MILD THUNDER

iTrader: (3)

Whats a rough estimate of the life of a aftermarket retrofit style hyd roller lifter? During a normal freshen up, is it a replace, rebuild, or just inspect and re-install deal?

kvogt

Joe
If your talking about your engines those lifters have been in there a while, I would replace them.

Kris Vogt

MILD THUNDER

iTrader: (3)

Thinking of going with Morel lifters? Probably replace valvesprings this winter also.

Not sure if you remember the brands used in mine, lifters looked like comps? Springs?

Oil psi after a hard run at idle is still 30-35psi at idle.

Dennis Moore

The life of a roller lifter depends entirely on how steep the camshaft opening and closing ramps are and the amount of valve spring pressure your engine has. Radical camshafts open the valves very fast and drop them very fast and can really play hell with the rollers. High valve spring pressures also can kill rollers very fast. Extended idle with high spring pressures is the biggest killer.

With mild camshaft specs and moderate valve spring pressures a roller lifter has a longer life span than flat bottom lifters (Stock automotive applications for instance).
Dennis Moore

mike tkach

iTrader: (3)

+1 a totally agree dennis moore

MILD THUNDER

iTrader: (3)

Makes total sense. I thought I read somewhere that merc recommends lifter replacement around 300 hours on the 525EFI? I believe the 525efi engines had a somewhat aggressive cam profile in them

Biggus

iTrader: (1)

Everytime I've had a roller lifter fail (tie bar rivet breaking) weak valve springs were the root cause. When the springs get weak, the lifters fly off the lobe stressing the tie bar/rivet causing breakage. The lifter then spins and is now skidding on the cam....it don't take long to completely destroy a motor when this occurs. Been there..

Call Bob Madara, he's got great prices on valve train components and is a dealer for Morel.

Kurt

Dennis Moore

The big super charged Mercruiser 800 hp needed the valve train rebuilt every 50 hours, as recomended by Mercruiser. This included a valve job.
Dennis Moore
Mercruiser Master Tech