Cam bearing problem

[jayb]

Have you checked for pushrod interference to the intake manifold?  Maybe the manifold sits differently with the new heads, and the cam profile is different, and you are getting some interference at high lift.  It  may be possible that if the pushrods are hitting the manifold and putting a bend into the pushrod at high lift, that force is being transferred down towards the cam and forcing it down, wiping the bearings.  Having said that, I've seen that issue a few times on the dyno and it hasn't caused a problem, so it's probably an unlikely scenario, but worth looking at, I think.  It would play into the new heads and cam.

[tommytt]

Jay,
Good thought. 
The 1st rebuild, I did have intake manifold interference with the pushrods. I bought another set of Manton pushrods with a 5/16th shaft.  It cleared but looked weak.  On the 2nd build (or 3rd, its all a blur now) I went back to 3/8's shaft and worked on the manifold to enlarge the holes while I had it off.

[tommytt]

Brent,
All 16 rockers went from .025" lash to .060" give or take a little after 4 or 5 minutes.  I did go through them 2 or 3 times originally at .025".
I'm really leaning toward the cracked block idea.  I just can't see, with all the checking I've done, how it could be a clearance problem.  I would love something simpler but I don't know where else to look. 
You guys have been great and I know you really know your stuff.  More questions are fine.
Also I'm not good at using this forum so sorry if I don't reply correctly.
I did post a long reply, a couple of hours ago, with lots of answers to many questions.
Thanks again,  Tom

[67xr7cat]

A side oiler oils to the crank and cam at the same time. I'd expect some bearing wear on the mains and rods if the main webbing were the oil hole is cracked and bleeding off enough oil pressure to matter.  I'd also expect it to be only on ones that have cracked webbing, and not happen as fast as your failure is happening.

One thing from your description the failures happen fast, within a few minutes of startup. Two things that are common so far is been same cam, and the cam journal to bearing clearance has not been checked. I'd check the cam for run out, measure the journal sizes, and look at the surface finish on the cam journals. I'd really be interested in the surface finish. I would also check the cam housing bores for size and roundness.  Finally, your description of the bearing failure is a bit odd (crushed).  If you could post some pictures of failed bearing may help. 

[tommytt]

67xr7cat
I hope I'm answering these questions in the right way for this forum. Not sure how this site works.
What started this whole mess, a year ago was a crushed thrust bearing.  The sides of the bearing were worn away. Even had to have the crank welded and machined where it contacts the sides of the thrust bearing.
I was worried about the cam itself.  I'll called Isky again to see if they had sold this cam to anyone else.  They mentioned, on a previous call, that it was a new core supplier from back east.  It was a special grind they did for me for the blower.  I asked several questions about how they ground the journals and how the polished them afterward.  The usual answer, "We haven't had any problems".  I'll call them again tomorrow.
The crushed cam bearings.  To describe them best the bottom half of the bearing was crushed to where a about 1/8" of the bearing was pushed out on both sides.  More so on #2 and #4.  I know that is the rocker feed holes.  I do have the holes to the rocker stand studs blocked about 80%.
I was so sure all would be good this time I tossed the cam bearings 2 weeks ago. 
Tom

[blykins]

You didn't, by any chance, install restrictors between the mains and cam did you?

[Barry_R]

40 psi on the air ratchet seems low, but I know those turn pretty slowly.
What kind of pre-oil pressure do you see when spinning the pump on a normal "plug into the wall" drill motor?

On the next assembly you could try what we have used a couple times for diagnosis on troubled complete engines.  Engine up on a stand.  Might be able to do it on a short block if you block off the head oil feeds at the deck with some pieces of plate and gasket material as long as lifter are in it.  Use a large plastic mortar pan from Home Depot (tell them its an essential brick repair...).  No oil pan on engine.  Cut off the "bell" on a stock oil pump pickup tube and attach a few feet of 5/8" heater hose with a couple of clamps.  Put a gallon or so of oil in the plastic pan, position it under the engine & set the end of the heater hose in it.  You now have a remote oil pan and can spin the pump with a drill and see where the oil is bleeding out.  If you see a geyser in one location you might have found your problem.

We have used this process to find two defective aftermarket blocks (two different and unrelated manufacturers) where casting flaws opened up oil passages.  Both were repaired and are in service, and both would have been nearly impossible to diagnose otherwise.

[wayne]

Take the pan off and put the pickup in a can of oil and have some one turn the pump. Look up at the cam and see what is oiling or not.You can turn the pump slow to see use a speed wrench to turn it.Its a mess but works.

[wayne]

Sorry Barry B you beat me too it i did not steal your post.

[shady]

Just my uneducated opinion on this. The bearings show no wear, spin, or debris. They are being hammered from the top down. I don't think it is oil related at all. What bothers me is that Tom used pushrod length to try and get rocker geometry correct. I'm thinking the pushrods maybe way too long causing a combination of tolerances stacking up.

[BigBlueIron]

Throwing out an idea, take it for what it is.. Possibly a cracked pickup tube? When warmed up a little it opens up and causes issues. Had this happen on a common rail Cummins once. (owner didn't want to spend any money so new tube and away it went  )

I ran into a bad gasket on the pickup tube once. 390 with unknown history. Oil pressure was 60 plus on the drill, but every now and then I noticed the odd little and I mean tiny bounce of the needle when bringing the pressure up, once spun up it held steady. Un hooked the gauge and let the line to a bucket. Spurting oil and air. I was shocked it wasn't more visible on the gauge but pressure is pressure to a gauge.

[tommytt]

Barry,
Thank you for the thoughts on how to look for the problem with the pan off. 
I hate to think I will be pulling this engine out again but at least I will have a plan on how to look for this mysterious problem.  Hopefully I can see up in there.
(Wayne, thanks too)
Thank you,  Tom Tucker
If you have time maybe check the YouTube video I posted in case you spot something wrong.   "427 Ford FE engine building tips 10 2019"
I shouldn't of posted this with all the trouble I'm experiencing.

ALSO a PS  to Brent too.  No restrictors between crank and pan.

[TomP]

Barry's idea works. I had a local guy call me with a 427 in his Fairlane that oil pressure went to almost nothing. I suggested that he try it with the pan off in the car. He used a hose into a gallon jug of oil and spread plastic all over the garage floor. He fired the car up and dived under it with flashlights and saw a huge plume of oil gushing at the back. The relief valve was in backwards.

[My427stang]

Nm

[wayne]

Tips on building a fe engine by Jim Dove check it out online may be worth a look.Tom