964 low oil pressure

Flat6pac · 10-01-2009, 06:59 AM

Thats the way it came in as described. turned it on and immediately shut it down with no oil pressure.
# 6 cyl was damaged at the bottom but no picture of it.
Oil pump was hit by 3 rods and the top attachment boss was torn loose but the bottom 2 were tight
the inside of the case on the backstroke of the rod was nicked. on #2,3, and 6
Crank bearings and rod bearings were factory mint
The intermediate shaft was broken at the circlip and extension.
the pump did not injest metal, Ive seen that before
So the question is, What Happened?

JoeMag · 10-01-2009, 08:40 AM

can not see the pics... tried refresh too.

ischmitz · ischmitz's Garage

I am confused, too. How can a moving rod hit the pump if the pump itself was tight in the case and the rod bearing and crank bearings were all fine.

My uneducated guess is that the intermediate shaft broke (why?) and a floating piece got caught between the pump and the moving rods smashing the tab and the pump housing.

Another scenario is that something foreign or something that broke off elsewhere was floating around and got caught between the moving rods and the pump. And the shattering of the pump caused it to lock up and snap the intermediate shaft. Now the question is what was floating around in the crank case and where did it come from.

Ingo

Flat6pac · 10-01-2009, 05:35 PM

I opened the case and the ear off the pump was bolted down, I didnt even know it was broken until I removed all three nuts
Taking off #6 cyl I could tell it was hung up or distorted but not knowing why the oil pressure was considered low, thats what I was liiking for.
When I got the cyl off I could see the tracks along the center of the piston skirt was chipped by the crank. when I split the case then I saw the pump was damaged and I saw the backside of the case.
Bruce

BURN-BROS · 10-02-2009, 08:53 AM

Pics of the rods?

Fast Corners · 10-02-2009, 09:38 AM

As long as we are requesting, can we see a better picture of the intermediate shaft ends where it broke. I'm interested if the shaft breakage was caused by a manufacturing defect (stress riser) or if it just sheared due to the pump locking up (however briefly).

BURN-BROS · 10-02-2009, 01:58 PM

If there were aftermarket rods/bolts then there was the problem. There is very little room between the rod and pump. Additional clearancing would have been needed. Apparently the rods "clearanced" the pump, broke the mounting boss, damaged the pump more, and sheared the intermediate shaft.

Flat6pac · 10-02-2009, 07:27 PM

The rods did have 6 point nuts where I would have expected to see the smaller 12 point and there was some damage on the nuts and bolt on the very threaded end.
Bruce

prschmn · 10-03-2009, 07:38 AM

Somebody sneak a stroker crank in there?
Have seen the drive break because of restriction on the return side.

JoeMag · 10-03-2009, 06:05 PM

+1 for the maybe non-stock parts (maybe). fyi... when you buy carrillo rods they send you pic of where you need to modify the oil pump for clearance. The crazy thing is I would have expected you would have felt the rods hitting oil pump when you spun the crank after the case was sealed.

Flat6pac · 10-04-2009, 04:22 AM

The case had 574 sealant on it and it did not do a good job of sealing as there was old oil all across the top of the engine
The engine had cooked the oil for at least a couple years with the amount outside the center seam.
So, It wasnt just put together and run
Bruce