Rocker Geometry stuff...

coupe · 03-23-2005, 09:06 AM

Took some pics while seting up stud-mount rockers. Here's a way I check the pushrod length:
I mark the top with a sharpie; then place the rocker down on the pushrod and spin the roller-tip to make a mark in the sharpie ink. This shows me the location of the tip when the lifter is on the base-circle. This witness mark should be at or just outside of the inner 1/3 of the valve stem top (see pic). This will allow it to move out over the middle when the cam lobe moves the valvetrain.

This area is the best for lowest side-loading of the valve on the guide and will increase longevity. If the mark is too far outside, get a shorter pushrod and vice-versa.

Anyone else feel free to add experiences/recommendations.

coupe · 03-23-2005, 09:20 AM

Here's a problem I ran into: the roller-tips were NOT on the centers of the valve stems. They were even off the edge on some cylinders. Only solution: I had to undo the guide-plates and shift the back side of the rockers to pivot the front around over the top of the valve. Only #8 was inline already. Can't believe I didn't notice this being so bad on the other set of rockers I had

2nd pic is corrected alignment. I did 50 ft. lbs on the rocker studs. (helicoiled)

Anyone have any input on this feel free to add.

QWKSNKE · 03-23-2005, 10:12 AM

Quote:

Originally Posted by coupe

. Only solution: I had to undo the guide-plates and shift the back side of the rockers to pivot the front around over the top of the valve. Only #8 was inline already. Can't believe I didn't notice this being so bad on the other set of rockers I had

.

You had to do what

What length pushrods are you using?

coupe · 03-23-2005, 10:45 AM

stock length. Length was not a problem; the alignment of the guide-plates (aligning the pushrods/rockers) was off. Ran fine w/ other rockers but I wanted everything to line-up straight.

QWKSNKE · 03-23-2005, 12:13 PM

gotcha now

coupe · 03-25-2005, 12:54 PM

Just an added note regarding the rocker-stud torque: I found AFR's torque spec for 3/8" studs on their heads to be 55 ft. lbs.

03-23-2005, 10:45 AM	#4
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Re: Rocker Geometry stuff... stock length. Length was not a problem; the alignment of the guide-plates (aligning the pushrods/rockers) was off. Ran fine w/ other rockers but I wanted everything to line-up straight. __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein

03-23-2005, 12:13 PM	#5
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Re: Rocker Geometry stuff... gotcha now __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

03-25-2005, 12:54 PM	#6
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Re: Rocker Geometry stuff... Just an added note regarding the rocker-stud torque: I found AFR's torque spec for 3/8" studs on their heads to be 55 ft. lbs.