mistermog

Just wondering, after seeing that stock heads with bronze and solid steel valves was showing minimal wear, a comment was made to see stock valves on bronze guides in that thread.

I want to take it a bit further and see if anyone has aftermarket heads with bronze guides but stock sodium exhaust valves and ever had them checked after any miles?

vertC6

That is all Katech will use in there heads and they "report no issues", but I haven't seen a used head off a katech motor yet.

mistermog

My understanding is that katech uses stock heads though.

I was thinking about PRCs or something along those lines. In all honesty though I don't think I've seen an actual measured report of stock heads with bronze and sodiums either.

Everyone abandons them and goes to solid.

I feel this is a bit premature. If the head is breaking off to valve wobble and impacting the seat at the wrong angle, fixing the seat alignment would stop them from breaking.

'06 Quicksilver Z06

Maybe. But we don't know that every broken valve, was in a worn guide. It is possible that some of these valves broke in valve guides which were still in spec.

Take a look at what this guy who has had the opportunity to section the stock exhaust valves and measure their wall thickness had to say.

mistermog

I hadn't seen that post but that makes me wonder, why else did the valve break. I think I would need to know that before making a conclusion there.

My post up there is just a theory, I'm right on the fence about what to do. I can't really afford head work right now and no way can afford an entirely new engine. So, she sits in the garage collecting dust while I find out info.

'06 Quicksilver Z06

Understood. Well, it's sounding like you are going to have eventually do something.

If that is the case, then it might be a good idea to look at the potential up sides and down sides to either option and go from there.

In other words, what's the worst that can happen with either option?

mistermog

Yep, which is what this thread is about. Trying to see if anyone has kept the stock valves for the weight savings and balance. I'm sure in ANY path there are going to be failures with parts.

vertC6

I am working on something with Del West and WCCH I will be posting it as soon as they give me the green light. I think everyone here will like it.

mistermog

please do!

Z.06

I think I have read that some aftermarket heads have a thicker deck, thus needing valves with longer stems than the stock valves. Can someone chime in on this? I think I read it about the PRC heads, but it may apply to others with beefier castings.

mistermog

I've heard they need different pushrods but that was all I heard? I don't evenk now if that was fact or not.

Random84

If you're truly parking the car out of fear (of catastrophic damage), why not at least pull the valve covers and inspect for any discernable valve stem play while the heads are still on the car?

For each cylinder, hand-turn the engine so the piston is at TDC. I'd have to double check, but I believe with the piston at TDC, the valve cannot drop enough to be lost so pressurizing the chamber with an air compressor shouldn't be necessary (hopefully someone can confirm or deny this?). To play it safe, place a strong magnet on the end of the valve tip to keep it from dropping down too far.

Borrow a spring compressor from AutoZone, etc (for free), remove the exhaust spring and retainer, and setup your dial gauge. GM specs are any lateral or vertical movement while looking at the valve should be 0.002" or less IIRC.

It wouldn't cost you more than a decent gauge and a weekend of your time - and it would help you know if you're parking the car for the right reasons or not: significant play = smart choice to park it; but if WNL you can reasonably expect no issues and enjoy the car until you move forward with the project.

Just a suggestion.

mistermog

I dont have the knowledge to pull off that kinda test. And no I wouldn't say its parked out of fear really, but I am concerned about it.

I did see the couple of dial gauge posts recently and interested to see how hard that would be to do though. I also thought the spring compressors dont work on the LS7?

LT5 John

I am going with Brodix heads when I am ready. I spoke with Richard at WCCH and he said the stock push rods will be ok...This is based on using the stock cam...

WhiteDiamond

Thicker deck usually means you need a longer pushrod. My understanding is the the stock LS7 head and the PRCs use the same valves.

'06 Quicksilver Z06

Not quite right.

You can however order PRC heads and reuse your stock valves.

http://texas-speed.com/p-1413-prc-ls...-exchange.aspx

http://texas-speed.com/c-506-cylinder-heads.aspx

Like some of the others, they have valve options, spring options, etc. and will sell you most anything you want in the way of a cylinder head, just like some of the rest of the people selling cylinder heads will.

Mark2009

There should be two ways to go with regards to weight:

1. Titanium exhaust valve. There may be an issue with heat, but there seem to be coatings available to deal with that. I believe one forum member went this route (at around $150 per valve), and I believe WCCH obtained and installed them (from Del West).

2. Non-GM hollow stem steel valve. I'm surprised someone has not come out with something along this line yet. I would kinda sorta expect Ferrea to lead the way....

By the way, my empty garage avatar has been replaced. I now have skin in the game

mistermog

Ive heard if you go titanium theres a bit of expense to that, with the seats or something needing to be machined?

I was thinking of going with the gm stock valves on bronzers, just not sure if i want to stick with the aftermarket or GM head

vertC6

Ferrea said they should have there hollow stem at anytime, they are waiting on them to come in from Argentina.

Del West is working on a coated Ti exhaust, I should have more information on Monday with all the details.

mistermog

this could be interesting, as long as they arent god-aweful expensive