Blown motor thoughts

[3dinter]

Went and raced the concrete track and the motor let go. During the heat race I got about 6400 rpm with a stock 355, 4 eyebrow, 450/450 cam, 4412, stock heads 1.94 / 1.50. Went out for the feature took the green and during the 3rd lap coming out of turn 2 something inside went thru the front of the oil pan...here's my crazy question....
I got back to the pits and the tach read 9900 rpm..I have in car video with sound and there is no way in hell that engine turned 9900 rpm...so how or why did the tach read 9900 rpm ????
Or am I deaf ???...highly unlikely.

[500BOMBER]

With that tach reading and the hole in the pan, I would look at the axles and see if one of them is twisted off or stripped splines. All of that kind of damage can happen in a 1/4 of a second.

[3dinter]

With that tach reading and the hole in the pan, I would look at the axles and see if one of them is twisted off or stripped splines. All of that kind of damage can happen in a 1/4 of a second.

i was thinking the same thing, i heard after the fact that a 26 spline mini spool on concrete aint to good.

[stockcar5]

a low compression 355 witha 2bbl and heavy internal parts will NOT rev from 6400 to 9900 in 1/4 sec. more than likely when the motor broke it may have done some damage to the distributor which could short the tach and cause the high reading.

[chevy370lsx]

I hit 8400 once in a stock crank stock rod motor once on a missed shift after getting spun out, still far from 9900

[3dinter]

a low compression 355 witha 2bbl and heavy internal parts will NOT rev from 6400 to 9900 in 1/4 sec. more than likely when the motor broke it may have done some damage to the distributor which could short the tach and cause the high reading.

i just spoke with my machine shop / engine builder and he thinks maybe the cam broke which in turn sent the rpm's crazy high.