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Series 41 P-A Engine, 6 Cylinder

pvbudx

New member
Question: What series Volvo would be appropriate to replace a model 41 P-A, Stern Drive ? This considering mounting an physical size of the replacement engine.

Thanks for your information.

pv
 
D4 would be the closest current model. You can get the hp from a D3, but they are a problem engine even at 190hp, let alone at 200hp+. A lot depends on why you are looking at changing. A proper rebuild on the 41 will probably last a long time and at a fraction of the cost of a new D4. D4 will be a little more fuel efficient and less smoky, but they are not cheap.
 
D4 would be the closest current model. You can get the hp from a D3, but they are a problem engine even at 190hp, let alone at 200hp+. A lot depends on why you are looking at changing. A proper rebuild on the 41 will probably last a long time and at a fraction of the cost of a new D4. D4 will be a little more fuel efficient and less smoky, but they are not cheap.

Aliboy: Thank you for the helpful information. At this point we are considering options about the AD41. We agree that a rebuid , if necessary, would be much more economical and would serve our needs.

We have a puzzling situation. At speeds below 3100RPM we have no oil problem. However, when we run above 3100RPM (not frequently) we get lubricating oil in the bilge. We cannot determine why or where the oil comes from. There is no oil breather filter on the engine, there is no oil in the air filter intake, no evidence of excessive oil in the breathing tube leading out of the valve cover to the air filter an no splash on the side of the hull.

Any thoughts?

pv
 
Sounds a bit strange. Is it at the back of the engine? Could it be from the rear oil seal on the crank? Oil gets hotter and under more pressure at higher rpm's, so where else can it come from that isn't visible? Another thought, check the sealing at the base of your dipstick tube. We fixed an oil leak on a KAD32 that took ages to find and found that the dip stick tube wasn't sealing to the block properly.
 
Sounds a bit strange. Is it at the back of the engine? Could it be from the rear oil seal on the crank? Oil gets hotter and under more pressure at higher rpm's, so where else can it come from that isn't visible? Another thought, check the sealing at the base of your dipstick tube. We fixed an oil leak on a KAD32 that took ages to find and found that the dip stick tube wasn't sealing to the block properly.

Aliboy, thanks again for taking time to help with our problem.

We will check on the dip stick tube, never thought of that! We cannot see the stern portion of the engine so we are not yet able to learn the source of the leak, or why it's only at high RPMs.

Also, we have noted Lasse's post about his oil leak at the Oil Filter Housing on his 41B, year model 1991.

All the best.
pv
 
May I suggest a weird idea... Stay dry anti persperent spray. If you can find it use a similar product.
Put it on thick, it leaves a white powder coating, which after it dries will stain with any oil contact.
As for reproducing the problem, IMHO you have to have load and rpm. Take it for a hot run, maybe with the
front valve cover off so you can see the oil distribution to the front rockers. If you cant access the rear part
of the engine this might be a easy starting point to rule out excess oil pooling.
 
I have had a number of oil problems with my AD41a.
Are you sure that there is no breather filter fitted, a silver cylinder at the back of the engine near the air intake filter.
My engine is breathing heavily, raising the crankcase pressure. What happens is that the filter gets clogged and the AD41 has a couple of relief valves at the back of the engine. There are a couple of areas the oil can collected in (without you seeing it), then you turn sharply and all of a sudden what seems like a lot of oil is in the bilges.
My suggestion is check for the filter and change it, they get clogged easily and always cause an oil leak problem when they do.
Good luck.
 
Rob,
If there s an oil breather filter we have not found it I have owned this boat for more than 10 years and neither professional working on it, over the years, has mentioned have identified an oil breather filter. The rear (sterndrive) portion of the engine is impossible to view even with mirrors.

Apparently your 41 has such a breather filter.

"Relief valves" are another item that have not come to my attention. I'll look into both of the subjects that you mention. Thank you.
 
Of course I could be wrong about your engine! Attached is a picture that is similar to my engine, the oil breather filter is the silver cylinder near the air filter. Of course your engine could be different.
The relief valves only operate if the crankcase pressure gets too high, otherwise you would have no reason to be aware of them, they are not a service item.
Good luck.maxresdefault.jpg
 
Of course I could be wrong about your engine! Attached is a picture that is similar to my engine, the oil breather filter is the silver cylinder near the air filter. Of course your engine could be different.
The relief valves only operate if the crankcase pressure gets too high, otherwise you would have no reason to be aware of them, they are not a service item.
Good luck.View attachment 9797

Rob,
Thank you for the photo. Can you describe where the "relief" valve may be? I cannot locate a provision for one on the various engine diagrams.
PV
 
Hi, Not sure if I know exactly, but they are certainly at the back of the engine, at the top. Sorry I cannot give you anything more.

Interestingly, when I Googled the engine to get the pictures, I did see a couple that did not have the Breather filters, so maybe your engine deals with it differently.
 
Sounds a bit strange. Is it at the back of the engine? Could it be from the rear oil seal on the crank? Oil gets hotter and under more pressure at higher rpm's, so where else can it come from that isn't visible? Another thought, check the sealing at the base of your dipstick tube. We fixed an oil leak on a KAD32 that took ages to find and found that the dip stick tube wasn't sealing to the block properly.

Aliboy: I think that you identified the problem. I have noticed 1 /4 -1/2 cup of engine oil in a small pool or crevice formed where the after cooler joins the block at the rear of the engine, the end opposite the raw water pump. If, indeed, the rear crank oil seal is leaking at 3,300 RPM, a question: Is the only solution to remove the engine from the boat to make repairs? Is there any other magical solution?

pv
 
If the rear oil seal is leaking it would be leaking inside the bellhousing and leak from there externally somehow. Could that leak get onto the area where you spotted the oil? If it is the rear crank seal I would think that you might see oil sprayed up onto the gear end of the starter motor as the flywheel flings it around. Have you pulled the starter motor and checked it for signs of oil on the end? To replace the rear seal if it is that, you will need to either move the engine forward or pull it right out. In reality I think you should pull it right out as anything else is going to be very difficult.
 
Dear Aliboy and Skiss, and others.

You guys are just great! Your helpful ideas keep me going.

I have two 41 P-A Volvos and I still find oil in the bilge after operating at 3,300RPM's, both engines (installed in separate compartments). There is no oil in the bilge if run at 3,000RPM or lower. I usually run a 2.700 to 3000 RPM's. I want to locate the source of the oil leak and will keep you informed.

Thank you for your replies and thoughts.
pv
 
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