Engine Roller Rocker to Valve Retainer Interference - Possible Source of Valve Train Noise

[AeroCoupe]

This is more of a lessons learned and me telling on myself than anything. Since I had the upper intake off to have the injectors cleaned I decided it was a good time to swap out the Crane Energizer roller rockers for the new Scorpion roller rockers. Reason for the switch is the Crane's are good to 450 lbs of spring rate which is right at what the springs on the heads are. Scorpions are good to 950 lbs and clear a bigger diameter spring which turned out to be a plus. Cranes are good for a 1.500" diameter spring and the Scorpions are good for a 1.625" diameter spring.

I pulled the Crane's of the motor and stacked them on a towel and then got the Scorpion's installed and the valves run. Installed the Jomar valve stud girdle and put the valve covers back on all with zero issue. Was wiping the Crane rockers down and noticed some light contact right where the valve spring retainer would be. I have been chasing a valve train noise on this car since the Ed Curtis cam went in and never once thought to check the clearance at this spot. The Ed Curtis cam is quite a bit more aggressive than the old Comp Cam that was used with these heads. I have had the same valve train on the heads with the Cranes so the only thing I can chalk this up to is the higher lift on the Ed Curtis cam causing the interference.

Hoping this gets rid of the noise as I still have some other things to finish before it gets fired back up. I will get a picture posted later today as I thought I had one on my phone but evidently I took pictures of everything but this...new rockers are pretty though! If you think you are seeing old oil or burnt oil I use Brad Penn oil which is green and the oil change is pretty fresh.

 

[rednotch]

It probably will, I have a old as hell set of the cranes I got when I bought my first pair of afr's used on corral, old gen 1 eyebrow heads with the 11/32 valve train.. I ended up clearancing all them with a dremel and sanding drum for the same reason, this was with a stone stock short block so stock cam but the heads had one of eds old ps1 sping kits from the previous owner... The 1.7 rockers all made contact with the retainers, had an oiling issue much later on with them that hurt some of the rollers and a couple valve tips. Have them in a box somewhere these days, been running scorpions since.

 

[AeroCoupe]

This is what most of them have contact wise:

 

[90sickfox]

I had Scorpions on my 347. Loved them and they worked great for years. I now have Comps rockers on my TW heads. When I go through it I'll check for this. Thanks.

 

[Noobz347]

So, what would cause that?

 

[AeroCoupe]

The contact on the rocker?

 

[Noobz347]

The contact on the rocker?

yes

 

[Noobz347]

Is it a geometry issue?

 

[AeroCoupe]

The retainer was just a fuzz larger OD than the rocker was designed for and at high lift it made contact.

 

[Noobz347]

Mine is pretty noisy but I always blamed on being adjusted on the 'loose' side

 

[Noobz347]

For reference, I have the Scorpion rockers.

 

[AeroCoupe]

Mine is noisy as well (actually got the car running) but the clatter is no longer there when revving it past 5,000. So I’m gonna call it a win and put the Cranes up for sale.