Pushrod help

[Dusty 997]

Ill be installing my new Oregon reground cam soon and I want to measure for push rods. Ive never done this before but The motor is a stock 360 magnum with the stock stamped rockers.

I am under the impression that because I have Hydraulic roller lifters there's some special tool or extra step i have to do to do this correctly?

I cant just buy an adjustable pushrod stick it in there and unscrew it because the factory lifters aren't solid and would just compress and throw off the measurements?

If anyone whose done it before can give me some advice and maybe link me to the tools i need that would help, all the videos i found on youtube only cover Non hydraulic lifter LA type motors.

 

[Bobzilla]

I cant just buy an adjustable pushrod stick it in there and unscrew it because the factory lifters aren't solid and would just compress and throw off the measurements?

That is exactly what you want to do in this application. You use an adjustable pushrod with everything else installed correctly and that cylinder on cam's base circle. Then you unscrew (lengthen) the adjustable pushrod until the hydraulic lifter plunger moves down the amount you want for proper preload, usually around .060" or so for those. That's it. Measure that adjustable pushrod and that is your length.

Do several cylinders to make sure you are getting good measurements and buy pushrods within the average number. If they are vastly different, start over and measure again, as they should be pretty close to each other, within about .010" most likely. You are not adjusting any geometry as that is all built into the rocker arm and cylinder head.

 

[Dusty 997]

That is exactly what you want to do in this application. You use an adjustable pushrod with everything else installed correctly and that cylinder on cam's base circle. Then you unscrew (lengthen) the adjustable pushrod until the hydraulic lifter plunger moves down the amount you want for proper preload, usually around .060" or so for those. That's it. Measure that adjustable pushrod and that is your length.

Do several cylinders to make sure you are getting good measurements and buy pushrods within the average number. If they are vastly different, start over and measure again, as they should be pretty close to each other, within about .010" most likely. You are not adjusting any geometry as that is all built into the rocker arm and cylinder head.

Just had a thought, If i adjust the push-rod out to 0 lash then measured the pushrod and added .060 that would give me the proper preload right?

 

[Bobzilla]

Yes it would IF you have correct zero lash. That is hard to get by feel. Watching the lifter plunger you go back and forth on the adjustable pushrod a tiny bit until you know it’s about to move the plunger but not actually moving.

 

[Dusty 997]

thanks!

 

[Dusty 997]

Yes it would IF you have correct zero lash. That is hard to get by feel. Watching the lifter plunger you go back and forth on the adjustable pushrod a tiny bit until you know it’s about to move the plunger but not actually moving.

Thanks again for the response, i measured the way you said and they came out perfect. no issues.