kricket

I have a WCCH heads car but still am a little worried every time I drive it. Should I be? I understand the harder valve guides, solid stainless exhaust valves, just curious if someone could give me the "science" behind it so I can sleep better at night haha. Thanks in advance!

phipp85

If you want to sleep better check them again lol. If you have a stock cam I don't think I'd get too worked up about it. Not hard to pull your valve covers off and poke around in there if you are curious. I like to tinker and do stuff like that. May be unreasonable to some but I like it.

AzDave47

WCCH does CHE bronze guides, so not much harder (if any) than factory PM guides. On many builds, the Pros recommend checking with wiggle test at 20K miles or less.

No one has all this pinned down. GM may have good data and know but they won't tell. Some reworked heads have had guides out of spec, but I can't give you numbers or details on each build.

I have an HCI Z with WCCH ported heads and will have wiggle test and springs tested before 20K miles. I do performance events with a fair amount of time in the 4-7K+ RPM range. My street driving is not all that spirited, compared with track use.

outhouse

One should check every 20-40k fixed or not.


The science is that the guides cool 75% of the heat that a valve has, out of spec guides reduces the actually cooling going on through the guide.


The aggressive valve train of the LS7 promotes faster wear of guides, but the largest problem was GM producing out of spec guides straight from the factory without any miles there were already past worn.


So far no guides have been out of spec as far as we know from rebuilt heads. With time that number should increase.


I would not loose any sleep over it unless this was 100k miles ago.




One sure way to sleep at night is check and know exactly what you have here.

LMB-Z

I think its about the same thing as buying a refrigerator, or washer, or dryer, or anything mechanical. You take your chances. Bought a dishwasher...brand new...lasted 6 months. Either drive it and don't worry about it, or park it in the garage and look at it once a week, or sell it. Your choice.

rio95

Actually there have been reworked heads out of spec....

Check every 10k miles no matter what your setup is, especially if u have a big cam.

I don't believe any AHP heads have gone bad, but maybe they can weigh in. Pretty sure they claimed that a while back. I'd consider guides from them if u ever do it again. I'll probably go with moldstar guides next time around.

outhouse

Lets call racing application a bit different here.


But even with that said I can only recall one guy who claimed his wcch heads were out of spec and he recanted and stated he was not sure they were even rebuilt, then the shop stated they did not do guides at that time.

rio95

Who said anything about racing??

outhouse

Have any links or threads?

MTPZ06

Depends on who fixes them, or what components were used...but yes, for the most part the companies widely used on here are considered to be the fix. Having said that; if you're running a high lift cam, as in beyond the stock rocker arm capabilities (improper wipe pattern), you're creating excessive side loading and that will accelerate guide wear. Thus, many recommend inspection intervals...

RamAir972003

They should be checked at 15 20k

Unreal

Will they wear again, yes. All "fixed" heads will wear again. There is no way around that. Valve guides are a wear item, they wear.

Will the valve head break off and destroy the motor like OEM? Probably not. It would take way way way way more stress to break the solid SS valve. So even if the guides go out of spec, you have a ton of added insurance with the valves you have in there now.

Lawdogg

My WCCH were checked at 20,000 miles. I run a cam with .660 lift and stock rockers. 30+ track days and 20,000 miles when checked and all was ok.

Unreal

I run PRC heads, .650 lift cam, stock rockers, and all checked out fine at 22k miles. That being said, I don't expect them to last forever. I do expect the solid SS valve to stay in one piece though, even if the guides wear.

Indepth

What is considered a 'high lift' cam? Like the ones listed below? (i.e. .650+?)

outhouse

I know stock heads have failed, which is to be expected.


Every heard of a AHP or wcch fail?

MTPZ06

Yes, that would be considered high lift. Many, many guys running cams that large; but that's reaching the limitations of the stock rocker arm. An ideal "wipe pattern" means the pad (tip) on the stock rocker stays on the center ~1/3 of the valve stem tip throughout the entire range of motion. Its been reported that the wipe pattern on stock rockers begins to degrade at about .635", which means the rocker pad is contacting the valve tip towards the outer edge. This can cause excessive side loading...but in a properly rebuilt set of concentric heads with quality materials, that may take a very long time to cause excessive wear. However; its now something that should be inspected at certain intervals, along with the springs. Anything above .650" lift, really should have a proper roller tip rocker setup.

Unreal

Define fail?

Reworked head with out of spec guides or reworked heads with valve failure resulting in a destroyed motor?

All reworked heads are going to fail if you think worn guides are a failure.

MTPZ06

A long while back Kohle had posted a YouTube video of a WCCH head with worn guides (head had the WCCH logo). But as to the origin of that head, what cam was used in that car, what rockers, etc., was unknown at the time I watched it. I believe it was a set of heads someone had sent him, so the car wasn't at his shop. Closest I've ever seen...and again, missing a lot of information. Could've been a car with stock rockers, .700" lift cam, and 100k miles with severe track duty for all we know.

Edit: And I should clarify by saying badly worn guides...as in hot dog in a hallway bad.

Unreal

Think of valve guides like tires. They wear. Now if GM messed up and ran -5 camber and your tires lasted 2000 miles you wouldn't be happy. Getting the heads fixed is like getting an alignment. You are fixing GMs mistake, and making it so hopefully the tires wear at a more normal rate. So you get an alignment and tires last 20k miles now.

If you run race tires with low tread wear they are going to wear fast (high lift cam with lots of racing/high rpm).

Solid SS valves are like run flat tires. Have some downsides, but extra insurance in case of a flat.