Valve train question

[Mrbill426]

I put the heads on today and then the lifters, push rods, and rocker shafts.  When I bolt down the shafts the push rods appear to be bottoming out in the (dry) lifters where the cam lobes happen to be at full lift, in other words I cannot push down those particular rocker arms towards those lifters (no lash) nor can I spin the push rods.  They also seem to me to be at a pretty steep angle with the plungers, touching the snap clip.  The lifters are new, as are the push rods which I opted for COMP cams #7820  5/16" that are thicker than original but the same length.  The camshaft is a pretty mild Lunati Voodoo with .475" / .494" lifts; stock rocker arms.

I don't remember how they were originally so maybe this is normal??

It just seems since there is no oil in the lifters yet there should be some "play".

[1 Wild R/T]

The angle is normal, it's always looks really odd but there's a reason for it... The LA engine is based off the old 318 Poly block architecture and on that engine the rockers are at very odd angles...

[Chryco Psycho]

The reason the lifters are bottomed out & there is no play is you on the top of the lobe where the valve should be wide open , if you are on the low part of the lobe opposite the max lift everything should be unloaded

[Mrbill426]

Got it, thanks... just seems weird... like at higher RPMs that angle would become a problem.

The angle is normal, it's always looks really odd but there's a reason for it... The LA engine is based off the old 318 Poly block architecture and on that engine the rockers are at very odd angles...

[Mrbill426]

@Chryco Psycho that makes sense; thanks for sending me outside the box.    Will it be damaging to have those few plungers (springs) fully depressed for an extended period?  Not sure when this will be started.

The reason the lifters are bottomed out & there is no play is you on the top of the lobe where the valve should be wide open , if you are on the low part of the lobe opposite the max lift everything should be unloaded

[Chryco Psycho]

They are designed to function as is , but you can always loosen the rocker shafts until you are ready to fire it up .

[Mrbill426]

@Chryco Psycho I might just do that.

They are designed to function as is , but you can always loosen the rocker shafts until you are ready to fire it up .

[RzeroB]

As Wild RT mentioned, the LA engine lifter to pushrod geometry is "angular" because the lifter bores maintained the 59 degree lifter bore angle of the Poly headed A engine. It looks wrong ... but it's right. To me, the lifter to pushrod geometry of this engine has always looked weird. Why Chrysler did this I have no idea but I'm sure it had something to do with saving a few bucks.

When Chrysler lured Glidden to run Pro Stock for them in '79, the LA engine used was extensively modified, to include cutting out the lifter bores and reinstalling them at an angle that aligned them with the pushrods. The research and development in that engine was eventually incorporated into the R3 block where the lifter bore angle is 48 degrees and aligned with the pushrods.

[Mrbill426]

@RzeroB that's interesting, thanks for the info.

As Wild RT mentioned, the LA engine lifter to pushrod geometry is "angular" because the lifter bores maintained the 59 degree lifter bore angle of the Poly headed A engine. It looks wrong ... but it's right. To me, the lifter to pushrod geometry of this engine has always looked weird. Why Chrysler did this I have no idea but I'm sure it had something to do with saving a few bucks.

When Chrysler lured Glidden to run Pro Stock for them in '79, the LA engine used was extensively modified, to include cutting out the lifter bores and reinstalling them at an angle that aligned them with the pushrods. The research and development in that engine was eventually incorporated into the R3 block where the lifter bore angle is 48 degrees and aligned with the pushrods.