Progress on the HZ one tonner and the Holden 308 has been slow, but this should give you a quick update about what's slowly happening behind the scenes. Includes checking rocker geometry and piston-valve clearance and next steps.
I'm sure we all get moments where things don't progress (for various reasons) as quickly as we would like them to. Noticed you've cracked 1k subs as well, congrats
If you have more thread engagement in the head than twice the diameter of the bolt {and you will} then the bolt break off long before it pulls the threads out of the head.
@staceonwheels Back in the day it wasn't uncommon for people to over tighten the rocker bolt and snap them off before they stripped the threads out of the head. Running shims under the standard rocker arms to set lifter preload was common too without having issues
Interesting one. My Chrysler 318 had a mild cam installed and upon start up the engine had valve train rattle! Now my rockers are not adjustable so after much research it turned out that the new cam had a smaller base circle which now meant my standard pushrods were to short! At the time I wasn’t sure how to measure for the right pushrod length and I couldn’t find anyone to help me so after seeking advice I ended up using 0.80thou lash caps which made the engine very quiet. So yes,a mere 1 or 2mm in length can make a big difference I found. I also had heavier springs added on the heads to compensate for the extra lift. Runs good but a learning curve.
Thanks for sharing that... shortly I'll be testing all the valves/rockers/pushrods to find the best way to get good lash. It will be the next video, I think.
@@staceonwheels. Just did 5 days away on dirt bikes. Everything hurts(injuries,like you know). But felt good. Normal life. Meh.... 4 wheels are ok. 2 are better.
I had a similar hydraulic lifter/rocker set up,and 1 problem I had, was lifters bleeding down overnight and sometimes a pushrod popping out from the rocker cup,due to the excessive freeplay and rattling,,I ummed and ahhed and then decided to wind the rocker adjusting screws til the lifter plungers travel were about .050" from the bottom of the lifter body.But make sure you bleed the plungers down,if full of oil, before turning/starting the engine or pistons might hit valves,Never had any more problems,ran fine,no lifter pump up ,although they say only 1/2-1 turn preload,Recently I found a David Vizard video of him saying what I did,about .040"-.050"from bottom of lifter plunger travel,saying it's more like a solid and a more direct valve lift,and in my case,no pushrod popping out lol
Well that's handy to know, thank you. I'm still struggling to get a consistent result with preload as I play with shims. My prob is not enough freeplay, even with bled down lifters, but I'm not yet sure yet if I need shorter pushrods to get it.
@@staceonwheels I've seen a few guys say they have to shim the Yella T rockers ,as Octagen suggested here.My rockers, although not Yella T,came with 9-10 mm pedestals,so my rocker shaft pins sit 9-10 mm above the rocker pads on the head,I would just shim it til I get at least 1 mm preload,then check the symmetry of the pushrod to rocker cup and valve tip angles from 0 lift to full lift.Too little preload can cause the lifter plunger clip to pop out,it happened to me.Some guys replace the wire type clip with a proper C-clip.Another trick is to shim the lifter plungers down to .070" travel and preload .020".I ended up going to a solid cam and lifters lol.Also check the new lifter lengths and plunger depth against an old lifter if you have one
Yeah I have the old pushrods and lifters that were used with these rockers. I've just bought my own set of test/check light valve springs and will do experiments with shims and preload. I'm loathe to mess with the lifter plungers tho, at this stage. I bet your cam sounds great.
@@staceonwheels Cool,,just go for more preload, than hardly any,up to 1-2 mm ,unless you plan on reving it to 7000 rpm lol,then go 1 mm,.Also check the cam lobes for the .001"-.002" taper,that is needed and check the lifter face, surface,should almost be flat and evenly ground,centre of lifter face should be .001"-.002" higher than the outer diameter.Lifter faces worldwide have had bad quality control in recent times....My setup is a 355 stroker,Crane cc272 solid cam,234 deg @.050,112 LSA,intake lobe centre 110,has a nice baritone grumble at idle lol,I built it in 2012,still going
Hey stace have you measured the length of the new pushrods? Some later 308/304 engines had a longer pushrod than the originals std is 8.684” and brock, hsv and walkinshaw came with longer for roller rockers from production. If your roller rockers are not original from Manufacturer you may need shorter pushrods
Yep, the new pushrods that came with the cam kit are about 3mm longer than the ones I took out. Haven't measured either of them, just side by side comparison. The cam kit was for my era 308 and for roller rockers, which as you know are yella terra. I'm yet to try some shims I bought to correct for it, as I'd prefer not to buy more pushrods... but we'll see!!
