fbh-velocity

I run a zz502 with Brodix RR oval aluminium heads 2.25 1.88 stock brodix valve and 14 psi Vortech V7 YSI Boost in my truck. Max rpm is 6000 and with less than 1500 miles the phosforos bronze guides was vorn BADLY on all intake valves. All exhaust valves are as new. I run roller cam with .554 .575 lift and crane gold roller rockers 1.7

All odds was wrong valve train geometry!. New pushrods with very little difference in length was installed and the roller was moving right over the middle of the valve stem.
I also added some GM EOS additive for better lubrication and made sure the valve stems had a good assembly lube.
Now 1500 miles later the intake valve guides are badly worn again.
I run castrol fully syntetic oil 10w-60 TWS
I wonder if the viton seals are avoid the oil to lubricate the guide? Its not fun to change guides and cut valve seat every 1500 miles. Brodix is not even respond to the question.
Any good idea what to do? Take the seals off?

BillK

fbh.
Another thing that can cause valve guide wear is if the valve seat is not machined perfectly concentric to the guide. If the valve tries to move a little each time it closes, it will wear out the guide in no time. How is your machine shop doing the valve seats ? Grinder ? Three angle cutter ? Either way, you should lap at least one valve with some very fine lapping compound to see if it is hitting the seat completely.

As far as the viton seals go, they are pretty much original equipment on everything now days and should not be a problem.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

fbh-velocity

BillK,
This is a thing I have not check as the first failure was brand new Brodix heads out off box with valve installed. I only changed the spring. Not sure what machineshop is using but I think its a 3 angle cutter. I will ask the machine shop to check that part.
Guides are vorn most at the seal end (rocker arms) oval and more than 1 mm. to almost zero vear at the valve seat end. All 8 intake valve are the same.
Guides are 2.37" long and 11/32 valve stem diameter. Something is putting some side load on the valves that fore sure but I canīt figure whats wrong. Roller tip turns free.

fbh-velocity

Would it be a good idea to go up from 11/32 to 3/8 valve stem diameter? How much will it hurt flow?

BillK

Fhb,
Your contact pattern look about as perfect as you can get. Going to a 3/8 stem really should not be neccessary. The 11/32 stems are fine. Its kind of hard to tell in your pictures, but is there any chance the rocker arm is barely touching the retainer ? I cant think if anything else.

Boat1

I'd try another set of rocker arms. Just seems like you have addressed everything else, the contact geometery looks very good.

fbh-velocity

Sorry for the late update. I changed the rockers to a set of stainless Comp Cams full roller.
I couldn't find any visual issues with the gold rockers but the problem is solved

MER Performance

I agree with Bill K, contact pattern, is centered and narrow. Depending on the year the heads were purchased, I know from one of my suppliers, Dart had a cheap guide they used at some point to cut cost. They than changed to a better quality one.