Quote:
Originally Posted by rigpig on juice
Check the retainer to valve guide clearance.
Check the pushrod length, make sure the stud isn't hitting the rocker body.
Possibly the lock and/or screw is being overtightened.
How much thread engagement does the polylock have? The studs could be too short.
What RPM did you run and how much lift does the cam have?
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The rocker body has some slight witness marks but they are on the wrong side if the pushrod were too long. I'm sure they had something to do with the rocker dismounting from the stud.
I couldn't get the adjuster nut out of the polylock, I was on the verge of breaking my allen wrench in half.
Found a spec that the effective stud length on the 7/16" studs is 1.900". The remaining stud on mine is 1.555" which would give me approx .345" of engagement. Seems like in a perfect world it could use more engagement but the issue wasn't thread holding, it was that the bolt broke which would happen no matter how long the bolt is right?
You gotta give me some slack though, I didn't even know what a polylock was until this morning :flipoff2:
I personally haven't had it over ~4K RPM before that, who knows...
Cam Specs:
Howards Mechanical Roller Cam
Max Torque
121153-10
Valve lift with 1.7 Rockers: 0.660 0.675
Duration in Degrees Advertised: 285 290
Duration in Degrees @.050": 248 255
Lobe Separation Angle: 110
Valve lash: 0.020 0.020
98631
Mechanical Roller Tappet 2500-6700 Good mid-range horsepower, rough idle. Needs 11.0:1 CR-up
Quote:
Originally Posted by rockbuggy84
That rocker possibly was a result of all the fuel you were dumping into the cylinder when it was not firing. Maybe it hydro locked and that was the weakest link  Also was this motor fired on a dyno and broke in? Or has its only run time since built been with misfires etc? |
I was told it was ran on an engine dyno and made 550+hp. For how long, I have no idea.
Not sure how long it had been running rough before I got it, but it has never ran right since I have had it. I haven't driven it more than probably 10 miles the entire time I have owned it.
There were quite a few issues leading to it being run with misfires etc. such as the 2 burnt plug wires, 3 broken plug ceramics, bad coil, fubar'ed distributor cap, and the MIA rocker.