala witch is also slightly different to the auto type

Well about 12 days to go and my 1998 Maxum 3000 SCR should be home then the fun will begin ( I purchased this boat by photos only how nuts is that lol)
I have a good feeling about this boat and know what to expect

[Ole Sarge]

Originally Posted by TonyA

( I purchased this boat by photos only how nuts is that lol)

You are a trusting soul! I at least sent a friend to view the boat, hear it run, and stomp on the floors to make sure they were solid prior to commiting. My wife has since been to look at it, and assured me that it was BEAUTIFUL.

I'll have to look into the water pump thing. A water pump is a pretty simple swap, cant be that much. I can get 350's all day, Its the bolt on marine stuff that gets pricey. spose all the 4.3 stuff would be the same with the exception of the manifolds? I think the motor mounts are even the same from 4.3 to v-8? Anyone know for sure?

I live for putting stuff together that god (or the law in some cases) never intended! This is my Hot Rod, 494 stroker, 585 hp at the rear wheels!

[Ole Sarge]

In fact, I bet the water pump will even fit from a 4.3 to a 5.7... A 4.3 is basically a 350 with 2 cylinders shaved off. Found this web site, might be worth checking into. Looks like about $1450 including core, shipping, whole 9 yards for a 4 bolt main 270hp 5.7. Not too bad

http://www.chevy350motor.com/Chevy_350_ ... mlb-4.html

[seapuppy]

sarge....first off.....thanks for being over there doing the thankless job that the obamanation sent you to do!!...stay safe..keep your head down....come home in one piece...

secondly....although the engines are the same basically...ie bore/stroke...etc...
.there are marked differences between a street engine and a boat engine....cam for one.....pistons .....all parts that touch water is stainless or bronze.....distributer is sealed or spark resistant....curve on the distr. is waaaay different.......alt. is spark resistant ....carb is not vented like a street model......and yes ..the freeze plugs are slightly different..........some may argue the points ..but also the serpentine belt is marine grade too....hoses are all marine grade...wires are marine grade....tinned for corrosion resistance.........the controller for the engine module is marine grade...meaning sealed more against the elements and salt resistant....the air cleaner isn't an air cleaner...it's a flame arrestor......and the list goes on and on...so ...yes ..there is a ton of differences between a street engine and a marine engine....with that said...the water jackets are the same....rods and bearings are the same....so...in one way the idiot is correct...but his technical capability is off ....

hope this helps....


SP irate:

[Ole Sarge]

Yeah, that makes a whole lot more sense. I have read some about water pumps and the freeze plugs being brass. It's about 12 hours ahead of you here, so I've been doing a little research. I am wondering about the validity of just working over the 4.3 a little bit. Looking at some Chevy forums it might be reasonable to milk a 4.3 to 240-260 hp with mild cam, 1.65:1 roller rockers, and maybe some head work. Anyone here done that before? The weight savings and cost of the swap alone might be worth "warming up" the 4.3 a little. On a car I'd say no way, cause I love the rumble of a good healthy V-8, but on a boat (without thru hull exhaust) who'd really notice? I gotta do some more looking into it, but it might be a viable option.

[seapuppy]

well..you could definitely heat up a 4.3ltr engine....they can get some serious hp when you do some things to help them breath better........and with some internal changes...make them spin a bit higher too....but with roller rockers and all...it should get some good hp/torque ratings ...enough for a boat to shoot and scoot for sure!!..


SP irate:

[Gazjen]

I'm currently looking at super charging my 4.3 or the 5.0 if I change my boat

Like SP says freeze plugs, cam, carb, head gaskets but it can be done, I rebuilt mine with auto motive parts and then just brought the marine parts like cam, freeze plugs and head gaskets,

That boat would go well with a 5.7 in it, mate of mine has a 5.0 MPI in a 2002 1900 Sr and that gets very close to 60 mph

[TonyA]

Yes SP you are dead right with all the other parts that are fitted to the GM blocks to make them a marine motor
I think we were trying to establish is that the blocks heads etc are same same as the auto blocks and could be used if you only needed a block or head so long as you set it up with the marine bits as you have mentioned. I am shore that GM doesn’t have special casting # on there blocks for marine application i.e. 5.7 auto /marine casting # same same,even with the same casting # still wont let you know if its a 2 or 4 bolt mains block. So If the idiot is wrong please correct me

[seapuppy]

Originally Posted by TonyA

Yes SP you are dead right with all the other parts that are fitted to the GM blocks to make them a marine motor
I think we were trying to establish is that the blocks heads etc are same same as the auto blocks and could be used if you only needed a block or head so long as you set it up with the marine bits as you have mentioned. I am shore that GM doesn’t have special casting # on there blocks for marine application i.e. 5.7 auto /marine casting # same same,even with the same casting # still wont let you know if its a 2 or 4 bolt mains block. So If the idiot is wrong please correct me

I'll try and remember to talk to my parts guy on casting numbers.....I'm not sure about whether they state marine or not....but I do know that in the casting number...it determines if it's a 2bolt or a 4bolt main bearings.....somewhere in the casting it says it..a 2 or a 4...not sure where in the sequence...


SP irate:

[Ole Sarge]

After further reading at several sites, It looks like you can't really push a 4.3 marine much over 220-230 hp without evacuation happening (water getting into the valves apparently). Something to do with the design of the heads I guess. The general consensous seems to be that not only do you get the throaty rumble, but the most cost effective way is to just swap in a 5.7

[TonyA]

Hi SP, yee I cant find were they distinguish the deference , on a 350 I have here the casting # shows upon as a 4 or a 2 so the only way I am going to fine out is by removing the sump one day