I am looking for some Volvo Penta AQ171a engine and DP 290 outdrive experts.

[ricardoedwardo]

I am looking for some Volov Penta experts other than IVSMarine and Coatsal Rides.
As I have tried them already to see if anyone has done the same or knows someone who can help.

Scenario: I have a boat with twin Volvo Penta AQ171a on DP 290 legs.

Question 1: Can I replace the two engines with engines that will run with the outdrives and has anyone doen this successfully.

Question 2: Has anyone swapped these out for different engines and legs.

Question 3: Can anyone offer any known solutions that maybe they have done themself.

 

[Tranona]

Better to post this on the Motorboat forum. However unlikely anybody has done what you suggest for the simple reason it is unlikely to be economic even if the technical difficulties can be resolved.

 

[QBhoy]

Hi. Very briefly (much more to the matter to be aware of),
The engines most commonly found driving a 290 would be usually a GM derived petrol like a v6 or V8. In diesel form…a VP 4 or 6 cylinder unit…in general terms. Quite uncommon that a 4 cylinder 171 like yours would be driving a 290 DP.
in terms of alternative engine options…your issue is that your particular engine(s) have their own rather unique engine mount pattern. So to change to the preferred or more reliable GM engine type…you’d need to glass in new engine mounts for starters.
The other thing to consider is around the gear ratio in the outdrives. If indeed your 171’s are original and set up to suit the 290’s…so will the gear ratios and certainly props, you’d assume. So throwing in the usual bombproof 4.3, 5.0 or 5.7 GM would certainly require at least a change in props pitch…and even a change in gear ratio. Your engine and those engines vary in power for sure…but more crucial perhaps is the variation in how they make their power, in terms of rpm range. Even more apparent when putting a diesel in there. Often a terrible result is found, should this not be considered.
just my thoughts on it

 

[tico]

1. Yes
2. yes & no
3. yes
Many years back I replaced a pair of AQ171s/290 in a Fairline Sunfury with FSDTIs from Mike Bellamy (Lancing Marine).... Ended up a great success and as far as I know the boat is still going.
HOWEVER it's not for the faint hearted/non-engineers. Many aspects needed to be modified - Bellhousings(altho Lancing did them), Sumps, oil returns, fuel system and complete redesign of the steering system.
(I kept the existing 290 outdrives)As the gear ratio was designed around the petrol engines the props had to be changed for 'long hub' versions and the pitch increased by 2" plus an additional 1" of 'cupping'
Ended up with a boat that would cruise all day at 30kts economically and had bags more torque to deal with big swells... very happy.
Google 'Fairline Sunfury Bermuda' to see some pics

 

[oldgit]

Better to post this on the Motorboat forum. However unlikely anybody has done what you suggest for the simple reason it is unlikely to be economic even if the technical difficulties can be resolved.

100% .
The end result probably will be a lot of time/effort/expence that will never ever be recovered, even if the boat in question was given to you free .
If the powertrain is U/S due to neglect , whats the rest of the boat like.
Is the hull sound ? and of absolute vital importance......... is the transom sound ?.
How about the interior or the electrics.
Where are you going to use it, any petrol power source is going to be horrendous to run offshore.
There are boats out there if you search diligently enough,lying in boatyards that could be bought for very small amounts of money and involve a lot less work to get on the water.
Forget brokers, this is not their thing, find a boatyard and ask if anything is for sale, virtually guarantee they will have a list of boats where the owner has abandoned a boat and "legged "it owing rent.
It propably will be full of examples of the perils that await old neglected outdrives .

If you do decide the press on regardless good luck and welcome to boating.