Hydraulic roller cam and stock rocker arms

[Doosterfy]

Since we're talking about roller cams and valve trains here I'm going to do a minor thread hi-jack. Why is it that with solid rollers, (the actual wheels and axles on the lifters) don't last for a long time and/or lots of miles while hydraulic rollers do hold up to high millage? I'm sure spring pressures, lash and the more aggressive cam profiles play a role but is there a difference with the roller wheels and axles on the lifters between solid and hyd rollers? I run a solid roller in mine and I love the performance but I now have two years on the engine and I'm short on disposable money now so I will have to use what I have one more season.

 

[Marcohotrod]

good question Dooster, and I think U answered it,also the factory used taller lifter bores with the taller hydraulic roller lifters. still waiting on IQ52 to get back on this, or did I get there first

 

[BigBlockMopar]

I think most folks run with too much (or the recommended) lash which hammers the rollers to bits.

With roller cams I always check/set what the cam-maker thinks the lash should be, and then after hearing the engine run (warmed up ofcourse), I decide how much quieter I want the valvetrain to be, and tighten up the lash accordingly.

I always tend to think cam-makers spec their lash on the loose side so they are safe and it won't cause issues for folks who happen to run their engine at very hot temps occassionally.

 

[hotrod360andy]

Just wanted to share my experience with upgrading valve train and using stock rocker arms. Notice the hole where the push rod went through the rocker arm after a few thousand miles

 

[IQ52]

I think most folks run with too much (or the recommended) lash which hammers the rollers to bits.

With roller cams I always check/set what the cam-maker thinks the lash should be, and then after hearing the engine run (warmed up ofcourse), I decide how much quieter I want the valvetrain to be, and tighten up the lash accordingly.

I always tend to think cam-makers spec their lash on the loose side so they are safe and it won't cause issues for folks who happen to run their engine at very hot temps occassionally.

Important thing to remember is that the hotter the engine gets, the more the block and heads expand, thus lifting the rockers away from the cam and increasing the lash. This is especially true with aluminum heads and blocks. The cold lash on an aluminum head and iron block should start at .006" tight and an aluminum head and aluminum block should start at .012" tighter cold lash than the recommended hot lash.

 

[Doosterfy]

Important thing to remember is that the hotter the engine gets, the more the block and heads expand, thus lifting the rockers away from the cam and increasing the lash. This is especially true with aluminum heads and blocks. The cold lash on an aluminum head and iron block should start at .006" tight and an aluminum head and aluminum block should start at .012" tighter cold lash than the recommended hot lash.

That's good to know. I have always set my lash cold. I'm pretty sure my engine will benefit from a little more lift and duration too so this will help.