Hi
Can anyone on here help me with which props I should be choosing?
I have a family 24 with 2 x Volvo AQ 131c Petrol engines with 2 x Volvo aquamatic 290 stern drives, if anyone else has this set up or has in the past I would be very grateful for your input.
Thanks James

15*17 would be my guess, must reach 5500 rpm's(max rpm)
Bjørn, DK

Jeg har 13* 13 på min 24 cabin
Men det kommer and på om du vil hurtig ud af vandet el du vil sejle økonomisk.

Thanks bjorn I will look a these 15-17.
I did have 14.75-15 4 blade props on before that I bought from America but I'm having trouble finding them again, so perhaps I'll go back to 3 at 15-17.

Thanks James

I can recommend propellertrim.
If you use their question form, they will return within 24 hours and tell you what propellers you need.
They also have 4 bladed ones.
Really skilled and also really funny to visit.
Good luck

http://www.propellertrim.se

Questionnaire...

http://www.propellertrim.se/reparation/forfragan/propellerforfragan/

If you go for the Swedish Propulse propellers you can change the pitch to whatever you need for your boat. They are all 4 blade models, pitch 14-22" both RH and LH. See links for more info.

http://propulse.se/en/butik/propellers-with-adjustable-pitch-and-replaceable-blades/propeller-9904-2/

http://propulse.se/en/butik/propellers-with-adjustable-pitch-and-replaceable-blades/propeller-9914-2/

Är detta OK? Reklam för Propulse direkt från ej medlem med intresse i företaget?
Sen är Propulse inte att rekomendera annat än på småbåtar och knappt det heller. Dyra och dåliga.

Är fullvärdig medlem sedan en längre tid, hade bara inte inloggningen tillgänglig från den dator jag skrev svaret. Är inte mer reklam än de förslag, råd och tips som förekommer i andra trådar i forumet. Jag är aktivt i företag Propulse inget att hymla med, jag bistår gärna med information och kunskap till klubbens medlemmar utan vare sig köptvång eller annat.
Din rekommendation om vår produkt vet jag inte vad du grundar på, men då det finns många tusen kunder i främst Skandinavien, men även i andra delar av världen som kör med produkten, så behöver du nog uppdatera dina kunskaper. För din och allas andra info kan jag meddela att vi löpande testar vår produkt bl a med en Formula 242 (ca 2600 kg) med en 7,4 l big block V8 på drygt 330 hk, fungerar hur bra som helst.

Jag hade en propulse på min flipper 570 med 90 hkr yamaha för en massa år sedan, den gjorde runt 30knop oavsett hur jag vred på bladen. Sista 1000 varven gjorde litet i hastighet. Nästa ägare bytte till en original aluminiumpropeller, då gjorde den 34-35 knop.
Numera kanske dom fungerar bättre med tanke på att det borde kommit nya plaster som kanske är mer vridstyva. Detta var ju kanske 15 år sedan.

I also have a 24 F with two VP AQD32A (diesel/106HP) and I can't yet find the right propellers in order the boat can run till the 25knots that everyone runs.

Dear James,

I don´t know how much this helps out but I have a 24 Weekender with Twin AQ151C together with VP290 drives. My props are 19"/15°Pitch

Hi guys

I've just been on the website that Johan recommended and it is saying I can reach a boat speed of 38 knots😳😳😳
Let's hope and see?! it is a very good prop calculator better than any I've seen in English although it's a little tricky for me to translate!

I will try and use all the information given by club members and post my results when back on the water.

Out of interest pehr do you know how many knots you are achieving ? Also is your hull smooth ?

Regards james

Really good you liked it, James!
I have a 26 family (in pieces), when I bought it it had 14x19 propellers on 280 sterndrives, I never tried it because there were no engines and I bought it on land. Previously there had been VP AQ130 probably, and then retrofitted with BMW165? (M30B28). With those engines it must have overrevved. I'm planning to mount two VP D3-130 together with 280 sterndrives, pretty much the same as you have so I'm interested in your findings. I have bought two 15x21 but i think it's too much. Good luck!

Gonçalo, do you have any picture when the engines are installed, also interested if any other have pictures of twin engine installation in 24/26 Family?

Has anyone used the propulse that Thomas is selling ?
I would be interested to hear?

Thanks James

Hi James,

I´m doing approx 35 knots @ 5500 rpm. Late season = not perfect hull conditions ;-)

Best Regards

Pehr

Johan

I don't havê any pictures of the instalation bit I van help you in what you Sant.
Please let me know how van I help you.

Johan

Sorry for the english errors but it was not my fault

Gonçalo, i shut off the corrections on my phone, so now I have to do the spelling errors myself...no problem. I have the choice to put two md21 in my boat so i wondered about the space, i think md32 is the same with as md21

yes you are rihgt

yes you are rihgt

Hey guys

My boat is now out of the water for the winter and will be re commissioned and put back in may I will post again on this thread as to my propellor decision and results. Merry Christmas to you all and see you on the flip side 🤓

Hi James

I am very interested in knowing your decisions and results about the propellers, because I don't know, at all, how to put my F24 running till the 25 knots that everyone runs.

Hi there
Just been through the same process.
What kind of motor, how many horsepower and external drive is mounted in the boat.
What is the top rpm you can reach with existing propeller - and what is the recommended top rpm for Your motor according to the motor manual ?
Have an Coronet 26 Family with a Volvo 4.3 GL Engine mounted and a Duo Prop Propeller Size 6 mounted.
With this setting our boat could only reach 3.200 rpm compared to recommended top rev from Volvo 4.300 - 4.600 rpm.
Talked with our local Volvo Marine Dealer - according to his computer calculation program the correct propeller shall be Volvo Duo Prop Size 1.
The top speed with this Duo Prop Size 1 is calculated approximately to 26 knots (todays top speed is approxiamately 20-21 knots

I have a 24 F with two VP AQD32A (diesel/106HP) completely rebuilt (with +/- 300hr) and it runs no more than 9 knots.
It's depressing!!!!

Just out of curiousity...
How many RPM's do your engines reach max?
Which model are your drives?
What is the gear ratio in your drives?
What propeller size do you use?

Bjørn, dk

The reason for only 9 knots can be to much weight in the stern The Aqd32 weigth is almost 400kg (included the sterndrive), and you have two. So you have 800 kg Engine and only 212 hp in your boat.

the engines reach about 2.500rpm and I have 270 drives.

I don't know the gear ratio. How can I find it?

I also think that 212 HP can be not enought for the 2 engines weight, but this model (F24) became from usine with such engines.

I do suppose that the problema is indeed at the gear ratio of the drives but I can't find the correct ratio. I wrote to Volvo Penta at Sweden and they haven't any documentation about the se engines (they also don't know the correct proppeler!!!).

I will be very grateful to anyone who can help me.

Finding the gear ratio:
Put the gear lever in forward position.
Turn your engine by hand until propeller shaft has turned precisely one revolution. If engine has turned 1,65 times gear ratio is 1,65:1, if turned 2,15 times gear ratio is 2,15:1 . . . . .
Four cylinder petrol engines usually goes with 2,15:1, so if the boat has had these engines installed, that may be part of the problem. Also, the weight of the diesel engines and drives combined is 300 - 350 kgs more the four cylinder petrol engines. (B20s)(As mentioned by SÅL)

I don't know if you have cheked this, but the gear ratio should be stamped on the bearing box behind the zinkanod on the prop.shaft.
It could be stamped in real numbers or as a single letter B,C,D and E
B 1,61:1
C 1,89:1
D 2,15:1
E 1,45:1

Thanks.
I will try next time the boat goes to the mechanic.