Valve lash

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1stgen

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Hi, I’m currently building up a stroker motor (408), I’ve just installed the rockers but can someone advise me on what clearance I should give on the valve lash? It’s a hydraulic flat tappet cam.

Cheers mark
 
No valve lash on hydraulic cams. Rotate push rod, that is on base circle, until it has tension. then I think it is turn a half, then lock.
Someone will confirm the procedure.
 
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I stick a pc of tape on em after each 1 is adjusted. Its easy to lose track of which 1 you are working on. Set em and forget em and get your valve covers on.
 
Thanks for your reply’s Also what engine oils do you recommend and would you use a break in additive?
 
I think I'd like to know which hydraulic lifter is being used and if he has aluminum heads before I'd recommend a preload setting.....but that's just me.
 
With my last LA motor, 318>390stroker low lift hyd flat. I used 273 adjustable rockers. As above, used the cam circle lift sequence to adjust. Hit the valve stem with rocker and went 180/half turn from there. I found that using the pushrod twist method was giving me more preload than I wanted. But if I watched the contact point between the valve tip and rocker while holding it on the lifter side and just as it hit, half turn worked for me.
 
I’m using Hughes cam and lifters with Edelbrock heads if that’s makes a difference?
 
TheGrateRonzini said:
I use HD diesel 10w30 and a bottle of additive.
Click to expand...
I don't care if someone uses water with a handful of sand LOL when I put out thousands of dollars on a one-time basis that's for sure for a new 408 stroker I'm using expensive break in oil... I just don't got it like that to take any chances on simple oil..
 
new cam? do the lifters have rev-lube on them and the cam?
let the blender blend the oil
some additives are incompatible with some oils and make ep worse
did you pre lube the system with some hex stock and an electric drill?
you want to make sure those pushrods are spinning
it should fire right away
if it does not fix it don't crank lt
 
I’m following the chart but it’s only working up to no 4 inlet and no 6 exhaust, the valves are open, I’m rotating the crank 90degree each time, is that correct
 
1stgen said:
I’m following the chart but it’s only working up to no 4 inlet and no 6 exhaust, the valves are open, I’m rotating the crank 90degree each time, is that correct
Click to expand...


For what you are doing just start over and use the firing order. When you are a TDC number 1 firing, set that pair of valves. Rotate the crank 90 degrees and do 8 and so on.

No need to do the 8 position valve setting on hydraulic lifters.
 
Cheers for that Also how free should the pushrods be once adjusted, these are pretty firm and tough to rotate
 
#1 intake goes down and as it comes back up, align the timing marks. Thats #1 on firing. Then use the chart. In case you are unsure of tdc firing. Good luck with your project!
 
1stgen said:
Hi, I’m currently building up a stroker motor (408), I’ve just installed the rockers but can someone advise me on what clearance I should give on the valve lash? It’s a hydraulic flat tappet cam.

Cheers mark
Click to expand...

I just put my 360 with Hughes cam/ comp lifters and roller rockers back together last week and went through this. I tried the whole spinning the push rods but found I was looking for more spin resistance than I needed and was preloading my lifters way too much so I restarted. The only cam lobes that are hard to see are cylinder #1, but what I did was starting on #1 I spun engine till both valves were on heel of lobes (compression stroke) and while rocking the rocker gently by hand I tightened both intake and exhaust to zero lash/ no rocker movement. Then I got cylinder #3 liters on heel and so on and so forth did that to each cylinder. I went around the motor counter clockwise getting them all to zero lash. Just to be certain I rotated the motor a couple revolutions in 90 degree increments and checked each rocker to ensure zero lash. I then went around again preloading them all 1/2 turn and locked em down. It may be the long way to do it but im confident they're all correct and I never lost track of where I was. That's just how I did it, with my simple mind I have to dumb things way down.
 
Yeah I worked my way through the firing order quarter turn at a time setting then to zero lash then 1/4 turn pre load but my concern is the push rods don’t rotate easily as mentioned in other posts but I guess they won’t if under load
 
Correct! Once you pre oil the valve train will become oiled. Lifters pump up and it will do its thing.
I started with the chart and corresponding valves, spinning the pushrod until a slight drag was felt then, I used a digital gauge on the cup to the valve cover lip, then 0 the gauge, then between -.015 to -.020 with the adjuster and tighten the lock nut. It turns out to be 1/4 to 3/8 of a turn. It worked great at the dyno and in the car. No issue at all. The lifters can have some tolerance between valves and they may make a lil noise when you 1st start it until the oil psi builds up in them. Header leaks can sound like they aren't adjusted right too..
 
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