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Discussion Starter #1 (Edited)
Everyone knows that D16Y8 motors are nortorious for spun rod bearings. There's not even a TSB for this problem. What are TSB's exactly? I've owned one of these motors with a spun bearing ( I bought it spun). I've been doing a little research and comparing the D16Y8 pump to other pumps and I have came to this conclusion.

The Y8 pump has a displacement of 8. something. Its not because of its ports, not being shimed, or because it only has one oil hole per crank journal for the mains and rods. Its because of the oil pumps rotors. The displacement of a pump is determined by its rotors. The Y8 pump has smaller rotors then the A6 and Z6 pump that have a displacement of 11.9.

Theory.
That they used this smaller displacement pump to reduce parasitic load, but the pump falls short of the amount of oil thats needed to lubricate the engine properly. Porting and shimming the pump isn't going to do anything. The pressure relief valve is only going to open if there's its relief pressure present, which isn't possible if there isn't enough flow which is the case. And I don't see any significant restrictions in any of the ports.
 

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Well bud, we know how to fix the problem...shim and a DIY port job to increase flow. The oiling holes, now that's not a pump problem but a manufacturers error in design.
 

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Cuz I'm leaving the office is a few I won't search...but this number jumps into my memory : .020 SS washer
 

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.025-.035 will give you a decent bump in pressure, i got the flow rates from the 92-93 manual, and the 96-2000 manual.

The rotors are the exact same with the z6/y8 the only difference is the casting of the alluminum housing shimming and porting will solve this issue, and you can swap out the 93-95 crankshafts (with the dual oiling holes) for better lubrication (Except on the y8's they have a larger crank snout, unless you have the crank pulley to go with it).
 

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my name says Guest, but Im really a MEMBER
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Discussion Starter #7 (Edited)
wait, the y8 pump has a larger snout? then I can't even use the y8 pump on my 1.5 CX motor. so only the z6 has the dual holes??

you know what I'm thinking, using the cx pump and tapping it (if possible) for the crank fluctuation sensor. o yeah, but if the snout bigger the triggering wheel/sprocket would fit loose.
 
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