New YT rocker failure
#1
Thread Starter
Joined: Aug 2011
Posts: 4,628
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From: Portland, OR
New YT rocker failure
This is the latest version of their rockers. Less than 1k miles.
These are on the car because I broke one of the previous version rockers.
4 of 16 look like this. The needles in the roller tip have failed.
I was removing these to put a better sealer on the intake bolt threads. Teflon paste wasn't working. So this was a surprise.
AFR heads with the 1819 spring upgrade.
Anyone else seen this?
Ron
#3
How much spring pressure are you running? I just removed Yella Terra rockers from my build and swapped with Jesels. I can not even begin to describe how much better I feel about the Jesels. They are salty but worth it.
#4
Thread Starter
Joined: Aug 2011
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From: Portland, OR
The 1819 spring is 412lbs @ .600 lift which is right where I'm at.
The failure in the prev set was the pushrod cup area. Where the high load is. 6 k on those. No issue with the roller tips.
The failure in the prev set was the pushrod cup area. Where the high load is. 6 k on those. No issue with the roller tips.
#6
This looks more like a machining issue on the roller end being too large. Rubbed right on the retainer. You were using steel retainers I presume? Have you made sure that your valve tips and locks are all correct? I have seen mismachined locks before that let the retainer ride too high and can cause this.
This is why most people go with the comp trunion upgrades for the stockers. We have them available if you need them instead. Just the trunions, or a new set with the upgrades already!
This is why most people go with the comp trunion upgrades for the stockers. We have them available if you need them instead. Just the trunions, or a new set with the upgrades already!
#7
Thread Starter
Joined: Aug 2011
Posts: 4,628
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From: Portland, OR
I set these AFR heads up very carefully. The wipe pattern was narrow and centered. Like I said, the prev set failed in the common way, broke through the pushrod cup on one rocker.
On this set, the one in the photo and the other three, the bearing in the roller tip is gone. The roller wheel moves .100" up and down.
The other 12 are fine, for now.
Retainers are titanium.
The new and improved version is supposed to drop in. I checked pattern one one, so just swapped them.
And yeah, valve train noise. But LS like. Cam is EPS custom. Doesn't have violent lobes.
On this set, the one in the photo and the other three, the bearing in the roller tip is gone. The roller wheel moves .100" up and down.
The other 12 are fine, for now.
Retainers are titanium.
The new and improved version is supposed to drop in. I checked pattern one one, so just swapped them.
And yeah, valve train noise. But LS like. Cam is EPS custom. Doesn't have violent lobes.
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#9
How do the TI retainers look? I would imagine they rubbed out as well. Seems like inferior quality bearing/roller tip material then.
No one uses the Scorpions even though lately the YTs have the worse track record. At least they are a US company that is easy to get ahold of and comes with a lifetime wnty. Just my .02
No one uses the Scorpions even though lately the YTs have the worse track record. At least they are a US company that is easy to get ahold of and comes with a lifetime wnty. Just my .02
#10
Thread Starter
Joined: Aug 2011
Posts: 4,628
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From: Portland, OR
Fortunately, the retainers look ok. Obviously harder than the alum rocker.
If I find out that the AFR guides are the good manganese bronze, I'll put stock rockers on.
I need to find my receipt and start with the supplier. Then contact YT.
I'm not opposed to trying Scorpions.
If I find out that the AFR guides are the good manganese bronze, I'll put stock rockers on.
I need to find my receipt and start with the supplier. Then contact YT.
I'm not opposed to trying Scorpions.
#13
Doesnt take much machine work to get them put in, but it will require a new valve job. Most places overlook that part.
I am not a fan of bronze guides anyway. Id rather put and engine together and not stay up at nights wondering about it.
I am not a fan of bronze guides anyway. Id rather put and engine together and not stay up at nights wondering about it.
#15
Thread Starter
Joined: Aug 2011
Posts: 4,628
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From: Portland, OR
I know the process.
Refreshed my Rat after 7 years, AFR heads. Several hundred passes in the low 10's. Guides and valve seats were perfect.
Valve springs were toast.
Refreshed my Rat after 7 years, AFR heads. Several hundred passes in the low 10's. Guides and valve seats were perfect.
Valve springs were toast.
#18
Wonder if those particular rockers were starving for oil for some reason. I have not seen any failures of this type in the past so wondering if there are other things at play here.
#19
just so I get it straight in my head,
the needle bearings in the tip failed, which allowed the rocker body to contact the retainer?
bummer deal. how's the rest of the motor? did those needles go lots of naughty places?
the needle bearings in the tip failed, which allowed the rocker body to contact the retainer?
bummer deal. how's the rest of the motor? did those needles go lots of naughty places?