Need Help pistons hitting my Exhaust valves

[Minimonkey]

Ok so about a two weeks ago I was on my way back from the beach and my cars starts knocking and the idle drops off, I also noticed a big power loss.
so I parked the car worried about a full motor tear down and rebuild i put it off till i could have the time to rebuild.
After pulling the head I find that all my pistions have made contact with the exhaust valves.. Like a noob I pulled it all apart with out checking if my timing marks were off... ugh

Question is, what would cause this?

1. Did i slip my timing belt? (keep in mind I've had a big power loss too)

2. Are all my crank rod bearings bad/wrong size?
could they be slapping? I have about only 7k miles total on the motor

3. Aliens?

4. V-tec?

[LJ851]

If all 6 pistons look similar to the one shown then the cam probably got out of time with the crank.

[Minimonkey]

yes all the pistons lok the same.

[LJ851]

The answer is #1.

[Minimonkey]

thank you, but ive been leaning torwards #4 i was really worried!

[LJ851]

If it was #4 the intake valves would have hit, not the exhaust.

[Minimonkey]

if it was #4 the intake valves would have hit, not the exhaust.

:d

[cwbaader]

Valve float will cause this as will a cam that is too retarded. When you rebuild the head, insure the cam is timed correctly, and I would add the second valve spring that came in the "i" motors.

Note: on reassembly you should check piston/valve clearance with clay. Install the head with the old head gasket and torque part way after you have put a thin (1/8") layer of clay on the top of the piston. Time motor and turn over to check clearance. Anything less that .050" and you will need the thicker head gasket. Good luck.

[MonkeyMadness]

#3

[TobyB]

Valve float will cause this

but the rockers will break first, usually.

And the intakes go first, as the intake valve is significantly heavier.

t

[cwbaader]

I have never broken a rocker but all my pistons on my race motor look like that. Minor interference does not break a rocker.

[TobyB]

Minor interference does not break a rocker.

no, the float does.

t