Help! Pushrod Clearance with 1.6 Rockers

[blewbyoutobad]

Has anyone had any pushrod clearance issues using a 1.6 ratio roller rocker with X heads? It seems I need to open up the pushrod hole in the head to allow pushrod more room for the adjusting screw ball to seat in the pushrod cup. Is this a common fix for running 1.6 ratio rockers? Also I have posted a pic of the roller pattern on the valve tip for the 1.5 roller rockers. Does this look to far toward the outside? My plan was to use a 1.6 on the intake and a 1.5 on the exhaust.
Thanks FABO

 

[valiant1966]

Yes on both counts. I've built 2 engines with 1:6 rollers and had to clearance both. And that does look too far forward on the valve to me.

 

[blewbyoutobad]

Yes on both counts. I've built 2 engines with 1:6 rollers and had to clearance both. And that does look too far forward on the valve to me.

Thanks for the reply. When you clearanced the heads was it at the bottom or top of the hole? Did you need to remove a lot of material and were you able to do it with a die grinder?

 

[valiant1966]

Did the top of the hole using a burr bit and a die grinder. It wasn't too difficult.

 

[fishy68]

I've only used 1.6's once but had to clearance the top and bottom. Used a die grinder same as Valiant66. I assume the rockers are rollers? If so the pattern is ok. Not perfect, but it's now where near ready to roll off the valve. Rollers don't produce nearly as much side loading as stock type scrub rockers so I think it's ok.

 

[blewbyoutobad]

Thanks fishy. I plan on using them the way they are. The picture is of the Speedpro's 1.5 exhaust at .487 lift. I'm using the 1.6 Racer Browns on the intake and they have a good roller pattern in the right location. I just need to clearance the pushrod holes for them.