Valve Lash question.
 

454 Cu. Inch big block.
Hydraulic roller tappets.
Roller Rockers.
What would the valve lash be?
Thanks in advance for the reply.
Brian

Zero. Bring down till all up and down movement in the pushrod is gone then give it 3/4 to 1 more turn and lock it down.

bring to zero then 1/4 for stock GM lifters. If you are using after market lifters follow the mfg's specs. Most H-Per Lifters are zero plus 1/16th of a trun no more than an 1/8th.

or snug all rockers till no up/down play in pushrod. run motor to operating temp. take off valve cover. while running slowly loosen each rocker till you hear tapping. then slowly tighten it till there is no noise, then add 1/4 turn and lock down.

Do a search on this topic and you can read until tomorrow morning.:drink:

I always go zero 1/2 to 3/4 turn.

35 years ago:eek: I was taught to take the valve covers off and adjust that way. To big of a mess. I still have the oil deflecters in one of my tool boxes.

+1

yea I actually have a set of valve covers dedicated for that for when my motor was hydraulic roller. Solid roller now, so now there is lash.

Going the messy route will make the most power tho from what I was told

X2

You do not set a solid lift cam with the engine running - is that what you're thinking?? No way no how. Get the spec's - exhaust is usually more than intake - follow the procedure for placing the cam in the correct position based on the other valve - use a feeler gauge and you're done.

IF I remember correctly - set the intake when the exhaust starts to open - set the exhaust when the intake is about half stroke to being closed...

Don't quote me on it - it's been a while...

UHHHHH.......I don't think anyone was thinking that.

I hope not... but ya never know!

riverrat.. i said my motor was now solid roller, so there is lash... re read everything, you misunderstood me..
if you tried that with a solid roller, not only would you be chaseing your own tail but sure would be a spell for some ****ed up parts!

slow but fool proof
 

ok this is slow but fool proof
take plugs out
rotate engine over by hand ( breaker bar on harmonic balancer bolt)
one cylinder at time rotate engine (in direction of rotation)until exhaust lifter starts to move up , install and adjust intake rocker ( as said in other posts follow manufactures guidelines usually 3/4 - 1 turn past 0 lash ie hold wiggle / rotate push rod as you tighten rocker polyloc by hand untill up and down play is out thats 0 lash
continue to turn engine over until intake has gone all the way up and is almost all the way down then install exhaust rocker

I know this is time consuming and there are those that say to turn engine over certain number of degrees and you can do various cylinders at once ( this only works on small cams )
the above method while slow works on all cam profiles ( of course on a solid lifter you adjust with feeler gage instead of preloading
also the hot lash method usually is not practical on a boat because most of the time one can not get the valve covers off with the exhaust on ( and it does make a mess even with those little clips to deflect oil ) they were made for the factory stamped steel rockers anyway and would not work for roller rockers
hope this helped

No $hit!!! I offered to help a friend one time who kept saying "I've done this a hundred times" .. so I left - went for a boat ride... came back later and they set it at zero lash... but the dumb a$$ bottomed out the lifter and considered that zero - then added 1/2 to 3/4 .... needless to say it never started - had no compression... I came back from riding and he asked me to run the rack - which i did. Fired right up.... sad part is he had them so tight on such a high lift motor it bent the valves ...one way .. then at 5K on the tach - they went the other way - via thru the piston into the block .. broke cam and all .... can you say ..oops??? Best of luck to ya!

I missed the fact that it was solid roller earlier. You have to set the lash based on the specs that came with the cam. You use a feeler guage. Lash should probably be in the .020-.030 area or so.

You didn't miss nothin Griff. Talk'n hydraulic roller here.

Yeah, I see that now. Hyd roller for the original poster, so a 1/2 to 3/4 is good and should give about .040 of preload which is what is needed on most hyd lifters. I think Morels require less preload.

Thankguys for the input. We adjusted the valves
and the motor started up and ran real sweet. We do have one noisey tappet that we will adjust today. A real pain in the ass getting the dome cover off and adjusting the valves while running. The boat has a fairly eratic cam. Timing it is another issue no marks left on the timing tab, so we basically went one way with the distributor, then the other until she idled fairly well. Started real nice and just left it. We have no specs on camshaft, so basically we are winging it.
Thanks