Engine choice

[smoothforce]

I have a Bayliner 2450 hull that was originally setup for a 5.7 liter, but it came without engine or outdrive. I ran across a Cobra 2.3 drive and I wander what engine I could fit for that outdrive that will match the bellhousing on the hull and won't kill the gears of the drive. I know the GM 4.3 liter will match the existing bellhousing and I don't mind to run it easy if that's what it takes to keep the gears safe until I can get ahold a proper set of gears. I have no need for speed. Your input is appreciated.

 

[Scott Danforth]

that drive will only match the ford 2.3 liter.

the gears are too small for anything larger than a 3.0 liter. I would not ever ever ever consider a cobra drive from behind a 2.3 unless I needed a different drive for a 2.3

find a good mercruiser 5.7 or larger with an alpha or bravo and swap or a volvo 5.7 liter or larger with an SX drive and swap it in.

but you need to ask yourself. no-one pulls a motor from a good boat. they either rebuild the motor or repower. since the longtail is gone, what else is wrong with the boat.

have you done a drill test on the transom and stringers.

 

[Bondo]

Ayuh,...... Welcome Aboard,...... That drive is of no use to you,.....

 

[smoothforce]

Perhaps a little history will add context to this story. I bought this Bayliner 2450 3 years ago, engine winter cracked, replaced the engine with a 5.7 vortec for which I bought a Edelbrock air intake, so I could fit the original quadrajet. The engine turned out to be flawed, prior owner installed custom conrods incorrectly, causing the engine to seize upon load. Parked the boat and in the meantime I found for free a Ciera 2450, also with a cracked engine, which I replaced with a 305 I had been building for the first boat, that one came out perfect, new rings, bearings, cam, heads redone, ect. I then ran across the 2.3 Cobra drive, just the drive, no bellhousing for 100 bucks. Now I have a bellhousing for a V6 or V8 with a drive that is geared for a 2.3 liter engine. I have been trying to sell the hull, as I know the drive gears are wrong for the engines that fit the bellhousing. I wandered if a V6, running at low throttle so as to match the power of the 2.3 would at least get the boat in the water. I've heard that the drives are identical, except for the gear ratios, so the drive is capable of running a V6 or V8 with the correct gears, which I've seen them for sale very expensive. Is just painful to see a good hull wasted in my back yard.

 

[smoothforce]

This is the engine on the "new" boat

 

[smoothforce]

find a good mercruiser 5.7 or larger with an alpha or bravo and swap or a volvo 5.7 liter or larger with an SX drive and swap it in.
have you done a drill test on the transom and stringers.

I've considered going Mercruiser, but I did not know the transom unit would be compatible with my cobra powered hull. If that is the case, I might go for it, using the Vortec I already have (after spending last winter re-fitting the connecting rods in their right positions, as they were mixed up, even the rod caps were bolted onto the wrong rods). The transom and stringers of the hull are solid.

 

[Scott Danforth]

OMC copied the Mercruiser key hole for the cobra.

Assuming test drills show your transom is rot free, get a complete long-tail and bolt it in.

 

[smoothforce]

I find myself lucky that the holes are the same, as the mercruiser units are readily available, unlike the OMC drives. What is the difference between alpha 1 and 2? these are the easier to find.

 

[Scott Danforth]

look for a complete long-tail from 1996 or later. then you get the A1G2 and vortec motor

 

[Bondo]

I find myself lucky that the holes are the same, as the mercruiser units are readily available, unlike the OMC drives. What is the difference between alpha 1 and 2? these are the easier to find.

Ayuh,..... The Gen.II has 2 more transom holes than the A1,.....

 

[smoothforce]

Ayuh,..... The Gen.II has 2 more transom holes than the A1,.....

Thx for the input guys. So I'd be better off with a gen 1, easier and cheaper. What's the story with the water pump, if it must be changed every season that's no problem, my outdrive comes off the boat every winter, so it won't get a cold, hehe.

 

[Scott Danforth]

The gen 2 is a much better drive

 

[Scott06]

Thx for the input guys. So I'd be better off with a gen 1, easier and cheaper. What's the story with the water pump, if it must be changed every season that's no problem, my outdrive comes off the boat every winter, so it won't get a cold, hehe.

if yiu were going to keep the boat on a 24 ft I would get a bravo.if you are trying to piece it together to sell yes an alpha gen one or two. They stopped making the gen one in 1990 so that is likely why you find them cheaper. The gen 2 has a better water pump And is a more robust drive.

not sure what you mean by whats the story with the water pump? change interval depends on use how many hours and if in fresh water. Most important is to get OEM merc parts for water pump. In fresh water I used to change my gen one every 3-5 years, you would see the temp creep up at idle after it was warmed up. The gen 2 water pump is larger and has a stainless steel housing I changed mine after 6 years was in perfect shape. Did my neighbors ten year old one was also in perfect shape, again use OEM parts.

 

[smoothforce]

The gen 1 water pump is widely criticized online. However I would think that they are exaggerating if the actual life of the impeller and related parts are 3-5 years. They also say that the drives are near identical, so I gather that the Gen 2 robustness is in the gear set or in the shafts and bearings, not visible from the outside. Most likely, I will repower the empty hull with a gen 1 so it can be sold, as I have a cleaner second hull with a working OMC/GM V8 power. The empty hull is advertised for sale, so I may have a buyer even before I get the Merc drive, in which case I might go on to install a merc drive on the keeper boat. I even have the Merc coupling for the gen 1 305 that is currently mated to the cobra drive and have started to look for either a drive or an old donor boat. I can do this on a long term basis, as my usage of the cruiser do not involve high speeds. My wife and kids enjoy just chugging along and stressing the old cobra at wot does not sound like a good idea for the long term cruising, not to mention the wife forcefully applying the brakes on me. I leave the need for speed for solo rides on my smaller center console.

 

[Scott06]

The gen 1 water pump is widely criticized online. However I would think that they are exaggerating if the actual life of the impeller and related parts are 3-5 years. They also say that the drives are near identical, so I gather that the Gen 2 robustness is in the gear set or in the shafts and bearings, not visible from the outside. Most likely, I will repower the empty hull with a gen 1 so it can be sold, as I have a cleaner second hull with a working OMC/GM V8 power. The empty hull is advertised for sale, so I may have a buyer even before I get the Merc drive, in which case I might go on to install a merc drive on the keeper boat. I even have the Merc coupling for the gen 1 305 that is currently mated to the cobra drive and have started to look for either a drive or an old donor boat. I can do this on a long term basis, as my usage of the cruiser do not involve high speeds. My wife and kids enjoy just chugging along and stressing the old cobra at wot does not sound like a good idea for the long term cruising, not to mention the wife forcefully applying the brakes on me. I leave the need for speed for solo rides on my smaller center console.

I think a lot of the water pump complaints on alphas is due to the use of junk aftermarket parts. I maintained a 1990 3.0/gen 1 in a 17 ft sea ray for 20 years. My folks bought it well cared for when it was 5 years old and i sold it when it was 25 years old After beating the **** out of it taking my kids and their friends water skiing and tubing….

when I used a sierra impeller and upper housing I felt I got half the life out of it that I did with the oem merc impellers. We are in a shallow cove so there is a lot of sand ingress as I have to be almost full out on trailer button…

people ***** about splitting the drive but seeing where some bravo and volvo impellers are in engine compartments it is six of one half dozen of the other. Yes the dog clutch is old school but the alphas are light in weight , about half the price of a volvo SX drive if you need a new one,and parts are available everywhere including NAPA .So under 22 ft and under 300 hp it is perfect.

not sure what parts in gen 2 are bigger I think a couple bearings and shafts...maybe one gear set is the same. The water pump and separate lube resevior on gen 2 are great additions. On a gen one if the input shaft seal leaks your upper gear set will run dry before enough lube fills bellow and ends up in bilge.

im not sure on a boat of that age if it is more sale able with a jackalope drive train (that has been out of production for 30 years) or not. id figure only folks looking for handyman’s specials would be into it so proving the transom and stringers are rot free or properly repaired would be key. Even running the floor stringers and transom condition will be top of mind for any buyer who has a brain… best bet is to troll CL or FB marketplace for rotten boats and jank the drivetrain pulleys to pro vs piece ing it together

 

[smoothforce]

Thanks for your advise on the Mercruiser swap, I took it to heart and will do it on the Bayliner Ciera 2455 that I'm keeping. The other Ciera 2450 will get a 305 as well with a Cobra that I have plus the upper gears of another cobra I just bought for the purpose. Now I have the proper gears for the V8 I'm assembling. The engine came to me extremely gunked up with oil, as it was burning large amounts of oil due to improper oil rings. The engine was recently re-ringed and I need your take on this mess. The upper and middle rings look like new and the gaps are 10-12 thousands of an inch throughout all the cylinders. Worse yet, the oil rings are too tall for the oil groove of the pistons. The groove is 4.6 mm tall and the assembled oil rings are 5.7mm tall. Ring groove depth on the piston is 0.215". The pistons were forced on the cylinders to the point that one of them cracked in the process of installing it (or maybe I did it while removing it). These are .30 over pistons and I wander if they used the wrong rings on them. What's your take on this mess?

 

[Scott06]

Thanks for your advise on the Mercruiser swap, I took it to heart and will do it on the Bayliner Ciera 2455 that I'm keeping. The other Ciera 2450 will get a 305 as well with a Cobra that I have plus the upper gears of another cobra I just bought for the purpose. Now I have the proper gears for the V8 I'm assembling. The engine came to me extremely gunked up with oil, as it was burning large amounts of oil due to improper oil rings. The engine was recently re-ringed and I need your take on this mess. The upper and middle rings look like new and the gaps are 10-12 thousands of an inch throughout all the cylinders. Worse yet, the oil rings are too tall for the oil groove of the pistons. The groove is 4.6 mm tall and the assembled oil rings are 5.7mm tall. Ring groove depth on the piston is 0.215". The pistons were forced on the cylinders to the point that one of them cracked in the process of installing it (or maybe I did it while removing it). These are .30 over pistons and I wander if they used the wrong rings on them. What's your take on this mess?

This was on a rebuilt engine you bought? Or one you rebuilt. Sounds like a bucket of chit, the more you stir it up the more it will stink …. Obviously a piston to ring mismatch. Two choices, take it to competent machine shop and start over, or get a truck vortec 5.7 from a wrecking yard and convert it to marine. Of course third and best option, except for your wallet, buy a new base engine or correctly rebuilt reman.

 

[Scott Danforth]

Thanks for your advise on the Mercruiser swap, I took it to heart and will do it on the Bayliner Ciera 2455 that I'm keeping. The other Ciera 2450 will get a 305 as well with a Cobra that I have plus the upper gears of another cobra I just bought for the purpose. Now I have the proper gears for the V8 I'm assembling. The engine came to me extremely gunked up with oil, as it was burning large amounts of oil due to improper oil rings. The engine was recently re-ringed and I need your take on this mess. The upper and middle rings look like new and the gaps are 10-12 thousands of an inch throughout all the cylinders. Worse yet, the oil rings are too tall for the oil groove of the pistons. The groove is 4.6 mm tall and the assembled oil rings are 5.7mm tall. Ring groove depth on the piston is 0.215". The pistons were forced on the cylinders to the point that one of them cracked in the process of installing it (or maybe I did it while removing it). These are .30 over pistons and I wander if they used the wrong rings on them. What's your take on this mess?

My guess is an idiot or a scam artist had the boat prior.

You have a core block that will need at a minimum $1500 worth of parts and machining. To do it right you are looking at about $2500

As Scott mentioned, there are choices buy a reman, properly reman the one you have, or buy a salvage yard motor and marinize it

 

[redneck joe]

Assuming you want to sell the 2450 and have a clear conscience make sure you are up on the shift cable issues with those.

 

[smoothforce]

My guess is an idiot or a scam artist had the boat prior.

You have a core block that will need at a minimum $1500 worth of parts and machining. To do it right you are looking at about $2500

As Scott mentioned, there are choices buy a reman, properly reman the one you have, or buy a salvage yard motor and marinize it

Prior rebuilder must have been ignorant, or ran out of money, or both. The block and heads were machined, the pistons were new, but the rings definitely did not belong in these pistons. The oil rings collapsed into the narrow grooves and allowed so much oil into the cylinders that I doubt the engine ran for more than a couple hundred clicks after it was put back together. Measurements of the cylinders are straight, as they came out of the machine shop and piston clearance inside the cylinders is also within specs so a replacement piston and a set of rings is all I will need other than gaskets and a timing chain set, as it was not replaced, with about 3/4" of chain displacement. It is not about how much money I must spend to "do it right", but instead how I do spend what I have allotted to this engine after assessing its current state. At this point, I'm inclined to sell the hull in its current ready-to-repower state and will rebuild that engine at my own leisure, as I realize that no matter how much time and coin I spend, most of it will be swallowed by negotiations while trying to sell the boat in functional condition.