Merc 2.5L on Seafari?
 

I noticed the 2.5L Mercury from the 90s weighs in at about 350#. Seems very light for a 245hp motor. Can I put one on the Seafari 20 or is that suicidal torque on the transom... And did they make lower horse (> 115) in that weight class?

Re: Merc 2.5L on Seafari?
 

i think the 200 is also a 2.5L ive got a 2.4L and its great. i think the 2.5 is fine for it

Re: Merc 2.5L on Seafari?
 

The 2.5L is fine for a solid transom. My '72 Seafari has the original metal decal saying it's rated for 240 hp. Most say 175hp, or 140 hp. There's a '71 CC locally with Yamaha 250 2s mounted on Porta-bracket.

Re: Merc 2.5L on Seafari?
 

2.4L mercs were the lightest (Late 70's 339lbs)
Mid - 80's 2.4L 200's were 363lbs
92 - later 2.5L (150 - 260) were about 390.

I don't have the specs on the race motors
245, 260, 280 . . . They had a different trim setup with the HUGE single ram pistons like the 84 and earlier Mercs with an external pump.

After messing around with the motor height . . . I can just touch 50mph with my seafari and an old old Merc Vertical Reed 2.4L 200 (really 175ish) with a 19Pitch Mirage plus.

http://www.wellcraftv20.com/gallery/...2/DSCN7023.jpg

2.5L Mercs are pound for pound the meanest motor out there. These motors have a LOT of bottom end torque and they pull HARD all the way up to WOT. I like the 2.4's b/c of the economy, chrome bore cylinders, and light weight. a 2.4L 200 has better fuel economy than the 2.5L 150 EFI Or Carb.

Re: Merc 2.5L on Seafari?
 

2.5L 280
http://www.youtube.com/watch?v=RT1N6...eature=related
2.5L 260
http://www.youtube.com/watch?v=wy8mz...eature=related
2.5L drag => 348 on a Dyno
http://www.youtube.com/watch?v=mM9l774zLo4

Re: Merc 2.5L on Seafari?
 

big, is 5800 rpm too much for a 2.4L? the prop im looking at has been used on here with a 20sf and 200 merc and gave 5800 rpm and 58mph. its a 13.75x21 stainless. they make the same size in aluminum that i was going to get.

Re: Merc 2.5L on Seafari?
 

http://www.youtube.com/watch?v=RLbV1hoeQ1s

twin 2.5 race O/B's. gotta love the sound of 7500rpm. the boat in the vid will do over 100

Re: Merc 2.5L on Seafari?
 

5800rpm is what I prop mine for . . . 5800 is the max recommend RPM in the factory manuals for the 2.4L motors. Without the spark advance/idle stabilizer module and the oil injection they're good way above 5800rpm.

Re: Merc 2.5L on Seafari?
 

Blue, my target RPM for my 2.4L on the back of my '72 Seafari was 6000. I actually turned 6050 at WOT, trimmed out, 1 person and 30 gallons of fuel with my reman'd 2.4L XR4. Originally 150hp, it dyno'd right at 190hp after the rebuild. I was turning a custom made 15.25"X16.5"P PowerTech OFS 3 blade. (still have the prop, the motor was sold)

Fully loaded, with 7 persons, 30 gallons of fuel, fishing gear and a full live-well, I could still turn 5700-5750 rpms. I wanted to be able to turn the maximum of the reccomended maximum rpm range with the boat a maximum load. I call that running "max of max at max" That way I'm never over-propped so that I cannot take advantage of the full power of my motor in an emergency.

BTW, Tim, on a cold day, after I had about 20 hours or so on the motor and my new prop, I once ran downwind in a light chop, 2 guys on board, and about 10-15 gallons of fuel, and ran and maintained 46 knots on the GPS, or about 53 mph for more than 10 minutes with that XR4 on the back of my Seafari. Had a nosecone and LW pickup, too. Threw one heck of a rooster tail for a Seafari, had to be 8-10 ft high. And yes, that's right on the edge of chine-walking for my boat. Actually fell into a chine walk a couple of times before re-stabilizing.

The reason? Trying to get in off the Gulf of Mexico from 20 miles out before the really nasty squall hit. We made it, too. :D

Re: Merc 2.5L on Seafari?
 

http://www.youtube.com/watch?v=5b90Fq7Cmvk

http://www.youtube.com/watch?v=5UG61hdwxjg&NR=1

Re: Merc 2.5L on Seafari?
 

Wow, Bigshrimpin, that's thrill seeking! Maybe I'll stick with a little less power and more hull in the water, even 50mph is a little spooky :D What kind of economy are you getting w/ the 2.4L? 2.5L?

I came across a '94 2.5L for $1500. Seller claims excellent compression and overall near perfect. Certainly looks clean. Price seems really good, no?

-McGill

Re: Merc 2.5L on Seafari?
 

1979 2.4L 200 vertical reed with the WH-11 carbs (small venturi) . . . I get better than 3.5mpg at cruise up to 35mph. After that economy falls off real fast. 2.4L motors with the small venturi carbs like the mid 80's 2.4L 175's and the early 2.4L 200's get great economy. The larger venturi carbs on 2.4L 200's and old 225 (wh-22's, wh-28's, wh-31's, wh - 15's, wh-20's) will feed the motor more fuel, but still will be better than 3mpg at 4000rpm pushing a 20. 2.5L motors are a different story . . . even 2.5L 150 EFI will burn more than a 200hp 2.4L Carb motor.

I think 2.5 - 2.75mpg would be ball park for a 2.5L on a 20, NoBones has one on his 20 . . . he could probably give you exact numbers. fgbiv had a 2.5L Mariner Magnum III on his seafari.



[img]http://groups.msn.com/_Secure/0RwA6DjoVavRAkn34DpSL6O4DZoaANV9jPwT!iUcLkvOSS8vYV *KDTRLRlMrHSptCLtxq64wr7wF98ztF!H8rwS2JL!X6yhbofYk iz*powz8/74_Safari.JPG[/img]



Honestly I think a 2.0L 150 is a fantastic match of economy and power on the 20's. The 2.0L's will get you to 40mph and cruise at a nice west coast 25mph . . . I had one on the MA when I sold it. 25mph was 4mpg cruise.

Re: Merc 2.5L on Seafari?
 

Thanks Bigshrimpin,
You've opened up the proverbial box so here are a few more questions.

Can I assume an '88 175hp would be a chrome bored 2.4L and be of reasonable weight? And is the chromed bore an advantage or disadvantage.

Also what is the 2.0L designation, is that the standard black max 150 or the inline 6 variety, or something else and how do I tell them apart? And what's the weight of the 2.0L.?

What should I expect/be willing to pay for these older motors?

-McGill

Re: Merc 2.5L on Seafari?
 

Here's a good link:
http://en.wikipedia.org/wiki/Nikasil

Most 2.4L 175 and all 200hp 2.4L 200 were chrome bore motors. There were a few steel sleeve 2.4L like the 150 XR4 and a 175 Ski special. I've seen many 2.4L rebuilt with 1 or 2 sleeves that run fine. These 2.4L engines are tough motors.

Chrome and Nikasil offers several advantages over steel which is why you find them in most race motors and airplane engines. Some of the advantages are

Better heat transfer.
Better lubricating surface.
Tighter tolerances.
Chrome is much harder than steel resulting in less wear to the cylinder walls.


Depending on the year the 2.0L blocks are the same as 2.4L or 2.5L blocks. They are just sleeved down to 2.0L with a thick thick steel sleeve . . . which is why they weigh more (20lbs or so) than the 2.4L or 2.5L motors. 2.0L are also pretty tough if you lose a piston, then they can be bored over easily.

Both motors can be bought for $1500 or so. 2.4L motors need to have at least 120psi when you test compression.


if you get one of these motors you must remove the oil injection and spark advance/idle stabilizer module if you want it to live.

If you can find a clean freshwater 25" motor . . . buy it!!

Re: Merc 2.5L on Seafari?
 

ive got no oil injection or any of that other stuff on my engine and it runs great. another member was running oil injection on his 89 merc 150 and he heard the alarm go off one day at WOT and now has 1 low cylinder. now he pre-mixes.

Re: Merc 2.5L on Seafari?
 

Thanks Bigshrimpin,
Here's what the owner wrote me:

"The engine was rebuilt by Ron's Marine in Yucaipa in June of 1998. I bought it blown up, it was worse then I thought..... The complete rotating assembly was replaced. One of the power packs went out 3 years ago when I was in Lake Havasu so I had Barnicle Bills replace both of them ($800.00). It is oil injected and has been run on Mercury Quicksilver oil ONLY! The engine is a 1988, I believe 2.0L. There is nothing wrong with it, it starts, idles, and runs perfect. I am having Jack at Marine Performance Design install a Jet and heavily built 460 Ford in the boat. That's the only reason I'm selling it. Here's a link to a youtube video of the engine running on my boat. http://www.youtube.com/watch?v=HklVSSs74yo Bad quality though, it was taken with a phone camera. The $1200.00 price is firm. This is not a junk engine. 20" shaft. If you need a 25" shaft I have an equally nice 235 Johnson I'd sell for $1000.00. The boat is in an enclosed storage unit so pictures are a bit of a hassle, but it looks like every other V6 Mercury, no cracks on the cowl or anything."

Any more thoughts on this. Or what else I should ask him? -McGill

Re: Merc 2.5L on Seafari?
 

eehhhh . . . I don't know. It's impossible to tell without looking at it. The only 2.0L 175's were made in 1976 - 1980 or 1981. He doesn't even know what he's selling . . . so that's kind of weird. I would probably pass and find a virgin 2.4L or low hour freshwater 2.0L.

Re: Merc 2.5L on Seafari?
 

Roger that,
I too, was thinking 2.4L based on the hp and year so he kind of caught me off guard with the 2.0L bit. I haven't talked to him yet - just swapped a couple of e-mails, trying to learn what I could. Anyway, thanks. And have a merry Christmas up there in the great white north. Saw Rhody's pictures and they reminded me why I moved to SD...

Re: Merc 2.5L on Seafari?
 

Here's a little inspiration.
http://www.youtube.com/watch?v=71pUVGYxNkk

I started to make a very disorganized image dump of 2.0L, 2.4L and 2.5L merc powerhead shots, so you can see some of the differences between the blocks and parts.

http://www.wellcraftv20.com/gallery/Mercury_Internals

Re: Merc 2.5L on Seafari?
 

Very cool BigS,

That brings back memories of running around in my dads 21 tunnel w\twin 175s on a plate(pic in seafari25 pics). It was said by the original owner to go faster than 80 mph but I could only get her up to 77mph at 36 gph...ouch. I guess thats why pops sold it...he figured he had about 12000.00 into fuel in 2 years.

Lotsa fun :D

Re: Merc 2.5L on Seafari?
 

There are lots of race motors for sale over here right now. My question to you, is how are you guys putting them on your boats, they all have 20" or shorter shafts. Have you guys not raised your transoms or mounted it on a lowered jack plate or something?

The reason I ask is that I have a 1980 115 Mariner/Merc inline 6 at 278lbs which is about to come off the boat this week so I can rebuild the transom. The original owner claimed it had 17 hours on it and the lower unit looks like it could be brand new except for the faded paint on the whole motor. I just tested the compression and it was 130 across the board if my cheap tester is not lieing. Besides the fact that it needs a switch box ($280 to buy 2 since you have to install in pairs), is it even possible to mount this or one of the 20in shaft racing motors on a 25in transom with a jack plate or is that just a bad idea?

Re: Merc 2.5L on Seafari?
 

That's an interesting question. I had thought about raising transom and using a jack-plate instead of a bracket also. The only problem I saw with the lowered jack plate idea was not being able to tilt the motor up fully. Also considering a 5" drive extension from Bay Mfg.

Re: Merc 2.5L on Seafari?
 

If I were to raise transom to 25" and had 20" shaft..I would want to purchase 5" extension as well...keep motor as high up out of water as possible especially when in the ocean. Also, purchasing a 20" shaft motor from bass boat will usually be corrosion free (especially tiller arm bracket etc from me shopping around last year) and then add 5" extension when time comes to enclose/raise transom. Seems to me that you would be defeating the purpose of raising transom to 25" and then use a jack plate to lower engine. Or you could buy a clean 25" shaft motor and use a 2 piece fixed height jackplate on your 20" transom until you enclose/raise transom (watch that waterline though...did it on a 18' formula with a 150). I think I am getting off topic..my apologies!!
-Fred

Re: Merc 2.5L on Seafari?
 

Hey Fred - Have you run that 135 on your seafari yet with the bracket? Any noticeable speed difference?

Re: Merc 2.5L on Seafari?
 

Big-
I still have to do rigging etc...will be a while...also need to figure out what prop to run...
Will post numbers in future though!!!
-Fred

Re: Merc 2.5L on Seafari?
 

Looking sweet Fred.