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mika01
07-17-2007, 07:35 AM
So my 360 had been burning coolant and there were metal particles in the oil. So last night I pulled the intake to look at the lifters and this is the second motor this happens. The last lifter on the cam did not break in and was eating away at the cam. Its the second motor I pull a cam in which the exact same lifter and cam lobe do not set. Why is this? Is the back of the engine the area that gets the least amount of oil? Curious minds want to know.
By the way I had a blown head gasket that was leaking oil into the coolant and coolant into the cylinders. Oh well in goes the 401. Bummer. :!:

BREK
07-17-2007, 10:25 AM
How were you breaking in your cam's? Single or double springs? Yes the back of the motor is where the least oil is returned.

mika01
07-17-2007, 12:07 PM
One of the motors I picked up for free, when removed the Crower cam noticed the concave lifter and chewed lobe on the last lobe. The one I pulled apart yesterday I revved it at 2000 rpm's for about 17-20 mins. I did have the distributor 180 out at the beginning so it cranked a bit without firing. Single springs. Thats what I thought, two cams same lifter and lobe :-| only logical explanation is less oiling at the back. Thanks for confirming my suspicions.

rockjeep
07-29-2007, 04:21 PM
This same thing has happened to me twice now. I was thinking it was a fluke thing wrong with my motor. I want to build another one but what can I do to prevent this from happening again? I have a 304

82Waggy
07-29-2007, 07:03 PM
Crower makes "cam saver" lifters - they have an oil bleed hole on the bottom to ensure oiling the lobes.

At the machine shop I have been moonlighting at, they always brush the cam lobes with molly paste, poor a pint of GM EOS over the lifters (lay lifters loose in the valley, cover them in EOS, drop them in the lifter bores, and then empty the remaining EOS over the lifters and installed rockers). Add Castrol GTX or Delo 10w30 for break in - less the 1/2quart for the EOS. Prime the engine while rotating the crank in increments through several revolutions, ensuring that all pushrods are flowing oil over the rockers. Run the engine in at 17-1800rpm for 20min. If you have a problem during break in (leak or whatever), shut down, fix it, and start the 20min run-in over. After the 20min, change the filter only (it will be clogged with molly paste and assy lube) and top off the oil lost to the old filter - then go drive it like you stole it (don't baby it) for a couple hundred miles or so and change the oil and the filter. Try not to let it idle for very long for the first several hundred miles. At the 500mile mark, change the oil and filter to whatever you plan to run (I like Mobile1 10w30 and WIX 51258).

Not sure why you guys are having trouble - if you have good oil pressure it should be equalized throughout the whole system.

Note that the cam and lifter contact surfaces receive lubrication from windage (crank splash), so don't baby the motor at first to ensure plenty of oil is slinging around in there for the first several hundred miles. This is also why I don't like crank scrapers and windage trays for street cars that see a lot of idle time.

AMX69PHATTY
07-29-2007, 07:15 PM
I lost #4 Exhaust lobe and lifter.
Sounds like what I did wrong was let it idle 2-3 times for 15
or so mins. after completeing the 20-25 min. cam break-in run
instead of driving it "hard" for a few hundred miles
right after completing the cam break-in.

There's always the $1000 drop in Crane Hyd. Roller Cam option. #-o

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