Running good...when suddenly...

[Kronoss]

Hello,

Had my CP vintage racer out to Blackhawk Farms (located in northern Illinois) this past weekend, and overall had a great outing. I qualified well, and was running in second position during the vintage feature.

On lap 8, I noticed smoke beginning to enter the cockpit, but oil pressure/water temp was good...so I pressed on.

On lap 9, entering turn 3A (a twisty section) the motor quit with a muffled bang, so I immediately took to the grass.

My initial thought was head gasket, and a preliminary inspection has shown zero compression on all 6 holes. When cranked by hand with a turnover bar, all appears to be functioning (valves actuating, rotor turning). The timing chain is in place, although there seems to be excessive lash (in my opinion, anyway). There was oil blowby evident on the RH side of the block towards the rear(just aft of the dipstick tube).

Before I pull the head off, does anyone want to venture a guess as to what may have happened? The motor seems to be way out of time, plus I doubt that I blew the rings (or valves) on all 6 pistions at the same time.

The car ran great all weekend, up to the incident...so I'm a bit puzzled.

-Thanks for any feedback

Mark Atkinson

[MikeW]

It sounds like the timing chain may have slipped. Since the car has an interference engine it is possible that the valves could be bent which would explain the lack of compression.

[tube80z]

Before I pull the head off, does anyone want to venture a guess as to what may have happened? The motor seems to be way out of time, plus I doubt that I blew the rings (or valves) on all 6 pistions at the same time.

Start pulling the head. Being out if time is a good indicator that something happenned with the chain. On my car all 6 intakes were bent, a couple of exhausts, and about three broken guides. Take the time to inspect the timing chaing bolts as they may have been damaged in all this.

I'm not sure how it happened on my car but the pin on the cam was sheared off. Cause or effect is unknown.

Cary

[Ed]

snip, although there seems to be excessive lash

Bent valves for sure.