Lifter Rant, the heist goes on......

[kd]

This has been discussed here plenty.  The "manufacture" stroke target in a hydraulic lifter we use is .200".  The factory recommended "adjustment" target for that stroke is mid way or .100".  I would guess that most of the members here (especially those with performance builds) bottom the lifter and shoot for anywhere just off the bottom to .140" deep (instead of midway at .100").  As the engine gets hot the heads and barrels grow up to .060" taller.  That adds to the cold pushrod setting travel.

For example, my twin cam with 660 lift and corrected geometry is set barely 1 flat off the bottom. Barely free from the resistance point felt spinning the pushrods when adjusting. When hot, if you add the .060" growth, that becomes (.200" - .060")  or .140" deep. That engine valve train is as quiet as a mouse and hits the 6200 rpm  limiter several times EVERY time it's ridden.  Your cold setting is never what it is when hot. If you set them mid section for .100", the depth will become .040" when hot.  Those, or one lazy one, or the front exhaust, may tick when that shallow when hot and fully expanded.

[Don D]

I know the story about growth but people forget the pushrods get warm too and even with steel at a ROM of 50% expansion VS Aluminum, worth considering is also the cylinders are aluminum with a cast iron integrated splined cast liner. So what is the real growth net?
Setting the lifters off the bottom works with springs that are stout and rpms controlled. A flat or two off the bottom provides the function of a hydraulic, noise/lash control, and the benefits of solids, less loss of motion due to bleed.

Much of this stuff doesn't matter much in context of a ~6000 rpm Vtwin. Stroke and the associated piston speed are the constraint not valve springs or lifters.

[kd]

Right you are Don. It's a tough nail to hit on the head. Hotter heads or barrels =     I remember way back testing the theory with my cast shovel head barrels and S&S solids.  I found even with cast iron barrels if I set the solids at "tight to twist", if I popped the covers when hot there was very noticeable pushrod shake present.  I never did check how many flats it took to get back to the cold setting because I knew it would hold the valve open cold and I would be kicking my guts out hoping to start it. 

The .060"  or .050" growth factor is thrown around lots and we have discussed its unreliability to fact, because of what you describe.  I certainly believe the pushrods are subjected to less heat (and less growth) due to the difference in conditions in comparison to aluminum heads and barrels that are containing combustion and friction heat. I haven't taken the time to actually measure mine because again, I feel it's irrelevant and probably wont compare to the next guy with less or more compression (heat) etc..  Using those figures is however helpful in painting a picture of changes that occur in lifter settings during growth brought on by heat of combustion.  It helps explain why so many have success in quieting down a noisy valve train by simply going deeper to .140 for example.  In fact, some of the builders here go .140" on initial assembly.

[Don D]

You bring up good points for sure. Not even sure if the archives go back far enough but Black Hills Ken ages ago did some testing and IIRC the number was closer to +.018" net on a fully warmed up twin cam.
If you took a set of lifters I sell and went .140 down you would risk keeping a valve open cold. They have .140 travel, Morels

[kd]

That Black Hills Ken stuff is interesting.  I remember FSG and a couple others (you may have been one) measuring lifter depth / travel on a number of different manufacturer's lifters.  There was a travel variance even within the same company let alone different manufacturers. I think the added effect of limiters could have been part of that discussion too. I believe that is when the practice to adjust off the bottom (regardless of the target) was discussed.  IIRC Max was a big proponent for it and had been doing it for a while. 

[thumper 823]

Being I have nodular Axtell cylinders the compensation is less.
I spent a whole night a couple of years ago researching big words
on expansion rates.
The linear is not the same for everyone.
The thermal dynamics has to include distance plus and minus for
Head types, cylinder types, valve material, P rods, ceramics etc etc .
The modulus in most of our HIPO situations is a composite.
I added and subtracted for the iron cylinders, type pushrods, Al heads with firewalls,  and the whole can of materials best I could for
a couple of hours.
  It was enough to pull my hair out.
The reason?
  I had been working with a standard .o30 squish, but because of some
machining operation ended up with only .026  (head porting)
I was quite worried.
Scott @ Hillside  (who did not do the porting)  said don't worry about it and so far he has been correct.
But My math says the clearances are within a  tattoo mark!. (He was doing something else for me.)
The point I guess here is-  no one size is a fix-all answer just ballpark if you want to live that way.
It turned out I should have about.035 , but not that much in the combustion chambers.
  This time I will be using the off-the-bottom lifter measurement rather than from the top.
The more we know the less we know we do realize.

[kd]

I think that is similar to what we all have realized and consequently favor adjusting off the bottom.  As suggested, the rest almost just amounts to noise that is mostly irrelevant at our level.

[thumper 823]

Well, shazzbutt, this is going to change my P.rod length...again.
Smith Bro? yea how ya doin.................

the devil is in the details and laugh at my indexed plugs if you want.
argh argh argh

[thumper 823]

Perhaps I have found Lifter utopia or ?
On the surface, it looks great-i have no information on then but waiting for a phone call.

https://www.compcams.com/big-twin-replacement-roller-tappet-2-cpg.html

[kd]

With the full length  body they may be heavier than the original evo lifter design.  You have made it clear that you are building a performance engine and any added weight to reciprocating valve train components is usually not desired.  It would be interesting to see a weight comparison.

[SP33DY]

With the full length  body they may be heavier than the original evo lifter design.  You have made it clear that you are building a performance engine and any added weight to reciprocating valve train components is usually not desired.  It would be interesting to see a weight comparison.

I think the full length body lifter in the photo does not represent what they are actually selling. Probably just a picture that the web artist grabbed without knowing the difference between Evo Big Twin lifters and later Harley lifters.

The wheel must be larger than the body o.d. to gude the lifter in the lifter block.

[thumper 823]

If their guy Chriss ever calls me I will ask him the specifics.
I want to know several things .