Okay, my post last night about needing a mechanic may have been a bit premature. After having a night to sleep on it, I am pretty confident that the situation I am up against is a custom cam in my engine that won't let it run correctly when lash is set to factory spec for stock cam. LUCKY13, if you're reading, sorry I never responded to this suggestion in my previous post.
Today, I now believe that you are correct.

So, what I'm trying to do now is plan a course of action. Ceej has suggested that I try to set valve lash while car is running. Loosen them to a clack-clack and then tighten until I get a more comfortable sound. Does anyone have any other suggestions or experiences involving this kind of thing?

The other course of action would be to get a good degree wheel and map out the events of my cam. I guess what I'm wondering is, if I am to do this, and provide detailed specs for this cam (intake open/close, exhaust open/close), do you think it is possible to ID the cam?
There must be dozens of aftermarket Slant 6 cams. Could the information I gather be used to figure out the correct valve lash retroactively (without actually ID-ing a specific cam)?

Finally, there's the option of trying to swap the cam in-car with the stock cam from my original engine. Has anyone ever done this on an early 70's Valiant? It looks like if I remove the radiator and grill and jack the engine up enough I might be able to get it out.

All suggestions are appreciated. Thank you.

-Matt

This does happen and here is a recent post about another member's experance with the same issue:
http://www.slantsix.org/forum/viewtopic.php?t=43251

Try to loosen the lash... a lot, to see if that helps.
DD

Yea just set them .028/.028 and see what happens.



You made a statment in one of your post about having to hold the PCV valve closed to keep the engine idling when the valve cover was off. This sounds to me like the carb is very lean. WIth todays e-10 gas the carbs can be very lean. Of course to tight a valve lash, or even ignition timing being way off can make the carb act wrong.

Can you take the choke and slowly close it until it hits a point that the engine smoooths out? If so this is a good indication of the system being to lean, either needing more fuel, or it has vacume leaks. If its got vacume brakes make sure the booster is not leaking on you. You cant tell most of time by checking anything, just remove hose and block off, if it runs right then it was leaking.


I really doute you have a problem with the timing chain/gear/cam not being degreed right. It may be off a little, but this normally won't cause the problems you are having. It will just change where the peak power hits in the RPMs, unless it is out a extreme amount.


Jess

You guys will be happy to know I have purchased a real cam-degreeing kit and I have educated myself extensively on intake centerline method of degreeing cams.

I have Thursday off of work, so I'm going to pull my radiator one last time ( hopefully!) and get TDC with the piston stop, the intake centerline and also map the intake open/close and exhaust open/close. I will post the results as soon as I get them and then hopefully we can figure out what the heck is really going on with this thing!!

-Matt

I sure hope you spent less than $0 on that degree wheel? http://www.tavia.com/free_degree_wheel.html

Haha. Well, no it wasn't free. All the calculations I've done up until this point have been with a downloaded degree wheel printed on cardstock, but it was hard for me to make sure it was positioned accurately on the damper. The real reason I bought the kit is because it came with a new dial indicator gauge with mounting hardware and a piston stop for finding true TDC. I'm tired of guestimating everything with sloppy equipment.

-Matt