1990 Mercruiser & BBC 454: Cautions or Concerns

[Koonzee]

iBoats Forum Members:

Hello. I am posting to learn from those who may have experience with a 1990 454 and a MerCruiser outdrive.

A bit of research from Google and local marine service managers provided the following:
The 1990 Mercruiser may be an Alpha One, Generation One (per Google).
The 1990 with a 454 may have a Bravo One outdrive, still pending clarification from seller.

Since I am considering a open bow 1990 Sea Ray with this power package (454 Merc), are there any cautions or concerns I should be aware of prior to purchasing this boat? Assuming the boat was maintained properly and not abused or driven aggressively (hole-shots), is there anything about the 1990 MerCruiser and the 454 that is prone to premature or recurring failures?

Would you recommend avoiding an older carbureted BBC boat and waiting for a newer EFI SBC, Bravo III boat if one's budget permits? I have read maintenance on a BBC can be more challenging due to minimal clearance. I consider myself a decent "wrench" with cars & trucks, but this will be my first boat.

Finally, what would be a ball park estimate of parts & labor on adding a closed-cooling system to a boat? Is this conversion common? Is it more cost effective to simply buy a boat with a closed-cooling system than to convert a boat to a closed-cooling system?

Thanks in advance for your reply and extra keystrokes.

 

[Lou C]

If anything you want a 454 paired up with a Bravo, vs an Alpha
and, for older boats you will have an easier time maintaining a carbed boat than EFI. Why, because on older boats EFI parts often become NLA whereas carb parts are widely available as are new carbs if the old one is too far gone to rebuild. A 454 with a Quadrajet, Weber/Edelbrock or Holley 4bbl is easy to maintain, parts are available and not expensive.

 

[Bondo]

Ayuh,..... Welcome Aboard,...... The drive is the deal breaker on that one, if it's an Alpha,.....
Gotta be Bravo,...

Closed coolin' ain't added to used motors, only brand new clean blocks,.....
Rust from a used motor clogs the heat exchanger in no time,.... the uncleanable side,....

Nothin' wrong with BBC's, except some of the operators,.....

 

[Koonzee]

Lou C. : Than you for your reply. Excellent feedback. I am leaning towards saving the approximate $7k-$15k with the older boat/technology and putting the money in the fuel tank. Casual boater/cruiser... thx again.

 

[Koonzee]

Bondo, Hello & thank you for your feedback, regarding my obvious newbie questions about closed cooling systems. Also, thx for 'deal-breaker' advice regarding the Alpha vs Bravo with the 454. Cheers!

 

[Lou C]

The thing I'd be most concerned with is the condition of the hull, deck, stringers and transom, those repairs are a lot more involved/difficult than engine repairs, at least in my opinion. Once you understand carbs they are easy to rebuild. As a young-un I recall being told that GM's Quadrajet (which was on most of the cars we had back then) was too tough for a backyard mechanic to rebuild. Well many years later having this old boat with a Quadrajet I found that it is not hard at all you just have to take your time. I actually think its easier to take apart and re-do than a Holley is having done both.

 

[Koonzee]

>The thing I'd be most concerned with is the condition of the hull, deck, stringers and transom<

Lou C.: Hello again & thank you for the above advice. Your items were added to my list. Btw, I agree with regard carbs... Youtube has been a great resource. I am YouTube certified! I refreshed everything on a '69 Corvette conv. recently that was in storage for 23 years, and couldn't have done it without YouTube! Lots of work... & now, I totally respect the effort car restorers, chassis and suspension technicians do everyday. Cheers!

 

[Scott Danforth]

SeaRay (owned by Brunswick who also owns Mercruiser) paired BBCs with Alpha drives in 1988-1990. Then they realized their folly after replacing many drives under warranty

However more importantly, a 1990 boat is 32-33 years old (2× its design life). I would be suspect of transom and stringer rot

 

[tpenfield]

1990 is going to be the Mark IV GM 454. A 32 year old engine (in a car or a boat) what could possibly be wrong with it

The Bravo outdrive was introduced in 1988, so a 1990 would be the first generation of the Bravo. 32 years of age . . . what could possibly be wrong with it?

32 years is more the issue than a GM (Merc) 454 and a Merc Bravo. Both of those were good in their day. Your challenge is to see if they are still good. You would probably prefer the 454 vs. a SBC for the sake of greater low-end torque, which boats need. The marine applications of the GM 454 were pretty mild vs. their automotive counterparts. This is because of the 'wet' exhaust needing a very mild cam, so top-end performance suffers, but low-end torque is still there.

As for the boat itself, I agree with Scott's comments. the actual condition of everything needs to be verified, and there is nothing to say that what is working today, won't fail tomorrow.

As for closed cooling . . . if the boat has been used exclusively in fresah water, then maybe. If the boat has seen salt water - forgetaboutit . . . The parts (kit) would probably be about $1,200 ish.

If the boat has been used extensively in salt water (with raw water cooling), don't waste your time . . . there is probably not much left of the engine block
.

 

[Koonzee]

Scott Danforth & tpenfield: Hello. Thank you for your very detailed and insightful replies. Perhaps owning an older boat simply isn't worth the savings in the long run. I have always been proud to own older, well maintained vehicles (cars, trucks & motorcycles), but I am learning that owning an older boat may be a time consuming and financial nightmare.

My initial thought was to acquire an older, loved, well maintained open bow boat that was only used in fresh waters, stored indoors and was not docked on the water seasonally. Essentially, my goal is to purchase an older boat in the mid-west for approximately $10k-$12k and enjoy it in the southwest (SoCal coastal waters & lakes) for a few seasons and eventually return to Ohio with it for seasonal recreational lake use. Used boat prices SoCal appear to be inflated relative to comparable boats in the mid-west. At this time, I can't justify $20-$25k for a newer boat for only casual use.

After reviewing many boat buying guides on YouTube, I am starting to understand the risks and associated repair/replacement costs identified in the various replies, especially with the first generation outdrives and transom/stringer rot.

All: Thank you for your prompt and detailed replies.

 

[Koonzee]

Ted/tpenfield: I enjoyed reading your search and maintenance story/journey of your 1991 Formula 242 and your 1996 Formula 330 on your website. Nice looking boats!

 

[Scott Danforth]

but I am learning that owning an older boat may be a time consuming and financial nightmare.

that is owning any boat. you have to remember, a boat has a design life of 15 years. how its cared for determines the service life, and that can be between 2 years and 20 years.

however if you are looking at a 32 year old boat, keep in mind, you may need to do a complete restoration and replace the stringers and transom.

unless you are buying a boat in the 5-10 year range, plan on it being a project boat

 

[Lou C]

Remember there are used boats (5-10 years) and used up boats (15+ years).
If you buy a used up boat all bets are off. I did, not really realizing this fact of boat ownership and wound up doing a partial restoration (stringers, deck, had hull painted replaced much of the interior) and top engine overhaul (reman heads & new exhaust)
If I ever buy another it will be 3-5 years old.

 

[tpenfield]

Ted/tpenfield: I enjoyed reading your search and maintenance story/journey of your 1991 Formula 242 and your 1996 Formula 330 on your website. Nice looking boats!

Thank you


I have bought older boats over the years (13 & 16 years of age), and there was a significant amount of maintenance and restoration needed to put some life back in them. In each case the engines were in decent shape, but I discovered structural issues in the hulls.

The Sea Rays of that era (1990) have a wood structure and you may run into the same sorts of issues.

One thing about the Mark IV Big Blocks is that the cylinder heads can have rust-through around the valve guides (particularly if used in salt water). My 1991 454 suffered that demise and then I sold the boat (with engine in pieces).

I did add closed cooling to my 33 foot boat, but the engines had never seen salt water . . . and at 16 years of age the internals of the cooling system were in great shape. I also had brand new exhaust manifolds just before the conversion.

My 1991 boat/engine would not have been a good candidate for closed cooling because it was salt water. When I did some work on the engine and looking into the internals of the engine block . . . what a horror show of flaking metal/rust from the salt water.

 

[Lou C]

With raw water cooling my experience (20 years in salt water) is that the cyl heads suffer more from the effects of salt than the block. At least here it is rare to see a block rust through. However when I removed the cyl heads on my old engine in 2017 due to blown head gaskets (caused by an overheat a few years before) and had them checked out by a machine shop they felt the cooling passages had been eroded by years of raw water cooling (plus they were cracked from the overheat) so I went with a pair of reman 4.3 heads ($550) and Fel/Pro gasket set ($100) and new ARP cyl head bolts ($100). Put it all back together and that gave it a new lease on life! So with old raw water cooled engines at least in salt I’d say replacing the heads at 15 or so seasons is a good idea; you can avoid a catastrophic failure that way.
BTW I did an oil analysis in 2015 a year before the HGs blew and sure enough there was sodium (from salt water) showing up in small amounts in the motor oil sample.
That said if you find a freshwater boat stored inside in a dry climate you may be able to avoid most of these problems.