Author Topic: Repower Bavaria 33 Cruiser  (Read 857 times)

Cabtrack

  • Cadet
  • *
  • Posts: 20
  • Karma: +1/-0
  • Boat Model: 33 Cruiser
  • Boat Year: 2005
Repower Bavaria 33 Cruiser
« on: April 08 2024, 09:14 »
Hi All
       Just wondering if anyone has upgraded there 20hp motor on a Bavaria 33 cruiser to a 30ph. If so was it worth it or not.

symphony2

  • Old Salt
  • *****
  • Posts: 473
  • Karma: +10/-0
  • Boat Model: B33
  • Boat Year: 2015
Re: Repower Bavaria 33 Cruiser
« Reply #1 on: April 08 2024, 10:15 »
Assume you have a D1 20. Fitting a D1 30 would be straightforward, but really not necessary. The 20 starts to struggle when displacement exceeds 5 tonnes (your boat is around 4 tonnes) and the limitations are mostly to do with performance at 6 knots+ in heavy conditions. If the engine is in good condition difficult to justify spending £6k+ (UK prices) on a new engine. If the engine is shot then different question as the marginal cost of the bigger engine is small.

Cabtrack

  • Cadet
  • *
  • Posts: 20
  • Karma: +1/-0
  • Boat Model: 33 Cruiser
  • Boat Year: 2005
Re: Repower Bavaria 33 Cruiser
« Reply #2 on: April 08 2024, 10:37 »
HI SYMPHONY2
                     We are on the heavy side and have a larger alternator. We have found we now struggle to do 6 knots. It really struggles in any chop or head wind.

symphony2

  • Old Salt
  • *****
  • Posts: 473
  • Karma: +10/-0
  • Boat Model: B33
  • Boat Year: 2015
Re: Repower Bavaria 33 Cruiser
« Reply #3 on: April 08 2024, 12:04 »
The alternator does not make much difference in normal running. You should be able to get 7 knots in flat water with the standard propeller. The displacements I quoted are based on design displacement and engine/prop sizing makes allowance for the extra weight of cruising gear, usually in the region of 800-1000kgs. I don't remember your model ever being offered with the D1 30, although later and heavier 33/34 footers were. I had a 2015 B33 (5500kgs) with a D1 30 that comfortably exceeded hull speed 7.4knots

Just to double check - is your engine a 2020 or a Di 30? as 2005 was the changeover year for engines. The newer engine already has a 115A alternator compared with the 65A of the 2020. What type and size of propeller do you have? as this can make a difference to performance.

Cabtrack

  • Cadet
  • *
  • Posts: 20
  • Karma: +1/-0
  • Boat Model: 33 Cruiser
  • Boat Year: 2005
Re: Repower Bavaria 33 Cruiser
« Reply #4 on: April 08 2024, 12:35 »
The motor is a 2020 the prop is a 3 blade folding on 130s saildrive

Yngmar

  • Administrator
  • *****
  • Posts: 1532
  • Karma: +18/-2
  • Boat Model: 40 Ocean
  • Boat Year: 2001
Re: Repower Bavaria 33 Cruiser
« Reply #5 on: April 08 2024, 18:48 »
A 100A alternator can take 3-4 horsepower, which may actually make a difference on a 20 HP engine. You can fit an on/off switch on the field current for the alternator (not on the output!), so in those situations you can switch it off and use all the engine power for propulsion (at the cost of zero charging output). Probably will have to also switch the alternator alarm at the same time, if your engine panel has that.
Sailing Songbird  ⛵️ Bavaria 40 Ocean (2001)

tiger79

  • Old Salt
  • *****
  • Posts: 903
  • Karma: +9/-4
  • 2014 Cruiser 37
  • Boat Model: Cruiser 37
  • Boat Year: 2014
Re: Repower Bavaria 33 Cruiser
« Reply #6 on: April 08 2024, 19:20 »
A 100A alternator can take 3-4 horsepower, which may actually make a difference on a 20 HP engine.

Unless he has a humungous battery bank, the alternator's unlikely to be outputting anything like 100A.

symphony2

  • Old Salt
  • *****
  • Posts: 473
  • Karma: +10/-0
  • Boat Model: B33
  • Boat Year: 2015
Re: Repower Bavaria 33 Cruiser
« Reply #7 on: April 08 2024, 23:54 »
The motor is a 2020 the prop is a 3 blade folding on 130s saildrive

That is a non standard combination and you may need to revisit your 3 bladed folder prop. The 2020 was normally fitted with the 120 drive which has a reduction of 2.47:1. The engine is rated at 3600rpm which gives a shaft speed of 1457rpm. The D1 engines are rated at 3200rpm and the 130 drive was given a a reduction ratio of 2.19 to keep the shaft speed the same at 1461rpm so the same propeller sizes would suit. Your boat was built during the changeover period when the drive change came in before the engine change so will have been fitted with a non standard fixed propeller as with the later drive it has a shaft speed of 1658rpm so needs either a smaller diameter or flatter pitch. Your folding propeller may be to "large" which might explain why you only get 6 knots. Suggest that you do a series of runs in flat water at 200 rpm intervals from 2000rpm up to the maximum. If the prop is right then you should get around 5.5 knots at 2400rpm and 7 knots at between 3400 and 3600rpm.

Just to emphasise the difference the reduction ratio makes, a fixed 3 blade prop for a 2020/120drive would probably be a 14*9 and a 2020/130 a 14*7. The factory fit would probably have been a 2 blade 15*7. These are only indications particularly for the folding props as they have different blade areas and shapes so are often different from fixed props.

The key message is that you need to use every bit of hp the engine can produce as for hull speed (7.2 knots) needs just over 21hp. So if your prop is restricting revs you are not accessing the maximum hp and will struggle in adverse conditions. Of course increasing power by 50% will enable you to easily exceed hull speed and reduce rpm at cruising speed but it is big expense when the boat is not massively underpowered.

First thing is to check that you definitely have a 130 drive - split anodes is the major indicator then run the speed/rpm test and revisit the propeller if you are not getting the sorts of revs and speeds indicated above.

I went through exactly this process when I replaced the 120 with a 130 on the 2030 in my 2001 B37. In that case we fitted a 16*11 2 blade folder instead of the 16*12 fixed.

BTW I have had both a 2030 and a D1 30 both from new and on balance I have a preference for the older engine, although there is nothing really negative about the D1 and it does have some nice features like the bigger alternator. I found it a little less refined in my newer B33

Hope this helps.

Cabtrack

  • Cadet
  • *
  • Posts: 20
  • Karma: +1/-0
  • Boat Model: 33 Cruiser
  • Boat Year: 2005
Re: Repower Bavaria 33 Cruiser
« Reply #8 on: April 09 2024, 00:15 »
Definitely a 130s sail drive with a 3 blade prop folding.

symphony2

  • Old Salt
  • *****
  • Posts: 473
  • Karma: +10/-0
  • Boat Model: B33
  • Boat Year: 2015
Re: Repower Bavaria 33 Cruiser
« Reply #9 on: April 09 2024, 13:38 »
OK So worth doing the test runs and checking the size of the propeller. If you do progress the re-engine route then suggest you consider the Beta 25 betamarine.co.uk/portfolio/beta-25/ which would be a much better match for the boat. Beta can supply with an adaptor plate to go onto the 130 drive and feet to fit the Volvo front mounting points.

JEN-et-ROSS

  • Old Salt
  • *****
  • Posts: 307
  • Karma: +3/-0
  • Boat Model: Bavaria 38 Lagoon
  • Boat Year: 1990
Re: Repower Bavaria 33 Cruiser
« Reply #10 on: April 09 2024, 16:31 »
 I concur with Symphony2..........
Below is an extract from a post we made a while back regarding Beta Marine and the excellent service they provided


"When we replaced the old VP 30hp, we mated it onto the existing 120 type saildrive, partly because when we commissioned a pre-purchase survey, the surveyor noted that the 120 was much younger than the engine....
As the old engine was low hour, and had simply succumbed to the corrosion that the raw water cooling system had inflicted.. We decided to keep the saildrive..
We shipped the saildrive to BETA for inspection and for them to mate the new engine to the saildrive in the factory..
This they did to ensure a proper fit, then test run the complete unit, separated them and shipped the new B30 and 120 back to us for installation..
They even sprayed the gearbox the same red colour as the engine....
This was done at minimal expense.......Great service from BETA MARINE.".

Cabtrack

  • Cadet
  • *
  • Posts: 20
  • Karma: +1/-0
  • Boat Model: 33 Cruiser
  • Boat Year: 2005
Re: Repower Bavaria 33 Cruiser
« Reply #11 on: April 10 2024, 09:47 »
I shall test this weekend weather permitting

Diverphil1

  • Cadet
  • *
  • Posts: 9
  • Karma: +0/-0
  • Boat Model: 33c
  • Boat Year: 2006
Re: Repower Bavaria 33 Cruiser
« Reply #12 on: April 20 2024, 19:14 »
We have a 33c 2006 originally fitted with a d1-30 as an upgraded choice when new. So that should go straight in as a swap.