bbc solid lift cam help
08-16-2007, 07:01 AM
#21
Originally Posted by ulakovic22
That happened to my engine builder once. He runs dirt and has someone regrind cams for him to keep it cheap. He wiped out the lobes in 20 minutes during break in (kinda ironic that it's called break in). He went back to the guy and found out that on flat tappet cams you have to offset the lobes something like .080 to get the lifter to spin. His wasn't so the lifter was digging straight into the lobes and took them right off. Roller's you don't have to do that apparently.
08-16-2007, 08:30 AM
#23
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Pull a valve cover & find a cylinder that doesn't have the rocker arm applying any pressure against the valve. Then take your thumb and push against the pushrod end of the rocker arm, you shouldn't be able to compress the lifter at all.
08-16-2007, 08:33 AM
#24
Originally Posted by 1997bird
Pull a valve cover & find a cylinder that doesn't have the rocker arm applying any pressure against the valve. Then take your thumb and push against the pushrod end of the rocker arm, you shouldn't be able to compress the lifter at all.
08-16-2007, 10:36 AM
#25
Originally Posted by ws6t3rror
the only lifters i will even use that are flat tappets are the gm ones with the hardened 'foot' and even then i eye them pretty close. on cheap lifters you can sit the lifters tight against each other and it'll sit basicly flat as in theres no crown on the lifter to speak of. the gm lifter is one that was used for taxi cabs police cars and heavy duty apps that did alot of sitting and idling they have a pretty good crown on them and a "hardened" foot. those are the only ones i've ever pulled out that looked like new in recent memory.
The first time I saw those lifters I thought they were some kind of reman'd junk, because of the way the foot looks, the parting line isn't real clean.
Anytime I get lifters now I inspect them closely. Usually 1-2 in a set that I won't use because of pitting on the face.
I also check for crown by putting them face to face and seeing that they "rock" against each other. An old trick a comp eliminator racer taught me because they don't worry what lobe the lifter goes back on when they do a teardown.
