What drive to use?

Red Rider

Petty Officer 2nd Class
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Jun 10, 2002
Messages
124
I am just about finished overhauling my 24' Reinell. I need to make a decision on what drive to use.<br /><br />It originally had a 1975, 302 Ford engine and a 1975 OMC stern drive. If I use this combination the Ford engine would be rebuilt/replaced to later model standards, i.e. roller cam, GT-40 heads, electronic ignition, fuel injection, etc. The other option would be a late model 350 Vortec, and a Berkley Jet Drive. <br /><br />Either option will increase the power from the original 190 hp to somewhere around 255-275 hp. (The OMC stern drive has been rebuilt and will handle the additional power as it is reted to 260 hp+). <br /><br />The boat will be used for fishing from inshore out 40+ miles to well within the Gulf Stream. I have other shallow draft boats that I use in the sounds, rivers, lakes, so the difference in draft between the stern drive and the jet drive doesn't matter. Also either option will give the boat at least 40-45 mph speed which from my experence around here is fast enough, and sometimes too fast. 9I am not interested in going 70 mph in a 24 foot boat!)<br /><br />What I need from all you experts are the advantages and disadvantages of both drives systems as you see it. No comments on the engines as I have an engine shop so the care and feeding of the engines doesn't come into the decision.
 

Realgun

Commander
Joined
Jul 31, 2003
Messages
2,484
Re: What drive to use?

I believe the jet is a bad idea for two reasons.<br />1. The jet will use 15% more power to get the same boat speed.<br />2. If the impeller were to ingest a turtle or whatever swims in your part of the world its gonna be hard to change.<br /><br />I would stick with the outdrive myself.
 

Bondo

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Apr 17, 2002
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71,137
Re: What drive to use?

I'm also rebuilding a boat like yours... a 25' Old Town Atlantis...<br />I've got an old berkley jet laying around,+ considered using it....<br />But, what I've read, jets have Really Lousey low speed handling.... And, I'm a Troller.. No Good...<br />And, I guess jets aren't that conducive to Bigger Boats... I Don't Know.....<br /><br />I Also Don't Want to do it Twice......... :D <br /><br />I'm going together with an Alpha1 drive....Cheap... Lots of Parts.......<br /><br />There's No Way I'd spend the energy to install that Dead Horse of an outdrive you have Now....<br />Sorry, But, That old OMC was a Marginal outdrive when it was New.... That was 30 years ago.....<br />And, They don't make the Parts for them anymore............<br /><br />I guess, If I was You,<br />I'd Sell what I had,+ Start shopping ebay for a Mercruiser...................... ;)
 
D

DJ

Guest
Re: What drive to use?

Red,<br /><br />I have issues with using the old OMC drive.<br /><br />1. It's hard to get parts for.<br /><br />2. It was not the most efficient system.<br /><br />3. It was prone to trim/tilt issues amongst others.<br /><br />4. That much HP will blow the gearset out of the lower unit (been there-done that) unless you are REAL careful.<br /><br />I have no issues with jet, other than it takes a major hull rework for the intake.<br /><br />If you are at the point where you can make transom/engine mount changes, I would go with a MerCruiser Bravo or Alpha. The Alpha is not as strong. The Bravo accepts much larger props, for a larger (heavy) hull.<br /><br />You can also go with a Volvo. <br /><br />Many MerCruise/Volve packages are available at far less prices than a similar HP outboard.<br />Both use GM engines and the Volvo carries a better warranty, The Volvo offers the choice of dual prop or single.<br /><br />See link below.<br /><br /> http://www.dougrussell.com/
 

Red Rider

Petty Officer 2nd Class
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Jun 10, 2002
Messages
124
Re: What drive to use?

After doing a lot more research, I decided to go with the Jet Drive for several reasons. First jets have better low speed performance that most other systems do. Second even though Jets require more hp to operate at low and medium speed, that isn't a problem as I have an excess amount of hp with the selected engine. And Jets are more efficient at high speeds than props, because they have a lot less cavitation. But the main reason is a lot fewer parts and a lot more reliability. 99.9999% of anything that gets into an Jets impellor does a lot less damage and is easier to get out than one wire fishing line does to an out drive. How many times have you had some idiot trolling cut across your bow? Also you can clean out the Jet impellor and system from inside the boat, and don't have to get in the water or lean overboard.
 

Bondo

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Apr 17, 2002
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71,137
Re: What drive to use?

Also you can clean out the Jet impellor and system from inside the boat,
Unless You've found a pump that I've never seen before,<br />You're Wrong.......<br />You'll Sink the Boat in a Heart Beat, taking the hand-hole cover off.............<br />
First jets have better low speed performance that most other systems do. And Jets are more efficient at high speeds than props, because they have a lot less cavitation.
I Question this Too......<br />It's Quite the Contrary to Everything I've Read.........
 

Bigfun

Petty Officer 1st Class
Joined
Jan 21, 2003
Messages
305
Re: What drive to use?

I'm ignorant on the in/out jets ability to ingest and expell seaweed, that whould be my concern.<br /> I took my outboard jet to the key's and had to stop and clean the intake grill numerous times. This is something you do not want to have to do in critcal situations. Low speed control ?, very little on mine.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
13,125
Re: What drive to use?

Before doing all the work to convert to a jet drive, I'd want to try a similar boat with one, or even try out a jetski and see if you are comfortable with how they handle at low speeds. No throttle = no steering<br />But the simplicity compared to an outdrive of any make is attractive.<br />There was a guy who ran a Yamaha jet boat around here, it looked like a conventional 20'bowrider but had twin engines and jet drives. Very cool looking and sounded different than all the other boats. Don't have any experience otherwise. Like Bondo says, for sure don't put money into an OMC stringer. A later Cobra is a different story, most of those parts are out there and you can find shops to work on them.
 
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