new cam, now engines burning a bit of oil?


The Grumpy Grease Monkey mechanical engineer.
Staff member
Grumpy, I installed a new cam in my camaro, it runs better , but it was not burning any oil, before the cam up-grade,
now it seems too be burning about a quart every other tank of fuel,
any ideas?

if the cam you selected has increased lift or you changed rocker ratios to increase the valve lift you need to accurately verify the retainer to valve guide and coil bind clearances, theres an excellent chance the higher lift on a new cam with a stock valve train, can significantly decrease the clearance between the lower valve spring retainer to the upper surface of the valve guide, and thats exactly where the valve oil seals are located, get that too close at full lift and the clearance crushes the valve seals rendering them nearly instant junk, in the process as a result.
I can,t begin to tell you the number of times I see this result when guys simply install a performance cam in an engine with out verifying the change in valve train clearance, in an otherwise O.E.M. valve train
most stock SBC valve trains only allow a .470-.500 lift without modifications to the valve guides, seals, retainers or valve springs.,
you can,t assume that clearance,
or that valve train clearance will remain in acceptable limits
after changes are made,

all valve train clearances needs to be accurately verified


you'll want to verify the retainer to valve seal clearance, IS A MINIMUM OF .090 AT FULL LIFT WITH THE CAM YOU'VE INSTALLED, DON,T ASSUME ITS OK, VERIFY IT to prevent valve seal damage,
theres several ways but the easy route is placing a bit of modeling clay shaped like a washer or ring on top of the valve seal,rotating the engine 4 full rotations and then use your calipers to measure the clay thickness after it was compressed by the valve spring retainer.



reading and paying attention to the info contained in the links below,
will go a long way toward avoiding expensive repairs
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