[Mariahman5.7]

Hello, I have a 94 Mariah Z212 bowrider, w/ (fully stock) 5.7L, 4 brl, engine. I was told it is a 300HP engine, I was also told it could be 330 HP. I've had it for 5 yrs now and never really cared that much but I'm thinking of selling and I'd really like to know now. Maybe it's 260 hp ????? anyone know ???? It most definitly will gitty up and go. Top speed is approx. 63 - 65 mph according to the speedo w/ just me on board. Thanx

[Mariahman5.7]

Also, would anyone know where i could find a new or used face plate for the sterieo console that is located below the trottle handle??? Mine is cracked

[Z 202]

Welcome to the club.

Unlikey you'll find the part you are looking for, like most of the in house stuff Mariah made, these parts are difficult to impossible to find.

However, there is a good thread in the How to's

http://www.mariahownersclub.com/foru...ead.php?t=1340

It details how to make a re-inforcement panel. I'd suggest just making one up and painting it black or powder coating it.

[WetWilly]

Hi Mariahman5.7, sorry to hear you might be selling your 94 Shabah.

From what I'm finding on the web, looks like your 5.7 w/4brl carb is rated around 260HP (300 for the 5.7MultiPointInjection) and the 94 Mariah brochure rates top speed between 52 - 56mph, which is pretty fast.

WetWilly

[launchpad]

I've got the same boat, similar questions. 5.7 4bbl, was told 250HP when I bought it, but the manual sounds like it's 260 hp. Mine goes 57-58gps all day long.

Curious the diff between 250/260 hp 5.7's and 300hp 5.7's from the same era. There has to be a good carb/intake combo to squeeze out a few more HP. any way to find specs on these engines with cam profiles and head flow number or anything?

First post.... cool website.

[indykoch]

Launchpad... awesome avatar!!! Fit's the name, too!!

As stated in another thread - I think the mid 90's had emissions or hp measures change the output of most MerCruiser engines. I haven't fully understood or researched it yet. Could be the way they rated the hp, could be certain restrictions that caused lower output, could be nothing different than today's engines just rated lower for some reason... I don't know.

Anyway, the '94 5.7 4bbl was rated at 250 hp. The 300 hp engine is the fuel injected, MPI that WetWilly pointed out.

I'm not sure where to find the info you're looking for. I do know upgrading a marine engine is terribly expensive and difficult for a matter of 2-7 mph faster.

Today's ratings are much easier - 3.0 135hp, 4.3 190hp, 4.3 MPI 220hp, 5.0 220hp, 5.0 MPI 260hp, 5.7 250hp, 350 mag 300hp, 6.2MX 320 hp, 496 375hp, 496HO 425hp

It looks like fuel system, cams, and computer programs are the main difference between engines of same size.

[launchpad]

Thanks for the info, wave came out of nowhere! Somehow, my buddy got a great pic of it..

I had a prop shop tell me it would take roughly 100 more HP to go 10MPH faster with the correct prop. While it's nothing to get 350HP out of a 5.7 these days, the hassle factor would be up there a ways. Plus, boating on lake washington like I do, I really need a bigger hull not a bigger engine.

Regards-

[ShabahZ280]

Yep, you're right. It will literally cost you a fortune to get a few MPH more. The best thing to do is live with what you've got until you can afford to buy a boat with a bigger engine, and a longer hull to keep you balanced.

I've seen lots of disappointed people who just swap specific parts on their engines, only to have something else fail; usually something they overlook. There's a lot of evidence on the offshore forums of guys who spend $5000-$8000 bolting up superchargers, and then end up destroying the rest of their engine block because it just couldn't handle the added stress. The only way to build an engine for high HP numbers is to build it completely from scratch strictly for high performance, using hardly any stock components. There's many places that'll build you a brand new custom high performance engine, starting at about $20k.

Mariahs were really never built as speedboats, even though they offered some good sized engines, the hulls are just not cut for extreme speed. I think there's a fine line between comfort and speed. I chose comfort, that's why I didn't buy a Baja.

[Z 202]

...that wave came out of nowhere eh?

I had mine like that once. Unfortunately no one was around with a camera. I know for a fact these hulls are built like no other.

I was told my '95 5.7L 4bbl was 260hp, by a fellow who been selling boats for a lot of years. As far a power is concerned, I think the combo is really well matched to the hull for excellent all round performance. I too, couldn't see any reason to upgrade the engine/drive without also moving up in hull size.