Mercruiser 470 - Oil Baffles In Pan?

[Dunromin]

I rebuilt the engine on my 1982 470 last year, and ran it in gently, but it gave up a rod bearing last week, due I am told, to a lack of oil, and I'm in the process of rebuilding it again. I'm keen to avoid having to do this a third time, and a contact has suggested that the absence of oil baffles in the pan may be a factor, possibly causing oil starvation to the pickup in rough water. I don't know what to think, but I'm having a hard time believing Mercury didn't latch on to this, if indeed it is a design fault. I'd really appreciate other members thoughts on this, I am in a position to add them right now.

 

[stonyloam]

Re: Mercruiser 470 - Oil Baffles In Pan?

Occam's razor says that the simplest explanation (the least number of assumptions) is usually the correct one. In this case that would be oil pump failure. To assume that the oil was sloshing around enough that the oil pump was sucking air is pretty far out, and that it was sucking air long enough for the bearing failure to occur is even less likely. Baffles might be needed in a Baja racer, but I am not sure that they would help in this situation just IMHO.

 

[Lyle29464]

Re: Mercruiser 470 - Oil Baffles In Pan?

The head is a ford. Some of the older fords had too much oil to the top end and not enough at the bottom. Some of the ford go fast bunch would tap the oil passages and put carb jets in there. That took care of the high rpm oiling problems. How far is your pickup from the bottom of the pan?

 

[Dunromin]

Re: Mercruiser 470 - Oil Baffles In Pan?

Occam's razor says that the simplest explanation (the least number of assumptions) is usually the correct one. In this case that would be oil pump failure. To assume that the oil was sloshing around enough that the oil pump was sucking air is pretty far out, and that it was sucking air long enough for the bearing failure to occur is even less likely. Baffles might be needed in a Baja racer, but I am not sure that they would help in this situation just IMHO.

This sounds right to me, thanks for the help. I checked the oil pump a couple of days ago, found 10 thou clearance between the outer rotor and the pump wall. The manual specifies something closer to 1-1/2 thou. I already bought a cast iron Mellor replacement.

 

[Dunromin]

Re: Mercruiser 470 - Oil Baffles In Pan?

The head is a ford. Some of the older fords had too much oil to the top end and not enough at the bottom. Some of the ford go fast bunch would tap the oil passages and put carb jets in there. That took care of the high rpm oiling problems. How far is your pickup from the bottom of the pan?

Well, its apart right now, but its a standard pickup tube, and if memory serves, the filter head is about 1" to 1-1/2" fom the floor of the pan.

 

[Lyle29464]

Re: Mercruiser 470 - Oil Baffles In Pan?

Sounds good. Might see how the holes mate up where the oil leaves the pump and goes into the block. If your going to a high vloume pump check the distributor gear for compatibility.

 

[stonyloam]

Re: Mercruiser 470 - Oil Baffles In Pan?

Yeah I think all of the oil to the heads in this engine comes up through the lifters and pushrods, so even at max WOT, 4400 or so it would not be a problem.