I have a 38 Cigarette with 94 502's Last week i was driving along at 4000 RPM @50 MPH when one of my motors just shut right down. Myself ad EPEEK tore the front of the motor down last night and found my cam in 2 pieces. WTF ?? What would cause this. The motors were gone thru and redone 47 hour ago and they have a total of 448 hours since new. I have had no problems with them except that both of them love to use oil. Proably a quart every 5 hours or so. I had just checked the oil the day before and add 2 quarts so I dont, and I repeat, dont think the oil was low when this happened

Any input would be great

We prepared the motor to come out of the boat last night, and should get it out this week and tear it all the way down. Hopefully not alot of internal damage ??!!

Bob

I've seen one that broke, probably due to a failed cam bearing. It also destroyed the block when it let go.
Gary

I've seen several break was it a flat tappet hyd. or solid ??? where did it break ?? useing that much oil it changed itself ,wow

you'll need to clean even the wrist pins ect that metal falls everywhere

I am curious what would make a cam bearing fail. Relative to the rod and main bearings cam bearings are lightly loaded. Does excessive oil temps hit cam bearings hard? With a BBC oil starvation will show in mains first. How can one tell if cam bearings are a problem before disaster?

BT

My wife did when she drove my Bronco in low loc at 75 for 25 minutes! 400 M at 6200 for 30 miles should about do it. Very different situation but a cam will break.

Well that sounds like an oil temp problem Bad dog I bet you got reamed for leaving it in low loc, if she is like my wife

BT

Bobby Daniels, It broke between the first & 2nd lobe. I dont
know the motors,but I think its a hyd flat tappet cam.


Rick

I beilieve the 502 run rollers.

A customers boat threw a rod and broke the cam. Customer said engine just died. Cranked fine but no spark!!

Things to look for with a broken cam:

All cam bearings-may have uneven wear on one.

Cam bore-may cause one brg to wear.

Loss of oil to cam brgs causing friction-look for scoring.

Too much endplay at cam-rocks back and forth and unevenly loads timing chain-force is transferred to cam.