turbotuner20v

I pulled my stock LS3 heads off to reuse on a motor I'm building and dropped them off at a cylinder head shop to have the deck resurfaced and a valve job/spring replacement done. They just called me up and said the valves are really worn, almost to the point that you can see grooves in some of the exhaust valve stems.

1. I want to know what could cause this so I can avoid it in my new build.

2. I want to know what bronze valve guides to swap to and what the best valves would be for an FI application

96capricemgr

iTrader: (1)

Honestly if the heads are unported you might consider getting new heads. Bronze guides will require roller rockers which require more spring pressure so the cost to run the heads after rebuilding them is going to be quite high.

I would wonder about the valvetrain specs for the 13K you ran it and look for a problem there to try and find the cause.

turbotuner20v

Everything is 100% stock

87silverbullet

iTrader: (11)

Get us some pics of said valve stems. I can't see valves going out that fast. Something else is wrong or the machine shop is trying to get in your pockets.

turbotuner20v

just picked everything up today un assembled, will post up in a bit

turbotuner20v

It's been run pretty hard. It's seen probably ~10 road course events, lots of 1/4 mile passes, lots of high rpms on the highway, and it's been boosted for ~6k miles.

Here are the pics. Shop said the intake and exhaust valves are both worn, the exhaust guides need to be replaced, and they'd recommend doing the intake while they were at it, even though they were just within the tolerences they felt ok about.

exhaust:




intake:



let me know if those pictures aren't good enough, i can try to take some in better light w/o the flash.

87silverbullet

iTrader: (11)

Yeah, going to need a little better pic than that. Get the worst valve you got and get a close up on the wear and post up.

Did you try to put one of the valves half way in and wiggle it to see there is any play?

turbotuner20v

Yea, there is play on the exhaust valve guides. Not sure if it's supposed to be 100% firm w/ no play on stock heads w/ powdered metal guides, but there is some room to wiggle it.

turbotuner20v

UGotBeaT

What type of fi app? Might look into a steel exhaust guide and you would be fine with just using a k liner on the intake if that shop can do it...

Are they checking the valve stems with a mic?

87silverbullet

iTrader: (11)

The motor was stock. No FI application

UGotBeaT

He wanted to know what valves to use for an fi app..so im guessing thats the route he will be going

turbotuner20v

It was stock from head to oil pan, but it did have a procharger @ ~10psi bolted on.

turbotuner20v

Supercharged. I think I'm actually just going to go with LSA heads. When they first came out I saw they were the same deck and just stopped paying attention, but now I see they have different alloy and are better for boost.

I'm not sure what they used to measure, they wrote this on the head:

Area47

granted i know you beat the crap out of it, but it seems odd the guides would shoot **** on ya. may have been flexing under high rpm and boost just a tad to cause the accelerated wear of the guides? or the soft casting itself i keep seeing issues with on these heads.

port the lsa heads. forget all about this.

studderin

iTrader: (28)

thats weird. how bad is the chew marks on the bottom of the guild travel on the stem? dose your nail feel it (roughness), or a step? that one big intake valve pic looks bad. On thous specs, I don't think it the guild clearance, 0013 is fine, but the stem finish dosn't look to be that smooth to get a numbers down that much, on those stems And they said the guilds should be replaced? How do they feel?


what oil did you run, have to checked out a bearing or anything on the motor for oil contamination?

redtan

iTrader: (5)

How much do you trust this place and how good is the reputation with others in the area? Not saying they did so in this specific case, but I wouldn't be surprised if they found some beatup valves around the shop and told you those were off your heads and that they should be replaced (all the while keeping your good condition stock valves).

I just can't see that sort of damage happening on a low mileage motor, even if it was ran hard as you say.