VandykeT/A

I took the valve covers off today and noticed that one of the tops of a valve on the pass side had more wear than the others. Its where the rocker tip meets the top of the valve. Say for instance (not exact measures) its suppose to have 1/4 inch this one had 1/8. I did run the engine a short time with stock length pushrods but changed them after. Is this ok to leave and more than likely this was done when it had stock length rods right?

Gordon0652

iTrader: (4)

That seems strange, I know when solid rollers are built ware caps are sometimes installed. Sounds like some of the geometry is off...

Darkman

iTrader: (2)

OEM rocker? How much open spring pressure are you running?

garygnu

big radical cams require more precise valve train geometry to work properly.

therabidweasel

iTrader: (5)

Also might look for missing needle bearings...if you haven't.

VandykeT/A

ive all ready done the trunions so yea stock rockers with whatever springs tsp sends out on the prc 215s set up for a ms4. they are dual springs. im just worried that over time itll wear down to the locks and let a valve go. how do i make sure the geometry is right. its got 7.450 pushrods which was double checked by heintz racing and new ls7 lifters.

Darkman

iTrader: (2)

You can check the geometry by looking at the wipe pattern. I believe your valve springs have an open spring pressure of 470 pounds. If that is the case, I would expect the valve tip wear to get worse; and it will not cure itself.

VandykeT/A

so what would actually be causing the geometry to be off is to much spring pressure?

Darkman

iTrader: (2)

No, the spring pressure (assuming I correctly identified the spring you are using) can accelerate wear on the valve tips. Incorrect geometry would also cause wear on the valve tips whether the open spring pressure was excessive or not.

VandykeT/A

what can cause the geometry to be wrong, pushrod length? if the spring pressure is causing the excess wear would a roller rocker help reduce the wear. im more than likely going to pull the head before i put many more miles on it. its fairly close to the locks. im thinking they said my springs were good to 675 lift maybe. the heads/cam have roughly 6k on them

TVWilkes

Can you take some pictures?

Darkman

iTrader: (2)

You may need to add or subtract shims underneath the rockers to get the proper geometry.

https://ls1tech.com/forums/generatio...cam-guide.html

vettenuts

iTrader: (4)

Obtaining good geometry with stock rockers and an aftermarket cam is near impossible as lift increases. Pushrod length has no affect on geometry. Brian Tooley had a very interesting post on valve stem damage from stock rockers recently where he discussed heads coming into the shop with the damage your describe. Here is a link to his post: Link

VandykeT/A

Well if I go to a roller rocker will it solve the problem. Also if it will solve the problem will I need to pull the head and replace the worn valve? I'll get pics as soon as I can.

VandykeT/A

No pics yet but I'm not really sure how to check the wipe pattern. I took two of the rockers off (one worn fairly bad and the other was worn but not quite as much) and colored the top of the valve with a marker and put the rockers back and cranked the engine a few times and took it the rockers back off. I honestly couldn't tell much about it but I do know that the valve is wearing at an angle. Picture your standing as if your changing a flat and looking down at the engine/valvetrain. The valve is wearing at a slope with the lowest point closest to the header and climps as it goes toward the intake. The rocker is only touching the lower 75 percent of the valve from what I can tell.

TransamGCS

iTrader: (2)

Vandyke i have the same setup as you when i measured for pushrod length i ended up using 7.500, the trunion on the comp upgrade is thicker than stock

VandykeT/A

I actually noticed the wear when I did my trunions about 1k miles ago but never really thought much about it. Have you had your valve covers off in a while? and how many miles have you put on yours since the heads/cam? Mine can't have over 5 or 6k on it but it was driven a short time on the stock length rods. What I don't understand about it is why its not wearing all the valve tips the same. It only seems to be one on the pass side and a few on the driver side.

TransamGCS

iTrader: (2)

vandyke no i havent had them off ive probably only have about 1,500 miles on the combo its not my DD i just take it out on weekends and what not. so you just recently did the trunion upgrade if so you have to remeasure pushrod length, ms4 is going to have a smaller base circle than stock and the trunion base is thicker than stock which causes the rockers to sit higher

vettenuts

iTrader: (4)

You need to check the wipe pattern first. You can't do it the way you are attempting to do this. The valve springs will depress the plunger in the lifter and you won't get full lift.

Do you have check springs? You can check the wipe with check springs and a dial indicator. If you don't have a dial indicator you can start with a small and accurate metal ruler, which will give you an initial indication of your sitation.