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Greg
Dodge Dakota
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7/17/2004
01:40:53
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 Subject: Rocker adjustment ? Larry or anyone
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Ok I would just like to start out this post asking one thing... Has anyone ever really experimented with the Crower rocker adjustment??? WELL I have here recently and was just wondering if I might have something wrong somewhere else... I started out with the regular 3/4 turn valve lash adjusted to while engine running so I know that it is actuall valve lash... I'm running the 1.6 crower rockers with the hughes #her0814al-v6 cam and crower 7.050 pushrods "longer due to the regrind cam"... Well long story short I got to wondering what tightening down the rockers a little more would do performance wise in 1/4 and 1/2 turn intervals... I mean it seemed to me that tightening them down a slight bit more would coil up the pressure in the lifters more providing better lift response and change the pitch of the rocker a little more in turn giving it a touch more movement to allow the valves to open more...
Anyway I wound up adjusting them to 2 full turns valve lash in which it would keep you pinned back in your seat on accelerations almost as if the engine were supercharged or something... My brother even rode in it as of this point and said that it would definately beat his 4.6l gt mustang... Of course it does have other minor engine mods as well... I got kind of worried that I might bend a pushrod or something and just adjusted them back to the 3/4 turn mark... I also put a little grease on the valve stem tip and checked the adjustment as far as rocker ride path and it really didn't seam to vary all that much just the tighter you made them the further out the ride path became which I know will induce valve guide wear but boosted power quite a bit... So what might other people's opinions be on this subject??? I'm just kind of curious as to what kind of damage this could cause because I've seen none so far, but that doesn't mean that that unlucky day will never come...
I'm sorry about the long post and would just like to thank everyone in advance for your responses...
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hater
Dodge Dakota
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7/17/2004
09:39:03
|  RE: Rocker adjustment ? Larry or anyone
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Take the rocker to zero lash then 1/4 to 3/4 of a turn past, just enough to quiet the rocker. Anymore is going to put too much preload on the lifter and cause the lifter to fail.
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J and J Auto
GenII
7/17/2004
20:13:50
| RE: Rocker adjustment ? Larry or anyone
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The roller lifters require .050 .060 preload which
on the crowers is about 3/4 turn, stock springs
I have run them completly bottomed with colasped
lifters and they ran fine untill the lifters were
replaced.
What happens the farther you push the plunger down
is you lose the hydrolic dampening and they will
be noisy, this takes about 4 to 5 turns from 0
lash past this point you do take a chance of
bending the push rods and holding valves open
They will run at 2 turns just be a little noisyer
from losing the hydrolic oil dampening which
creates a harder hit but will not harm anything
If they run better at 2 with no noise thats fine
the lifters have a plunger travel of around .120
to .150 travel and with stiffer valve springs
would give you better performance because the
cushon dampening effect will drop lift and duration, stifer springs do requier more preload
upto .100
I would contact hughes and see what they recomend
for the cam and springs you are running they will
probable recomend .080 to .100 preload which is
about where you are at 2 turns
Larry
J&J Auto
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Greg
Dodge Dakota
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7/18/2004
18:36:50
| RE: Rocker adjustment ? Larry or anyone
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Larry, has anyone told you lately that you are a complete genious when it comes to engines... AND not just the magnums from my understanding of some of the work you do on big blocks and so forth... Thank you for everything and I will be contacting hughes shortly... Well I don't think hughes has an email now that I think of it, so I'll be contacting them first thing Monday... I'm running the R/T springs .5?? load capable as advised by you during my build earlier and of course the hughes regrind cam... I Also replaced the lifters with the some what performance "or I guess stock replacement, but much better than", also the one's you advised ealier, so hopefully they'll be able to compensate for the more preload...
Thanks again for everything,
Greg
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Greg
Dodge Dakota
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7/20/2004
01:38:40
| RE: Rocker adjustment ? Larry or anyone
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Larry I'm not going to say that you were wrong on this subject at all, but I will say that hughes engines made slight sense and confused me more than anything else on this... Here's what they told me... To start with I told them my situation and that you had told me to check with them on this... To start with they let on like they didn't even know who you were, which alone doesn't make much sense since you have bought stuff from them and have steered a few people over their way for performance parts... Then I told them about the valve springs possibly causing a difference in the valve lash settings and they said that they recomended 1.5 turns valve lash for their rockers, but the springs would cause no effect on valve lash... So I told them that you had mentioned having yours turned down to as far as 5 turns or what you said was bottomed out and the guy just kinda laughed and said that you bottom out the lifters at 3 turns which doesn't make much sense to me since I'm pretty sure I've turned mine down further than that... The guy went on to say that no matter what someone else might say if they run better at 2 turns valve lash to run them there oh and every 1 turn of from zero valve lash is .060 preload which kinda would make sense on the bottoming out part at 3 turns... .060 x 3 = .180 or lifter preload capability...
I'm think I'm just going to go with you and run them at about 2 to 2.25 turns preload for the springs...
I'm am kinda curious as to you experiances on the rockers in your motors... Did you notice more power with the more preload or less???
Thanks Again for Everything,
Greg
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hater
Dodge Dakota
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7/20/2004
10:32:53
| RE: Rocker adjustment ? Larry or anyone
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Why in the flucking hell would you have more power with more preload? Once you get oil pressure and the lifter is pumped up its gonna open the valve the same amount no matter what. The more head milling you have, or block decking the shorter the pushrod needs to be. the longer the pushrod is the less turns you are going to need to go to get to o lash. Turning the adjustment 2 or more times past 0 lash is just going to kill the lifters internal spring with too much preload.
The valve spring itself has no effect on lash, having a different installed height would though.
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IntenseDak39
*GenIII*
7/20/2004
10:52:42
| RE: Rocker adjustment ? Larry or anyone
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you could get more power with less preload.
If you only turn the adjusting screw in about 1/2 turn, you could get more lift at the valve.
(pushrod seat in lifter would sit higher then with 3/4 turn)
"Once you get oil pressure and the lifter is pumped up its gonna open the valve the same amount no matter what"
that's incorrect. Set a lifter at 0 lash and one three turns past 0 lash and check for yourself. When you set 0 lash, your lifters need to be primed... not dry.
If you mill your heads, you need to have the correct shortened pushrods to keep the geometry of the valvetrain correct.
6.6 Lt. Big Block, 727 TF shift kit, 452 heads, edelbrock 750 cfm, .513/.513 284/300 crower cam, comp cams springs, comp cams pushrods, 1.5 roller rockers, dp intake, mopar ignition, mopar windage tray, dual exhaust w/ 40 series flowmasters, 4.10 gears, coilover drag suspension, approx, 3500 lbs
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rtdkota
R/T
7/20/2004
11:08:30
| RE: Rocker adjustment ? Larry or anyone
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I've run mine at 1/2, 3/4, 1, 1 1/4 & 1 1/2.... 1/2 turn was too noisy 3/4 was good----- 1 and beyond produced less hp on the dyno + truck felt sluggish compared to 3/4....
Have run 3/4 for over 20k miles and checked twice-- nothing worn funny, etc.
Running 6200 rpm no problem.
www.socaldakota.com
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Greg
Dodge Dakota
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7/20/2004
23:15:35
| RE: Rocker adjustment ? Larry or anyone
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Well I've heard people say both ways... I guess it just depends on all your other mods... I see the preload the same way as Larry does on the subject... The more preload the tighter the spring is and inturn the more pressure it would have built up to force that spring up open... I also know a few people who have run the lifters completely bottomed out simply so they can run at higher rpm's... I do know one thing the truck since put back to 3/4 turn does not pull the mountains around here nowhere near as good... I have to downshift into 4th a whole lot more...
The things I have had done to my valve train and heads are as follows if any of them would explain why this is the way that it is...
hughes HER0814AL-V6 idle - 5500 "was degreed"
dual roller timing chain
Due to regrind cam had to get longer pushrods "crower 7.050"
performance lifters from mopartsracing "appeared to be minorly shorter than stock and had wider wheel to ride over the cam a little better along with a little better surface area for less wear in lifter journals"
crower 1.6 rockers
crower guideplates
all new valves with one extra angle ground into them "wound up with something like 5 on intakes and 4 on exhaust or the other way around"
completely ported and polished heads "big improvement over stock"
.020" head shave
all new valve seats
.512" lift R/T valve springs
Not sure if it really has to do with rocker adjustments, but
hughes stage 1 intake "with bores opened to 52mm"
Holley TB with torque step removed for full 52mm
timing and fuel sync advanced 3 degrees
ignition and exhaust upgrades as well
Maybe knowing all of this was a waste of time and maybe it might enlighten someone as to why I get so much more power with more valve lash, because right now at 3/4 it sucks and fuel mileage is way back down as well... It was up to 25 to 27 mpg at best, now it's back to something more on the lines of 20 to 21 mpg... This just isn't making much sense to me either???
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rtdkota
R/T
7/21/2004
10:49:57
| RE: Rocker adjustment ? Larry or anyone
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"performance lifters from mopartsracing "appeared to be minorly shorter than stock""
That part worries me--- that may be the reason you must run more the 3/4 turn...
I've had people call me re: running a fast ramp rate cam, high lift (anything over .500)-- and had issues with Mopar Perf. lifters... They got the Crowers, and then things were much better. Possibly you've hit upon something with the possibiliy of a shorter than stock lifters.
Sam
www.socaldakota.com
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Greg
Dodge Dakota
JOIN HERE
7/21/2004
18:42:52
| RE: Rocker adjustment ? Larry or anyone
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Sam you may be right there... But I don't have the money right now nor will for awhile for the crower lifters... So you really think that might be the reason... They may be running or rather have less coil pressure in them allready built up which is why I have to run the more preload... Do you think that if this is true, if it would hurt anything to run them at 2 to 2.25 turns valve lash??? I still haven't reset the rockers to this because I haven't had time yet... But I'm thinking about doing it this weekend...
"SIDE NOTE" -- The lifters when held side by side appear to be the same length, but when you put them side by side with the pushrods in them the performance lifter is slightly "maybe just a few thousanths" shorter and when I pushed in on the performance lifer the plunger seemed to move fairly easy for maybe up to 1/16" and the stock lifter does not move or give at all... Both lifters are dry "no oil in them" or rather pumped up...
So maybe the lifters are where all of my problems are coming from??? Any thoughts towards this...
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rtdkota
R/T
7/22/2004
11:15:35
| RE: Rocker adjustment ? Larry or anyone
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That sure sounds like it's the lifters--- P part # mopar lifters are suppose to be identical to stock-- minus any sort of warranty. I doubt that the QC at DC has gotten any better, and most likely you have an odd ball set of lifters... the additional preload you put on them-- possibly weakened the springs (just a thought)
Sam
www.socaldakota.com
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Greg
Dodge Dakota
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7/22/2004
23:58:05
| RE: Rocker adjustment ? Larry or anyone
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OK I've just gotten through disassembling both the performance lifter I had left over "bought enough for the V8" and the old stock lifter that I had replaced and here are the differences...
All the parts are identicle except the spring and the body that the parts all go into... The spring in the old lifter is actually slightly shorter and slightley harder to compress... May be because it's used and just got stiffer over time???
The body of the lifters are different around the wheels and the oil hole... The insides are the same depth...
Cups and everything else are identicle... So maybe the performance lifters just provide more give???
I don't think that running them with more preload caused them to weaken because I allready had a 1000 miles on them with the same sluggishness that whole 1000 miles until I started experimenting and these lifters that I disassembled have never been used... I have a little over 6000 miles on the motor now since top end rebuild 2 months ago...
Oh well who knows??? I'll just adjust them to 2 or 2.25 turns tomorrow or this Saturday and see how things go from there ://
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