Proper rocker clearancing

[Kenny]

Okay guys I've been seeing some problems with cams hitting rockers because the rockers have been improperly cut. There are a few rockers out there being sent around with a flat cut across the bottom that need to be radiused  at two critical points. The dead giveaway is the exhaust lobe is the only one getting hit. The lobe seems to clear just fine when you visually inspect the clearances, but as the rocker goes through it's travel, it will hit the leading and trailing edge of the cam lobe.

Here is a pic of the offending area highlighted with blue dye;


Here is lobe damage on a cam with only .389" lift. The shape of the performance style "square" lobe is the issue here. This style of lobe is very beneficial for max performance.


Here is the correct way to radius the bottom. This allows you to get proper clearance while maintaining maximum material thickness for durability. You can actually grind through the hardened surface of the rocker body, so keeping the max material thickness is good practice.

[Krandall]

Kenny, do you by chance have another rocker to show a top view comparison between a good and bad?

[DL700]

some more pics of clearanced rockers.... these are done by WEB with some additional work

[Krandall]

Why the spot weld on the outside of the roller 

[Kenny]

This has cost me 2 ruined cams (customer installed)........ It doesn't even make extra noise, just low dyno numbers were the only obvious indicator that something was wrong. I would request no tack weld. The heat can cause stress fractures and failure. All you need to do is slightly swedge the axle sleeve and it will never come loose.
Here is the difference. The left one is a go, the one on the right is a no go

[DL700]

 
never seen one cut life that.. that wont do a whole lot of good

[Kenny]

never seen one cut life that.. that wont do a whole lot of good

That one came straight from miss Laurie

For those that are fans of my hillbilly ingenuity.......Here is a roughed-in drag rocker, sorry no final product pics(intentionally)

[Colorado700R]

patent pending

[Kenny]

patent pending

Believe it or not it saves more weight over the valve than swapping stainless valves out for Ti. I will love to see the first guy to copy these.....One bit of grinding in the wrong spot, or not cryo treated, BOOM! Grenade time

[DL700]

pushin your luck on those IMO... but NICE!!

[preddy08]

patent pending

Believe it or not it saves more weight over the valve than swapping stainless valves out for Ti. I will love to see the first guy to copy these.....One bit of grinding in the wrong spot, or not cryo treated, BOOM! Grenade time

Kenny have you had good luck with the cryo treating?

[robkd]

Seems like flirting with disaster to me grinding that much down, but i am no expert.  I would be interested to see how these hold up!

[Colorado700R]

I like gernades, with a family full of former Marines, they make family reunions more interesting

[Kenny]

pushin your luck on those IMO... but NICE!!

Thank ya very much

patent pending

Believe it or not it saves more weight over the valve than swapping stainless valves out for Ti. I will love to see the first guy to copy these.....One bit of grinding in the wrong spot, or not cryo treated, BOOM! Grenade time

Kenny have you had good luck with the cryo treating?

Yes. Especially with chains(drive or timing). Nitriding and certain coating treatments work well too. I have seen no real difference when using thermal barriers though, except for less carbon buildup.

Seems like flirting with disaster to me grinding that much down, but i am no expert.  I would be interested to see how these hold up!

I have had a set running for about a month now. The hardest part was finding narrow adjusting nuts in the right thread pitch. There has been substantially more material removed from non-critical areas since that picture. There has also been some "clocked" oiling mods done as well.

I like gernades, with a family full of former Marines, they make family reunions more interesting

Never retired, only former. But always a Marine.......Semper Fi!

[robkd]

sweet