Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

[UFIXAMYBOAT]

I would like to know if I could use a Chevy Vortec v6 engine to replace a Mercruiser engine? I have heard of this being done and I would like to verify that is it an acceptable alternative. Does someone know what is the range of engines I can look for? Someone told me that I can use model years 1993 to 1996, is that correct? Also, my current engine has a two barrel carb and intake that I would like to change to a Edelbrock Performer 4 bbl intake and carb. I would like to bring the hp up to 275. Is this possible without also changing the cam? If I would also need a cam, any suggestions?

Thanks.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

I would like to know if I could use a Chevy Vortec v6 engine to replace a Mercruiser engine? I have heard of this being done and I would like to verify that is it an acceptable alternative. Does someone know what is the range of engines I can look for? Someone told me that I can use model years 1993 to 1996, is that correct? Also, my current engine has a two barrel carb and intake that I would like to change to a Edelbrock Performer 4 bbl intake and carb. I would like to bring the hp up to 275. Is this possible without also changing the cam? If I would also need a cam, any suggestions?

Thanks.

I have managed to identify that there is a casting number change between the 1993 and 1996 model years I believe that it is relative to the increase in intake port size. What... No one out there that can field my questions?

 

[cr2k]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

If you are planning on using an automotive engine it should be out of a truck or van as these are cammed closer to marine. You must also use ALL of the marine externals, dist, fuel pump, circulation pump, starter and alternator as these are spark shielded. You can use an edelbrock manifold but again any carb you put on MUST be marine approved. If you run in salt water you MUST change the steel core plugs out for brass, it is also a good idea to change the head gaskets to stainless steel ones.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Understood, I have found a new long block from a GMC Jimmy through Advance Auto for 1700. I was interested in the larger intake ports in that model year. What is the difference in a Marine Cam?

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

I only run fresh water. Is the marine Carb still a must have?

 

[JJJ]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Marine carb is a must.
If you have ever considered a closed full cooling system, now would be the time to do it. Never have to buy manifolds again and winterizing is much easier since the manifolds and block are always full of antifreeze. This would also make it so you do not have to replace freeze plugs or head gaskets on your new engine.

 

[Bondo]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

I would like to know if I could use a Chevy Vortec v6 engine to replace a Mercruiser engine? I have heard of this being done and I would like to verify that is it an acceptable alternative. Does someone know what is the range of engines I can look for? Someone told me that I can use model years 1993 to 1996, is that correct? Also, my current engine has a two barrel carb and intake that I would like to change to a Edelbrock Performer 4 bbl intake and carb. I would like to bring the hp up to 275. Is this possible without also changing the cam? If I would also need a cam, any suggestions?

Thanks.

Ayuh,.... A 1996 to current production uses the Vortec heads,...

A marine cam mirrors an Rv cam in profile, 'n power band...

A pickup motor, with a 4bbl. carb, 'n vortec heads runs 'bout 235hp or so, at the crank,...

275hp, Ain't gonna happen... that's 350 territory...

 

[kewlkatdady]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

If you ok with the autozone truck motor for $1700...why not just a Rapido Marine engine. This is who I used and so far so good.

http://www.rapidomarine.com/default.aspx?p=/engines/default.aspx

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

I have heard some horror Stories regarding mail order engines. So, i was shopping locally. I want to make sure that I can get the good heads (113 casting) and I can specify that with Advance Auto. I checked out rapidomarine before, unfortunately I knew of no references.
I gotta ask this... I was told that the drive unit needs to be removed in order to replace the engine, any truth to that? I was reading a document that indicated you only needed 10" clearance forward to get it out.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Ayuh,.... A 1996 to current production uses the Vortec heads,...

A marine cam mirrors an Rv cam in profile, 'n power band...

A pickup motor, with a 4bbl. carb, 'n vortec heads runs 'bout 235hp or so, at the crank,...

275hp, Ain't gonna happen... that's 350 territory...

You might find this article interesting.....
http://www.hotrod.com/techarticles/engine/113_0208_chevy_43l_262ci_v6_engine_build/viewall.html

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Interesting, I have wondered what would need to be changed / upgraded to make it a closed system? Care to explain?

 

[Don S]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

You should stop looking at hotrod sites and start looking at marine engine sites. You try to get 275 real HP out of a V6 and you will be learning about a thing called reversion due to valve overlap. Few automotive engines run water cooled exhaust systems.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

If you ok with the autozone truck motor for $1700...why not just a Rapido Marine engine. This is who I used and so far so good.

http://www.rapidomarine.com/default.aspx?p=/engines/default.aspx

What performance improvement did you notice after upgrading intake and carb?

 

[Bondo]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Originally Posted by Bond-o
Ayuh,.... A 1996 to current production uses the Vortec heads,...

A marine cam mirrors an Rv cam in profile, 'n power band...

A pickup motor, with a 4bbl. carb, 'n vortec heads runs 'bout 235hp or so, at the crank,...

275hp, Ain't gonna happen... that's 350 territory...

You might find this article interesting.....
http://www.hotrod.com/techarticles/engine/113_0208_chevy_43l_262ci_v6_engine_build/viewall.html

Ayuh,.... You said yer buildin' a Boat motor, not a Dragster motor....

With that cam, it'll never leave the dock...

Good luck,.... I see problems in yer future...

 

[JJJ]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Interesting, I have wondered what would need to be changed / upgraded to make it a closed system? Care to explain?

Well with a new engine, there wouldn't be rust in the block to blockup the heat exchanger. So all you would need is a full closed cooling kit - I would probably replace the manifolds at the same time so that they are new also or at the very least make sure they are really clean and not full of rust.
Here is some info too. hxxp://www.perfprotech.com/store/articles/fresh-water-cooling-basics.aspx

google for fresh water kits.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Has anyone done business with Rapido Marine? They offer a replacement Marine engine in leu of buying a truck engine.

 

[kewlkatdady]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

I installed a Rapido long block last year...no issues what so ever. the motor seems very strong. Come to find out my old block isn't crack, the problem was the 1 piece (batwing) exhaust manifolds. I replaced them with the 2 piece conversion and all issues cleared up. Now i just have an extra long block in my garage.

As far as the carb upgrade. All I can say is


I forgot to mention, there was one minor issue. The original block was all Standard bolts. The one I got from Rapido was mostly metric. So sorting out the engine mount bolts, starter bolt and bell housing bolts was kind of a ***** whippen but nothing a trip to Ace didn't take care of. I'm please with the Rapido motor.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Nice, I have been surfing their site quite a bit, getting ready to call em. My existing engine had a water problem, took it out ran nice from dock to about a mile out, significant power loss and that infamous NASCAR smoke! Shut her down dropped the trolling motor and cruised back to dock. Found crankcase full of that milky fluid. I disassembled down to block never finding any crack. Being that the block needs a magnafluxin, might be better to just drop in a new one. I have the two piece manifold that I replaced two years ago due to a crack.
Thanks for the info.. I feel better about placing an order.
Hey, do you know if they follow all the machining processes they claim, did they bore out your motor to .030 over?

 

[kewlkatdady]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

I didn't measure the bore as I didn't remove the head. I checked the torque settings and assembled the motor and dropped it in. They seemed to have a pretty good reputation around here so I didn't second guess things.

 

[UFIXAMYBOAT]

Re: Mercruiser Engine Replacement for 1993 Starcraft 4.3l V6

Ok, done deed. I spoke with the owner and he was very informative. Order placed.