1980 OUTRAGE V-20 with 250-HP

Optimizing the performance of Boston Whaler boats
Looney wheelz
Posts: 1
Joined: Thu Aug 03, 2023 4:55 am

1980 OUTRAGE V-20 with 250-HP

Postby Looney wheelz » Thu Aug 03, 2023 8:56 am

Q1: should I re-power a 1980 OUTRAGE V-20 with a 2010 E-TEC 250-HP engine?

Q2: will the weight of a 2010 E-TEC 250-HP engine thought to be 524-lbs be excessive for the 1980 OUTRAGE V-20?

Q3: will the 1980 OUTRAGE V-20 have a tendency for the bow to oscillate up and down when on plane if I re-power the boat with a 250-HP E-TEC engine?

Q4: what propeller should be used on an E-TEC 250-HP engine on a 1980 OUTRAGE V-20?

BACK STORY

I have been restoring an OUTRAGE V-20. This boat, engine, and trailer are all from 1980.

I have discarded the original engine, a Mercury BLACKMAX 150-HP.

I have purchased from a friend at a good price a 2010 E-TEC 250-HP engine with only 250-hours run time.

I can’t justify spending over $25,000 on a new engine when I have this 2010 E-TEC 250-HP.

I am not a fan of four-stroke-power-cycle engines.


ASIDE ON ANOTHER BOAT, NOT THE BOAT THAT IS THE TOPIC OF THIS THREAD: I have a 1989 MONTAUK 17 with a 2008 E-TEC 90-HP engine. The 2008 E-TEC engine has been running very well since I bought it in 2010.

User avatar
Phil T
Posts: 2624
Joined: Thu Oct 22, 2015 6:08 pm
Location: Was Maine. Temporarily Kentucky

Re: 1980 OUTRAGE V-20 with 250-HP

Postby Phil T » Thu Aug 03, 2023 2:20 pm

The V-20 is sensitive to porposing as outlined in the reference article from Sal Mercurio's owner testimonial.

See https://continuouswave.com/whaler/reference/V20Outrage/

I think with proper engine mounting (three-holes up from lowest, as high as possible) and a good stern lifting propeller, you should be good.

I would suggest a BPR Viper or even a four-bladed propeller.

As for propeller pitch, check with, and purchase from the E-TEC and Whaler gurus at Lockeman's.

http://www.lockemans.com
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: 1980 OUTRAGE V-20 with 250-HP

Postby jimh » Fri Aug 04, 2023 10:25 am

Looney wheelz wrote:Q4: what propeller should be used on an E-TEC 250-HP engine on a 1980 OUTRAGE V-20?
I will first estimate the boat speed potential to determine a target boat speed. Then I will calculate the appropriate propeller pitch needed for producing that boat speed.

TARGET BOAT SPEED

The OUTRAGE V-20 hull form was a very moderate V-hull, so the boat can be more easily driven onto plane than later OUTRAGE models with a deeper V-hull.

An informed estimate of potential boat speed can be made using the Crouch Method, which uses only three factors: power, weight, and hull form coefficient.

For weight I will used a fairly good approximation by taking the bare hull weight and doubling it. Using the hull weight at 1,650-lbs gives an approximate weight for the rigged boat at 3,300-lbs.

For power I will use the rated horsepower, 250-HP.

For hull coefficient I will use 210, an increase over the usual 180 to 190 hull coefficient. With these inputs the Crouch method as implement by me in the Crouch's Calculator gives an estimated top boat speed of 58-MPH.

CROUCH'S CALCULATOR
https://continuouswave.com/calculators/crouchCalc.php

TARGET PROPELLER PITCH

Using the engine's gear ratio of 1.845, and an estimated value of SLIP as 10, my propeller calculator shows that a propeller pitch of 21-inches is needed.

You can try other input values if you would like to make your own estimates.


PROPELLER CALCULATOR
https://continuouswave.com/calculators/propCalc.php

If want to use Evinrude branded propellers, the three-bladed REBEL propeller is an excellent choice. For a four-bladed propeller, the CYCLONE propeller is an excellent choice.

Let me know if you found this information useful.