Re: Would pushrod length make this much difference?
[Re: BradH]
#2448199
02/07/18 09:13 PM
02/07/18 09:13 PM
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Joined: Dec 2007
Posts: 12,587 Great Neck,LI,new york
hemi-itis
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I Live Here
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Pushrod oiling is the answer to anything that has an issue with burnt cups.
HEMI-ITIS has no cure. My condition is fully BLOWN!!
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Re: Would pushrod length make this much difference?
[Re: BradH]
#2448280
02/08/18 12:35 AM
02/08/18 12:35 AM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
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master
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Canton, Ohio
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Your pics don't give the minute differences justice.
Longer pushrod equals more max lift while a shorter pushrod gives quicker more mid lift but with less max lift.
Significant difference??, in the scheme of the whole overall lift event, either way, long/short pushrod, doesn't make any significant difference in performance on the engine involved. The valve train, does like the longer pushrod though, less stress on the rocker arm because of the lesser angles involved. IMO
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Re: Would pushrod length make this much difference?
[Re: BradH]
#2448310
02/08/18 01:47 AM
02/08/18 01:47 AM
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Joined: Oct 2007
Posts: 4,205 New York
polyspheric
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master
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New York
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The minimum adjuster length isn't a specific number of turns. What matters: 1. no contact throughout the range of travel 2. enough adjustment to get lash
Boffin Emeritus
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Re: Would pushrod length make this much difference?
[Re: BradH]
#2448348
02/08/18 04:37 AM
02/08/18 04:37 AM
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Joined: Aug 2003
Posts: 43,099 Bend,OR USA
Cab_Burge
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I Win
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Bend,OR USA
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I've seen adjusters and pushrod cups broken off due to using to short of pushrods, way to short To long can and may beat up the bottom of the rockers also so my choice is to see between 1/8 of a thread to three complete threads max exposed under the rocker arms As already mention on the single shaft T&D system they like 1 1/2 turns out to three turns out max on their adjusters for oiling the push rods properly I think I have 1 1/2 threads exposed on my 440-1 with the Jesel pair shaft system with pushrod and spray bar oiling
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Would pushrod length make this much difference?
[Re: Stanton]
#2448629
02/08/18 06:13 PM
02/08/18 06:13 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
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The lobe lift only changed because I reversed-engineered the lobe lift for the same valve lift to account for the ratio change. If I'd left the lobe lift the same, then I'd have had to increase the lift curve on the valve side. It was simpler to leave the rest of the rocker diagram the same and only tweak the pushrod adjuster arc to match the ratio difference.
Last edited by BradH; 02/08/18 06:16 PM.
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Re: Would pushrod length make this much difference?
[Re: Stanton]
#2448661
02/08/18 07:42 PM
02/08/18 07:42 PM
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Joined: Jan 2003
Posts: 14,492 So. Burlington, Vt.
fast68plymouth
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I Live Here
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So. Burlington, Vt.
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Be a good excercise with the rocker on the head, an adjustable pushrod, a checking spring, and a dial indicator.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Would pushrod length make this much difference?
[Re: BradH]
#2449070
02/09/18 01:08 PM
02/09/18 01:08 PM
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Joined: Jan 2016
Posts: 216 America
WedgeFED
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America
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Re: Would pushrod length make this much difference?
[Re: Cab_Burge]
#2449182
02/09/18 06:41 PM
02/09/18 06:41 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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I wonder if these instructions apply to stud mounted rockers only? Nope. Adjuster position affects geometry on stud and shaft rockers.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Would pushrod length make this much difference?
[Re: madscientist]
#2449215
02/09/18 07:53 PM
02/09/18 07:53 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
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I wonder if these instructions apply to stud mounted rockers only? Nope. Adjuster position affects geometry on stud and shaft rockers. Adjuster position on a shaft system has no effect on geometry; that's determined by the rocker fulcrum location with respect to the valve.
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Re: Would pushrod length make this much difference?
[Re: BradH]
#2449253
02/09/18 09:19 PM
02/09/18 09:19 PM
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Joined: Jun 2003
Posts: 9,225 Charleston
sixpackgut
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Drag Week Mod Champion
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Charleston
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Geez, and I'm just happy when the pushrods stay where they belong
Gen 3 power 6.22@110, 9.85@135 Follow @g3hemiswap on instagram
performance only racing, CRT, ultimate converter, superior design concepts, ThumperCarbs
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Re: Would pushrod length make this much difference?
[Re: AndyF]
#2451869
02/14/18 10:11 PM
02/14/18 10:11 PM
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Joined: Oct 2011
Posts: 3,036 bean town ....Ca
WHITEDART
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Pushrod length was one of the things we explored when I went to competition engine building school.. by adding .050 a pushrod length we gained about .06 at Max lift.But the early and mid numbers suffered slightly... made absolutely no difference on back-to-back on the dyno.. I would say picking a pushrod length with the adjuster set and it's recommended location would be your best bet
In the 8s N/A.with Brett miller W8's 5.07 at 133 at 2700lb
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Re: Would pushrod length make this much difference?
[Re: AndyF]
#2452179
02/15/18 04:03 PM
02/15/18 04:03 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
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Taking time off to work on my car
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Taking time off to work on my car
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Val-haul-ass... eventually
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You aren't an idiot, you just haven't learned everything the hard way yet. Once you learn everything the hard way you'll be a bitter, grumpy old man with no patience for whipersnappers who haven't learned everything yet. 1. I've told my friends & family for years, I learn EVERYTHING the hard way. 2. I'm already a bitter & grumpy old man with no patience for others... and I still don't know sh!t.
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Re: Would pushrod length make this much difference?
[Re: Cab_Burge]
#2452546
02/16/18 02:11 PM
02/16/18 02:11 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
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Taking time off to work on my car
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...actual valve lift at the retainers with the race valve springs will never be as much as the advertised valve lift...
That's entirely dependent upon how the rocker arm is designed. AndyF's rocker arm articles touched on how some of the brands he checked were "over-ratioed" w/ checking springs, but came in at or above the advertised ratio when checked w/ the actual valve springs. As far as deflection, I believe it can be in the pushrods, the rocker bodies, and/or the shafts, depending upon the components used. Not sure Joe Average's budget can eliminate it entirely, but I've seen some cases where it certainly went beyond my idea of an "acceptable" amount in terms of lift/ratio loss.
Last edited by BradH; 02/16/18 02:12 PM.
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Re: Would pushrod length make this much difference?
[Re: BradH]
#2452890
02/17/18 01:15 AM
02/17/18 01:15 AM
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Joined: May 2017
Posts: 72 WI
Brewzer67
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Oh, I came across some pics of "stuff" that Mike at B3RE did w/ some Hughes rockers used on Trick Flow heads that included switching to cup-style adjusters (requires pushrod oiling). I can't say exactly what differences would result from such a mod, but it's pretty obvious the pushrod tip's relation to the rocker fulcrum would change big-time.
I'm curious where you found these pictures. These look like my heads and rockers. They came out great with Mike's kit and the change to cup adjusters. The sweep is small and centered and there is minimal lift loss. I am running dual taper 9/16" (.165 wall) oil thru pushrods from Trend and lose less than .008 lift on a .716 lift solid roller. With the change to the cup adjusters there is almost no change in pushrod angle from full closed to full open. Even though the pushrod side doesn't add too much in the way of harmonics issues, I can't help but think this minimal movement goes a long way to promoting valve train stability.
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