Valve geometry 1.25 rockers

[wynand]

Hi this is my first post. I would like some help as this is my first time trying to set valve geometry. Is it better to try and get the rocker tip to sweep the centre of the valve or to rather get the rocker to be vertical at half lift.

[modok]

If you are lifting over .400 with swivel adjusters it is important to get them straight at half lift, just because they only have so much travel. They can only sqivel so far each way.

minimizing the scrub is also important but it would be less important than that.

[wynand]

half lift

full lift

Would this be acceptable it's with 2 shims

[Dan Ruddock]

What cam are you running? How much shim? Dan

[modok]

looks OK from here

[wynand]

It's a scat c25 lift at cam .350

I'm in the process of assembling the motor it's 78x94 and 35x32 valves with 40idf's

[GARRICK.CLARK]

With swivel feet you need a lot of shim.

[wynand]

It's swivel ball adjusters. Do they need as much shims as the feet adjusters do. It's just that as i increase the shims the tip of the rocker moves further over the tip of the velve away from the center. How do I correct this situation

Thanks for the help much appreciated

[GARRICK.CLARK]

On ones I've done, the Rocker tip is at the top of the valve. At half lift the tip is more central on the valve. At full lift the tip moves down a tad.

Paint the valve tips with some engineers blue.
Make sure the swivel ball footprint is just off the valve centre.

I've had to machine Rocker blocks on the side to move the number 1,and 2 inlet valve over to the left
And also the 3 and 4 inlet over to the left as well

Make sure at full lift the push rod isn't Scraping on the pushrod tube we're the tube/seal fits into the head

[mark tucker]

1 the rocker needs to be back cut flush with the beam part of the rocker. 2nd the adjuster needs to be screwed up fully and geo set about 1/2 turn out. 3 you need to make sure the oil hole/groove in the adjuster is aligning with the oil hole in the rockers( each rocker needs checked as they are all diferent) I usualy slot 1 or 2 threads at the oil hole to line them up. it dont take much. I also recommend lash caps. .060" is usualy close+-.020" (.5mm) be sure to thoroughly clean the rocker galleys for any debris. pushrods may need shortening. I almost always undercut the pushrod end on oe style pushrods so it does not bind in the rocker arm cup and give false lash setting and result in noisey valve train and posiably dead parts. some engines I rework the pushrod cup end too.there is a lot of unneeded material there. cb made theirs much better than the oe style stuff. also set all rockers side play to .002"~-004" for quiet operation.

[wynand]

I will definitely do everything you have suggested. And try the Rodeking / Rugblaster method the combination looks foolproof

[modok]

[wynand]

Ok i was able to gind 2mm from the rocker and still have thread engagement under the nut. For the oil hole I'm going to slot it. I'm using chromoly pushrods hopefully that helps with setting the valve clearance.
What do you think does the geometry look better now this is with 2 shims that is wear i gave up last knight i was getting a headache from the cold in the garage will have to invest in a heater im not going to stop drinking cold beer

[GARRICK.CLARK]

I don't mind a stack of washers. As long as the rocker angle at full open replicates the Rocker at full closed with a nice straight line at half lift. You will have to check the Rocker ped nuts are still tight after its run a few times.

[jfdestree]

You may want to give a try to this tool.
No more guesswork.
http://www.slideperformance.com/product_info.php?products_id=81150