Stock 1.76 Adjustable Rocker Strength

[frnkeore]

I know Jay used a these on his 390 stroker @ 7K and .640 with 360 lb open, Ford used them with the "D" cam @ .600 x 330 lb but, what is the limit?

Will they take the TFS valves & springs @ .635 net lift, shimmed to 450 lb @ up to 7400?

[MeanGene]

I have run them with .660 and 7300- the shaft/ mounting system is the weak link

[frnkeore]

Gene, what was your open pressure?

[MeanGene]

Don't remember- was the late 70's 

[blykins]

I have ran both factory non adjustable and factory adjustable at 425 lbs open and 7000 rpm.

[frnkeore]

Thank you both. I looks like I may be able to use them successfully with end supports.

[MeanGene]

The stock rockers are pretty strong, makes a good combo with HD shafts and supports. Just remembered, springs were the old reliable Isky 8005-A's

[frnkeore]

Gene, I checked out the springs, they are 395 open. Thanks again.

[427John]

Not a good thread for the aftermarket rocker guys,did any of these examples show valve tip or rocker tip wear?

[wowens]

I ran the same set of stock adjustable rockers in my street racing  days on a low riser, then a high riser, then a tunnelport for about ten years. I also drove it 36 miles round trip to work 5 days a week for 5 of those years. Reground the pads before the tunnelport cause I could. Cam was a H/M 882 grind with .577 lift and over 400 lbs over the nose. It had no end stands, didn't know they existed. No oil restriction to rockers and used drip tins.
Never had a valvetrain problem.

[blykins]

Not a good thread for the aftermarket rocker guys,did any of these examples show valve tip or rocker tip wear?

Factory rockers have their place and there is a limit to them.   One con is the shoe style nose leaves a lot to be desired in terms of valve tip loading.  It's easy to lose lift because the rocker takes such a broad stroke across the valve tip.  Another con is the fulcrum is not bushed or rollerized, so it will be limited in what you can apply as far as spring pressure. 

I've ran the factory adjustables on engines where the rules dictate they have to be factory rockers.  In those cases, I had them cryogenically treated and the adjusters swapped out.  Seems to work ok, but I wouldn't feel comfortable about applying more spring pressure. 

Dennis Towle has a set of factory non-adjustables on the TFS headed 390 that I built for him.  The heads were setup with 400 lb open pressure beehives to work with a hydraulic roller cam.  Shafts were HD, plus we used billet end stands.  He launches the car at 5500 and shifts at 7000.  So far so good, but it's probably getting close to an inspection time.   I used that setup before I came out with my roller tipped, bronze bushed non-adjustable rockers.  They will handle 700 lbs of spring pressure and will allow you to dial the valve tip pattern in to about .050".