Rebuild or replace engine?
 

So after pulling my risers and seeing the level of corrosion, I will have to replace my manifolds, risers, and backflow preventer. The parts alone are a little over $1,000. So if I do replace them, I know that I will probably have more issues soon thereafter. So I am thinking to save up and replace the engine. Would it be better to rebuild the existing engine so the serials match? Or would it be better to go with a 383 stroker? I do like the idea of more HP, but I do not have alot of money right now. I have seen online that I can pick up a rebuilt 383 for just under $3,000. Any advice would be greatly appreciated...:)

Re: Rebuild or replace engine?
 

If you trust the builder thats not a bad idea any warranty with it? According to some research I did and I research the crap out of things the stories of higher nickle content in marine blocks is not true so a good build wether auto or marine will work its your maintenance that keeps it running great and reliably if that helps. I forget did you say it was in salt water or you are still in salt water?

Re: Rebuild or replace engine?
 

The original owner was 100% salt water usage. I run about 70-80% fresh water and the rest salt water. And unlike the original owner, I am pretty religious about flushing the motor out!

Re: Rebuild or replace engine?
 

Just a thought here then not sure though you could probably find one of those ZZ crate all alum small blocks and I ran alum manifolds and risers on mine shaved off alot of weight on my old boat but if your in a fair bit of salt I hear alum not so great.

Re: Rebuild or replace engine?
 

Yea, I have always been told the same thing that if you run salt alot that you need to stay away from aluminum. I hear it corrodes faster than cast iron or something.

Re: Rebuild or replace engine?
 

Yeah maybe one of our more experienced memebers can add but I run only fresh so it was perfect for me up here I think it shaved 44olbs off the boat in there somewhere would have to see if I have the scale slips before and after still.

Re: Rebuild or replace engine?
 

If you are in salt at all, you should budget for a closed cooling system. There is no way i would do all that work and run salt water through the block again. No matter how well you rinse after use, you will be much better off protecting the block and manifolds with fresh water coolant and then all you worry about replacing is your risers.

I am in salt 50% and have always rinsed after use even with a closed cooling system.

I think the difference in auto vs marine is the rotation, left hand or right, and there are intake differences and some ignition differences, I dont think you can do a clean auto engine replacement even though it seems like you save a bunch it will bite ya in the end. I am no engine expert, but I say "Go marine".

Re: Rebuild or replace engine?
 

I had my 350 built to a 383 stroker and LOVE it. Great torque and good top end speed, best of both worlds.:wink_thumbup:

Re: Rebuild or replace engine?
 

I built my old 5.7 up out of a 4 bolt main street engine, same build I have used in countless cars and its been super reliable and no prob but I don't see salt water with it or I never did see salt water with it. But I would agree with a closed system if you see salt and hey Zack has probably been boating longer then me the land locked guy lol.

Re: Rebuild or replace engine?
 

I agree, I will always go marine. No reason to chance that. About this closed cooling system, not sure about those. Don't you have to add a radiator or some type of cooling system? Not sure if its worth it to do all that though. one of my friends has a cruiser that he has had for 11 years, and he is just now replacing his engine and he runs as much if not more salt water than me. I agree that salt is bad. I guess if I can do the cooling system easily enough, then maybe I should. If I do, then I would feel alot more comfortable about getting an aluminum engine instead! Yea!!!!!

Re: Rebuild or replace engine?
 

I am a firm believer in any salt is not good salt in the block.

You can read my recent experience of installing this system on my Mariah on the thread " fresh water cooling system" ( I don't know how to paste a link yet), but I tried to show what I did and why.

There are many advantages to this, and I understand the theory of why not just run her and replace her, but I think it best to take care of her as long as possible. I think the closed cooling is a must either way.

Re: Rebuild or replace engine?
 

Well another idea.. I had to replace my engine this spring and went with a brand new 5.7 long block (vortec) with four bolt mains for under $1,800.00 yes I had to replace gaskets and swap out the oil pan etc, but it came with brass plugs as a small bonus....
But I guess you'll still need to replace your exhaust setup.... :(

-Doug

Re: Rebuild or replace engine?
 

Ok, now I am confused. How did you get a new engine for that cheap? I was looking at a remanufactured marine 383 stroker from usengine.us and that is $3,395. And as far as my exhaust goes, I am not installing my Captain's Call until I figure out what I am doing with the engine first. :(

Re: Rebuild or replace engine?
 

Call tech support at PPT. Very helpful! Tell them what you are doing and they will tell you what you need. They even gave me a discount when I ordered it over the phone for my 383 stroker. Great source of knowledge and they are willing to help.

Mercruiser, Marine Engines Parts, Mercury Boat Accessories, Quicksilver, Volvo, Crusader, Motors , Exhaust - Performance Product Technologies

Good luck!

Re: Rebuild or replace engine?
 

Okay, keep in mind I did have to switch oil pan etc.... Search the internet for gm part number 12530283 for the four bolt or 12530282 for a two bolt main (these are vortec roller cam setups)

Doug.

Re: Rebuild or replace engine?
 

I would recommend finding a used 496 HO or Mag or even a Merc Blue Motor like a HP 500 or EFI 550 version. The reason I say this is because the 275 is a big heavy boat and the added torque of the Big Block is greater than even the Stroker can provide at lower RPMs.:wink_thumbup:

Re: Rebuild or replace engine?
 

If I go from the stock 6.2L to the Stroker, I will be going from 320 HP to 400 HP. That is a huge jump! I do agree that the 275 is a big heavy boat, but honestly I fly out of the hole right now and have a great top end already..even with alot of kids on the boat. Maybe this is due to the Duoprop on my B3. Not sure. But given everything, I believe that 400 HP will be enough for me. :wink_thumbup:
Plus, the big block wouldn't bolt right up and my engine room is already a bear to work in...I couldn't imagine it with a big block!!

Re: Rebuild or replace engine?
 

hhmmm..so how difficult would it be to go from a small block to a big block?

Re: Rebuild or replace engine?
 

The stroker is full of torque though. I havent compared them to see the difference but keep in mind the weight differences as well. One of my buddies who builds alot of engines for all the go fast guys wants me to go the stroker route if I decide to do anything to mine.

Re: Rebuild or replace engine?
 

So here is the dilema..go with the 389 Stroker small block which will bolt right up and give me 400HP, or go with the 496 HO which I believe is 422HP. And I am guessing around 100-200 pounds heavier, correct? I would also assume that fuel consumption would be greater as well with the 496. I love the idea of even more HP, but is it worth alot more money for 22 more HP? And I still don't know how difficult the big block will be to install after removing my small block...

Re: Rebuild or replace engine?
 

Well if anything like cars the bbc and sbc back ends bolt up the same. But for 22 hp and 200lbs dif I would stay small block myself. Run some small block headers shave even more off.

Re: Rebuild or replace engine?
 

Look at the extra expense of Labor, exhaust, etc. to mount a big block. Whats 20 HP gonna give you? 2 mph? I dunno. Who's going to do this work for you? Keep that in mind too.

Re: Rebuild or replace engine?
 

I think I am agreeing with Raj and Dark here. Not alot of gain for something that won't bolt right in. Plus I won't be able to get my stock Captains' Call put back in and will have to go with a custom built exhaust system which will add even more expense. And yes, Captains' Call is mandatory! :)