stamped steel rocker arm delection
 

just seeing the results you guys are getting on how much lift are you loosing on your stock steel rockers ?? with 220 lbs on the seat ,i see a sizable loss between the difference against measuring with a checking spring and these rockers are not cryoed these a 1.6 ratio rockers gmonde

Re: stamped steel rocker arm delection
 

I've never been able to measure it or verify it. I'd say you'd just about have to do it on a Spin Tron to accurately measure it.

Try checking a roller rocker the same way.

Re: stamped steel rocker arm delection
 

alan,i am sure the a roller rocker will not loose as much if not anything ,i guess i didnt realize how much of the actual lift you mite not be using with the actual valve spring load to get the maximum lift you are required,checking the lift at the retainer with a checking spring vs the actual valve spring is sizable difference gmonde

Re: stamped steel rocker arm delection
 

The deflection I've measured is about .015" from checking spring to race springs on my 396 stocker motor. This is a combination of the pushrod flex, rocker stud flex and the rocker arm itself, not sure how you'd isolate the amount in the rocker alone but it is significant. NHRA checks lift at the retainer, using a solid lifter of the same height, so you can adjust the lobe lift to compensate for the loss from what I understand....

Re: stamped steel rocker arm delection
 

I have .006 extra ground into lob lift to get closer to max lift on the 6cyl engines.

Re: stamped steel rocker arm delection
 

grant:how much spring presure are you running??i know big blocks have a 3/8 push rod but you probably run a 7/16" or 1/2" and the ratio is 1.7 ,,.015 is not bad i am getting more ..020 -.025 and thats with a 3/8 push rod gmonde

Re: stamped steel rocker arm delection
 

Keep in mind, your lift values change as you lose race spring pressure, too.

Wade

Re: stamped steel rocker arm delection
 

[QUOTE=Grant Eldridge;237444]The deflection I've measured is about .015" from checking spring to race springs on my 396 stocker motor. QUOTE]

Grant, sometimes it can be WAY more difference than that. I learned the hard way on this too. Never use checking springs, use the race springs at the pressure your going to run to be accurate.

Wade

Re: stamped steel rocker arm delection
 

gmonde, I run 240 on the seat, 440 open pressure.
wade, I was surprised how much deflection there is in these parts. When I ran the stock size studs you could see them bend turning over the motor! I have since gone to Clark Holroyd's nice stainless thick studs and rockers, but still have deflection.....Clark now welds a re-inforcement onto his rockers above the pushrod seat, like a small bridge across, that might further help....

Re: stamped steel rocker arm delection
 

is welding a brace on the rocker legal in stock??? hhmmmm gmonde