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Old 03 December 2014, 05:33   #1
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Revenger 23

I have just introduced myself in the new member thread as the recent purchaser of a Revenger 23. I bought the Revenger off ebay and it is need of some careful refurbishment. The boat is a 1999 model and is fitted with a Mariner 135 two stroke of about the same age. The boat is basically sound with no repairs to the tubes and only minor scratches and chips to the hull. Unfortunately, it has suffered from a previous owner who was less than careful with modifications. There are numerous examples of poor workmanship which will be corrected over the next few months. The most serious is connected with the reason for this post. For some reason the engine has been moved about 20-25mm from the centre line of the boat to starboard. The original mounting holes had been badly filled with silicon sealant (removed on Saturday). Even worse, the engine had been mounted with lower bolts that were ordinary steel. I removed them on Saturday, and they had rusted to about 2/3 of their original diameter.

Now the question.

Can anyone provide a good explanation of why anyone would go to the trouble of moving the engine off the centre line?

This cannot be done easily so someone must have had a good reason. I cannot see what it could be, but perhaps there is something about the Revenger 23 that makes it work better with an off-centre engine, or perhaps always turning to port is beneficial for some form of watersport. I don't know, so help would be greatly appreciated before I move the engine back.
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Old 03 December 2014, 06:05   #2
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It's usually done to counter prop torque by balancing that heel-to-port moment with the weight of the engine.

There was a discussion somewhere on here about it recently, but I don't think there were any firm conclusions about whether or not it was particularly useful. Some said it was, some said it wasn't.
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Old 03 December 2014, 06:14   #3
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Thanks for the reply, James. That is one possibility I had considered but if it is necessary other owners will have done the same. Hopefully, another Revenger owner can let me know. What troubles me about accepting the current position as correct is that to do so is to put trust in the judgement of someone who can use plain steel bolts for engine mounting.
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Old 03 December 2014, 07:57   #4
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Most larger Hp outboards, compared to hull size will be offset.

Smaller boats with comparatively modest Hp wont be offset as the effect is not as pronounced and therefore not worth trying to correct. Hence some people have it on their boats and some do not.

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Old 03 December 2014, 08:10   #5
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Quote:
Originally Posted by gareth9702 View Post
I have just introduced myself in the new member thread as the recent purchaser of a Revenger 23. I bought the Revenger off ebay and it is need of some careful refurbishment. The boat is a 1999 model and is fitted with a Mariner 135 two stroke of about the same age. The boat is basically sound with no repairs to the tubes and only minor scratches and chips to the hull. Unfortunately, it has suffered from a previous owner who was less than careful with modifications. There are numerous examples of poor workmanship which will be corrected over the next few months. The most serious is connected with the reason for this post. For some reason the engine has been moved about 20-25mm from the centre line of the boat to starboard. The original mounting holes had been badly filled with silicon sealant (removed on Saturday). Even worse, the engine had been mounted with lower bolts that were ordinary steel. I removed them on Saturday, and they had rusted to about 2/3 of their original diameter.

Now the question.

Can anyone provide a good explanation of why anyone would go to the trouble of moving the engine off the centre line?

This cannot be done easily so someone must have had a good reason. I cannot see what it could be, but perhaps there is something about the Revenger 23 that makes it work better with an off-centre engine, or perhaps always turning to port is beneficial for some form of watersport. I don't know, so help would be greatly appreciated before I move the engine back.
There is split opinion on the matter of off-set....I'm no expert,but A longstanding Marine engineer who's dealt a lot with Big Race Boats,and who's opinion I respect tells me,for Race and Big Ski Race Boats (some 100mph+!)it's largely a thing of the past...and a Hangover from the days of Mechanical Steering systems.
Things like Load distribution ...Fuel...Crew..Engine height/trim and Helming.... have a much bigger effect!
Having said that mine is off/set and I'm very happy with performance,and handling,so I wouldn't stress it too much...especially the amount your talking about
I'd be more concerned to make sure the Transum is 100% dry and sound before you fill any holes properly with with Fibre glass/resin.
Is your Boat Yellow by any chance?
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Old 03 December 2014, 08:10   #6
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First effect is to work against the torque of the prop, to let
the hull run better ballanced. (Torque wants to push the left
side of the V-Hull down, with right direction spinning prop, you
offset to starbord)

Second effect should be, that you "create" a second keel line
with the fin of the outboard beside the center keel line of the
hull, wich gives you a bit more "stable" run, instead of dancing
on only one keel line. (Keel hull & fin outboard in one line)
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Old 03 December 2014, 12:20   #7
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Thanks for all the answers. It seems there are potential benefits of being offset. I need to remove the engine in order to correctly seal the unnecessary holes and will decide what to do once I can see the true state of the transom. If anyone else has an opinion I will be pleased to hear it.
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Old 03 December 2014, 13:07   #8
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hi Gareth, welcome to the Revenger club

we've got a 715, which is basically the same hull as the 23 but was built as a package rather than a custom build, ours is fitted with a Honda 150hp, and is offset to starboard by approx 30mm, so I'd say yours is probably spot on

if you want any info about you rib, then the best option by a long way is to contact Phil Morris, he was the Sales Manager at Revenger before it was sold to Ribeye, he's a fountain of information about Revengers and a top bloke best way to contact him is via the Revenger facetube page:

https://www.facebook.com/pages/Reven...0?ref=ts&fref=

let me know if you need anything, more than happy to help
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Old 03 December 2014, 13:12   #9
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Quote:
Originally Posted by gareth9702 View Post
Thanks for all the answers. It seems there are potential benefits of being offset. I need to remove the engine in order to correctly seal the unnecessary holes and will decide what to do once I can see the true state of the transom. If anyone else has an opinion I will be pleased to hear it.
Hello Gareth and welcome to RIBnet.

As has been said already, please make absolutely sure that the integrity of your transom hasn't been compromised before sealing anything. It sounds as if you might actually have a bit of remedial work on your hands before you're able to re-attach the engine, centred or offset.

Oh, and please don't expect anyone on RIBnet to express an opinion because everyone in this forum tends to sit on the fence for fear of offending fellow members....

And if someone does express an opinion please accept that you might not actually be pleased to hear it!

Joking aside, enjoy the forum. It's a goldmine of information, expertise, knowledge and experience.
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Old 03 December 2014, 13:25   #10
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Originally Posted by Barrowboy View Post
Hello Gareth and welcome to RIBnet.

As has been said already, please make absolutely sure that the integrity of your transom hasn't been compromised before sealing anything. It sounds as if you might actually have a bit of remedial work on your hands before you're able to re-attach the engine, centred or offset.

Oh, and please don't expect anyone on RIBnet to express an opinion because everyone in this forum tends to sit on the fence for fear of offending fellow members....

And if someone does express an opinion please accept that you might not actually be pleased to hear it!

Joking aside, enjoy the forum. It's a goldmine of information, expertise, knowledge and experience.
I was very careful not to express any opinion other welcoming Gareth to the Revenger club

I'd agree with Tony, best remove the engine and have a VERY good look at the transom before you do anything else
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