OFHs Oil Flow Pathways For The Engine (Questions)

[jnf63]

I have a few specific questions about the oil flow pathways concerning the oil filter housing and the engine (not necessarily the head). Please, refer to my picture because I find it difficult to explain my inquiry.

I would like to know how the oil moves between the OFH and the engine regarding the orifices labeled #1 to #4. I would like to understand whether the oil moves from the OFH to the engine, or if oil moves from the engine to the OFH, for each labeled orifice. Also, for the orifices where oil flows to the engine, could it be explained where specifically in the engine that the oil flows (as in to the crankshaft, to the block area, to the bearings, or to ?). The only orifice that seems obvious (to me) is the one labeled #1, yet I am uncertain whether this orifice flows to the engine block area, or from the block area (I “assume” all the orifices flow to the engine from the OFH,…but, some may not, or some may be useless/unused).

After searching, the only information that I found was this Engine Lubrication diagram. However, it lacks showing the specific things that I am trying to understand.
Thanks,
Jim

 

[19Eclipse90]

#1 is the oil pressure relief valve. It opens when oil pressure gets too high and returns it to the oil pan.
#2 is unfiltered oil from the oil pump.
#3 is filtered oil to the engine.
#4 I'm not totally sure.

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This is a 6-bolt block but the 7-bolt is similar enough. The oil pump pulls the oil from the pan through the strainer and sends it along the block (behind the front cover/case) in the channel to the oil filter housing (your #2). Once the oil filter is done doing its job, it flows out of the housing (from #3), up to the main oil gallery just to the right of the front balance shaft hole. From there, your front balance shaft bearings are lubricated as well as your main bearings (and by association, your rod bearings). The flow continues from that main oil gallery up into the head by the passenger-and-exhaust-side-most head bolt hole.

 

[jnf63]

Brian,
Thank you for your excellent explanation! Your picture definitely strengthens your explanation. I have given you well deserved reputation points.

To illustrate my understanding of your picture and description, I labeled (numbered) the corresponding pathways. Also, when I used a wire to attempt tracing the pathway of orifice #4, it seemed to simply be an indentation that went nowhere.
Jim

 

[19Eclipse90]

Glad to help, Jim.

I wanted to say I didn't think #4 went anywhere. The front cover/oil pump that came off the 6-bolt I pictured above is relatively clean in that area compared to the rest of the piece. It doesn't show signs of oil passing through it at all where as the area for the oil pressure relief valve (which is just to the right of it) is brown-ish from use. It sounds like that is correct though, with what you have tried. Anyway, your labeling is correct.