211 Liberator prop question

[HT32BSX115]

Re: 211 Liberator prop question

So would a viper, stilletto or solas all be better props for a heavy boat then the ballistic?

I have the same boat. It's not all that heavy. (2900 lbs dry excl engine/drive according to FW) .................and It's really NOT a super performer with a SBC. I really don't think you're going to see a huge difference between the above props and the stock OMC props (in the same pitch/dia).

OTOH, Put a built 383 or 454 in a 211 Lib, and prop differences might come into play.....but again the additional HP will mask slight differences in props.

 

[onebadbowtie86]

Re: 211 Liberator prop question

Would it be worth doing a vortec head, intake, and roller cam swap on the 5.7? to make it a better performer?

 

[HT32BSX115]

Re: 211 Liberator prop question

Would it be worth doing a vortec head, intake, and roller cam swap on the 5.7? to make it a better performer?

Vortec head upgrades usually always improve an SBC. Several people here on iBoats have done it. I don't know what kind of performance improvement they got however.

I do know that most 211 Libs will do about 50-55 MPH lightly loaded with an SBC. I got 60 with a 460. (running it way over max recommended RPM)
HP difference between a 350 and a 460 is something like 250 hp -->340HP

I don't think going to Vortec heads gives you more than about 20-30hp but I could be wrong!




Even with the 460, it was a real dog out of the hole. (but not now!) Making all the above upgrades is not going to fix it much.

What I did absolutely fixed the hole shot.

 

[onebadbowtie86]

Re: 211 Liberator prop question

The boat is doggy out of the hole, but I am pretty happy with the performance with the sbc. If I can get the right prop on the boat for decent hole shot and break 50 mph I will be happy for this summer.

 

[HT32BSX115]

Re: 211 Liberator prop question

The boat is doggy out of the hole, but I am pretty happy with the performance with the sbc. If I can get the right prop on the boat for decent hole shot and break 50 mph I will be happy for this summer.

You want a prop that will give you top of the recommended max engine RPM at WOT when the boat is lightly loaded, and trimmed to max speed on smooth water or very light chop.. (pretty much All engine manufacturers suggest this)

It'll also give you the best hole-shot (which with a LIB is still going to be somewhat "sluggish")

The only way to improve holeshot is to reduce slip (increase hole-shot thrust).

You do that by increasing blade area of the prop. I.E. 4 blades, twin drives, DUO-PROP or Bravo III.

I did the Bravo III. I can beat most similarly sized boats out of the hole. It launches like a rocket now compared to when it had the 460
(even when it was new.....my brother bought this boat new and couldn't believe the difference)

If you do use a 4 blade prop, you'll improve the holeshot but your top speed will suffer (a bit)

 

[Tail_Gunner]

Re: 211 Liberator prop question

I have the same boat. It's not all that heavy. (2900 lbs dry excl engine/drive according to FW) .................and It's really NOT a super performer with a SBC. I really don't think you're going to see a huge difference between the above props and the stock OMC props (in the same pitch/dia).

OTOH, Put a built 383 or 454 in a 211 Lib, and prop differences might come into play.....but again the additional HP will mask slight differences in props.

2900 llbs that is far ligher than i thought. A stilletto baypro 2 in a 18p would give that boat a much better low end and midrange punch.It is a 4 blade ss and you would lose maybe 1-2 mph but by far a better responsive prop in the usable power band...think about this a bit you will be spending very little time at WOT maybe 3% and the rest below 4000

 

[HT32BSX115]

Re: 211 Liberator prop question

2900 llbs that is far ligher than i thought. A stilletto baypro 2 in a 18p would give that boat a much better low end and midrange punch.It is a 4 blade ss and you would lose maybe 1-2 mph but by far a better responsive prop in the usable power band...think about this a bit you will be spending very little time at WOT maybe 3% and the rest below 4000

That 1-2 mph loss from a 4-blade would be far outweighed by the MUCH better holeshot.

That's what I would probably do if I didn't already have 6 blades!

 

[onebadbowtie86]

Re: 211 Liberator prop question

Well I have a little while before I can get the boat out, so I will continue reading up on props. I appreciate all of your guys help. I would love to fine a wrecked boat with a 7.4/bravo3 to put in this boat!

 

[HT32BSX115]

Re: 211 Liberator prop question

Well I have a little while before I can get the boat out, so I will continue reading up on props. I appreciate all of your guys help. I would love to fine a wrecked boat with a 7.4/bravo3 to put in this boat!

I'll tell you what, You do that and you will be amazed.

My brother bought my 211 Lib new in 1987. He drove both the SBC and the 460/King Kobra model. He also said the 330 (crankshaft) hp454 Mercruiser/Alpha model was there too..........he selected the 460 model because it was rated at 340 crankshaft HP.

A few years later, in the early 90's, in the SF Bay area, there was a severe cold "snap" and he ended up with a cracked block as a result........... so he had the engine "rebuilt" by a guy in Redding, Ca that builds hotrod 460's. It got a different cam, different pistons, and a few other "upgrades" including Capt's Call exhaust etc.

He wasn't happy with the holeshot performance when it was new and he thought the engine upgrades would improve it a little. It was ALWAYS a dog out of the hole from new.


He also tried different props including a 21p 3 blade which turned out just perfect, giving about the right WOT RPM (4600-approx 4800) but the holshot was STILL "slow"

Going to the 19p that was repitched/cupped to 20P gave 5000 RPM (which the engine rebuilder assured him was "ok") gave an acceptable top speed and a little better holeshot. (but still slow in my opinion!)

He ran every summer until he bought a "regular" Ski-Boat (Nautique etc) in about 2000. He kept the Lib until 2005 when I bought it from him.


When I got it, it only needed a "tune-up" It actually needed an engine! (had several flat lopes on the camshaft) which would have hindered the holeshot performance (and did!)

When I found out I couldn't buy certain OMC parts for not only the engine (coupler/manifolds etc) but the drive as well I started looking for replacements.

I originally intended to find either a 7.4L/Bravo I or a 5.7L 350 MAG MPI Bravo I ( BOTH rated at 300 propshaft HP)

There was a few, of the above set-up's around but the prices or locations didn't impress me!

Quite by accident I found a 1997 454/Bravo III out of a damaged 1998 24ft Bayliner locally that had a tree fall on the bow in a big windstorm.

I read all about the Bravo III and heard that it would perform about same with a slightly slower top speed (for the same propshaft HP) and everybody talked about the slow speed/reverse handling etc..... but no one said a LOT about holeshot.

AND I found NO ONE with a Bravo III equipped 211 Liberator...... So I was completely in experimental territory.

But the price was "right" for the engine and drive and the seller was willing to bring his boat to me and help me remove the engine, drive, accy's etc. I had a big shop with a lift, tools, etc to do it.

We had the engine and drive sitting on the floor in about 2hrs and he was on his way!

This was Winter 2006..........I needed to do a little fiberglass work in the transom and engine compartment area to clean it up and I added closed cooling and a Lowrance NMEA Network, gages and some other stuff........ I had it running by Spring.

I remembered how slow this boat always was out of the hole.......My previous boat that was my Dad's 1966 18ft MarkTwain with a 150 6cyl Mercruiser. I remember my Dad racing my Brother when the Lib was new.

He'd ALWAYS beat him out of the hole up to about 35 MPH. Then the Lib once up on a plane would "roar" by at nearly 60mph!


In Summer 2006 after I got the boat running with the "new" engine and drive, my brother visited from Ca. I took him over to the local lake and had him drive his old around boat around.

He couldn't believe it! On essentially the same HP engine the boat was a veritable ROCKET out of the hole and was just about as fast as before (roughly 57 vs 60) and NOT having to exceed recommended RPM...much quicker out of the hole than even after all the 460 "upgrades"

In a later Summer I took the boat to Ca and "raced" his Ski-whatever" (350 MPI Mercruiser Inboard, 300 propshaft HP) 18ft Ski boat

I cannot get out of the hole quite as fast as his very light similar hp Ski boat But it's VERY close.

He only gets a about boat-length or two away from me before I literally BLOW PAST him!

Now I want a Stroked 502! ......... I'll fix him!...Sibling Rivalry at it's best!:lol:.........


Your Liberator will absolutely be a performer with either a 300HP SBC or a 454 with a Bravo III on the back. (both are rated at 300 propshaft hp.


[Hey guys, sorry for the long rambling post!!]

 

[onebadbowtie86]

Re: 211 Liberator prop question

Thats awesome! I know they make a conversion to mate an alpha up to the omc. What about switching a cobra outdrive to a bravo? would you pretty much need a complete setup out of another boat? Would and alpha live behind a 400 hp 383?

 

[HT32BSX115]

Re: 211 Liberator prop question

Thats awesome! I know they make a conversion to mate an alpha up to the omc. What about switching a cobra outdrive to a bravo? would you pretty much need a complete setup out of another boat? Would and alpha live behind a 400 hp 383?

Yes, you can do the SEI "conversion" (Alpha type drive only)

To go to a Bravo, you MUST use a Bravo transom mount, flywheel housing, inner plate, etc and drive. you have to drill 2 additional holes in the cut-out. Otherwise it's the same bolt pattern and cutout. You'd need a donor boat or a complete "Firewall-Forward" engine/drive etc.

You could do it but you would have to remove everything OMC and replace it with everything Mercruiser.

You could use the engine (long block only....remove OMC stuff add Merc stuff) , and I wouldn't put more than 300 peak HP in front of an Alpha.

Lots of people have successfully ........... I think they're pretty careful with the throttle hand though. remember, you have a Liberator! YOU WANT TO HAMMER THAT THROTTLE! I do, everytime out! Do that a LOT with a BBC or High HP engine and an Alpha, and you'll be calling for a "Tow"

Mercruiser only offered the 454 in front of the Alpha for 1 year....... then the Bravo came out.

After I removed all the OMC "stuff" I spend the next few years selling everything piece by piece (ebay, craigslist, etc) . After it was all said and done, I got about $3500 for all the OMC pieces. I only paid about $5K for the complete 454/B3 setup

 

[onebadbowtie86]

Re: 211 Liberator prop question

You go a steal on your big block/bravo3. If I ran across something like that for $5k it would be mine. Everywhere I have looked 454/bravo1's are going for $7500.

 

[HT32BSX115]

Re: 211 Liberator prop question

You go a steal on your big block/bravo3. If I ran across something like that for $5k it would be mine. Everywhere I have looked 454/bravo1's are going for $7500.

I will say that right after I got it installed and running, someone posted a MUCH newer 496 MAG MPI (425 prop HP) Bravo III out of a damaged boat with something like 80 hours on it for about $8000.

I would have gotten that one if I could have!! I am thinking I could have gotten it for about $7000-7500.....

 

[onebadbowtie86]

Re: 211 Liberator prop question

I know your a good couple thousand miles away, but let me know if you run into any more smoking deals! I would love to be able to run 65 mph in my liberator, and I know it wouldnt be a problem with a little work to a big block and a bravo3!

 

[HT32BSX115]

Re: 211 Liberator prop question

I know your a good couple thousand miles away, but let me know if you run into any more smoking deals! I would love to be able to run 65 mph in my liberator, and I know it wouldnt be a problem with a little work to a big block and a bravo3!

That's essentially the top speed for a Bravo III.

According to Mercury:

Bravo Three?/ Bravo Three X?/ Bravo Three XR

Efficient. Maneuverable. Unbeatable. Single/twin applications up to 65 mph for gas engines up to 525 hp
The twin-prop design says it all. Whether in a single-unit or twin-unit application, the Bravo Three? is an efficient drive built without compromise. Perhaps it's the best-in-class shifting or its counter-rotating propeller design - enabling agile handling in reverse for precision maneuverability. And the greaseable gimbal bearing makes for an easy ownership experience-allowing for service without removing the drive unit. The Bravo Three X? drive, standard on big block 8.2L high-output engines, is a superstrength drive with high performance attributes.

There's no doubt in my mind that the 211 Liberator would FLY with a Bravo I !!

But it would still be slower out of the hole due to low-speed "slip"

There was a guy over on the Offshoreonly.com Forum that had a 211 just like mine with a 460 Ford bored/stroked out to something like 540 with the King Cobra.

He said it would "BURY THE SPEEDOMETER at 80 MPH! I have no no doubt that it was fairly quick (compared to stock) out of the hole too!

I am not sure I would want to go 80 in a 211 though. It's somewhat unstable at 60!

 

[Tail_Gunner]

Re: 211 Liberator prop question

I know your a good couple thousand miles away, but let me know if you run into any more smoking deals! I would love to be able to run 65 mph in my liberator, and I know it wouldnt be a problem with a little work to a big block and a bravo3!

Find yourself a junk boat with a bravo on it..there out there

 

[onebadbowtie86]

Re: 211 Liberator prop question

I have been watching craigslist religiously. My omc 5.7 cobra stuff works fine, but I would still like to find a junk boat with a 7.4/bravo setup. even if the engine is bad I can rebuild the motor, or get a different one if the block is cracked. I'm going to keep looking,I would like to find something over the summer, so I can swap it over next winter in my heated pole barn.

 

[onebadbowtie86]

Re: 211 Liberator prop question

Any tips on other places to look for a complete motor/stern drive? or know of any wrecked boats?

 

[HT32BSX115]

Re: 211 Liberator prop question

If you're where you get hard freezes, this is about the time when people start discovering that their winterization job was less than satisfactory!

I found all the engines and drives I mentioned in Craigslist.

There's a LOT of stuff on ebay but unless I could go and inspect, I wouldn't want to get one sight unseen.....

Here's an example up here in the NW.

MercCruiser 383 Boat Engine for Sale

I think they're a little optimistic on the price because it's high time (2400+ hrs) and a salt-water engine (I presume)

It's a Bravo III drive (he calls it a Bravo II )

If it were me, I wouldn't want this one. high time, high price and salt-water. But, Bought right it could be a good start.

I think the 383 would run every bit as good in a 211 LIB as the 454 except, you couldn't get much more HP out of it where getting a 454 (or 502) you can always stroke them...

If I could have gotten that guy with the 5.7L 350 MAG MPI (300hp) + Bravo I to come down in the price, I would have bought it.


NOW, I'm glad I didn't. I just LOVE that Bravo III..... even though the 350 MAG/Bravo I would have probably been a tad faster at the top end and probably a lot more fuel efficient. I have a Lowrance fuel flow gage that I installed when I did the job. At 30 mph, I run 3000 RPM and 10gal/hr. I don't think the single prop 460 did as good (nor would a 454/Bravo I)

I looked for quite a while and I always looked for fresh-water engine's only or closed cooled engines. (I still didn't want salt water drives though)

There's a LOT of deals around the country where there's a large recreational boating public.


EDIT: I want this one! 2007 Mercruiser motor and outdrive

 

[onebadbowtie86]

Re: 211 Liberator prop question

Wow, if that 383/bravo3 was closer I would be dealing on it right now! For a stock bolt in mercruiser setup that should be capable of 60 mph in my boat, with a huge gain in out of the hole I would think.