Only bent 1 valve on cyl 4!!

[1glaserfwd]

Well the joyride continues this year for me! I was doing some street tuning and I was wot and at the top of 2nd gear it hit the rev limiter 7500 and as soon as I went to shift to third the car was sputtering badly and running on 3 cylinders. Limped it home to find cyl 4 was dead. Compression test showed 0 and the others had 150! Did the wet test and it stayed at 0. I checked timing and it was dead on. I figured I burned a valve or maybe a piece broke off of one. Pulled the head today and 1 intake valve hit the piston!!

Pulled everything out of the head besides the valve and springs and to the naked eye it all looks fine. I am going to get a valve spring tool and pull them out this week and see if anything looks bad. The car has dual valve springs so I did not think it was possible to have valve float at only 7500 rpm. Any input would be appreciated! Thanks

 

[killercolt]

Make sure the spring is not broken. Make sure the stem was cut shorter when the valve seats were cut. The lifter can bottom out and the valves will not seal. Also make sure the lifter is not over extended.

 

[BogusSVO]

Sing or dual valves, it matters not if the installed height is not checked and shims added under the spring seat.

If the springs were just "dropped in" you have no clue what your pressures are.

So Yes, I can see a dual valve spring float at 7500 rpms

 

[Blindsey]

I spoke with him on the phone earlier. There are shims installed, we're going to check it out tomorrow or the next day the be sure they were installed properly.

 

[BogusSVO]

What did you find out?

 

[1glaserfwd]

Have not pulled it yet, hopefully tonight and will report back

 

[Blindsey]

I've been way busy this week, goings to try and rip it apart tomorrow.

 

[DSM1G90]

What I thought too, was valve float due to his descript on how high the rev counter was and the sudden engine sputter...

 

[BogusSVO]

What guides are in the head? Bronze? Cast?

Stock or Stainless valves?