Bavaria 37 RPM limit problem

[Andriy]

Hi Owners,
Has VP D 1-30. As per manual RPM must be 2800-3200. At idle boat give around 3000 but during sailing max 2200 which was not enough to resist in 5 bofforts wind. Hull has no sea growth. Engine is after overhaul. Charter Company claim that is normal...
Pls advice your opinion.

[Craig]

I have a D1-30 on my Bav 38 ( 2010 model year).

In neutral the engine easily revs to 3000 rpms. If I engage gear and motor forward while tied up in the marina, I can only get about 2400rpms. If the boat is in calm conditions and at sea, at full revs it easily gets to 2800rpms.

The size of prop you have may be limiting your speed. I have a 3 blade folding prop.

Otherwise, the limit on speed may be a fuel issue. Are you seeing black smoke come from the exhaust?

Craig
"Shirley Valentine"
Gold Coast
Australia

[Kibo]

I see your other post about oil/coolant contamination. I agree with the possible head gasket diagnosis and suspect that if true your two problems my be connected. Loss of compression due to head gasket failure could lead to lower power even at high RPM. Also your assertion of 2800 - 3000 rpm being normal is outside my experience. I owned a 2010 Bav 35 with 35 HP engine and never needed to push it past 2000rpm at any time, loaded or not, and never had any issues pushing the boat through force 5 winds/sea state. You say the charter company says the issue you have is "normal" ... I really doubt that to be the case from what you have shared so far. Good luck with it but it sounds like you might have an issue with your engine.

[Moodymike]

Sounds like blocked exhaust elbow.

[tiger79]

Sounds like blocked exhaust elbow.

That doesn't sound logical. If the engine will rev to 3000 out of gear, the exhaust elbow must be fairly clear.

[Nigel]

... Charter Company claim that is normal...

I think we need to establish if this is your boat or a charter.

Possible causes of lack of revs at WOT: oversize or fouled propeller, fuel starvation, air starvation, exhaust blockage ...

[Lyra]

Quote from: Moodymike on Today at 11:24

    Sounds like blocked exhaust elbow.


That doesn't sound logical. If the engine will rev to 3000 out of gear, the exhaust elbow must be fairly clear.

I experienced the same thing - at neutral there was no problem to reach 3000 (actually when the elbow is clear you should be able to get well above 3000 in neutral), and when engaging the engine would not rev up.

But, a blocked elbow would also give the following signs:
Problems to start a cold engine
When it finally turns on - black smoke for several seconds and signs of black soot on the water under the exhaust

[Wayne]

Had the same problem. Eventually traced to a blocked elbow. The exhaust was "spitting" black soot like gunk onto the water and I was lucky to have 2000rpm. Had the the elbow replaced and problem fixed.

Wayne

[Jackho]

 D 1-30 ON My boat matches Volvo Spec. Max revs 3200 with  Volvo 3 blade folding prop.  Any more or less at max. revs when motoring suggest prop not ideally sized.  (Accepting other issues may be involved as suggested.)

[Impavidus]

You may want to read this thread........... http://www.bavariayacht.info/forum/index.php/topic,1413.msg8128.html#msg8128

[Andriy]

Tday my charter Company report that they have put 3 blade prop instead of 2 blade and it might be the reason. Anyway in the manual says that max torgue for D1-30 is at 2200 which actually boat gives. Thank you for the advices !

[Symphony]

Tday my charter Company report that they have put 3 blade prop instead of 2 blade and it might be the reason. Anyway in the manual says that max torgue for D1-30 is at 2200 which actually boat gives. Thank you for the advices !

That is wrong. If the prop is the correct size then the maximum revs is in the range of 3000-3200. volvo will not sign off an installation for warranty without achieving a minimum of 3000 rpm. The propeller fitted at the factory will achieve this.

Just having a 3 blade prop will not necessarily reduce the maximum revs. It is the pitch and diameter that is important. If the prop is so oversized that the engine will only rev to 2200 rpm the engine will be wrecked very quickly.

Tell them to change the prop back to the original size that was fitted at the factory.

[Kibo]

Symphony I don't think he said that max rpm is 2200 he said "max torque is at 2200 as manual says"   I do agree however that simply changing to a 3 blade prop without knowing pitch and dia is not sufficient info.... 

[Symphony]

Symphony I don't think he said that max rpm is 2200 he said "max torque is at 2200 as manual says"   I do agree however that simply changing to a 3 blade prop without knowing pitch and dia is not sufficient info....

See the original post. His engine will not rev higher than 2200 rpm. The maximum torque figure is irrelevant. The boat should be propped to achieve a minimum of 3000 (out of a governed maximum of 3200).

[Kibo]

Ok thanks