New Cam and Rockers - odd looking at 500+ miles

[z-ya]

Any 3/8 drill will spin the shaft fast enough to see oil from the spray bar alone, internally oiled cam alone, or both. Done it many times.Make sure you have the drill turning in the right direction. I don't remember what is the correct rotation, try both. You will know when you start sucking oil as the load on the drill will increase.

 

If you can't get oil to the top end with a drill, it's time to take it apart and find the blockage.

Edited September 9, 2013 by z-ya

[Lazeum]

I'm very sorry for this outcome

The root cause of your problem is most likely not in your cam but somewhere else. I would remove the head, disassemble it and check everything.

It seems damages were on the first 2 cylinders. Oil supply for the head is in the middle, most likely bottom end is fine otherwise you would have the issue accross all rockers.

I would pay special care on cam towers.

 

Open questions for all members: what would happen if clearance between cam & tower would be out of specs? What would happen if straightness/concentricity would be out of tolerance between same parts? 

 

I would also check oil, oil pan, oil pickup & oil pump to make sure they're in perfect shape.

Edited September 9, 2013 by Lazeum

[Tony D]

There is a feed port at the front of the block as well. Both need to be free and clear ... The middle one supplies the cam, the front is cam peripheral and chain.

 

Direction of rotation is indicated by your plug wires "153624"...

[NewZed]

For the money spent already, it probably would have been worthwhile to modify a valve cover with a plexiglass window to see what's happening while running.  Might still be.  Cold running only of course.

Edited September 10, 2013 by NewZed

[Lazeum]

There is a feed port at the front of the block as well. Both need to be free and clear ... The middle one supplies the cam, the front is cam peripheral and chain.

 

Direction of rotation is indicated by your plug wires "153624"...

That's a very valid point.

I believe a very careful & methodic approach should be taken to find the root cause. It almost means engine removal and analysis on stand to me.

[HowlerMonkey]

I've seen guys get debris down the oil supply hole on the deck which then get's pushed by the oil and could be restricting flow somewhere downstream.

 

You would be surprised how much stuff from the 3m wheels people use will go down a hole.

[NewZed]

After reading the various cam destruction threads over the past few years, if I ever install a new cam I'll leave the rocker arms off and spin the engine with all valves closed before starting.  Probably build a little aluminum foil shield to direct any spray then check each lobe for flow.  Or even cut a plexiglass tube lengthwise to allow viewing as the cam turns.  Confirmation of flow before applying any pressure to the cam or rocker arms.  If it still gets destroyed at least the oil supply question will be clear.

 

Inline, you could still do that if you haven't taken things apart yet or taken a sledge to it.  It would tell you something.

Edited September 12, 2013 by NewZed

[madkaw]

http://www.classiczcars.com/forums/engine-drivetrain-s30/23392-cam-oiling-investigation.html

[clarkspeed]

You have a big problem somewhere that has nothing to do with internal vs. External oiling of cam. Even a small amount of oil pressure up top should prevent this damage. Either a blockage or path that allows oil to escape. Does the cam have the ends plugged?

[inline6]

You have a big problem somewhere that has nothing to do with internal vs. External oiling of cam. Even a small amount of oil pressure up top should prevent this damage. Either a blockage or path that allows oil to escape. Does the cam have the ends plugged?

 

 

I had to pay $100 just to have the rear of the new cam drilled/tapped for an NPT plug which I did before assembly this second time around.  Front is sealed by the cam gear bolt of course. 

 

I'm in the middle of moving this weekend, so I can't do much with the car at the moment.  Rocker arms have been removed but the cam is still in the engine.  I am on the lookout for the pressure outfit my builder is sending me. 

 

Garrett

[Xnke]

How do the bearing surfaces look? Any scoring or marks in the top-side of the cam towers?

 

Two cams failing this way, something's not right in the lube flowchart.

 

Low spring pressure, clean fresh rockers, good wipe pattern, cam and rockers lubed with a good moly disulfide lubricant, quality oil, 2000RPM break in speed with good oil pressure in the block...All the checkmark things to break in a flat tappet cam.

 

Gotta be a lube flow problem, I think.

[inline6]

Finally got moved and had a chance to hook up a pressure kit.  I put a quart or so into the small tank and pressurized the tank to 120 psi.  Didn't take the best video footage on the first one.  Second one was much better.  With the second video, I had an estimated 80 psi left in the tank.  The spray bar is clearly useless. Take a look:

 

Video 1:

http://www.youtube.com/watch?v=rXAo8S7Wetc

 

Video 2:

http://www.youtube.com/watch?v=sFZM4P1Dfqo

 

So...  Is that enough flow?

[Xnke]

Yeah, your spraybar is totally broken. I run both the spraybar, and the drilled cam, and right now both the restrictors in my block have only been opened up 0.010" diameter over stock. I have oil streaming out of my spraybar at idle, at 15PSI of oil pressure.

[NewZed]

  I put a quart or so into the small tank and pressurized the tank to 120 psi.  Didn't take the best video footage on the first one.  Second one was much better.  With the second video, I had an estimated 80 psi left in the tank.

Still seems like you have too much restriction between the main head supply passage and the oil pump. 

 

Since there's a restriction at the head/block interface there should really be another measurement point in the head to show if the cam is getting proper oil pressure.  Pressure is generated by restriction to flow.   If you could measure there you'd probably get a low number.  Did you get a pressure reading from the car's gauge, showing what it was in the main gallery, or just have 120 psi in the tank?

 

And did you plumb in to the center port to the where the oil filter mounts to pressurize and feed the oil?  Not really clear.  Seems like 120 psi would blow oil all over the place, even cold, if it was the main gallery at 120. 

[z-ya]

I agree with NewZed above. You have a restriction between the head and the block. When you put it together did you check that the head gasket didn't restrict either of the oil feed holes in the block? If not, then the restriction is either in the block or head. At 80 psi oil should be going everywhere from both the drilled cam lobes and the spray bar. When I use a drill I get a good 1" stream coming from both the spray bar and the cam  lobes.

[inline6]

Still seems like you have too much restriction between the main head supply passage and the oil pump. 

 

Since there's a restriction at the head/block interface there should really be another measurement point in the head to show if the cam is getting proper oil pressure.  Pressure is generated by restriction to flow.   If you could measure there you'd probably get a low number.  Did you get a pressure reading from the car's gauge, showing what it was in the main gallery, or just have 120 psi in the tank?

 

And did you plumb in to the center port to the where the oil filter mounts to pressurize and feed the oil?  Not really clear.  Seems like 120 psi would blow oil all over the place, even cold, if it was the main gallery at 120. 

 

I took the oil pressure sender out and used that hole in the mail gallery for the tank supply location.  I did not measure psi while operating it.  I have a regulated air supply from my compressor that I set at 120 psi when I filled the tank.  I also have a 60 psi air gauge.  Just before doing the second video, I measured the pressure in the tank, and judged it to be about 80 psi by the amount the needle was past 60 psi. 

 

During the 20 minute run with fresh cam and freshly re-ground rockers I saw 70 psi coming from the oil pressure gauge - this being read from the oil pressure sender which was in the stock (and same) location in the block.  I have no idea what oil pressure the head is seeing.  I might be able to remove the npt fitting at the back of the cam (I had one installed there instead of a press fit plug) and rig some kind of pressure gauge there to see what I've got for oil pressure inside the cam.  

 

Would that be helpful?  Does anyone have a good number for me to compare to?  I can regulate the tank pressure to 70 psi or whatever and then get a number for pressure at the cam...  

Edited October 18, 2013 by inline6

[NewZed]

I have an engine on a stand (old used JY engine), with a mechanical gauge in the pressure sender hole, so went out and hooked up a battery to the starter, pulled the spark plugs and the valve cover, and gave it a spin.  It spun for about 20 seconds before any oil pressure showed on the gauge.  20 seconds seems like forever watching a fairly dry cam spin with no oil supply, especially after reading threads like this one.  The engine has been sitting for months since I last started it.  Oil pressure finally came up to 20 psi, with the slow RPM of a gear reduction starter.  Once pressure came up, oil flowed freely from the internally oiled camshaft, stock N47 head, but did not shoot out, only caused an oil bump on the cam lobe about as big as the bumps in your first video, maybe even a little bigger.  Looked like more flow at 20 psi than yours.  The engine wasn't even spinning fast enough to fling the oil off of the camshaft either.  So, basically, at 20 psi through the oil pump, I was getting what looked like about your oil flow rate, or better.  The above should give people with gear reduction starters on new engines something to think about.  They don't spin fast and don't build pressure fast so the cam will be dry for a while if the engine doesn't start right up.

 

I'd take a video but also found that the drain back holes on top of the head are pretty small and the oil would rather run over the edge, so I had to put the valve cover back on to avoid a mess.  Think of it as I pumped more oil than could drain back through the small holes in the top of the head.  At 20 psi.

 

Hope that gives you more to think about.  I would run your test again but at about 20 psi to see if any pressure builds in the camshaft at all.  If there's not enough flow to fill the camshaft and build some pressure at idle, braking or sitting on a hill could leave one end of the shaft dry.

 

 

Edit - sidenote - looking around about gear reduction starters I see that many people say that they spin the engine faster.  I don't see how you can have higher torque and higher speed, that seems incorrect.  Regardless, my engine was spinning slowly.

Edited October 19, 2013 by NewZed

[NewZed]

Another thought - since you have a way to push oil and you're thinking about pulling the threaded plug on the camshaft, you might run some oil backward from the camshaft down.  Maybe there's debris blocking the jet in the top of the block and you can push it back down.  You'll want to make sure you divert the oil out from the head supply channel so the debris doesn't travel down to the crank bearings.  I get the impression you're avoiding removing the head so that might offer a solution.  Good luck.

[Tony D]

Do you have "head saver" shims under the towers? Without an oil hole perhaps?

 

I see more oil flung off than in your video. Ugh....

 

Are you running a non-bypass oil filter that is restricted (stock will be pretty plugged before lifting and bypassing dirty oil to bearings. You would thing bottom end bearings would be affected...have you inspected a random main or rod bearing to make sure the bottom end is not similarly being starved / affected? I recall bleed over from the sides of the cam bearing journals...I don't see that on your video, either. Is this a Japan cam core? The spray bar gets fed from the galleys feeding the cam journals...are the gaskets there perforated? No RTV was used during assembly was it?

 

I had an old fire extinguisher that I would fill engines with....put 80-120 psi in the thing after a full charge of oil. We learned to keep the oil cap on charging the sump by putting it in through the oil pressure sender hole, it would spray out pretty good.

 

As stated above, what is going on down below? There appears to be a restriction going to the top end...you say the pressure gauge gave 70 PSI during the run.... But that is all upstream of the filter. Is it possible lower end is sloughing off enough flow through excess side clearance or something in the bearings that there simply isn't any flow remaining for the to end? The priority oiling is the mains and rods.... If they're hosing oil, there simply may not be enough left for up top.

 

The common link is the filter in both scenarios.... Has it been changed? What can you tell us about the filter you are using? Along with oil weight?

Edited October 19, 2013 by Tony D

[HowlerMonkey]

My thought is that debris went down the oil supply hole when the block surface was cleaned and was pushed back up by oil pressure until it ran into the gasket and got stuck there causing a restriction.

Edited October 19, 2013 by HowlerMonkey