79 corvette 350 engine started popping back thru carb ,pulled valve covers and watched rockers ,#5 exhaust doesn't move , what would be my next step ,should I pull intake and check lifter ,how will I know if cam is wipped out ,did compression check, all have 150

 

Not a good sine. yes, pull the intake, see if you have a wiped lobe on the cam.
When i got my 79 it had a miss a good tune up didnt get out, so i pulled my valve covers and found one pushrod gone and one rocker not moving. Pulled the intake, the cam had two wiped lobes.
I allso had good compression so i replaced the cam and lifters and rods and all went good.
Hope your's is in better shape, good luck!

 

If the lobe is wiped then you can verify this before intake removal by removing the rocker arm. Inspect the pushrod ends for excessive wear, roll the pushrod on a mirror or sheet of glass to make sure it isn't bent. The pushrod should come up a bit while being loosened if the lifter isn't collapsed. Take out all the spark plugs and then spin the engine over by hand and see if the pushrod moves up and down at all by holding your finger on the tip of the pushrod. No/very little movement again means no lobe.

 

Out of curiosity, what oil have you been using?

 

very good question,since I have just been looking on the web the last 2 hours about todays oils not containing the sufficient amount of zddp for flat tappet engines ,I just bought the 79 vette 2 weeks ago ,and was told it was a 350 400hp crate engine with 10k miles ,performer intake, 600 holley, mallory ignition ,electric fuel pump, was told it had roller cam ,lifters ,rockers (which it does not after pulling valve covers) I changed the oil the other day and used peak oil , nice of the oil companies to let people know about their changes ,any suggestions on what I should do ,easier the better ,I think I'm going to have to replace the cam ,oh what oil should I use when I get this done? thanks for all help

 

In my 383 I used Joe Gibbs Break in oil to run the cam in. When I put the motor in the Car I changed it out with Joe Gibbs Hot Rod Oil. It is a synthetic oil, devoloped for Joe Gibbs Racing Team. Apparently they have to run Flat Tappets cams...or so the story goes. Anyway i did some research and found out that the ZZDP (antiwear agent) has gradually been reduces in the newer oils because most newer cars use roller cams, high anti wear properties not so critical, and the higher ZZDP created havoc on the catalic converter.
Joe Gibbs has a ZZDP of 1270 ppm. Some oils claim to be 1500. but most newer oils are around 8-900 ppm. Way too low for our old flat tappets. Anyway do some research, decide for yourself which brand you have avaliable, and would work best for you, just make sure it has a high ZZDP rating..... These oils can be a little more expensive $10.00/ltr and I have a 7 ltr pan, but still cheap insurance for your engine.....
P.S: There is a good wright up on the sticky board on this forum on this subject.
Clyde

 

Maybe it's just a collapsed lifter...use something that won't damage the lifter, guide it onto the lifter and push down...if you get about 1/8 to3/16" of give, your lifter is good. If you have no play at all, your lifter is shot.
C

 

removed rocker ,turned engine over, with finger on pushrod, no movement looks like lobe is gone, where can I find instructions on how to replace cam and breaking in new cam requirements

 

yup, that's a wiped lobe.. been there, done that... I bet the lobe will look like a golf ball and the bottom of the lifter isn't much better when you pull it apart...

 

I was going to suggest a rebuild but I think your compression is good so no need. Pick up a book on how to rebuild a small block chevy from Amazon. Good reference material if anything else.
Many folks on here know how to do a cam swap so post up what you need and go from there.

There is a pretty long list of things to do for a cam swap. I've listed some but not all of them here.
Get engine to #1 TDC first (look at valve action) and foremost then don't rotate it any more. Makes life easier later on during reassembly.
Remove distributor (replace cap and rotor upon reassembly if old).
Remove carb (new fuel filter would be nice).
Remove fan and clutch.
Remove accy's Alternator, smog pump, waterpump (belts if they are old).
Remove radiator and shroud (new coolant time if old).
Remove intake. (hmmm time to go aluminum????)
Loosen rocker arms and remove pushrods. Check them for trueness and wear.
Remove lifters. (get a whole new set for the cam) DO NOT REUSE!!
Remove balancer.
Drain oil and then loosen oil pan bolts to facilitate the timing cover.

You'll need to buy a cam swap gasket kit. Don't get cheap stuff either.
Buy new timing gear chain if original has any slack in it.

I don't know if it is possible to drop the pan without other work but now would be the best time to replace the rear main seal if possible.

Blow out the intake ports on the heads before reassembly to get any dirt or other stuff that magically finds its way in there.

 

don't I need to clean out the bottom end and oil pump if the lobe is gone ,the metal shavings would be in everything even the bearings?

 

are there any engine experts here ,I found problem with my 79 vette ,pulled cam today lobe on #5 exhaust is near gone ,#1 exhaust lifter is cupped bad ,#5 exhaust lifter has worn down so bad there's a hole in the bottom of it .#5 intake push rod went thru rocker and stuck ,would it be safe to put another cam and lifters and push rods , in this engine everything else looks good ,what would of made this happen? also it has double valve springs ,I assume because of the high lift cam ,but I would not be going back with one that big