possibly a lifter collapsing, a question..
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From: Manhattan, NY
possibly a lifter collapsing, a question.. my dyno looks sorta like a heart monitor 
Matt @ TTP said it might be because a lifter (or a few from what i understand) might be collapsing.
Seems like everything is breaking around me..
So..
My question is - if it is in fact a lifter, what will happen if it will collapse as I am driving? will it damage anything, and take something with it?
I am just curious, cause I am broke right now, and dont have the money to tear into the engine.. I'd like to change at least a cam, hopefully heads too, while we'll be in the engine.. so saving up for that.
So. What will a collapsed lifter take with it, if anything, if I wait until it breaks before fixing it?
Matt @ TTP said it might be because a lifter (or a few from what i understand) might be collapsing.
Seems like everything is breaking around me..
So..
My question is - if it is in fact a lifter, what will happen if it will collapse as I am driving? will it damage anything, and take something with it?
I am just curious, cause I am broke right now, and dont have the money to tear into the engine.. I'd like to change at least a cam, hopefully heads too, while we'll be in the engine.. so saving up for that.
So. What will a collapsed lifter take with it, if anything, if I wait until it breaks before fixing it?
I collapsed a few lifters on my old Chevelle, granted it was a Gen I 283cid motor. I wound up with a messed up exhaust valve on one of them. I don't think the lifter collapsing caused it though...It was more related to the fact of the valve sinking into the head. <--Non hardened valve seats.
I'd just watch my driving and keep the RPMs low.
I'd just watch my driving and keep the RPMs low.
Thread Starter
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From: Manhattan, NY
Originally Posted by JsLS1
I collapsed a few lifters on my old Chevelle, granted it was a Gen I 283cid motor. I wound up with a messed up exhaust valve on one of them. I don't think the lifter collapsing caused it though...It was more related to the fact of the valve sinking into the head. <--Non hardened valve seats.
I'd just watch my driving and keep the RPMs low.
I'd just watch my driving and keep the RPMs low.
correct me if i'm wrong, but camshaft's lobes move the lifter up and down.. doesn't really matter if you're going 2 mph or 200 mph - your lifters are working at pretty much the same rate
Originally Posted by firechicken2k
how do rpm's even matter, with a lifter?
correct me if i'm wrong, but camshaft's lobes move the lifter up and down.. doesn't really matter if you're going 2 mph or 200 mph - your lifters are working at pretty much the same rate
correct me if i'm wrong, but camshaft's lobes move the lifter up and down.. doesn't really matter if you're going 2 mph or 200 mph - your lifters are working at pretty much the same rate
As the engine turns faster the cam turns faster. As the revs increase the velocity at which the lifter follows the lobe increases. At peak lift the inertia mass of the lifter increases exponetially exerting more force on the valve spring which must control and dampen the inertia. RPM is not a friend to hyd roller lifters.
Chris
Chris
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From: K-W, Ontario
Don't forget the lash/preload clearances also get thrown out the window.
You may risk the chance of bending pushrods, breaking rockers, etc.
That would be the difference of a lifter moving up and down at ~20 times per second, or 200+ times per second.
Which case would cause more damage if a lifter collapsed?
Force/Velocity explained:
http://othello.mech.northwestern.edu...h5/Sources.htm
You may risk the chance of bending pushrods, breaking rockers, etc.
2 mph or 200 mph - your lifters are working at pretty much the same rate
Which case would cause more damage if a lifter collapsed?
Force/Velocity explained:
http://othello.mech.northwestern.edu...h5/Sources.htm
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Originally Posted by Adrenaline_Z
Don't forget the lash/preload clearances also get thrown out the window.
You may risk the chance of bending pushrods, breaking rockers, etc.
That would be the difference of a lifter moving up and down at ~20 times per second, or 200+ times per second.
Which case would cause more damage if a lifter collapsed?
Force/Velocity explained:
http://othello.mech.northwestern.edu...h5/Sources.htm
You may risk the chance of bending pushrods, breaking rockers, etc.
That would be the difference of a lifter moving up and down at ~20 times per second, or 200+ times per second.
Which case would cause more damage if a lifter collapsed?
Force/Velocity explained:
http://othello.mech.northwestern.edu...h5/Sources.htm
TECH Resident
Joined: Dec 2004
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From: K-W, Ontario
I wasn't making a reference to the frequency per second as it applies to RPM
( I didn't list RPM).
I was just stressing the extreme of his example (2 MPH to 200 MPH) to highlight
the effective mass, inertia, and job of the valve springs to control all of that
reciprocating weight.
But in any case, you're correct. Sorry for the confusion.
( I didn't list RPM).
I was just stressing the extreme of his example (2 MPH to 200 MPH) to highlight
the effective mass, inertia, and job of the valve springs to control all of that
reciprocating weight.
But in any case, you're correct. Sorry for the confusion.
