Figuring out pushrod length for roller cam
#3105773
12/26/22 07:39 PM
12/26/22 07:39 PM
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Joined: Nov 2003
Posts: 1,032 illinois
bigblk66_coronet
OP
super stock
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OP
super stock
Joined: Nov 2003
Posts: 1,032
illinois
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Hey guys i need some guidence here. I'm building a 512 and was talked into switching to a roller cam not realizing what all was involved in doing that, I bought a Howards 565 lift hydraulic roller can and i ordered 1.5 Harland Sharp Roller rockers. I need to figure out pushrod length and i have no clue how to go about it. from what i understand you have to have an adjustable pushrod tool right? Well it looks like there is different lengths? How do i figure all this out. This roller can stuff is all new to me. I've been running a 292 purple shaft for 30 years. Im an old school guy and just sticks with what works. Any help would be greatly appreciated. The pushrods are the only thing left before i can finish the motor. Anyone? I'm an old school guy and don't like change and man have i paid for it...lol
66 Dodge Coronet 500
440w/727
11:10 30 over 440 w/292 purple shaft,stock Eddy heads,3:23,full exhaust
Best ET. 12.38 @110 in street trim
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Re: Figuring out pushrod length for roller cam
[Re: Cab_Burge]
#3105832
12/26/22 11:33 PM
12/26/22 11:33 PM
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Joined: May 2019
Posts: 713 Lake Villa Il
INTMD8
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super stock
Joined: May 2019
Posts: 713
Lake Villa Il
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Not sure if you have old pushrods but when switching to solid roller I took a couple of the original flat tappet pushrods, removed the cup, slotted the end (so could easily install/remove cup) and ground them down until they were the right length.
I was going for 2 threads below rocker lashed.
I then used head shrink around the pushrod to determine max diameter that would fit.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
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Re: Figuring out pushrod length for roller cam
[Re: bigblk66_coronet]
#3105843
12/27/22 02:39 AM
12/27/22 02:39 AM
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Joined: Jun 2014
Posts: 3,237 Md.
carnut68
master
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master
Joined: Jun 2014
Posts: 3,237
Md.
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Comp Cams 7719 it adjusts from 8.8 -9.8. $ 37.95 from Summit. That's what I use 511 RB with Indy Ez and Harland Sharp rockers.
America First!
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Re: Figuring out pushrod length for roller cam
[Re: fastmark]
#3105900
12/27/22 12:20 PM
12/27/22 12:20 PM
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Joined: Dec 2006
Posts: 2,117 Byron, NY
W.I.N. Racing
top fuel
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top fuel
Joined: Dec 2006
Posts: 2,117
Byron, NY
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The better way is to purchase the push rod tool that with adjust to the proper length and configuration, both end type and diameter (ball/ball, ball/cup, 5/16, 3/8 etc) most are etched with a scale to determine the change in length from nominal (ie. purchase a 10" nominal push rod and every turn is some know value) When doing so the adjusters in the rockers should be set so if the oil squirt hole is slightly above the intersection of the push rod/adjuster. Then set your preload as normal using the measuring Push rod. Now using the nominal length and the amount of adjustment added, that will be your required push rod length. It is preferable to use a test spring to run the valve thru its range of motion to ensure no issues are present and also check multiple location both int and exh.. the $37 spent on the tool is well worth it
'01 P1500, Blown/Inj BAE,/Veney ,Bruno/CS2,Dana 60 '01 Dodge 3500 S Cummins Auto, Fresh air kit, 4" Exhaust, '05 Dodge Magnum R/T - Too Much to list '60 Willys CJ5 '01 International LPX - Project,DT466, Allison '64 Plymouth Valiant, Inj 528 Hemi, 2spd
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Re: Figuring out pushrod length for roller cam
[Re: bigblk66_coronet]
#3106065
12/28/22 05:52 AM
12/28/22 05:52 AM
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Joined: May 2008
Posts: 5,399 Aurora, Colorado
451Mopar
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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On my 512 RB stroker with a Comp hydraulic roller and HS 1.6:1 rockers on 440 Source stealth heads, the pushrods I bought were just a bit short of 8.5". Looking at my notes, I think 8.4750"? I used the Comp cams adjustable pushrod, with light checking springs on the valves. I used Smith Brothers 5/16", and fairly sure the 0.083" wall pushrods. I came up with a range of pushrod lengths for between 0.020 and 0.040" lifter preload, and the minimum number of adjuster threads (where the pushrod / adjuster starts getting oil from the rocker), to about three turns down (any more and the oil to the adjuster starts getting cut off.)
Your measurements might be different. My block was cut to zero deck the pistons, and used a 0.040" Cometic MLS head gasket.
Last edited by 451Mopar; 12/28/22 05:54 AM.
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Re: Figuring out pushrod length for roller cam
[Re: 451Mopar]
#3106131
12/28/22 02:42 PM
12/28/22 02:42 PM
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Joined: Jan 2003
Posts: 7,497 Minnesota
Hemi_Joel
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master
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Minnesota
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I made an adjustable push rod by taking an old one and cutting it in half at the proper spot, threading both ends with a die, then threading them into a coupler nut. After I have adjusted it to the proper length, I measure it with a dial caliper.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
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Re: Figuring out pushrod length for roller cam
[Re: Hemi_Joel]
#3106191
12/28/22 07:18 PM
12/28/22 07:18 PM
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Joined: Jul 2005
Posts: 712 California
BigDaddy440
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super stock
Joined: Jul 2005
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California
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Once you have an adjustable push rod, you can determine the exact length you need to create proper load on the center of valve stem. If you're unsure how to do that, make sure you ask or you look into it. It's not hard, but you do want to keep the rocker tip centered on the stem at peak lift / open pressure.
1969 A12 Roadrunner 1970 Plymouth Cuda 1968 Dodge Dart
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Re: Figuring out pushrod length for roller cam
[Re: carnut68]
#3106506
12/29/22 09:56 PM
12/29/22 09:56 PM
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Joined: Nov 2003
Posts: 1,032 illinois
bigblk66_coronet
OP
super stock
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OP
super stock
Joined: Nov 2003
Posts: 1,032
illinois
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So i ordered the pushord length checking tool. Ive been watching videos on youtube on how to do it. Some say you need to pull off a valave spring and put on a checking spring? but then ive been told its no necessary? I get the whole concept but its very confusing and i dont want to screw it up.
66 Dodge Coronet 500
440w/727
11:10 30 over 440 w/292 purple shaft,stock Eddy heads,3:23,full exhaust
Best ET. 12.38 @110 in street trim
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Re: Figuring out pushrod length for roller cam
[Re: bigblk66_coronet]
#3106563
12/30/22 09:08 AM
12/30/22 09:08 AM
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Joined: Jun 2014
Posts: 3,237 Md.
carnut68
master
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master
Joined: Jun 2014
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Md.
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So i ordered the pushord length checking tool. Ive been watching videos on youtube on how to do it. Some say you need to pull off a valave spring and put on a checking spring? but then ive been told its no necessary? I get the whole concept but its very confusing and i dont want to screw it up. It'll be much easier with a checking spring and probably more accurate.
America First!
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Re: Figuring out pushrod length for roller cam
[Re: carnut68]
#3109844
01/07/23 06:11 PM
01/07/23 06:11 PM
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Joined: Nov 2003
Posts: 1,032 illinois
bigblk66_coronet
OP
super stock
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OP
super stock
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illinois
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ok i ordered the comp cams pushrod length checking tool 8.8 to 9.8.. went to try to figure this whole mess out and it looks to be way too long! Either that or im missing something. look at the pics. This whole process is a complete confusing pain in the ass and im kind of over it. One step forward 2 steps back.
66 Dodge Coronet 500
440w/727
11:10 30 over 440 w/292 purple shaft,stock Eddy heads,3:23,full exhaust
Best ET. 12.38 @110 in street trim
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Re: Figuring out pushrod length for roller cam
[Re: bigblk66_coronet]
#3110044
01/08/23 01:00 PM
01/08/23 01:00 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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the utube vid "engine tech valvetrain geometry" by "straub technologies" may help. EDIT & UTG had something on preload amount for hyd lifters, probably not valid here but I wanted to throw it out there. he was loosing alot of power till he corrected it.
Last edited by RapidRobert; 01/08/23 01:05 PM.
live every 24 hour block of time like it's your last day on earth
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