Valve setting w/aluminum block and heads

Hi, never having had an aluminum headed, aluminum blocked motor before, what is a good starting point on valve lash with a cold engine? Calls for .018 when hot, but gotta get it there first. Jim

All aluminium? Set at .010 cold and check again once heated up.

With the all aluminum engines here in our shop I start at hot lash minus .012". So in your case .006". The .010" stated above is certainly not a problem.

Yup, it's all aluminum. Used to do .004 under spec with just aluminum heads, so was curious what difference aluminum block would have. Jim

I would get nearly .020 growth on my Keith Black al block and heads. Since the cam card wanted .020 hot, I set the valves at .005 cold (the minimum recommended lash) and called it good.

That engine grew so much that I had to kinda ignore the hot lash setting in favor of the minimum cold gap allowable. The hot lash was usually .025 or so.

This engine was dyno'd by builder, and valves set, but was checking spring pressures with my gauge for future reference, and noticed that a lot of the lash settings are under .005 cold, couple are no lash. Oh, and just found 1 spring 155# less than other 15. UghhhJim

My all aluminum hemi grows .013" when it gets hot. I set them at .010" cold so I have about .023" when hot.

I can tell you on my B1/KB deal we run .016" hot and if it was cold enough out it would not start cause the valves were open. When I say cold I am talking in the 40's. I really could not set them cold, on first fire up we would set them to .004 and then readjust them hot. When cold it was pretty much impossible to get anything in there but you could wiggle them a bit. On my Predator/World deal we have .006 cold..My other B1/KB deal is at .004 cold.

Crane had recommended settings in one of the older catalog, set the lash .006 tighter cold with aluminum heads on a iron block, set them .012 tighter cold with aluminum heads and aluminum blocks. Set them .002 looser with iron block and heads I have had one set of aluminum heads that would opened up .001 once warmed up My message is to set them cold and check them once the motor is up to operating temps and use the settings needed to get what you want

A lot of it depends on how hot "hot" is.
On a couple of the drag motors I built where I was doing the pulls at around 140-145deg, and setting the lash at that same temp, world blocks and Indy 440-1 or 572-13 heads it would only grow about .006-.008.
I would set them at .012 when I assembled the motor and they were real close to the desired .020 at 140deg.
One customer ran his motor at closer to 180-190, which made a pretty big difference in how much the lash changed from cold to hot.
As I recall he was down around .004-.005 cold to end up at .020 hot.

It's an Indy block and 572 heads. I'll set them at .004 after the spring problem is resolved, then set them hot. Kinda surprised valve spring went away with only 47 passes plus dyno time, but since its only one I'm hoping it was just a fluke. Company is going to send some replacements. Jim.

Be sure to check the net coil bind height of the springs you put in, and make sure that works with your actual net lift and installed height.
If you're using "all" of the spring, you need to check every one..... They often don't all coil bind at the exact same height..... Or the c/b height spec.

Are you oiling the valve springs through the rocker shafts? If so are you oiling the rocker shafts full time? If not maybe you should

PSI 1281 springs with .867/,850 gross lift cam. Build sheet says 390# @2.200 and that looks to be about where they are at on the ones I checked. Have to wait for compressor to get here to verify installed height. 14 springs were 375 to 390#, one was 350, and the worst was 255#. Dave @ PSI very good to work with, he is gonna send me a few replacements.

I'm probably just a wuss, but that seems like an awful lot of spring for an .867 lift cam.

Fast what is this term "c/b"

coil bind

That would be may guess on those letters also
OP, I have been told by more than one cam and valve spring company racer reps. to set up the solid roller race valves springs up so they have between .060 and .080 from coil bind at the actual lifts, hence mocking up the motor with checking springs first to get the actual measured valve opening instesd of using the calculated opening on all 16 springs I do that now and tell the customers to not mix the springs, shims or rocker arms up down the road

Most all aluminium water passage engines grow .015 to .018 when at 180 to 190 degrees.We usually set the valves .015 tighter but never less than .005 for initial startup.Once you warm the engine to temperature you can guage the expansion and calculate for a cold setting.We like to do all final settings hot.