Well i hope someone has an idea.I got 1967 327 block.so i thought i would build it up a little.went to the machine shop had it tanked, new cam bearing.pistons,rods.oil pump,everything in the short block.Then i decided to put in a mild cam,went with Comp Cam 268 duration 454 lift 110 degrees of sep.#CCA-CL12-210-2 said to work well with stock components but got valves springs to with it,My problem is that ive bent 16 exhaust valves and broke and bent the same amount of push rods,they hit the top of the pistons,they are flat top with reliefs in them,only taken out the vavle lash when adjustment, and only did this when i spun it over on the starter not trying to start it. this is not my first rodeo, but it sure feels like it.also have .o49 head gaskets. any help would be great. thank you

 

sorry to hear about the problem's,what head's have you ,stock rocker arms ?

 

stock heads and rockers.do you think the cam timing is of?

 

ma that dosent sound like too much lift you need to go and start from scratch ,make shure the timing chain gears are set to were you are not 180 out call the manufacturer of the cam's tech department see what they say .run some good felpro head gasket's not the steel shim .you usually dont get into much problem untill you get close to 500 deg lift cams and 1.6 ratio rocker arms ,then you have to check for valve to piston clearance to see if you have fly cut the pistons for clearance .or if the head's and block were radicily milled for compression .

 

Correct me if iam wrong,timing gear crank and cam dot to dot,#1 piston up on compression stroke,mark on balancer align with timing mark,??? 327 chevy

 

you are correct !

 

Sure does sound like a cam timing issue,but I wanted to add this question too,which way is the eye brows on the pistons facing??.Towards the lifter valley or towards the outside of the block??.

 

Thanks all turned out to be cam timing, i have to admit i screwed up, well i can say i was wrong once,Ha ha,thanks again all.