Morning gentlemen,

I recently had my 1972 Corvette 350 rebuilt to stock.  I have only put less than 500 miles on her driving no more than 40 mph in my neighborhood.  Over the labor day weekend, I heard a knocking noise so I stopped the engine immediately.  The knocking noise is coming from the top end on the passenger side.
It is not smoking.  Any ideas?

Is this something that being low on oil could have caused? I was down about 3//4 quart.

Any help would be appreciated...
 

How did your initial camshaft break-in go?  

I had no problems with it breaking in.  Its been running fine since the break in six months ago.

This happened all of a sudden while i was cruising at around 30 mph.

I was hoping it was the cam or valvetrain it starts fine and idels fine it just knocks. Sounds like its coming out of the carb.

Any ideas?
Thank you,  

I doubt 3/4 quart would have caused a problem unless there were a issue with the pick up or return flow. "Rebuilt to stock" implies a flat tappet cam. I think Gib may be correct in suspecting a cam lobe failure. With todays motor oil this is all too common. I hope for your sake this is not the case. If you end up going through the engine again, give the roller cam a good look see.  

First check to make sure you didn't have a rocker arm back off. If all the rockers are tight, then you could have a bad lobe issue.  

I appreciate your time and help. I'll pull her apart this weekend and take a peek.  I'll post my result next week.

Thank again,

PS: this engine is in my 1976 fj40 with an SM465 trans.  

I removed th valve cover last night and found that the #1 cylinder (1st valve rocker stud was broken clean off). Now my question is since its pressed in... Can I get it out without removing the head?

Any ideas...  

Have you tried anything on it yet or are you waiting for tips. I have never had to do it so I cant give the best advice. I would be careful with heating the stud boss if anyone recommends that because you cant heat up the cast to fast or it will crack. If you buy a set of stud extractors and very slowly put some heat on the stud boss you may be able to get it to turn. If you get it to turn you can get it out. Let me know how you make out.  

The correct answer is to pull the head, take it to your machine shop and have ALL of the studs pulled and replaced with screw in studs. I fought one for a while that kept pulling out. the only way to correct it is to replace with screw ins.  

i agree with zman123..i had the same problem with one of my 400s i tried everything that people told me to do without pulling the head and ended up cracking a brand new set of heads(it happened on both sides) now ive got a new set of darts with screw ins and glad i do because one of the studs broke when i let my cousin drive it for first break in and he decided to take advantage of the 800 horses and get into a race...i didnt like getting a call to come tow my car home because of motor problems  

800 horses...

Any 120 pound fish you've almost caught with your cousin?  

haha gib...ur sooo funny   800 horses is possible..it was a nitrous motor and with the 150 shot it was making 796hp @ 624 ft/lbs TQ...if you do enough research and how all the right machine work done its possible without the nitrous!