Revenger 27 w/t Opti 250 XS

[ChrisRev92]

Hi to all,

I just finished my full rebuild project of a barn find Revenger 27, which was in an almost totalled condition, waiting for me for many many years..

Considering all various aspects including vfm rib was fitted with an optimax 250 XS.

Engine was fitted one hole before the lowest on transom.
Full on water (90lts tank placed in front of the console) and full on fuel (360lts tank placed in the original position almost center - back) and 3 person on board, boat made 49knots @ 5500 rpm with revo 4 21'.

From consumption figures and wot rpm, something is off, maybe high pitch for revo? Also below the prop slip calculated

Revolution 21
RPM LT/H Speed LT/M Slip
3500 40 26.5 1.51 25%
3700 45 28 1.61 24%
4000 55 34 1.62 14%
4200 60 35 1.71 16%
5500 -- 49 -- 10%


Any prop recommendation for this setup would be highly admired

Thank you in advance

[gtflash]

Prop recommendations are guesses. REV4 is a great prop and runs almost as fast as my laser, bravo and 25" raker2 on a twin stepped hull.

Back to basics. How high is prop shaft relating to bottom of boat. To increase RPM to WOT you can reduce prop size, remove a blade or lift engine height. I wouldn't do anything until engine height is established. Most ribs come buried far too low and the revenger is a great little fast hull.

As a comparison my 8.1m twin stepped runs 71mph on 25 rev4 or 66mph on 23 rev4. 71mph on raker2 with 700rpm left but planing is downwind with ballast upfront or she doesn't get up. Prop shaft is approx 4-6" above bottom of V. Water pressure gauge fitted and stable on a 2008 250ho etec without low water pickups and lightning gearbox.

Lovely vvvvvvvv noise from the slightly surfacing props.

[gtflash]

Roosters at dawn

https://youtube.com/shorts/26D-ll9rE...5rrlAwjzJfWoFO

[ChrisRev92]

Thanks mate!

Hoped to receive some indicative rigs from people used to have this setup in the past, as it was common back in the day..

Then I could work around the pitch at least with some more fresh prop options

[ChrisRev92]

A photo of her

[Voodoo]

Beautiful.....

[ChrisRev92]

Originally Posted by Voodoo

Beautiful.....

Thanks mate!

Updated figures with Bravo 20'FS

Bravo FS 20
RPM LT/H Knots LT/M Slip
3900 36 29 1.24 25%
4000 41 33 1.24 16%
4200 46 33 1.39 20%
4600 58 39 1.49 14%
5200 68 46 1.48 10%
5650 49

Next one to try Trophy 21'

[ChrisRev92]

Some more summer photos of her

[gtflash]

Got any pictures of engine height? Prop shaft or AV plate to bottom of hull?

[ChrisRev92]

Hello,

Unfo only this one I could find, where engine is a bit trimmed



If I remember correctly cavitation plate is 1-1.5inches higher than hull

[gtflash]

Originally Posted by ChrisRev92

Hello,

Unfo only this one I could find, where engine is a bit trimmed



If I remember correctly cavitation plate is 1-1.5inches higher than hull

That's a great looking bum! Tidy boat.

Almost standard setup at 1-1.5 above. If you have low water pickups and some engine holes left you could increase engine height. It's sounds scary but if you really want more speed 👍🏻. Revengers are fast hulls.

[gtflash]

Good article.

https://community.brunswick.com/area/blog/service-spotlight-setting-outboard-height/article/17129

I have a 6" jack plate but so not specifically like for like. Even with standard water pickups you can see the extra engine height I ended up at for speed.

[ChrisRev92]

Thanks mate, really interesting

Have already thought about lifting the engine, but due to the conditions in Aegean (which most commonly is arnd 4bf) am afraid that wave riding ability will get worse with a lot of airtime

[gtflash]

It's always a compromise. And also an expensive black art. It would likely mean swapping props and increasing pitch. Height will change everything and is in my opinion the first change to make.

I had no choice but to experiment. With large 3 blade props my boat sometimes struggled to plane when I got it as it was setup beautifully for top end. I had to run downwind or send people up front to get up in rough conditions and that wasn't safe.

Height change, some setback and prop experiments and I luckily stumbled across a good setup. I now have a 23 and 25 (I think) rev4 to give me grip and speed. I probably lost 3-5mph over the 3 blade raker. I use 23" 99% of the time, it grips, pulls the kids in toys and still runs 65mph. Only slight feathering of throttle if I am lazy with trim to get up on plane. If I went any higher I'd be concerned about acceleration and water pressure.

[ChrisRev92]

Thanks for the assistance mate! You help me brainstorm and work around set up :-)