77vetteLS1

I just finished my head/cam swap. I was tuning the car when I notice white smoke coming from one of the tail pipes (true dual exhaust). Shame and disbelieve set in... I figured I somehow blew my head gasket. I checked the oil, it was good as new. Then I pulled the valve cover...

When I opened it up I immediately saw the #4 cylinder intake roller rocker was bent upward and still on the broken shaft. The shaft connecting it to the exhaust roller rocker was also broken.


The heads are trick flow
Roller Rockers are Harland Sharp 1:7 ratio
228/230 585/585 cam



My questions are:

1. What could have caused this? Why did the bolt snap? My engine was running fine before the issue. I checked all the torque on the rest of the bolts and all were normal, I can't see myself missing a bolt. Did the bolt just fail?

2. What caused the white smoke? The obvious thought is that I blew my head gasket when the intake valve failed to open. Is there another possible reason for the white smoke? Without an intake valve allowing fresh fuel and air into the cyclinder, thus not having anything to combust, how would coolant burn/evap if it did get into the cylinder anyway?

Before I call and give Harland Sharp a rash of sh*t, I'd like to know if it is justified first.

I obviously need to change out the roller rockers on that cylinder, but I'm praying that is all I need to do... What are the odds?

orangeapeel

iTrader: (18)

Did this happen on initial startup? You said you were tuning it when you noticed. I was just wondering if it happened right away or if a load on the valve train did it. That is pretty puzzling though for why you were getting white smoke.

vettenuts

iTrader: (4)

How did you install them?

77vetteLS1

I had allowed the car to idle for about 30 mins and I drove the car easy for about 10-20 miles. No ticking or rattling was heard during initial idle/driving. I started the car to get it to operating temp, I walked to the front of the drive and when I turned around, I could see the white smoke. So when the shaft snapped it was at idle. I ran to the car and turned it off, I didn't even think to pay any attention to the valvetrain noise, but I don't remember hearing anything.

As for installation, this is the first time dealing with these type of roller rockers. I followed the instructions provided by harland sharp. As I recall, it wasn't anything too complicated, but follow the sequence and bolt to 22 ft/lbs. Was that my problem?

what about the white smoke? The smoke was only visible for less than a minute. Do I need to plan to do a new head gasket, or possibly even rings???

garygnu

was the headers on the car during the H/C swap?maybe you got some coolant in the headers when you pulled the old heads.was the lifters on the cam base circle when you torqued each rocker pair ?