i bought a 392 from a friend. it was running but making noise. he determined that the adjustable pushrods were rubbing the cast holes in the heads & block. a few of them bent. he said i need to open up the holes a bit for clearance. question: can i just drill the hole larger, or do i need to slot it on a mill, or start grinding with a carbide cutter? i dont mind pulling the heads off, but really dont want to pull the whole longblock all apart. any suggestions?
i dunno about hemis,but most old engines have a ton of meat on the castings,and drilling bigger holes for the pushrods is usually no problem.UNLESS somebody has gone hog wild with the porting,then it's kind of a crap shoot.i saw a neat tool once that would measure port wall thickness,can't remmember where i saw it though BTTT
On my one of my 331s the large pushrod holes have aditional pushrod size (apx.) holes drilled at 12 & 5 O'clock. Theye'r apx 3/8-7/16 wide.
WOW! sure are a lot of people ignoring this thread.i thought we had a few hemi folks on here but i guess i'm wrong.i think what you need is as simple as what my dear old dad used to call a "rat-tail" file.look down the pushrod holes and see where they're hitting,then yank the heads and hit'em with the file a little bit.reassemble and see if they clear.i think you might be overthinking the project there tim...
George, leave him alone, least he can do is play with the mill after the 'Friday Night Effort' BTTT.....
Sounds like some good advice from some of the fellas here. I was kinda hopin' to hear some more about it myself. I am currently debating gettin' a 331 and was wonderin' how good a motor they are. I've heard good things. You might try www.hothemiheads.com. They've got some good info on early hemi's and some good links to other hemi pages with some tech articles and searches. I've been fairly impressed with what's out there, good luck and let us know what's up. I'm interested to know.
hey derek, hot heads is the place to go for early hemi stuff! good luck with your 331. remember any motor is only as good as the guy doing the machine work on it.
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