valvetrain carnage

[mebe007]

well yesterday started off great. got all my welds grinded down and the whole floor self etched then seam sealed. ruberized undercoated the underside and painted the topside. looks great. then i filled up all my fluids, primed the oil system and lit off the motor. all was well and about a minute in it started making a loud pop noise so i shut it down. pulled the valves covers and it broke 5 rocker studs, broke 3 pushrods, and bent the other 13 also chewed up some rockers. its wierd because it was running rather well i thought for nothing being adjusted yet. i checked the dist and it was a little loose. what could have caused this? i need to pull the intake so i can get a broken pushrod out of the lifter valley. any input would be great.

 

[buwagon78]

Re: drivetrain carnage

Hydraulic cam...valve adjustment with lifters down? Valve piston clearance issue? Need more info...

 

[mebe007]

Re: drivetrain carnage

Hydraulic roller. Not sure what caused it. Never used 1.6 eatio till this. Never ysed roller rockers bwfore this. Machinist/friend suggested 1.6 scorpion rockers for the 7/16 studs. He did tge pushrod length when i wasnt there. He suggested zero lash and one full turn till it was run then re adjust. Well it didnt make it tgat far. Noticed di clamp a lil looser than normal

 

[bracketchev1221]

Re: drivetrain carnage

Coil bind? Or the pistons were whacking all the valves.

 

[mebe007]

Re: drivetrain carnage

Yeah not sure. The sprinfs were matched to cam. Maybe my machinist got the pushrod length wrong and the 1.6 rockers didnt help it

 

[buwagon78]

Re: drivetrain carnage

How much lift? Is this an all new build or just new top (rockers, studs etc.). This should show an obvious problem when you do the following...

Leave the intake off, pull the plugs, mock up only one cylinder with push rods and rockers, and turn it over with wrench gently (this won't give you piston valve clearance but might show you what's binding on the top end). Watch for spring bind, rocker arm binding against studs. If the motor stops without the valve spring or rocker being in a bind, the valve may be striking the piston and you have a piston clearance issue (less lift or have reliefs cut in pistons. Never messed with hyd/roller but I assume it adjusts like normal hydraulic lifters (make sure they are pumped up before zero lash setting). Half turn is fine passed zero for warm-ups.

I'm sure others wil chime in if my roller lifter advice is wrong. Hope this helps.

 

[mebe007]

Re: drivetrain carnage

All the specs of the car. Motor is fresh

Parts list:
Profiler 195 cc 64cc alluminum heads with port work by chad speier
Edelbrock performer rpm intake with gasket matched to 1206 and ported by chad speier
KB +.060" #231 pistons 2valve relief 6cc
Scat forged 5.7 rods
Howards retro roller cam PN: 110265-12 (.533 .548 234/242@ 50)
cloyes billet roller timing set with torrington bearing
Cloyes 2piece timing cover with button
scorpion 1.6 roller rockers

 

[mebe007]

Re: drivetrain carnage

Sorry copy paste from gbody forum. Will delete photis once im not on my phone

 

[lilbowtie]

Re: drivetrain carnage

Sorry to here of your delema you have to be sick. I'm suprised you didn't feel anything barring the engine over to do the setting of the valves but if the lifters weren't pumped up it might have masked it. The guys have pointed out the probable causes and I have even seen pistons in wrong to improper cam timig. Good luck and hope damage is just what you see.

 

[LS6 Tommy]

Re: drivetrain carnage

Sorry to say, but it sounds like a clearance issue...

Tommy