Quote:
Originally Posted by spf2551
I have two sets of the Dove HD rockers (1.200” wide). with end stands. The oldest set is in a 427 that has 850 # of open spring pressure and the engine has seen 8500 RPM on the tach. I did pay close attention to the push rod length and had a custom set of manton pushrods made. No issues after 5 years. The second set is in a 427 that only truns 7200 RPM with 550 # of open spring pressure two years old, no issues. Custom manton push rods in this engine also.
SPF 2551 Lyle
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SPF 2551,
Is this a drag motor... pressure at 850 open is pretty agressive. Also how old are these rockers.
After the first rocker broke I rechecked everything( not saying I am perfect) I really dont think it was a push rod length issue because everyone I spoke to including Dove said to make sure you have 3 threads out.
Now, I finally switched to the Erson and noticed just by changing to the Erson rockers I had 5 -6 threads at the bottom of the rocker. Many have said it should be fine and I probably would not have a problem.
Well, I decided to remeasure the pushrod length and to have the 2 -3 threads on the bottom of the rocker with the Ersons. I then cycled the motor several times to make sure the cup is not touching the bottom of the riocker.
It will cost me an additional $200 but will save me a possible tow home.
Its funny, since I had down time I decided to check a few things. If my push rods were at 8.926 and I had 5-6 threads at the bottom. Each thread being .050 I could have easily add .100 to my existing push rod .
My final pushrod length needed for me to have 2-3 threads were 9.037 (EA) or 9.197 for a overall length