Problem with Edelbrock Stage 2 heads

[fe468stroker]

Awhile back I purchased a pair of Edelbrock Stage 2 CNC ported from a known vender.  After breaking a roller rocker on #5 exhaust I noticed that the valve and spring were not in line with the others on the head.  It is tilted towards the intake enough to make the rocker arm ride off the valve tip and hit the retainer.  I am sure that out of the box all the valves were in line.  Before I contact the vendor I need to pick the brains of the gurus on here as to what would cause this and what might be the fix.  I did change the cam from a hydraulic roller to a solid roller with the recommended springs if that has anything to do with it.  Thanks in advance.

[blykins]

Can you post a picture?

[Joe-JDC]

Sometimes the CNC program or the porter will cut too much metal out of the roof of the port around the guides, and the guides will move with spring pressures that are needed to control solid roller camshaft lifters.  That is why I never cut the guide bosses completely out of a head when porting them.  The additional flow is not really there, and it shortens the life of the heads considerably, and they create turbulence around the guides.  Joe-JDC

[fe468stroker]

After some research on aftermarket aluminum heads they all say that they are set up for hydraulic roller applications.  That was initially what was in the stroker and was OK but there seemed to be a lot more potential HP on the table.  So I switched to a fairly mild solid roller with the recommended springs thinking that this should be all that was needed.  I assumed (yah-I know the definition) that high dollar CNC ported heads with premium hardware in the head build would take a solid street roller cam and I still do.  1.  What exactly is the difference in the head build between hydraulic and solid cams?  2.  Is it feasible cost wise to upgrade the heads to solid compatibility especially since one seat has decided to relocate itself.  I am very close to 70 so my days of wrenching are numbered and I want to get this right because the car is going to be passed down to my grandson.

[Joe-JDC]

So the seat has relocated itself?  That is a different issue that the guides giving way.  Sounds like a seat install problem which needs to be determined by disassembly.  Not enough interference fit on the seat at initial installation, soft aluminum at heat treat, etc.  Joe-JDC

[fe468stroker]

Joe,  The whole spring assembly has tilted toward the intake which leads me to believe that the seat has shifted.  The spring appears to be still seated squarely on the bottom.  You are right about disassembly but that will have to wait until warmer weather and motivation.  Just trying to get my ducks in a row about repair or replace and getting needed gaskets etc to do the job.

[67xr7cat]

Sounds like you bent an exhaust valve.  Did you check P-V clearance when you changed cams? I'd see if that cylinder holds air, if not figure head has come off. If it does hold air I'd remove the valve spring on that valve and see if the valve is true and if moves freely without binding. Also give you a chance to assess the condition of the valve guide.

Regarding difference between a head set up for Hydraulic roller and one for Solid roller is going to be the spring package.  Other difference can be the valves used, but any quality valve that work with a hyd roller should be good for a mild solid roller.

[cleandan]

With the valve tip visually in a wrong location, as you described, I forsee three potential problems.
1) The valve has been bent.
2) The seat insert has come out of its seat and is binding the valve,possibly bending the valve in the process.
3) The guide has shifted from too much porting.

All three are a guess.
All three require head removal to repair the problem.

Remove the head carefully, knowing you are seeking clues about what happened, so as not to disturb those clues in the head removal process.

Stick with the simplest issue, bent valve, until you have proven otherwise.

Good luck.

[fe468stroker]

Update on problem #5 exhaust.  After removing the valve cover, I was surprised to see that the valves were perfectly in line.  Now I know that #5 exhaust was tilted towards the intake last time I checked WTF.  But after removing the rocker shaft assembly there were witness marks on the bottom side of the rocker where it had contacted the retainer (nice semi-circle pattern).  Now I know I'm not crazy and the valve was at least at one time tilted.  Next step is to remove the intake and head.  I will keep you informed on the continuing saga.

[allrightmike]

Bought  a set of TF heads once off the internet, popped the valves out and lo and behold one of the intakes had no valve guide at all. To make it worse they had  destroyed the guide bore in the head when they drove the guide out! Quite a few hours in the milling machine to fix this. The reward was when I went to grind the seat, the new guide was almost perfectly on center, doesn't happen every time, at least not for me.

[fe468stroker]

Got the head off the engine yesterday.  Now I'm stumped as to cause of the problem.  There are no witness marks on the piston or valve, valve is not bent and the guide is still tight.  Told you wrong on last post - it is #5 intake instead of exhaust.  Because of the markings on the underside of the rocker there has to be some movement of the valve or rocker shaft just on this one valve.  I am using Precision Oil Pumps thick wall shaft, his gen 2 rockers and rocker shaft studs (probably ARP).  When I installed the solid roller (.645 gross lift) I changed springs to the recommended ones from Comp.  I did not change the retainers if that has anything to do with it.  The engine has seen several twilight zone twists but not over 6500.  The heads are Keith Craft Stage 2 Edelbrocks so I know they were quality built.  Sort of wish I had found something amiss that could be easily corrected.  Any ideas would be greatly appreciated but if not I guess I will button it up and go on down the road.

[GerryP]

Take the heads to a quality machinist.  Give him a sheet of paper fully describing the problem.  Talk to him about what you found.  Let the machinist earn his pay and tell you what happened.

You haven't really provided any additional detail that would help anyone get you closer to a problem, so this becomes is one of those deals where there needs to be some disassembly, some careful inspection, and some measurements.  Take the rocker shafts with you.

[428 GALAXIE]

 Photos would be  helpful, and if it is what Joe said I just want to see that my own eyes..

But what you have described sounds like Joe have a clue about what's happened.

Photos 

[67xr7cat]

When I installed the solid roller (.645 gross lift) I changed springs to the recommended ones from Comp.  I did not change the retainers if that has anything to do with it. 

Not changing the retainers may have a lot to do with it. The retainer has to fit the spring properly, not too tight and not too loose. Unless the inner diameters for the old and new springs are the same you likely have the wrong retainer for the current spring.  Also is the step the correct depth. If it is deeper you may be coil binding the inner spring and not knowing it. It all depends on how close you are at full lift. If the retainer is wrong it can cause several problems all depending.

I'd recommend finding out what retainer comp recommends for your springs, look up the dimensions for that retainer and then measure your current retainer.  If the dimensions are different get the right retainer.  I'd also measure the seat and over the nose pressures and shim accordingly.  You should also check how close you are to coil bind at full lift.  Finally measure the distance from the bottom of the retainer to the top of the valve seal make sure is more than your cam lift.  This is all part of setting up a set of springs. Hope this helps, Steve

[My427stang]

Recap

1 - You changed springs and more radical solid lifter cam
2 - You saw a valve/spring leaning away
3 - You see marks on a retainer that see something was hitting
4 - Everything looks square now

I'd take those heads to someone check to see if you have a broken guide, check open and closed pressure, coil bind, and retainer to seal clearance.  It could settle back straight I supposed, but if a guide was broken, it will be clear when taken apart. 

FYI - Comp recommendations are often wrong, more than right, because of the various different ways heads can be set up

What are the specs of the cam, and did you degree it, did you check piston to valve clearance?  Not trying to reinvent the wheel, but it sounds like things need to be checked closely with real numbers