The Mariah Owners Club - 93 Barchetta Vortec upgrade

Well I got it done. Only took me all summer though :rolling_laugh:

I give some insight and tips and tricks for those who have to replace their 4.3 in the future.

So lets start with the stock engine. Its a 93 4.3L Mercruiser producing roughly 170hp. There are 4 Generations of 4.3's mostly changing balancing tweaks but from 99 up they changed the heads and intake and gave it the Vortec name most are fuel injected and use serpentine belts so there's that.

I was first going to have a local marina replace it but was kind leery when he said it would be in the range of 6K and he wouldn't have an engine for 2 months. I told him I can have the 02 Vortec in a week and he said he wouldn't mess with anything that is not OEM. Which to me means you are really just a parts swapper not a mechanic. So my good friend said just go with the Crate longblock and you'll be on the water by July :).

The 02 and up "Vortecs" upped the horsepower from 170 to 200 and used roller rockers. They also decided to use plastic timing covers and smaller Harmonic Dampners causing the water pump to be different as well to accommodate the plastic/thicker cover.

I used a Summit racing marine longblock crate engine from ATK HME-DMW4 costing $1973.99 shipped with a two year warrenty.

So that's where the fun begins. I couldn't use my old Water pump, Intake, Harm Dampner, or oil pan. I found a new Sierra water pump and Harm Dampner at Orielly's and sourced an Aluminum oil pan and new plastic timing cover from Ebay.

I used a new Eldebrock automotive intake but should have stuck with a marine as it does move the thermo housing a half inch to the port side. Not a huge deal but you have six hoses that run to that thermo housing ugh that was a headache. Also you lose the choke stoke mount because not many 02+ Vortecs had carbs at that point. Not a big deal if your going EFI but can be troublesome on cold start days with a carb. (You just have to rubber band the rod for 20 sec but I still am going to put it in here because I can :)) Since I didn't want to mess with serp. belts I had to modify the 02 Harm balancer as well by trimming the rim. You should bring your pully so you know how much to trim I did not :(. But we made it work. Also I had to cut the oil dipstick tube as the larger heads don't let you insert it with the long suck shaft. No big deal because I would rather drain the oil with a petcock and run a hose out the plug hole than suck it from the dipstick tube.

I did have a mechanic remove the old engine and install the new one but kinda wish I would have done the whole thing myself because he took a month just to pull it out and bolt it back in and that was it. Me and a friend had too rewire and replumb everything else because summer was flying by lol. The mechanic then did not use gasket sealer on the water pump or oil pan/timing cover at the front so it leaked like a mess and we had to fix that as well.

So all in all I'm happy with the outcome so far but will not be using him again and hopefully this saved someone some headache in the future ;).

So cost and all I was out $3600.00 and that includes hardware and having to buy two timing covers ugh.

We only have 4 hours on the engine now but it definitely overpowers the stock three blade SS prop and I am babying it till she is nice and broken in.

Ill probably purchase a new 02 and newer thermo housing as they route the hoses better and go EFI if things hold up.

Thanks for reading and I hope this helps other DIYers thinking about upping the anti on their 4.3 fuel sippers :)

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