1988 7.4/Alpha Repower Options

[Sorrento 25]

Since we are moving to Tampa with the old, HEAVY Sorrento that I intend to keep for a long time I need to face my repower options soon since I have raw water cooling. It has been performing well this year, and I will continue to trailer it for a while and flush well, but it won't be long before the painted steel trailer is done either and at that point I'd like the best saltwater drive and big block I can afford in it so I can keep the boat in a slip some day.

If cost was no object I'd like to have a new Volvo 8.1/DP but they seem to only be available new. Would the transom cutout need to be filled and recut to convert to Volvo?

I'm probably going to end up with a low hour 496MPI takeout and a new complete Brave drive and transom assembly. Would there be anything else I need for this conversion? I'm assuming the ECU, fuel pump, etc. are all integral to the engine and that I can use existing gauges etc. and maybe only need to add a fuel return line??

What is the best Bravo drive? The B3 corrosion issues concern me. A friend's 1995 250DA 7.4/B2 far outperformed mine. Are the B3 dual prop benefits really worth it? What is the most corrosion resistant Bravo drive? SeaCore?

Are there any options that I am not considering? I guess the long block is out since I would need a freshwater cooling conversion anyway.

Thanks for any advice!

 

[rodbolt]

Re: 1988 7.4/Alpha Repower Options

my vote would be for the 8.1 volvo with an XDP drive.
merc nor volvo use fuel return lines.
if you opt for the bravo make sure you buy the refernce electrode kit and a DVM and check it,

 

[Sorrento 25]

Re: 1988 7.4/Alpha Repower Options

That package would get my vote too except for the 22K price tag and probable glasswork. I think I could find a 496MPI for around 8 and a new Bravo with transom assembly for maybe 6? Is it really that much better? Maybe its worth it.

Now that I think about it I have that notched transom. The actual surface within the notch that contains the drive cutout is rather small (2' x 3' max). Once the old drive is out it probably wouldn't be a very big job to remove the glass and core wood from the inside, replace the wood and reglass the inside, and then fill the hole from the outside in the outermost layer of glass.

 

[rodbolt]

Re: 1988 7.4/Alpha Repower Options

the merc,XDP,SXDP and SX use the same basic cut out. the big block volvo shield will require an additional 2 holes.
other than that its all fun.

 

[Sorrento 25]

Re: 1988 7.4/Alpha Repower Options

So does the Bravo. Other than its just a direct bolt-in? The package includes the gauges and gauge harness and it's basically just plug-and-play if I understand correctly? If so I'm all over it. I'm not a marine mechanic but I restored cars for 15 years. Where can I find the best price on this drive package?

 

[HT32BSX115]

Re: 1988 7.4/Alpha Repower Options

I only paid $5k for my 1997 454/Bravo III package (with 125hrs on it). I found a pretty good deal on Craigslist on a boat that was total-ed by a tree falling on the front part of the hull...

If you're going to keep it in the water you MUST have a Mercathode installed and possibly 2 of them. The set-up must be done by someone who knows what they are doing because of the large amount of exposed stainless steel (props). If the electronic anti-corrosion system is not set up properly it can increase the rate of corrosion exponentially.....hence all the Bavo III corrosion blogs!!

The main things I had to do for the install was drill 2 additional holes in the transom and move the front engine mounts. The other studs in the Bravo transom matched the Cobra bolt pattern EXACTLY. I did a lot of other stuff but it mostly cosmetic. I also completely replaced the harness and used my original gages.

I considered new but......lessee....$5k vs $20k ok....I'll take the $5k!!


I will add also.....I considered a Volvo too. It was my first choice if I went new (but there was the price thing again)

Used, I would go Merc. Look on Ebay for example, at any one time there's usually 3-4 times MORE used/new Merc parts/drives/engines/etc than VP "stuff" .

I don't think there's a lot of difference in quality (others would argue that I'm sure)



Cheers,

Rick

 

[Sorrento 25]

Re: 1988 7.4/Alpha Repower Options

Thanks Rick! Cost may become the deciding factor and the used market sure is dominated by MerCruiser. I'd still like to hear more about the details of a carb-to-EFI swap and the benefits of the Volvo DPS (XDP??) drive.

 

[HT32BSX115]

Re: 1988 7.4/Alpha Repower Options

I would LOVE to put EFI on my 454!


I would REALLY like to get rid of the carb. EFI eliminates a lot of temperamental starting/running issues.

Mercruiser has a great fuel injection. I've seen a few on ebay for sale but they were not cheap!

I think that's the only way I would go if I was going to swap it out since the higher HP engines are optimized for that injection and are still able to operate reliably on 87 octane fuel.

I can't speak to the Volvo DP drives but my Bravo III runs like there's no (propeller) slip! (I know there is) Other than what I said earlier about corrosion I'm not worried about it. Mine resides on a trailer in my garage and doesn't go in salt.

I originally wanted a Bravo I and looked pretty hard for one. I found a 300hp smallblock EFI (2000 model, 400hrs) They wanted $7000. It was a Saltwater only boat.


I almost bought it until the 1997(125hrs) carb'd 454/B-III (fresh water only) came up....it looks new. and was $2k cheaper.

I am not a boat mechanic(or any kind of mechanic) by trade but I was able to do the entire swap by myself. So it's not really that hard if you have the overhead hoist and normal mechanics tools. I even made an alignment tool when the one I bought turned out to be bent!

It wouldn't be cheap but if I was going to leave a boat in salt I would ask people who know about the composite Volvo drives. .... They're pretty new so they're probably not going to be plentiful on the used market.

If you find a super deal on a used engine drive it may be worth it to repower.

If you're considering new.....it might be more cost effective to just find yourself another boat.



Regards,

Rick

 

[Sorrento 25]

Re: 1988 7.4/Alpha Repower Options

Thanks again Rick. I'm definitely keeping my eyes open for the right used package. A better boat would still cost me double what even a new repower would. I know I'm breaking rule number one but this boat is a keeper and I have very little into it.

I am curious about the new Volvo composite drives especially behind an 8.1. I've read about a few failures, but there isn't much general info out there.

 

[QC]

Re: 1988 7.4/Alpha Repower Options

I would NOT feel like I was compromising if I found a 7.4 MPI or a 454 Mag MPI. There are some reasons to like them better than the 496s and there are a lot of them around. Are you looking for more speed?

 

[Sorrento 25]

Re: 1988 7.4/Alpha Repower Options

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