Burned pushrod

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Hemi Dart

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Got a problem with #8 exhaust pushrod burning on the cup end, 572 Hemi with Indy Legend heads and roller rocker arms. Getting about 200-300 mi. before the lash increases, adjuster threads showing 1, restricters on intake side .043. All holes in rocker arm are open and holes in rocker shaft are positioned correct. Any idea's welcome.
 
ask Damon at diamondback engines. i think he,s built a few of these. are the lifters bushed or are the lifters coming unshrouded ,high lift, check out his website.diamondback racing engines
 
The Idnys are fed with an external oil line, and he's got the restrictors in it. The #8 exh is the last rocker on the shaft. The cup end is fed by the shaft oil coming thru the rocker. If the passages are clear, I'd say it's a simple case of not enough volume getting to the shafts. If there was a starvation isssue, I'd think there'd be more going wrong. Hemi, you're sure that rocker is fine? Have you tried swapping that one with another to see if the issue follows it?
 
Chamfer lifter hole? Checked for oil flow when I installed restricters, larger on restricters would let more oil go to Intake side, lifters are not bushed I need to pull lifter valley cover to check, lift is only .691 In. .652 Ex. something worth checking out. Indy Legend Hemi heads don't have exteral oiling. I was thinking of buying a new exhaust rocker, but at a 100.00$ a pop was looking to try anything else first. Oil pressureat idle is 40lbs. 80lbs. running.
 
I'd run the oil pump with a priming rod hooked to a drill and make sure oil gets to that rocker as a first step. You might also want to get some cheap Summit chrome valve covers, cut the tops off, and run the engine and watch that rocker to make sure oil gets there.
 
Yeah, that's not a massive cam. It's got to be a minor issue if it takes that long to scar it. That's why I suggested a little more up top. Yes, all the rocekrs will have more oil to them, but that may not hurt you, and it may be enough to prevent the repeat performance. I'd also swap rockers... like swap 6 and 8....
 
I primed motor when I installed the restricters, can't cut valve covers spark plugs are in them, the restricters are on the intake rocker shaft the oil passage splits when it goes into the rocker shaft support one to the intake and one to the exhaust rocker shaft. I'm thinking I will try a new rocker arm, running out of spare exhaust pushrods. Thanks for the ideas, still got a few months before good weather.
 
Measure the shaft bore ID on the bad rocker vs. the new one... Maybe it's just a hair larger...
 
Finally got a chance to tear into my engine, it seems that the cam grinder didn't get the groove for my rocker arm oiling in the right spot. The groove was only partly covering the hole to the rockerarms. Thanks to everyone for the ideas and thanks to Muscle Motors for working with me on this. Now if I can get my car put back together before we get my wife's car home, 64 Belvedere 22000 orig. miles!
 
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