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Re: Hemi Rocker Arm Deflection
[Re: liteweight]
#1120669
11/27/11 01:37 AM
11/27/11 01:37 AM
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Joined: Jul 2010
Posts: 3,502
SOUTH JERSEY
HEMIFRED
master
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master
Joined: Jul 2010
Posts: 3,502
SOUTH JERSEY
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If you have selected your "perfect cam" are trying to reduce the deflection number have a cam ground making adjustmentsd for the loss 
home of the
Sox and Martin Hemi Duster
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Re: Hemi Rocker Arm Deflection
[Re: liteweight]
#1120670
11/27/11 02:31 AM
11/27/11 02:31 AM
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Joined: Mar 2006
Posts: 2,675
Mt. Eden Ky.
Hemi Allstate
master
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master
Joined: Mar 2006
Posts: 2,675
Mt. Eden Ky.
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With the numbers I'm seeing on my motor it has me thinking if I purchase a different set of rockers, I'll order them with more ratio, just to make up for the loss of lift from deflection. As far as timing, I think I'm going to start checking at the valve with the intended to use springs, instead of degreeing it at the lifter. I'll post some measured numbers later AND, Still waiting for some input from Stage V users  . liteweight
The Stage V ratios are slightly higher. I can check my notes but I don't think I will have what you are looking for in measurements. It seems I had more lift with the "checking" springs though. My pushrods are Smith Bros. (3/8" IIRC) good for about 600lbs.
FYI Stage V rockers are as follows.
Stock ratios are Intake 1.57 , Exhaust 1.52
Stage V ratios Intake 1.60 , Exhaust 1.56
Mark
1996 Ram 1500 Sport
1968 road runner
1952 Sears Allstate licensed, pump gas, Hemi 5.98 @ 115.73 1.33 60 ft. The best is yet to come. Painless Performance / Street RODDER magazine Top 100 for 2019
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Re: Hemi Rocker Arm Deflection
[Re: quickd100]
#1120672
11/27/11 11:25 AM
11/27/11 11:25 AM
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Joined: May 2004
Posts: 12,397
Taxes & Virus's R-US, NY
Dragula
I Live Here
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I Live Here
Joined: May 2004
Posts: 12,397
Taxes & Virus's R-US, NY
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Quote:
Daryl; I do feel your pain. I sent more time sorting out valve train issues than on any other aspect on my 528. I sent my stockers out to Tim Banning to have them rebuilt and 'blueprinted'. They came back better than they were but the ratios are all different. A set of aftermarket rockers are on the list. Even as bad as they are,(rockers) the Hemi still makes good power. I'm currently running the stockers with a solid roller, .722/.699, 285/290@.050. Dave
That's is the lift range where problems show up. I was running a conservative .630 lift cam, and switched to a .750 lift cam on my stroker, and deflection, oiling issues, lash cap issues, etc all showed up. Hemis are great, but high lift big spring pressures make them a pain.
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Re: Hemi Rocker Arm Deflection *DELETED*
[Re: liteweight]
#1120673
11/27/11 01:25 PM
11/27/11 01:25 PM
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Joined: Oct 2007
Posts: 4,209
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,209
New York
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Post deleted by polyspheric
Boffin Emeritus
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Re: Hemi Rocker Arm Deflection
[Re: polyspheric]
#1120674
11/27/11 10:21 PM
11/27/11 10:21 PM
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Joined: Oct 2005
Posts: 290
Manitoba, Canada
liteweight
OP
enthusiast
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OP
enthusiast
Joined: Oct 2005
Posts: 290
Manitoba, Canada
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Yes I have. When I started looking where all my lift went to. There's .002" @ the shaft., .007" on the pushrod. All the rest is at the rocker.
Check out the attached file. A buddy, Big Wedge came over this weekend to give me a hand to get all the measurements & put all my chicken scratch onto a PDF file. Thanx Garth
We did tests on stock rockers, Indy rockers, & DLI rockers. Not only is there alot of lost lift, but also lost duration even using aftermarket roller rockers.
I am looking at Hemi valve trains completely differently now. I'll bet there's alot of Hemi owners out there who have no idea how much power they're lossing in the valve train on these motors.
liteweight
Last edited by liteweight; 11/27/11 10:23 PM.
68 Hurst LO Hemi Dart
70 hemicuda 4 spd. R code owned since 76
70 GTX 4 spd. 21,000 orig. miles
55 Ford F100 chopped,slammed,bagged & supercharged
96 Ram 2500 4X4 Twin turbo'd Cummins 550hp 1200 ft. lbs tow vehicle
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Re: Hemi Rocker Arm Deflection
[Re: quickd100]
#1120675
11/27/11 10:31 PM
11/27/11 10:31 PM
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Joined: Oct 2005
Posts: 290
Manitoba, Canada
liteweight
OP
enthusiast
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OP
enthusiast
Joined: Oct 2005
Posts: 290
Manitoba, Canada
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Dave
Are those numbers calculated from lobe lift or measured?
liteweight
68 Hurst LO Hemi Dart
70 hemicuda 4 spd. R code owned since 76
70 GTX 4 spd. 21,000 orig. miles
55 Ford F100 chopped,slammed,bagged & supercharged
96 Ram 2500 4X4 Twin turbo'd Cummins 550hp 1200 ft. lbs tow vehicle
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Re: Hemi Rocker Arm Deflection
[Re: liteweight]
#1120676
11/28/11 12:01 AM
11/28/11 12:01 AM
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Joined: Jan 2003
Posts: 6,392
nielsville, minn.
quickd100
master
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master
Joined: Jan 2003
Posts: 6,392
nielsville, minn.
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Quote:
Dave
Are those numbers calculated from lobe lift or measured?
liteweight
Daryl; Off the cam card. As usual the measured numbers at the valve are different, some better most worse. Most Wedge racers don't realize how lucky they are when it comes to the valve train. On the initial build I pulled my hair out on the valvetrain for a month. This summer when switching to the roller the motor was tied up for 2-1/2 months waiting on, finding, and recieving parts that would work. I finally was able to make a few dyno pulls on the motor. I still had to pull the motor down again to have the exhaust valves clipped to gain enough valve to valve clearance to live on the street. I'm hoping when it's all done it will crack 800hp.
Oh by the way Daryl, you think you can keep the snow up there a couple more months for me?  Dave
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Re: Hemi Rocker Arm Deflection *DELETED*
[Re: liteweight]
#1120677
11/28/11 02:15 AM
11/28/11 02:15 AM
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Joined: Oct 2007
Posts: 4,209
New York
polyspheric
master
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master
Joined: Oct 2007
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New York
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Post deleted by polyspheric
Boffin Emeritus
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Re: Hemi Rocker Arm Deflection
[Re: polyspheric]
#1120678
11/28/11 08:08 AM
11/28/11 08:08 AM
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Joined: Jan 2003
Posts: 6,392
nielsville, minn.
quickd100
master
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master
Joined: Jan 2003
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nielsville, minn.
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Quote:
Thanks, those numbers sound safe to me.
Has anyone read the Kevin Cameron article on valve train instability?
Jeff; You you have a link to the article? Dave
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Re: Hemi Rocker Arm Deflection
[Re: polyspheric]
#1120679
11/28/11 11:53 AM
11/28/11 11:53 AM
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Joined: Oct 2005
Posts: 290
Manitoba, Canada
liteweight
OP
enthusiast
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OP
enthusiast
Joined: Oct 2005
Posts: 290
Manitoba, Canada
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Quote:
Thanks, those numbers sound safe to me.
Has anyone read the Kevin Cameron article on valve train instability?
Not sure meaning 0f "Safe Numbers"????
Definately interested in reading that article, if you can forward a link. Googled it, but only found a book entitled TDC.
Breaking down the previous PDF File, it's interesting to see that there is NO advantage to higher rocker arm ratios available on aftermarket roller rockers. They all flex back to approximately stock ratioed delivered numbers at the valve.
Stock Intake-1.58:Deflection-.044", Duration Loss-10.5*
Stock Exh.-1.52: Deflection-.039", Duration Loss-11.5*
Indy Intake-1.64: Deflection-.047", Duration Loss-12.0*
DLI Intake-1.7: Deflection-.052", Duration Loss-14.5*
DLI Exh.-1.56: Deflection-.039", Duration Loss-13.5*
Attached is another PDF file Big Wedge put together on the delivered valve lift.
Liteweight
Last edited by liteweight; 11/28/11 11:59 AM.
68 Hurst LO Hemi Dart
70 hemicuda 4 spd. R code owned since 76
70 GTX 4 spd. 21,000 orig. miles
55 Ford F100 chopped,slammed,bagged & supercharged
96 Ram 2500 4X4 Twin turbo'd Cummins 550hp 1200 ft. lbs tow vehicle
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Re: Hemi Rocker Arm Deflection *DELETED*
[Re: quickd100]
#1120681
11/28/11 12:05 PM
11/28/11 12:05 PM
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Joined: Oct 2007
Posts: 4,209
New York
polyspheric
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master
Joined: Oct 2007
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New York
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Post deleted by polyspheric
Boffin Emeritus
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Re: Hemi Rocker Arm Deflection
[Re: hemi-itis]
#1120683
11/28/11 03:10 PM
11/28/11 03:10 PM
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Joined: Mar 2007
Posts: 314
Manitoba, Canada
Big Wedge
enthusiast
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enthusiast
Joined: Mar 2007
Posts: 314
Manitoba, Canada
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Quote:
 Am I reading that the stock rockers produce the least loss  
Hi Al,
That is not quite correct. If you look at the chart, the intake rocker arm ratios are not equal therefore this is not an apples to apples comparison. I think the data is linear therefore can be interpolated.
Check the exhaust rockers. The ratio is much closer and the deflections are equal. This being linear would mean the DLI exhaust rocker is stiffer.
Garth
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Re: Hemi Rocker Arm Deflection
[Re: liteweight]
#1120685
11/28/11 09:30 PM
11/28/11 09:30 PM
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Joined: Dec 2003
Posts: 3,957
West Coast, CA
Troy
master
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master
Joined: Dec 2003
Posts: 3,957
West Coast, CA
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Are those HI TECH ROCKER STANDS in this picture??? If so the owner needs to change out the split lock washers that are under the shaft hold down bolts. If you dont you will be low on oil pressure. I was checking my oil pressure with the valve cover off and when I hit the drill motor to build pressure, oil shot out from between the bolt and the stand. What was happening was oil was coming out of the shaft...going through the split lock washer and past the bolt. I changed over to a standard washer and all is good.
....there is nothing like driving my 1968 Hemi Dart around town and having people looking at you like you're nuts!!
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Re: Hemi Rocker Arm Deflection
[Re: Troy]
#1120687
11/28/11 11:15 PM
11/28/11 11:15 PM
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Joined: Jan 2003
Posts: 3,505
DFW
mr_340
master
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master
Joined: Jan 2003
Posts: 3,505
DFW
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The engineering community has abandoned split lock washers for any purpose. The opinion is they don't work and in some cases aid the fastener loosening. I've found NASA and US Navy documents confirming this opinion. http://gltrs.grc.nasa.gov/reports/1990/RP-1228.pdf
Floyd Lippencott IV
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