Author Topic: Rocker spacers and pushrods  (Read 4384 times)

Offline dodj

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Rocker spacers and pushrods
« on: May 23, 2015 - 07:29:29 AM »
So I'm installing a set of PRW stainless rockers today...or maybe tomorrow. Reading the instructions it says that mopar used a few different cylinder heads and spacers MAY BE REQ'D. How do I determine if I need a spacer? Just eye balling the roller tip with the valve stem? If so, it seems like a pita to do seeing as you would have to pull everything off the shaft to where you needed to add a spacer.
« Last Edit: June 03, 2015 - 12:54:25 PM by dodj »
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.




Offline dodj

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Re: Rocker spacers
« Reply #1 on: May 23, 2015 - 08:30:12 AM »
And one other thing. I have been told it is a good idea to buy new pushrods. How do I determine proper length? I put on stealth heads. I have an adjustable p-rod, but lack the knowledge on how to use it.
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline cudabob496

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72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline Chryco Psycho

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Re: Rocker spacers
« Reply #3 on: May 23, 2015 - 09:56:37 PM »
Yes it is a pain to get the spacer right You need to make sure the roller tip is centered on the valve tip , I usually use lash caps to increase the surface area & protect the valve tip , you want a little side play , .010 or so for heat expansion , & you can move the roller tip over slightly if the pushrod is too close to the casting of the intake port .
 To get the right pushrod length you have to be sure the lifter is on the back side of the lobe so as low as possible you want the adjuster set as high as possible then turn it down 2 full turns , put a feeler gauge in place for lash & measure the total distance left between the lifter & rocker , if this is using a solid lifter !
With hyd you need to preload the lifter so I would start with the adjuster 1 turn down from topped out'
 I would order pushrods from Smith Bros in Bend OR , great service & fast .

Challenger - You`ll wish You Hadn`t

Offline dodj

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Re: Rocker spacers
« Reply #4 on: May 25, 2015 - 08:04:38 PM »
you want a little side play , .010 or so for heat expansion , & you can move the roller tip over slightly if the pushrod is too close to the casting of the intake port .
So if i understand correctly, in the below pic, I need to insert enough spacer to fill up the gaps on eith side of the rocker pair except for about 10 thou?
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Chryco Psycho

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Re: Rocker spacers
« Reply #5 on: May 25, 2015 - 10:18:34 PM »
Yes , with everything in place you can fit the spacers by inserting them in the gaps & slide them all on the shaft in one step if you keep them seperated in order

Challenger - You`ll wish You Hadn`t

Offline dodj

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Re: Rocker spacers
« Reply #6 on: May 26, 2015 - 04:32:12 PM »
Yes , with everything in place you can fit the spacers by inserting them in the gaps & slide them all on the shaft in one step if you keep them seperated in order
Thnx CP.
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline dodj

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Re: Rocker spacers
« Reply #7 on: June 03, 2015 - 12:54:01 PM »
With hyd you need to preload the lifter so I would start with the adjuster 1 turn down from topped out'
 I would order pushrods from Smith Bros in Bend OR , great service & fast .
So with the lifter riding on the base circle of the cam, and the rocker adjuster one full turn from topped out, I expand the adjustable push rod to just fill that distance. Then remove the rockers, take out the adjustable push rod, measure it,  and then that is the length of pushrod I need to order?
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Chryco Psycho

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Re: Rocker spacers and pushrods
« Reply #8 on: June 03, 2015 - 05:47:27 PM »
With hyd cam yes

Challenger - You`ll wish You Hadn`t

Offline dodj

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Re: Rocker spacers and pushrods
« Reply #9 on: June 03, 2015 - 07:59:23 PM »
Excellent. Thanks again CP.  :cheers:
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline dodj

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Re: Rocker spacers and pushrods
« Reply #10 on: June 06, 2015 - 08:38:15 AM »
Last couple of questions (hopefully).
Should I use loctite or something on the rocker shaft studs?

Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Chryco Psycho

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Re: Rocker spacers and pushrods
« Reply #11 on: June 06, 2015 - 09:12:26 AM »
I used grade 8 bolts torqued & never bothered with the studs , no harm in locktite on them into the head though , just do NOT over torque the nuts & oval the shafts !

Challenger - You`ll wish You Hadn`t

Offline Strawdawg

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Re: Rocker spacers
« Reply #12 on: June 06, 2015 - 09:36:08 AM »
Sand the rocker adjuster one full turn from topped out,

What does that mean?

Offline dodj

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Re: Rocker spacers
« Reply #13 on: June 06, 2015 - 07:51:02 PM »
What does that mean?
I think it means your computer somehow inserted an 's' into my text, I guess?
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Strawdawg

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Re: Rocker spacers and pushrods
« Reply #14 on: June 06, 2015 - 09:03:05 PM »
okay, what does topped out mean?  Is that a term that means one thread emerging thru the rocker arm on the pushrod side?   :bigsmile: