Originally Posted by 27Tall T
Just when I thought I had it all figured out this happened. I have a rebuilt 327 sbc that has not as yet been run. I should have set the valves and timing before installing it into the car, but oh well. Found TDC and adjusted the valves in the proper sequence and then set the distributor according to #1. Primed the engine with a little gas and it started to fire on a few cylinders, but not enough to run it. Poured a little more gas and it fired or should I say it liked the extra gas in that it exploded through the carb, blew the oil filler cap off, bulged the passenger side rocker cover and bulged the timing cover enough (1/4") so that I cannot see the timing line as it is hidden by the timing tab (bolt on). What gives?
I checked the TDC and the distributor and it was right on. I then went through the motion of setting all the valves again, BUT......one rocker had a termendous amount of play in it, as if it wasn't adjusted. Then I remembered.... the phone rang, I answered it and then returned to completeing the adjustment of the valves, missing that one.
I assume that there was ignition in that cylinder and it had no where to go but up and every where else. And so my question is, will the timing cover still suffice as is or is it needed to prevent the cam (hydraulic) from walking? I've been told that the cam stays or walks to the back of the block and the timing cover is not needed to do this job as this is a hydraulic set-up. Any comments would be greatly appreciated.
In the case of an engine that has not been broken in, the fuel you poured down the carb to start it leaked past the rings, into the crankcase. Then when the engine tried to start, the same lack of ring seal- aided by the valve being shut because it wasn't adjusted right- likely allowed the flame from that cylinder to force its way into the crankcase where there was now an explosive atmosphere.
Result = *BOOM*.
As long as the covers are still sealing and no gaskets were spit out in the explosion, and that there's nothing rubbing against rotating parts, I suppose you could continue the break in process and hope for the best.
But I'd rather see you take the time NOW to take the covers off and straighten/replace them along w/the gaskets and seals if needed.