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New Cam and Rockers - odd looking at 500+ miles


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As far as time for oil to show up top after rebuild or pump, my Mitsubishi 3000gt vr4 that I rebuilt never showed oil up top until I got impatient and simply started.

 

Upon starting, I got almost instant oil pressure and a check of the vr4 forums showed similar stories.

 

What I took from that experience is that a liberal amount of super slick assembly lube combined with the substantially higher rpms encountered by running the engine might work best.......provided your pump isn't dry or there is another problem.

 

I'm pretty sure even cranking rpms are bad for lobes after a certain amount of cranking.

 

Me? I prime the engine turning it backwards while filling from either the sender hole or front hole in the filter boss but turning an engine backwards also has it's own set of risks depending on tensioner or chain condition.

Edited by HowlerMonkey
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Can you get the cam you have ground on a Nissan cam core?

 

If you can, get one done on a Nissan cam and see if it fixes it. If it does, then the Estas core is is the problem...too close in hardness to the rocker arms.

 

This is a good thought.  Based on all my research on Kinetic/Sunbelt Z cams, they always used the Estas blanks.  Since I am using OEM rocker arms, I think the odds are against this being the problem.  I mean, Kinetic sold some decent number of cams for Datsuns based on the people here on Hybrid alone that I know about.  Those include Dan Baldwin, John Coffey, Mark (Zrebaron), and Erik (Erikr).  Seems like it would have been discovered long ago if this was a problem.

 

A new one of these from Megacycle is near $800.  I'm not sure what a regrind would cost.  I guess I'm not going to rule it out until this problem is behind me.  Thanks for the input.

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Wow what an ordeal, sorry to hear your frustrations especially with a rebuilt set up. I was also going to point out the same thing, that the cam core might be the constant here for your issues. Could just be a bad one out of the batch, and not necessarily their entire cam core line up to be blamed. Like you said, if that's the case, tough luck there.

 

I've had 2 different cams successfully swapped on my n42/n47 set up using the same rocker arms, both cams from OEM regrinds, and this was my experience with both. FYI for you to reference and others.

 

 

Cam #1, OEM cam that came in the motor, regrind with Schneider ($120 for regrind, I think another $200 or so for all hardware)

 

- .460 270/280, used their springs, hats, lash pads

-  Confirmed with Kevin @ Schneider, that the new rocker arm purchases are in fact redundant, and he was weary of off the shelf arms not knowing their source, and attribute to being inferior metal
- Was told to visually inspect and rub fingers over it for smoothness, reuse if checks out
- Cold valve adjustment

- Used their vaseline type break in compound, rubbed it liberally over the cam lobes, used their break in zinc formula and Vr1 oil

- Started it up, revved to 2k, and pulled out of the drive way and went for a cruise at 3k or so for 30 minutes

- Used it for over a year without any issues, lobes were shiny when pulled

 

 

Cam #2, OEM cam regrind (bought a different OEM/stock cam core and sent it in), this time to Isky ($135 for regrind, paid another $130 for correct lash pads)

 

- .490/.480 276/268, kept the schneider springs and hardware

- Confirmed with Ron Iskendarian himself on the phone, same advice over the rocker arms, recommended visual/feel inspection and reuse, dismissed 'myths' (his words) about new arms and warned against surfacing services taking too much off the pads

- He recommended setting timing/idle so it'll crank up to 2 to 3k upon start, and run it about 20 to 30 min
- Cold valve adjustment

- Used their vaseline/jelly type break in compound, poured oil over it, cranked it (didn't listen to his idle spec advice, actually bunch of times because the motor had low compression)

- Went for a 20  /30 min drive 

- *The lobes, that were mostly black and bare, were already polished and evenly worn even after this short period.

- **Was running Turbo oil pump for higher pressure / blow through turbo set up. Maybe something to look into?

 

It sounds like you were wayyy more meticulous than I, so hopefully you'll get to the bottom of this.

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  • 2 weeks later...

I drove the car yesterday for the first time since early 2013.  I put about 100 miles on it and inspected the cam when I got back home.  It looks really good.  Rocker arm pads show faint signs of wipe patterns... and cam lobes are clean and shiny to match.

 

The start procedure (which is a pain) is currently:

  1. Heat the oil in the oil pan with a drum heater blanket to get it nice and warm
  2. Remove the spark plugs and cam cover
  3. Apply 30 wt oil by hand to the cam lobes
  4. Engage the starter for very brief intervals (in between starter engagements, apply more oil to the lobes by hand) until oil flows from the cam.  It takes about 3 tries of around 5 seconds each until I see oil.
  5. Re-install spark plugs and cam cover
  6. Start

 

Looking back on all of this, I really don't see anything (yet?) that I can point to as the real problem.  

 

So, I guess it would be good to toss in a few summaries as this thread starts winding down. 

  1. It appears that it takes a "long time" for the six cylinder L-series to get oil up to the cam during a normal engine start situation.
  2. Long duration cams, or valve springs with high static/compressed loads, or a combination of both... added with the above "long time" until there is oil, substantially increase the chance of doing harm to your valve train during the first few seconds of engine operation.
  3. Do not count on dry oil pumps to pull oil from the pan.  Oil weight and temperature differences are factors, but setting those aside, it has been demonstrated that at least one oil pump (mine) pulled absolutely no oil from the pan (with a suitable "dummy" shaft made for engine priming prior to start) even when driven by a corded DeWalt drill at full speed for a lengthy duration of time.

And finally, some speculation from me.  Since I can't pin-point the problem, but am very aware at this moment of all the things that I did to try resolve it, and more importantly, all of what I did that did not resolve it, my advice to anyone reading this in the future is to be wary of utilizing both internal and external oiling... when running high performance (esp. big duration) cams. For stock or mild spec cams, perhaps it doesn't matter, but I recommend you go internal only instead.  

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  • 3 weeks later...

"I drove the car yesterday for the first time since early 2013.  I put about 100 miles on it and inspected the cam when I got back home.  It looks really good.  Rocker arm pads show faint signs of wipe patterns... and cam lobes are clean and shiny to match."

 

So, how is it doing now? How many miles on it?

Edited by Davey G
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I've put maybe another 50 miles on it. The last time I drove it was two weekends ago.  I was recording some air fuel ratio runs with an Innovate wideband O2 sensor.  After that weekend I ordered some more Mikuni jets from Wolf Creek Racing.  I also drained the Brad Penn break in oil out of it, and changed the oil filter to another new, Nissan OEM one.  The plan was to get the jets so I could do some more tuning this past weekend.  However...

 

It seems that I harmed the HI 6 Crane ignition while trying to prime the engine prior to starting.  Since I had a new filter, and I've been having so many cam lubrication problems, I wasn't going to risk starting the engine without seeing oil come out of the cam first.  I heated the oil for 2 hours, I went ahead and re-adjusted the valves since the engine had run 150 miles.  I pulled the spark plugs and laid the spark plug wires across the top of the carbs.  Tried 5 times to engage the starter to prime the engine, each time dipping my finger into the oil pooled around the valve springs and putting it on the cam lobes.  Couldn't get oil to come out of the cam.  So I said screw it, the oil pan was actually a bit hot to the touch at this point, so I figured I'd start it and immediately get it up to 2k to get oil pressure rather than screwing around with a gear reduction starter speed to prime the cam.  

 

When I had it ready to start, I turned the key and the engine just spun... no hint at starting.  :angry: Checked for spark on plug wire 1 and had none.  Many hours later, I determined that the HI 6 wasn't indicating that it was seeing the spark trigger (an optical trigger in the distributor).  I had a new optical pickup in hand from Summit Racing three hours later, but unfortunately that didn't solve the problem. 

 

I think somehow while cranking the engine with the spark plug leads off, I fried the trigger circuit in the HI6.  That was the end of the plans to test different jet last weekend.  

 

This car is really testing me... makes me appreciate the other cars in the garage a whole lot.

Edited by inline6
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Sorry if I missed any details, but at this point did you for sure rule out the cam blanks/materials as the culprit? The measures you're having to take (especially heating up the oil), in my opinion is nearing useless in terms of having a fun car, whether track dedicated or not. 

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Sorry if I missed any details, but at this point did you for sure rule out the cam blanks/materials as the culprit? The measures you're having to take (especially heating up the oil), in my opinion is nearing useless in terms of having a fun car, whether track dedicated or not. 

 

Heating the oil is a pain - no doubt.  But let's consider what that is doing.  Essentially, it is only doing one thing, allowing for quicker flow through the internal passageways at engine start and for a low number of minutes of operation just after start.  Once the oil comes up to operating temp from normal engine operation, we have the same thing going on in both scenarios - i.e. pre-heating oil vs. not pre-heating the oil.  Since I have driven the car on 3 or 4 different occasions now, for a total of 150 miles, and the cam is fine, then my problem couldn't be cam blank material, or I'd still have the problem.

 

The problem is more narrowly defined at this point based on all my prior info: there has been a lack of flow at the time of engine start which has caused this damage.  What I haven't been able to conclusively determine is precisely why that is the case.  I have eliminated:

  • poor quality rocker arms/pads (my rockers are OEM)
  • incorrectly reground rockers (pad surfaces were checked after each regrind for parallelism with the rocker tips
  • inadequate pre-lube of cam 
  • blockage in oil passages by foreign substance/material
  • inadequate amount of oil in sump
  • wrong oil pump when utilizing a drilled out oil restrictor jet in block (can't use the stock pump - use turbo pump which has more volume - which I am)
  • worn or damaged oil pump
  • broken oil pump drive gear lock pin holding gear to oil pump drive shaft
  • poor oil choice such as those with low amounts of ZDDP

Probable culprits, which remember, could be exasperated by this rather high lift, high duration cam are:

  • installation of dry oil pump
  • installation of dry oil filter
  • installation of large oil filter (for example, the OEM nissan ones are smaller capacity than some of the "correct" aftermarket ones)
  • rifle drilling of cam core (for weight reduction - has increased empty volume displacement inside cam)
  • dual cam oiling (internal and external at the same time - more outlets reduces oil pressure at the orifices)

It seems likely to me that the actual cause or causes are in this second list, and my current thinking is that it is most likely a combination of some of these factors.  

 

But I am not emboldened enough yet to not heat the oil and see if my problem is still present if I don't.

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What viscosity of oil are you running? If you're running straight 50 weight, going to i.e. 20w50 would probably be a good substitute to having to heat/loosen the oil... but you might already be running something close to that so I digress.

 

As you've said, even though I haven't read too much about the dual cam oiling being an issue, it could very well be amplified with the aggressive setup. I guess no concrete way to figure that out short of swapping in a non drilled cam to see what it does.

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What viscosity of oil are you running? If you're running straight 50 weight, going to i.e. 20w50 would probably be a good substitute to having to heat/loosen the oil... but you might already be running something close to that so I digress.

 

As you've said, even though I haven't read too much about the dual cam oiling being an issue, it could very well be amplified with the aggressive setup. I guess no concrete way to figure that out short of swapping in a non drilled cam to see what it does.

 

I was running straight 30 weight until after I finished driving the car last weekend.  I changed out the oil while it was warm to Valvoline Racing 10W-30.  Of course I haven't started it yet since.

 

And yeah, I could roll the dice and try to start the car without heating the oil, or what you said, or remove the spray bar and use the internal cam oiling only... if I want to risk it.

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  • 4 weeks later...

Don't feel bad - I just destroyed my 3 liter 2 days ago at the track. Oiling was my issue, I ran the spray bar for extra added measure to the isky internally oiled cam and that backfired big time! Spray bar bolts backed out the cam towers so no oil was getting to the head - destroyed the cams and rockers, metal got to the bottom of the engine and I lost #6 connecting rod bearings. Hope the machine shop can save the V07 crank. 

 

I know it sounds crazy but make sure oil is actually coming out the spray bar and getting to the cam also. With my spray bar failing, it destroys the rockers. If you are running a NISSAN spray bar I would ditch it ASAP. Buy the billet spray bar that won't crack and fail. Also safety tie the bolts that hold the spray bar to the cam towers. 

Edited by EvilC
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Don't feel bad - I just destroyed my 3 liter 2 days ago at the track. Oiling was my issue, I ran the spray bar for extra added measure to the isky internally oiled cam and that backfired big time! Spray bar bolts backed out the cam towers so no oil was getting to the head - destroyed the cams and rockers, metal got to the bottom of the engine and I lost #6 connecting rod bearings. Hope the machine shop can save the V07 crank. 

 

I know it sounds crazy but make sure oil is actually coming out the spray bar and getting to the cam also. With my spray bar failing, it destroys the rockers. If you are running a NISSAN spray bar I would ditch it ASAP. Buy the billet spray bar that won't crack and fail. Also safety tie the bolts that hold the spray bar to the cam towers. 

 

Yikes!  I am sorry that happened... it's disheartening when stuff like this happens.  I did ditch the Nissan spray bar - I have a Rebello unit now.  As often as I am taking off the valve cover, I think I'll be putting some red loctite on those bolts this very next time!

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Maybe over-simplifying but wouldn't drilling an extra hole in the camshaft give the same effect as the added spray bar?  The holes in the stock camshaft are somewhat randomly placed.  A person could pick a spot, maybe at the start of the ramp, to improve the odds of sufficient lubrication.  Same increased volume, better placement of the oil.

 

With that in mind, it might be useful to know where the hole is on the lobes that fail, assuming an internally oiled camshaft.  Maybe there's a clue there.

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Have you primed the oil like you did in the video with and without the spray bar? I am interested to see if the "time" it takes to reach the cam is the same at the same drill speed. Also would be interesting to see if the "volume" coming out the cam holes are noticeably higher. Sucks to have oiling issues and since I am kind of in the same boat you are in more questions come to mind. 

 

I might have missed this but are you running an oil cooler or a competition pan? 

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Maybe over-simplifying but wouldn't drilling an extra hole in the camshaft give the same effect as the added spray bar?  The holes in the stock camshaft are somewhat randomly placed.  A person could pick a spot, maybe at the start of the ramp, to improve the odds of sufficient lubrication.  Same increased volume, better placement of the oil.

 

With that in mind, it might be useful to know where the hole is on the lobes that fail, assuming an internally oiled camshaft.  Maybe there's a clue there.

 

Well... you are onto something there.  Years ago, I had a Datsun 510 that I put a 490" / 290 cam in. I think it is in the How to HotRod your Datsun book that any lifts over .490" require the addition of an external spray bar for the l series 4 cylinders... (I don't feel like taking the time to double check the specifics right now).   Anyway, I had the cam in the car and it was fine.  But on a trip back home (college days) I spent some extended time at 100+ miles per hour, and when I got home I had one wiped lobe (around number 5 or 6).  Tom Howen (friend and co-conspirator of David Weber of Malvern Racing Fame) put it in his "varsol" tank and shot the fluid through the cam bolt hole and observed the flow.  It became obvious in an instant that the location of the oiling hole for the lobe that wiped was 180 degrees from optimum placement.  So, on the new cam that went in, only one mod was made - Tom set it up in his mill and drilled straight through the oil hole in the lobe that had failed.  Thus, that one lobe had two oiling holes, and the cam was unmodified otherwise from the previous one.  

 

I had no issues ever again - and I beat on that car mercilessly.  

 

So, you could absolutely "fix" a lot or improve things substantially by better placement of the oiling holes.  That said, I do recall someone saying that oil "spray" from a spray bar in addition to cam oiling helps cool valve springs which will extend their life.  FWIW. 

 

 

Have you primed the oil like you did in the video with and without the spray bar? I am interested to see if the "time" it takes to reach the cam is the same at the same drill speed. Also would be interesting to see if the "volume" coming out the cam holes are noticeably higher. Sucks to have oiling issues and since I am kind of in the same boat you are in more questions come to mind. 

 

I might have missed this but are you running an oil cooler or a competition pan? 

 

No, I haven't primed without the bar.  And, I am not running a cooler, but I do have a competition pan from DP Racing.

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