Technical bbc failure

i heard a pop and had poor idle and a valve ticking after a mild flogging limped home 4 mile and pulled valve covers # 7 had bottom tip of pushrod gone on exhaust and intake had bent pushrod and no retainers on valve which was opened about an inch and most likely bent.. to disgusted to pull heads right now and wondering what led to this mess. have flat tappet hydaraulic with 525 lift heavy duty springs and guide plates with stock rockers.and pushrods motor has 5000 miles and ran great. any ideas as to the cause

 

Possibly stock pushrod failure? Lippy

 

Your guides were too tight or you had poor oiling to your top end? Those would be my guesses..

 

"This is the life we've chosen." Hyman Roth

Hope you get it worked out. I have much respect for a well run BBC.

 

I agree with Black Panther. I had a similar problem where there was not enough clearance between guide and valve stem. Pulled both heads, had them rechecked and clearanced properly. This also occurred withing about 5000 mi. Now the engine is at 40k and going strong.

 

Just don't get how both failed in the same cylinder

 

How tight did you buzz it? Lippy

 

Not at all was cruising about 30 punched it ,it popped I lifted no more than 3500

 

One caused the other I guess.
Lost the retainer, bent that valve and it hit the other valve and busted the push rod?
While it's still together I'd look for an oiling issue too.

Heads off is more *****ing and moral dropping than just doing it. If it were your buddies car you would have the heads off in an hour or 2 and on your way to back on the road.

 

^^ yep, my guess too. Aluminum retainers?

 

Take it apart, post nice clear large pictures of all the parts, then we might be able to figure out what happened. Without all the information, we can guess all day long and be wrong.

 

Steel retainers one keeper is still in the retainer other is gone

 

yes I hear you and you are correct thanks all

 

FWIW, Had a 427 blow up due to intake valves fitted too tight in the guide acted almost the same, expect it died. Much more violent, happened at the top of second gear at about 6800 at the track. Popped hard, quit, driver pumped the pedal, spit and died again, LOTS more damage than what you are describing.
Check the valve to guide clearance in the remaining cylinders, and carefully inspect the valve stems for galling/scoring. But like squirrel says, could be lots of other things too.

 

This no doubt will add nothing to the thread but I am going to say it anyway when I saw the ***le "BBC failure" my immediate thought is that is what ****** is for. LOL

It could be that the motor stuck a valve or that the valve keepers let go, that is why they make 10 degree retainers for high performance use ( or is that 7 degree I always get those two confused). If you loose a retainer then you have nothing to keep everything else in place same if you stick a valve. The valve drops which in turn releases the pressure on the pushrod and the lifter and things just start unraveling from there.

I hope that your repair is inexpensive and no more difficult than just replacing the bad stuff.

 

A friend recently had a similar failure with his BBC that has been his driver for years. He replaced all the pushrods with new ones, set the clearances and is going again. Just fatigue, everything wears out over time and some things go before others. Murphy's Law