Thread: Are we sure regular SR20DE engines don't have piston oil squirters?

I've got your piston oil squirter!

Your question about the wrist pin lubrication can be found in the FSM, here.


Here you can see how the arrows are labeled by Passage, Gallery, By passage and drain. Take a look at the connecting rod bearing to the connecting rod shows the oped wide arrow which is a passage. In other words crank supply's oil to the bearing, then oil passes through the bearing to the connecting rod and from there the squirter. Then from the connecting rod to piston, wrist pin, and cylinder wall, you see a solid arrow representing "drain". Well oil doesnt drain upwards, so how it is being described is the piston, wrist pins, and cylinder wall are all lubricated by the squirter on the rod.

That's where my money is too. It seems to a be a combination piston/wall squirter. I'd still like to see how much of each it does by determining the direction of the spray.

What goes up must come down.

This is pretty interesting and I am glad this topic came up because I have a set of aftermarket rods that I was going to use in my next build. And if what you find Ben shows that it is more beneficial to have OEM rods over aftermarket, I'm going to stick with OEM.

Out of curiosity, does the rod bearing oil hole line up with any holes on the connecting rod? If it does, it would lead me to believe that the spray is momentary vs constant.

No. I could be wrong, but I'd venture to guess this hole design is nothing specific or new to Nissan and is probably on a lot of cars from a lot of different manufacturers. In other words, nothing too special. Piston oil squirters are not on every engine and are a pretty specific part. I'd propose a new word for the rod oil sutation instead of 'piston oil squirter'. Maybe 'cylinder oil spreader'. I'd say it spreads, not squirts oil. The oil squirters are an active design w/a spring and this is much more a passive system.

-G

I think it's safe to say if a rod doesn't have an integrated oil squirter and it's going into an engine without dedicated oil squirters, you're flirting with some form of disaster. You'll find this PM interesting I'm sure:



The spray is going to be constant, and at all RPM and oil pressure (whereas the dedicated oil squirters we know and love have valves to keep them closed at low RPM and low oil pressure where the spray isn't really needed so oil pressure is there where and when you need it).
The hole lines up with a hole in the bearing, which always has oil and pressure riding all around it, escaping from the integrated oil squirter at all times.

I don't think it's specfic to Nissan either, and I agree it's probably on a lot of cars from a lot of different manufacturers. I don't see why we would call it anything else but an oil squirter though. That's what the Izusu crowd calls theirs, and that's exactly what it does. Just because Nissan improved the design and added dedicated units with valves on some of their later engines doesn't make the originals any less of an oil squirter.

Now where they actually are aimed is maybe still up for debate.


My 2 cents of course.

Izusu crowd? hmmph! Only if Izusu AND Daewoo crowds call it the same should we all. I know Izusu carries a ton of weight in the car world, but w/out Daewoo's help I don't see the name catching on w/all of us

-G

Here is an image of a Mitsubishi 3000GT/Dodge Stealth connecting rod with oil squirter. A piece of broom straw in the oil squirter on the left rod shows the direction of spray. Without knowing how it looks in motion, this looks like a good combination of wall and piston spray. The engineers seemed to be aiming for a 50/50 distribution as the crank rotates and angles change.




Looking at the DE piston I have I'm positive now the Nissan engineers made no such compromise and went for a straight shot to the piston bottom. I need to buy some angel hair pasta...