212 Hemi Pushrod length

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Dingo286

New Member
#1
#1
I am building a predator 212 hemi and don’t know what length pushrods to order.

The stats: Predator 212 Hemi, .010 thick head gasket, no milling work done, NR racing steel 1.2 ratio rockers, and a gopowersports .265 fire cam.

I am also running 26lb valve springs, stainless valves and automotive style retainers, but I don’t thing these would impact the length I need for my pushrods.

Any help is greatly appreciated.
 
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panchothedog

Well-Known Member
#2
#2
If you go on the " Gage " website. The company that manufacturers the expensive aluminum roller rockers, they have an excellent video on how to determine pushrod length.
 
ole4

ole4

#4
#4
That will not work for the valveside geometry. The NR rockers on the hemi are fixed fulcrum, and not shimmable. They do not take into account the new valves length. To get the correct pushrod length you want to make or buy an adjustable pushrod, set the adjuster to the middle of its range with the cam on the base circle and extend the pushrod to just touch the adjuster cup. remove the pushrod and measure it and that is the length you want. You still may be way off on the valveside geometry but its not possible to change it without changing valve length. You need to have weak stock springs for using the adjustable pushrod as strong springs may bend it.
 

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Dingo286

New Member
#5
#5
Would grinding a stock pushrod down to size work as well? I’m a little hesitant to buy an adjustable pushrod or the tools to make one, just to use them once.
 
ole4

ole4

#6
#6
No, you would grind the end off as the pushrod is hollow. it does not sound like you have all the equipment to even check the geometry. So use the stock pushrods and if the adjuster does not have to go to one extreme or the other then call it a day.
 
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Dingo286

New Member
#7
#7
Yeah, this is just a fun project for me on the side, not looking to drop too much money on it. I’ll just ballpark it with the stock pushrods, if I lose a small amount of horsepower due to imperfect rocker geometry, I doubt I would even notice or care.
 
sparkwizard

sparkwizard

#10
#10
For what it's worth, I use .010 head gaskets and 1.2:1 rockers on about 6 of my own non hemi Predators. I have never checked pushrod length, and I have never had a problem.. But, that is with stock cams and "tweaked" governors.
 
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Dingo286

New Member
#14
#14
I think I’m going to go with some 5.200 pushrods. 5.26 might be too long, or require the rockers to be adjusted almost all the way out, which might decrease performance. 5.16 might work, but I think it would require the rockers to be adjusted all the way in to keep the pushrods from coming out and bending.
 
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Raccoon

New Member
#15
#15
Did anyone come up with a length for this application? I am building the same set up I believe... New hemi 212 predator with Stage two non-hemi head, the Hot .265 cam, champion rockers, and .010 steel head gasket. These are bought straight from go power sports. Has no one done this before to find out what length push rod to use? I too would not want to buy all of the specialty tools to make a one off if possible. I would think by now someone would have had to have figured this out already.
 
sparkwizard

sparkwizard

#16
#16
Raccoon said:
Did anyone come up with a length for this application? I am building the same set up I believe... New hemi 212 predator with Stage two non-hemi head, the Hot .265 cam, champion rockers, and .010 steel head gasket. These are bought straight from go power sports. Has no one done this before to find out what length push rod to use? I too would not want to buy all of the specialty tools to make a one off if possible. I would think by now someone would have had to have figured this out already.
Click to expand...
Have you asked Go Power Sports for a suggestion? Maybe your cam supplier?
If I was starting a build like that, I would get some stock, non hemi pushrods and install them, measure the difference if they weren't quite right.
Each engine is different, and that might be why nobody has entered the "correct" length for your application.
Have fun and be safe. Dave
 
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SAS289

SAS289

Well-Known Member
#18
#18
Raccoon said:
Did anyone come up with a length for this application? I am building the same set up I believe... New hemi 212 predator with Stage two non-hemi head, the Hot .265 cam, champion rockers, and .010 steel head gasket. These are bought straight from go power sports. Has no one done this before to find out what length push rod to use? I too would not want to buy all of the specialty tools to make a one off if possible. I would think by now someone would have had to have figured this out already.
Click to expand...
Are you doing the build with no push rods to check with?

See post #6 in this thread. You are using Champion rockers. You'll know right away if the push rods you have are too long or too short. If it seems that the adjuster is going in too far then the push rods are too short. If the adjuster seems backed out too far the push rods are too long. If you are somewhere in the middle of the adjuster then set the lash and be done.

You have to figure out what you need for your engine. Heads can be different.

What about the GPS "stage 2" head? If it's had .080" milled you would want shorter than stock push rods.

And don't put the push rod guide plate in there. It's not needed with the Champion rockers.
 
ole4

ole4

#19
#19
Raccoon said:
Did anyone come up with a length for this application? I am building the same set up I believe... New hemi 212 predator with Stage two non-hemi head, the Hot .265 cam, champion rockers, and .010 steel head gasket. These are bought straight from go power sports. Has no one done this before to find out what length push rod to use? I too would not want to buy all of the specialty tools to make a one off if possible. I would think by now someone would have had to have figured this out already.
Click to expand...
Your not building the same set up. Whenever you change your valvetrain you should check geometry. You are using different rockers than the OP and you may be using the same cam but that does not mean it is the same base circle. If you dont check it and just put in the stock pushrods. you can eyeball it and as long as the tip of the rocker stays more or less in the middle of the valve it will run and probably be ok. Look up checking valve sweep using a black marker.
 
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DR&R

Member
#20
#20
GX200, BSP "Clones", 6.5 Chinese OHVs
  • 5.260" Stock Length: Use with Stamped Rocker Arms
  • 5.160" (-.100): Use with Billet & Roller Tip Rocker Arms
  • 5.110" (-.150): Use with Billet/Roller Tip Rockers along with extensive milling (>.065")
  • 5.440" (+.180): Allows use of 160 lifters in 200 blocks to reduce valve train weight. Reduces combined lifter/pushrod weight by approximately 7%. Use with Stamped Rocker Arms
  • 5.340" (+.080): Allows use of 160 lifters in 200 blocks with Billet or Roller Rockers. Also use with Aluminum Rockers
212 Predators (Old Style)
  • 5.200": Stock Length
  • 5.110": Use with Billet & Roller Rockers
  • 5.260": Use with Aluminum Rocker Arms
212 Predators (Hemi Head)
  • 5.540" Stock Length: most applications
  • 5.440" (-.100): Use with extensive milling
  • 5.260": Use with NR Racing Hemi Rollers
  • 5.160": Use with NR Racing Hemi Rollers and heads milled .065 or more, also with large base circle cams.
 
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