The discussion was about adjusting rockers using the "turn" method to measure preload. Which in my book includes both type rockers mounts. Nice try again, but once again, you've stuck out.
From the very first post the thread was about pedestal-mounted bolt-down rockers. Period. Maybe "your book" needs to be revised. And yet again you managed to increase your post count without adding anything meaningful to the thread. In the 12 years I've been on this forum I've never seen anyone that gets into so many pi$$ing matches with other members as you do. I'm guessing it's a form of entertainment for you.
I adjust my pedestal rockers old school. I cut an old valve cover to expose the bolts. With the engine warm and running, I back off the stud until it starts making noise. I tighten till it stops and continue to 20 ft/lbs. If it takes more than 1/4 turn to reach spec, I shim accordingly. Just my way........6500 and no problems. Mark EDIT: This is on my Cougar NOT my Comet(totally different valvetrain)
From my reading, in the Ford service manual, and what Ford Racing publishes, "Pedestal Mount" rockers, are torqued to 25 ft/lbs, and that's it, If you want any geometry adjustment, you use shims. You lock them down, and forget em, there is no 1/4" turn adjustment on them. Pedestal mount rockers are found on the newer heads, E7TE, GT-40, GT-40P etc...
Is it just me, but are you on the rag ? I'm not the one pickin fights here. That seems to be your department.
From the factory there was no reason to verify lifter preload, all of the engine components were pretty much the same. When you start adding aftermarket cams, heads, rocker arm, etc, that are dimensionally different is when you need to check the preload.
Isn't that why you check pushrods length ? To me, tight is tight, and loose is loose, if it's suppose to be 25 ft/lbs, then 15 would be loose, and loose comes apart. I've read everything I could about it, using GT40 heads, and everything says torque em down, and forget it. http://www.cranecams.com/pdf-tech-tips/hydro-lift.pdf
Well I'm betting that my geometry on my intake rockers are jacked up. I remember when I put everything in that it was slightly off center but not scary far. The shims are cheap so I'm going to buy them and a set of new channels and shim my intake rockers to closest to center I can and see what happens.
Push rod length sets geometry only. You don't change push rod length to adjust valve lash. With the mix/match of parts after a rebuild, I can see checking the preload as stated in an earlier link. If you change the cam, lifters, rockers, mill heads or block, change or grind valves - you could have a geometry problem they didn't have at the factory when it first went together. My one problem with the link above to check pre-load is they mention using a "metal scribe" to mark the push rod. NO! Use an ultra fine Sharpie. A scribe line on a push rod could cause a stress failure to start. How to do it? Simple, Figure your push rod length first. Make sure the geometry is correct. Adjust your valve to zero lash and torque to 25 ft-lb. If you went over 3/4 turn to get to that torque figure, put a small shim in and recheck. If you went over 3/4 turn you put too much pre-load in the lifter. If you went less than 1/4 turn, you didn't pre-load enough. and the pedestal needs milled. SPark
You can get by on a stock block with that BUT the OP has 1.7s (as do I) so shims come into play. The 1/4 turn comes into play AFTER zero lash.
Exactly! There's too much blurring of the lines between stock and high-performance going on in this thread. This is not a stock motor and should not be treated as such. It boils down to this. If you're a "set it and forget it.. it was close enough for Ford" kinda guy who doesn't care if longevity and absolute power is compromised to some degree?.. then why bother and it's a done deal. Personally speaking.. I don't really feel that Ford did the greatest job at building these things in the first place and those of us that check factory tolerances usually find that quality control has not always been perfect. After all.. they're not hand assembled highly toleranced engines. Why do you think that blueprinting procedures where developed and can find hidden power while also improving upon longevity? The one thing that I do know for fact is that no savvy performance engine builder that I know to be worth their salt would ever consider doing anything by factory spec's on any performance oriented build. Hell.. most usually stray from the factory spec's too just because they fell so short from the beginning. Also consider that lifter bleed down rates(which surely can and often does affect noise levels) can be affected to some degree when spring pressures start going up. What may have been good enough for a crappy rated stock cam, spring and rocker combo.. leaves a stock lifter whining(more like a ticking) after it gets rolled over the nose of a much higher lift cam and considerably stouter spring being leveraged an extra amount from a higher lift ratio rocker. It's a well known fact that the more you preload the lifter?.. the greater the chance it will hold the valve open the same amount when and if you tend to over-rev the engine beyond what the spring can keep up with. And most know that spring rates don't INCREASE over time either. I'd rather keep that amount of pump up to a minimum. Even at the cost of additional noise.
I don't know, mines not a stock motor either, and it's longevity seems just fine, it's still running after 6 years, but I guess I'm just some hack, not worth his salt....
