Recommendations for repower

[Alaboat]

Here's what I've got:
1995 Chris Craft Concept 18' with 4.3 OMC Cobra (I think same as VP SX outdrive) Mechanic ran some tests and did some visuals and has suggested a replacement engine. He suggested a VP reman long block rather than other aftermarket options. From what I know, my outdrive is fine even though its 20 years old. According to the previous owner, there's about 250 hours on boat. Should I go back with same size engine or step up with a 5.0 or 5.7. I'm still waiting on written estimate but mechanic said that the V-8 would be a little cheaper. What exactly would be used from old engine if I go with 4.3 and would any of the components be useable on a V-8? What would need to be changed on existing outdrive to make a V-8 work?

Why put a new engine in a 20 year old boat? Boat is in really great shape and I just bought it 2 weeks ago for $5600 (with trailer). Engine crapped out because PO overheated it the week before I bought it. Thought about taking the loss and just selling out but I think its worth investing in...thoughts?

 

[Sparkinator]

If you like the boat and it's in descent shape, I wouldn't hesitate on re-powering it. I had to rebuild the transom in my 95 and it was well worth that effort.


If everything on your block is in good shape, you just have to transfer them over to your new block that's of the same displacement. If you go to a 5.0, then you've got to worry about if your bilge is big enough to fit a larger engine for one. I'm sure your motor mounts won't match up and you'll have to build new mounts. How are your fiberglass skills? Your entire exhaust system wouldn't work and would have to be replaced, and those are expensive. Not sure if your Y-pipe will work, you'd have to cross-reference those part numbers. Not sure about your flywheel cover either. I would be surprised if that is the same for 4.3 vs 5.0. That's where your rear motor mounts attach from your transom shield. I'm pretty sure your transom shield will not need to be replaced though.

It would just be a lot of work and expense to change engine size, and I don't think I personally would want to tackle that.

Everybody wants to go bigger and faster, but sometimes it's just not cost effective. I would love to get more HP out of my rig, but then I realize that it's just not practical on a 20 year old drive train. I'm really more concerned about reliability and longevity than going a little faster maybe once or twice a year. I'm normally just pulling skiers or tubes, and just how fast do you need to go to do that.

 

[Alaboat]

Thanks for the great input sparkinator. Not really needing to go faster, just thought bigger engine would have to work less for same results. Yeah, not really wanting to refit everything and I'm guessing all of the reusable parts would not fit different size engine. Maybe fuel injected vs. carbureted or 4bbl vs 2 bbl might be an option at this point. Any others?

 

[batman99]

I recently replaced broken OB engine from one brand to a different brand. On white board diagram, simple. In reality, complex (and very time consuming).

Since your boat is an IO, I bet replacing a V6 with V8 would be even more complex. Besides the differences of hole size, wiring, cable attachments, etc. etc, is your little 18ft boat "weight balanced" for a heaver V8 engine? Would a V8 in a little 18ft boat be too much? If it were me, I'd go V6 with V6 block replacement - for a 18ft boat.

Hope this helps.

 

[Sparkinator]

Thanks for the great input sparkinator. Not really needing to go faster, just thought bigger engine would have to work less for same results. Yeah, not really wanting to refit everything and I'm guessing all of the reusable parts would not fit different size engine. Maybe fuel injected vs. carbureted or 4bbl vs 2 bbl might be an option at this point. Any others?

Yeah, that faster rationale was probably more the conversations I've had to have with myself. :laugh:

Fuel injected is going to be pretty expensive on a boat as well. You'd have buy a ton of parts to make that conversion. And they would have to be marine specific parts. If you could find a donor boat with a good FI engine, you may make it worthwhile. Or maybe find a complete engine on Craigslist or Ebay.

4.3's have come with 4bbl carbs. That would be the cheapest/easiest route. My 5.0 has a 2bbl and I considered replacing it with a 4bbl, but it would need a new intake as well, and just not worth it to me. (At least I have to keep telling myself that anyway)

 

[bruceb58]

Replace with another 4.3L If yours is not already a Vortec, switch to that. You will get more power. If it's not already a Vortec, you will have to buy a new intake manifold. I put a link on your other thread to a new Vortec.

Stick with a carb if that's what you already have.

You want to consider new manifolds if your old engine had freeze damage.

 

[Alaboat]

Replace with another 4.3L If yours is not already a Vortec, switch to that. You will get more power. If it's not already a Vortec, you will have to buy a new intake manifold. I put a link on your other thread to a new Vortec.

Stick with a carb if that's what you already have.

You want to consider new manifolds if your old engine had freeze damage.

Thanks bruceb58,yes I thought that other thread had reached its usefulness and I saw the link you had, useful info and I'll pursue that option through my mechanic. Supposedly, they were having trouble with suppliers getting back with them but mentioned something about directmercury or something like that. He is suggesting a VP reman. No freeze damage that I am aware of. Issue with old engine was caused by overheating I think.

 

[Alaboat]

So I got an estimate today for a reman long block including installation of .......$4960. This was a non Vortec engine just like the one I have. Otherwise, it would require electric fuel pump and new intake. What are the advantages of the Vortec other that increase of 10HP for 2bblm carb.

 

[bruceb58]

You should already have an electric fuel pump so the only difference would be a new intake manifold. I would switch to a Vortec in a heartbeat. The price difference between the 2 should be minimal if anything.

Out of curiosity, how much of that price is the engine and how much is labor?

 

[Scott Danforth]

for $4960 I could have a healthy 383 stroker in my boat with new stainless e-tops (of course I would be doing the install)

If you can turn a wrench, I would simply get a 1996 vortec motor and get a new intake and be boating in a week.

 

[muskyfins]

Price sounds high. Reman long block shouldn't be more than $2500. Maybe less. 10 Hours R/R and a few extra odds and ends. $4000 MAX.

The above is my personal opinion and in no way constitutes advice of any kind..........but he's a little high.

Are you capable of the work yourself?

 

[Alaboat]

I can turn a wrench but just don't have the facilities to do the work. The reman engine quote was 2700 and labor was 1904 at 119/hr. About the Vortec, no, I believe mine is a mechanical fuel pump but the cost of pump is only about 200.

 

[Scott Danforth]

You can have your motor rebuilt at a local machine shop for under $1500. Only difference between the 95 motor and the 96 is the heads and intake

 

[bruceb58]

I believe mine is a mechanical fuel pump but the cost of pump is only about 200.

Definitely electric. Volvo never had a mechanical fuel pump on that engine with an SX drive. You do have an SX right?

 

[Alaboat]

Definitely electric. Volvo never had a mechanical fuel pump on that engine with an SX drive. You do have an SX right?

Yes, as far as I know its an SX. Scott, the reason I decided to go with a reman rather than rebuild my engine is that there is also a crack in the block near the starter probably from trying to start engine with water in cylinders. Not interested in trying to have cracked cast iron "fixed".
I'm gonna propose the Vortec option to my mechanic. I found one including the below for 3095. Going this route should decrease labor time since this engine includes more components than long block alone. This seems like a better route by not reusing a lot of the older components from original engine too.

• Block, heads, and all internal components
• New Valve covers
• New Timing cover
• New Marine Oil Pan
• New Harmonic Balancer
• New Circulation/Water Pump
• New 14" I/O Flywheel
• New 4bbl Cast Iron Intake Manifold
• Remanufactured 4bbl Edelbrock Marine Carburetor (9909)
• New Flame Arrestor
• New Delco Ignition System (includes spark plugs, wires)
• One Year Parts & Labor Warranty
• [h=4]Engine Specifications:[/h]
• 1 Piece Rear Main Seal
• Standard Rotation (Left Hand Rotation)
• 185 hp @ 4400 RPM / 245 lb-ft @ 2400 RPM
• 223 hp @ 4800 RPM / 267 lb-ft @ 2800 RPM
• With its Vortec cylinder heads this 4.3L produces great power for the performance enthusiast.

 

[bruceb58]

Brand new for $2699 plus shipping
http://www.michiganmotorz.com/vortec-base-marine-engine-1996current-replacement-p-283.html

 

[Alaboat]

Brand new for $2699 plus shipping
http://www.michiganmotorz.com/vortec-base-marine-engine-1996current-replacement-p-283.html

Bruceb58, what do you know about michiganmotorz? I know you put a link to this before in another thread. Compared to the one I am looking at, this one does not have the 8 bolt intake manifold or 4bbl carb included.My current engine has 12 bolt intake and 2bbl carb. I just figured with all the new components, the one I was looking at would be a better deal. Take a look and let me know what you think.
http://www.ebay.com/itm/Reman-GM-4-...007-/311238462317?vxp=mtr&hash=item4877420b6d

 

[bruceb58]

The one I linked you is a brand new engine.

Carb will run you around $425.
Intake $290

Total = $3414

Easily worth it for a brand new motor over the one you are looking at.

The one you are looking at does include a new distributor and water pump but if yours are fine, then you just bolt them on.

 

[Alaboat]

So I am kind of at the mercy of the shop who has my boat unless I want to wait in line at another shop for probably 3-4 weeks before they even can look at it. I talked at length in person with the shop who has my boat and they are pretty particular who they use as suppliers of engines and understandably so. His best recommendation is to go with a Mercruiser reman and second to that is Indmar. I mentioned going with the newer Vortec that I found on Ebay and he said my engine is actually considered a Vortec, just an earlier version with 12 bolt intake instead of 8 bolt and it does have electric fuel pump. He convincingly defended his position of not going to a newer version at the risk of running into other compatibility issues. They are going to get a price on the engine options we discussed and get with me tomorrow. After talking with mechanic today, I am confident of the quality of work tha

 

[bruceb58]

The earlier engine was called a Vortec at times but it doesn't have the free flowing Vortec heads which really makes the engine a true "Vortec". Before GM came out with the new heads they started calling the engines Vortec. When they did the major redesign of the heads in 96, they kept the name but the new engine is known as the Vortec.

The fact that this mechanic claims that the 12 bolt intake versions are at all the same would make me walk away from this mechanic immediately.