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| | | | Joined: Jul 2003 Posts: 141 Member | | Member Joined: Jul 2003 Posts: 141 | On my 235 head (848 model) there is a small plug that looks to be 3/8 or so that is located on the passenger side, middle of head, just below the valve cover and just above the distributor.
I'm curious as to what it is for? | | | | | Joined: Sep 2003 Posts: 343 Member | | Member Joined: Sep 2003 Posts: 343 | This was just discussed not to long ago here and the answer that was given, was that plug was tapped and installed after they drilled the oil channel that feeds oil to the rocker oil tube assembly.
1954 GMC 1/2-ton Longbed
1971 Pontiac LeMans Sport
| | | | | Joined: Feb 2004 Posts: 60 Member | | Member Joined: Feb 2004 Posts: 60 | Shoeless,
This question goes right along with an issue I had with no oil to the rocker assembly. Please read this thread and I'm sure you'll have a better understanding about the whole top end ie valve/rockers. http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=006285
Basically, pull your valve cover off and make sure you're getting plenty of oil when the engine is running. The plug you mentioned is access to a passage that oils the rockers/rocker assembly. The head bolt located inward from that plug should have a tapered end that allows oil to flow up the "rocker oil tube"(aluminum looking tube connecting both rocker shaft ends). If you're not getting oil (like I was) someone may have installed the wrong head bolt (non-tapered) and you'll have to find it, ONE by ONE re-torqueing to 90-100lbs.
So, in a nut-shell other that it being helpful to identifing oil flow I'm not sure of any-other uses.
Good luck,
j | | | | | Joined: Dec 2001 Posts: 1,745 Member | | Member Joined: Dec 2001 Posts: 1,745 | That modified head bolt is in very few engines. In fact, you were the first I know that ever found it. You only need it with later blocks and earlier heads.
54 3100 with 235
62 flatbed dump C60 with 261
| | | | | Joined: Sep 2003 Posts: 343 Member | | Member Joined: Sep 2003 Posts: 343 | JOoftheworld, Didn't that bolt have a drilled hole up the center and then out the side above the threads? Or was it tapered like you said in this last post? I've heard of this infamous Special head-bolt, but I have never actually seen one. Any chance you took a picture of it while you had it out?
1954 GMC 1/2-ton Longbed
1971 Pontiac LeMans Sport
| | | | | Joined: Feb 2004 Posts: 60 Member | | Member Joined: Feb 2004 Posts: 60 | No pic, but if you looked at it from the bottom of the threads it would've looked like a "D". The threads were ground off about half way up (threads not entire bolt) and when we installed it the oil started pouring out of the tops of the rockers (not spraying).
So, for not much being ground off the side of the bolt I got really good flow, from where there was none!!
When I bought the truck it was "rebuilt" and I imagine thats obvious since this was put together wrong and the carburetor had the wrong float needle (pouring gas at idle). As for the rocker shaft it had very little signs of obnormal wear so I think I should be fine.
RUNNING STRONG, like it should.
You guys are the pros, I'm just learning. | | |
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