Re: rockers
[Re: 65dragnet]
#843712
11/01/10 11:09 PM
11/01/10 11:09 PM
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Joined: Oct 2003
Posts: 7,506 Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Yes, and Yes. Adjustable pallet tip rockers are not a bad thing and they can have some advantages over roller tip rockers. They are strong. They can have a weight advantage over roller tip rockers - not so much in over all weight, but where the weight is located. They do have a higher friction loss ( actually less of an issue with the new lubes out there ), but they are easier on valve stems due to a larger contact pattern than a roller tip rocker. Less moving parts in your valve train. That's always a good thing. And don't believe all that garb about all pallet style rockers not being up to their advertised ratios. That issue has nothing to do with the style of rocker.
Fastest 300
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Re: rockers
[Re: Cab_Burge]
#843716
11/02/10 04:53 PM
11/02/10 04:53 PM
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Joined: Oct 2003
Posts: 7,506 Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Quote:
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Thanks Crizila ! I normally run Crane ductile iron and the stock max wedge actually look stronger. I have a perfect set of them and I'm contemplating trying them on my 499 lowdeck.
I've check a lot of ductile iron rockers and none of them where anywhere close to perfect The ratio where all over the plce, some sets varied .130 from the lowest lift to the ighest lift when checking at the retainers I have sent several sets(Craen, ersoin, stock Mopars and Iskys to Rocker Arm Specilaties in Cottowood,CA PH #530-378-1075 to have the rockers bushed, blueprinted and have the ratio corrected Many other racers looking to make all of there parts perffect(as you can make them) for blueprinting use them also The bushings alone will make them last forever and never gall again
I sure don't claim to be an expert when it comes to rocker are geometry. Fortunately, for me, I happen to know someone who is. It's a very complicated topic, with much more going on than just the ratio change due to the travel arc of the rocker arm. For instance," the effective rocker arm ratio is related to the travel of the contact point accross the tip of the valve stem. The large raduis of the tip of a pallet tip style rocker arm or the larger diameter of the roller on a roller tip rocker arm, the greater the travel of the contact point accross the tip of the valve stem - - - and therefore the greater the change in the effective rocker arm ratio as the valve goes through an opening and closing cycle. Since, in general, pallet tip style rocker arms have a larger tip radii than roller tip style rocker arms ( as reflected in the diameter of the roller on the tip of the roller rocker arm), pallet tip style rocker arms undergo a larger change in effective rocker arm ratio than roller tip rockers ( through a valve opening and closing cycle )." A typical 1.5 stock chevy pallet style rocker ( which seems to be the one abused most by those selling roller rockers ) can check ( if ploted )anywhere from 1.4 to 1.7 ratio through it's travel arc. Another area that can effect ratio is the rocker arm fulcrum point as it relates to valve stem height. Most advocate they should be the same height. Wrong! Due to the change in dynamics ( rpm and cyl pressure - which is usually never measured or taken in to consideration ), there is no perfect relationship between the rocker fulcrum and the valve stem height, but - one that is better than the accepted "same height "is to place the rocker arm fulcrum 1/3 of the maximum valve lift below the tip of the valve stem. I told you this crap was complicated . I'm just touching on a few points here. I still use the 50/50 or half lift method ( per Lunati, Comp, and many others ) cause it's easier to do and seems to be good enough in most instances. Sorry for the rambling.
Fastest 300
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Re: rockers
[Re: Crizila]
#843720
11/02/10 07:20 PM
11/02/10 07:20 PM
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Joined: Oct 2007
Posts: 535 Ohio
racerAL
mopar
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mopar
Joined: Oct 2007
Posts: 535
Ohio
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well, i can't comment on/about the ratio of the max wedge rockers and i can't comment on how they vary..what i can comment on is the $100 set that i'm using(150 passes)seem to be holding up fine, and i've had NO issues with valve tip wear or rocker arm wear...if you end up not using them,and want to get rid of them, get ahold of me.. ..i would be interested in them.
-1967 Plymouth Satellite #3555 446 cid on E-85 best 1/4 et 10.577 @ 127.58 best 1/8 et 6.722 @ 100.68 best 60ft. 1.419
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Re: rockers
[Re: racerAL]
#843721
11/02/10 08:23 PM
11/02/10 08:23 PM
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Joined: Oct 2003
Posts: 7,506 Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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I'm not down on roller rockers. As Mr P Body said, if you are over .550 lift, a pallet tip rocker ( with it's large tip radius ) could be getting pretty close to the valve tip edge. I run roller rockers ( .615" lift ) for that exact reason. I'm sure some of the more high end roller rockers are more accurate ( regarding ratio ) also. Just saying that pallet tip rockers have their place, and are overly and unjustly "blacklisted".
Fastest 300
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Re: rockers
[Re: Crizila]
#843725
11/03/10 12:02 AM
11/03/10 12:02 AM
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Joined: Jan 2003
Posts: 25,200 Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
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Here is an excerpt from an article in a Mopar mag.:
1. Magazine tech "experts" are - limited - and usually in bed with the equipment manufacturer - for obvious reasons. I can't remember the last time a mag did an article on a "something" where it turned out to be a total turd. Big mistake to believe everything you read in a magazine.
This from our own Dulcich (sp). Besides it was backing up a lot of what you were saying. Hughes has a tech space saying that (and I have known this) that the bottom small rollers are the only ones that do anything. the top ones never see any pressure because the action is back and forth action not spinning the rollers on to around to any pressure point. This true not only on the tips but on full roller rockers where the shafts have needle too. BTW have you ever had to clean up small needle bearings after breakage. Not fun
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Re: rockers
[Re: Crizila]
#843726
11/03/10 05:06 AM
11/03/10 05:06 AM
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Joined: Jan 2003
Posts: 3,943 Melbourne.....Oz-land
Moparmal
master
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master
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
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Quote:
Quote:
Here is an excerpt from an article in a Mopar mag.:
1. Magazine tech "experts" are - limited - and usually in bed with the equipment manufacturer - for obvious reasons. I can't remember the last time a mag did an article on a "something" where it turned out to be a total turd. Big mistake to believe everything you read in a magazine.
Crizila - You should read that article again - it actually supports what you were saying
- that after a certain lift height the factory paddle style has a limitation - but before that works very well.
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Re: rockers
[Re: Crizila]
#843729
11/03/10 12:28 PM
11/03/10 12:28 PM
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Joined: Oct 2003
Posts: 7,506 Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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rocker ratio testing tool.
Fastest 300
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