Small Block Dry Tappet Clearance?

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1967Dart273

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On the road with no manual and unable to do search with my phone...

Can someone post the dry hyd tappet clearance for the 273-360's?

Thanks!
 
Not sure what spec you're looking for. You mean lifter to bore clearance, lifter preload, or something else?
 
.010 intake and .020 exhaust will get you going with a mechanical cam, but the preload on a hydro is fixed, you cant change it on a stamped shaft rocker.
 
moper said:
Not sure what spec you're looking for. You mean lifter to bore clearance, lifter preload, or something else?
Click to expand...

OK, now I'm back to a real computer!

I guess you'd call it lifter pre-load... I see it referred as "Dry Clearance" in an early Hemi manual. .060-.210

I'm used to calling it dry tappet clearance from working on the smaller aircraft engines...

What I'm looking for is the clearance between rocker tip & valve stem when the hydraulic unit is fully depressed.

Thanks!
 
green1 said:
There should be none; pre-load of at least.030.
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Yes, there will be the way he's talking about, but I've never seen a spec for it anywhere. What he means it with the valve closed, depress the pushrod FULLY into the lifter plunger and bottom the lifter plunger out, then measure the clearance between the valve stam and rocker tip.

You need to be concerned with lifter preload. That is the only measurement that's critical there. Lifter preload should be between .020"-.060" with the valve closed. Sometimes with anit pump lifters, you run zero preload or even up to .002" lash. I like lifter preload on the light side around .010"-.020", but that's my personal preference.
 
StrokerScamp said:
Yes, there will be the way he's talking about, but I've never seen a spec for it anywhere. What he means it with the valve closed, depress the pushrod FULLY into the lifter plunger and bottom the lifter plunger out, then measure the clearance between the valve stam and rocker tip.

You need to be concerned with lifter preload. That is the only measurement that's critical there. Lifter preload should be between .020"-.060" with the valve closed. Sometimes with anit pump lifters, you run zero preload or even up to .002" lash. I like lifter preload on the light side around .010"-.020", but that's my personal preference.
Click to expand...

With the light pre-load, do they stay quiet or do they go out of adjustment frequently?

Do you just check that with a small flat feeler or round wire feeler between the hyd plunger unit & the clip, or just eyeball it?

I found someone who posted the specs online, supposedly from the 79-89 CPD Service Manuals and they were same as the early Hemi @ .060" - .210" Dry Lash http://www.angelfire.com/ca/mikesspot/318specs.html

Most looked by eyeball to be pre-loaded around .060, but a few were barely pre-loaded at all (my original concern) I'll check 'em again in the morning.

Thanks!

This whole mess started with a leaky freeze plug and "While it's out I'll just freshen it up!" :banghead:
 
Theres usually about .180 plunger travel on a standard hyd. lifter. So if you push it all the way down you should have .130-.150 lash.
 
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