454 rebuild or repower?
 

Last year a thunderstorm ripped the cover off of my Baja 29 outlaw while the engine hatch was off for repair. When I tried to start the motors after I reinstalled the hatch, I found the engines would not crank and after inspection found that rainwater had leaked down into the cylindrs and oil pan rusting everything. The insurance company refused to pay the claim because the adjuster and the inspector said that they did not see how that much water could have leaked in to the engines. So I have two mercruiser 7.4 lx motors trashed. My questions are: 1. If I rebuild the motors, what changes can be made to increase the horsepower output? 2. Would I be better off just buying 2 remainufactured 330 motors?

Also, If someone had two used take out motors for a reasonable price, I would be interested.

Here are some spec on my current setup:
1998 Baja 29 outlaw SST
Motors are Merc 7.4L 454s Carb motor, not FI
4 Bolt mains, internals were Hydr Roller
Stock merc Iron exhaust, with Silent choice
Bravo 1 drives 1.50 gear
23 pitch Mirage 3 blade props

The engines were rusted pretty bad, but some if it can be saved.

Thanks for any help!!!

It all depends what you want to do with it. If you're happy with the performance you got out of your 330Hp motors, or if you're happy with a small kick, you can do a fairly cheap rebuild, but you're going to have to see what is bad first. If you want to gain a bunch of Hp, now is the time to do it (while you have to tear it down anyhow) but you should set your Hp goal before you start ordering a bunch of parts.

Your pistons and bores are likely shot, but that's not that big of a deal. You should be able to get a set of used pistons for $100 or so, and it should cost around $220 or so to bore and hone your block to get your pistons to fit. If you do the work yourself you may be able to get it back together fairly cheap ($500-$700 or so per motor).

I would tend to think that you'd be better off rebuilding the motors you have if you've done it before. If you have to pay to get everything done you're probably better off buying a set of 330 Hp long blocks. I would buy a set from someone on here before I bought a reman set. IMO they rape you on those remanned 330's... A couple of guys in the swap shop (I think GRD is one of them) have them for around $1,200 a motor...


*** You may want to have some sort of professional mechanic or marine mechanic look at your boat, get his opinion of the water leaking into the block, and talk to an attorney and your insurance co. again. They may be willing to work with you after you've consulted an expert and attorney.

Thanks, Those engines look awesome, but thats a little steep for me in this economy.

Trying to keep everything under 10k this year

buy the time you rebuild them,you have spent more than if you baught jeffs motors,and you would still have 454s.if you buy his,you will have 500 hp 496s,and you can sell your old stuff.seems to me like a no brainer.:coolcowboy:

I liked the 330s, but ya always want a little more.
Yes, the Piston and the bores are shot, Heads and Intake are also rusted. Crank is ok.

If I can change a few parts during the rebuild to get more power say 385 (mag) or 420 merc. I might be interested. Just don't know where to start.

Might be able to work something out if you send me your old ones, add a few dollars, and pay all the freight :coolcowboy:

Or if you have anything else to throw in for trade??

Or take 3-4 days off and bring the boat and we can switch everything out.

I really can't do anything with you old ones as they are all cast internals, and small heads, but all the accesories, and other parts could come in handy on a project in the near future. I can make a few mods to mine to make everything work in your boat.

If I can get the insurance company to pay the bill, or I can put back a little extra cash in the next month or so, I might be interested Jeff.

Send me a PM and let me know what you have in mind.

Sounds like you already have it apart... Might be too late to talk to an atty or professional, but its worth a shot. I would tell an atty to write a "nasty letter" with a quick opinion of a good marine mechanic, and offer the attorney 1/2 of whatever he can collect from the ins. co. It's amazing what they'll pay to stay out of litigation, and it sounds like you have a legitimate claim.

Do you need a new intake or can you use the one that is there (your old one is cast iron?)? You can get a new intake for $100 if you don't mind sticking with the stock type stuff. Stock carbs can be had for around $100 as well (if you need one).

If you keep your motor, get a new set of heads (GM 049 or 781 heads are a really nice upgrade for the 330Hp motors), and rebuild your lower ends with new cams you should be able to come out of it fairly cheap, and add at least 50Hp, and be fine with that cast crank.

Cash is king right now. I am away from home on business, so it will probably still be 2 weeks before I get back and can do anything anyway. PM me when you are ready to talk about it.

Jeff