JeepsAndGuns
So over the weekend I had my 401 start acting up. Missing real bad, funny exhaust sound, generaly running bad. It just kinda started all the sudden. Wasnt overheating, and still had great oil pressure. After checking all normal things I was stumped. I even pulled the dist to make sure the cam gears were not eating each other. They were fine. I was taking to my dad on the phone and let him hear it idle and he said it sounds like a bad valve.
So yesterday I decide to pull the valve covers and see what I could find (if anything). I had nightmares of cam lobes worn flat or or other broken parts. I pull the passenger cover first and right away see that the exhaust valve spring on the #6 cylinder is broken. I just sat the cover back on and didnt even check the other side, untill I figure out what I want to do.
So I figure I have come to a point to make a choice. I have had a problem with a very jumpy vaccume readings on this engine ever since I have checked it. (several months after I rebuilt it) I have sealed and re sealed the intake, carb, and checked everything vaccume related and can find no leaks, and no matter what adjustments I do to the carb or the timing I can not get a steady reading. (I even checked the vaccume guage on a diffrent engine to make sure it wasnt messed up) I have had suggestions of burnt valves, and warped sealing surface (on the heads) for the intake. The needle just jumps from one side of the guage to the other, really fast.
So I figure I could replace the broken spring and be back on the road, but still have the other probelm, or pull it apart inspect things and put on a extra set of heads I have. Figure I could use this as a good time to make a slight upgrade. I am thinking about haveing the extra heads rebuilt, and while I am at it (since I now have a air compressor and die grinder) doing a little mild port work. I figure that there is no reason to replace just one spring, so I might as well do them all (a set is only $65 from summit) But if I am gonna do that, I might as well rebuild the extra heads and put the new springs on them.
I went and pulled the heads out of storage and started looking them over and noticed a couple odd things. I think they may have been rebuilt at some time in the past. Some of the springs have one washer under them, a couple have two. The spring retainers do not match. Some are shaped diffrently than others. I held a straight edge over the tips of the valves (where the rocker arms touch) and they are not all the same height. They are supposed to be, right? On the cylinder side, on one head both valves are even, on the other the exhaust sits lower. On the head where the exhaust valve is lower the intake valve measures 2.01 (head still together) on the head where they are even, the intake measures 2.03. The exhaust measures the same on both heads.
So it looks like I have mis matched valves, some more worn that others, or something. So I am thinking about just getting all new valves. Hopeing to find some that wont break the bank. Anyone have any good sources? Also, what about the spring retainers? Since not all match?
Sorry for the long post, any and all help/advice is welcome.
