Dmac88sport226

Hey guys this is my first post on this forum. I'm kinda new to performance boating and I'm asking for some help/ info. Just bought a 88 baja sport 226 a few months ago. Just last weekend water got in the head thru the exhaust and bent a valve. 1 cylinder is shot and I was told since it's a mag they can't get pistons for it any more. One of my friends builds performance car motors and stuff and I was going to have him look at it. My question is I'm thinking of trying to bore it and stroking it to a 496. I have read in other places it's better to just do a 489 so you have the other .030 incase you ever for some reason have to bore it again. What do you guys think? Don't need crazy hp because I don't have the money and don't feel like rehabbing the out drive. Also I was told for the rotating assembly you can just used car stuff but for cams it's different. Anyone know of what cam and stuff I should get? Still want to be able to run pump gas. Thanks guys

SB

iTrader: (1)

So, what was it that broke or is not working correctly that let the water in ?

IMHO - don't get the cheap cast steel stroker crank kit. I'm not up to debate it (been too many times) but willing to say my opnion.

That said, if you read thru this forum you'll see that exhaust systems have everything to do with what performance levels you seek.

Lastly, if your friend has not done any performance boat motors, ever, either don't build one or kindly turn him down and use a known one. Be careful with that too...lol.

That said, what exhaust do you have and if stock what exhaust can you afford ? Hold on to your shorts as most start at $2k and then go up from there.

KRAUSMOTORSPORTS

iTrader: (2)

Lets start with these answers ^^^ good questions. I'm in the same debacle. You may be better sticking with the 454 depending on Funds available.

Dmac88sport226

Yeah that's exhaust is crazy. I only have a stock thru the hull. I think it's because I don't have any risers in it. The exhaust is under my swim platform and I think one of the flaps in the exhaust is broken. I don't think I can keep the same 454. The one cylinder I think might be scored. So it would have to be bored anyways. He hasn't done any marine motors but he has done stroker truck motors.

ezstriper

I have a fresh out of the machine shop 482 stroker, eagle crank/rods, KB forged pistons, balanced, ready to go 4 bolt main short block $3500

MILD THUNDER

iTrader: (3)

The stock mag pistons are still available from speed pro.

A stock rebuild,, a hydraulic roller cam upgrade, intake, carb, and exhaust, you'll gain a bunch over the stock setup. Or, you can spend 2000 for a new stroker rotating assembly, a new harmonic balancer, and a new flywheel to gain about 35-40hp.

Before you do anything, I'd take a good look at the condition of the block itself. If its been a marine block since 1988, even freshwater, its got 25 years of crap water going thru it. I'd strip it down, drain it, dry it out. Then turn it upside down on a stand. Tap on the sides of the block, and if you get piles of rust pouring out on the floor, I'd question using it. If you decide to use it, have the cylinders sonic tested for wall thickness.

These old 454 marine blocks, are nothing more than a 454 4 bolt car block. Usually can find a virgin bore, clean block that was from a automotive application, like possibly out of an older 1 ton truck, old chevelle, etc, on craigslist cheap. Not worth messing with an old marine block that prob has corroded head bolt bosses, rust scaling, etc.

airjunky

iTrader: (2)

Mild thunder is right it ,block may have given up a lot of important cyl wall and head chamber meat from the cooling passage side . Sonic check passes , sleeve that thing and let it rip .u may have beefy a gen 4 block ,forged crank and large rods ,worthy of saving if you can save it .and under a thou to make it fresh again .

dereknkathy

22 baja. 500 inches is unnecessary. where are you? if salt water boat, block is scrap. there are lotsa 454 blocks to be had for about the price of 1 sleeve. like airjunky says, you have the good crank and rods. the heads are scrap whether fresh or salt water. they have a thin spot at the valve guides that rots through, might even be what got the motor. so you need heads and pistons. first off are you sure it is a mag? in 87 they called 330 hp motors mags. peanut head-cast crank-small rod-cast piston magnum. and merc and boat manufacturers aren't real fussy about what year any one component was made.

Dmac88sport226

Yeah it's a mag. It has the forged dome piston and the rectangular heads. It says gm high performance right on the head. Possibly thinking of keeping the forged crank and just boring t with new pistons to save the money. Haven't really had a chance to rip it apart yet. What do you think would be a good build for a decent price if I didn't stroke it? The heads look like they are in really good shape. There is one cylinder that has a little low compression at 125. But the other ones are 150 which I guess is right on. That is the original motor for that boat and still has the bronze tag on it that says 454 mag. It was custom ordered for a owner of a marine with the 454 mag with the bravo one. Think one thing that killed it was think water came up thru the thru hull exhaust which is under the swim platform.

TylerBurich

I had great results switching over to roller cam and upgraded heads same time a couple years back. Mine started as 420's but the short blocks are similar if not the same as the mag motors. Put your money in your valve train and you won't regret it. Good luck