propain

Yeah that's not the reason....

Mark2009

No they haven't.

They have claimed that, in their experience, bronze has better wear characteristics.

The "vehemently" part you made up.

.

bearcatt

LOL, I still can't get over that username Z06POS's.

Over on "tech" Chad has been posting on there. I see the third page on that thread has a link to this thread.

http://ls1tech.com/forums/generation...-guides-1.html

http://ls1tech.com/forums/generation...-guides-2.html

http://ls1tech.com/forums/generation...-guides-3.html

I knew about Madsen's car. Under those conditions breaking a solid stainless valve doesn't surpsrise me.


As far as 1stZ's car goes, he spent a lot of time and money. What I get out of that is 1.) You have to pay to play. 2.) Thus far there is no panacea or true "fix" to this valve problem. 3.) Now matter what you do there are no guaranties of non-failure. It may have seemed egregious at the time but to me, looking at it now, I think hindsight is 20/20. His car looks absolutely stunning in those pictures.


Oil is a very controversial topic to the point where it's almost personal.
For me I go by the myriad oil analysis on Bob the Oil guy. I can't speak of the LS7 specifically but I've seen many oil analysis for the LS1, LS6 motors that show Pennsoil Platinum seems to have some very good reports on Dyson and Blackstone Labs oil analysis reports. Also there is a guy that goes by the username "Sarge" on LS1.com that knows a lot about oil. He is also a moderator there. He has been a good source of information in the past.

The thing about oil formulas is that they change every so often. For most the mainstream oils, they are not true synthetic anymore. They are extreme hydro-fracked. It was a legal battle back in 2003/3004 involving Castrol. Another major company took the issue to court and lost. That changed the definition of what true synthetic is.

One can go with the boutique oils like Amsoil, Redline, etc and get true synthetic. But there's still not absolute proof that those oils will prevent accelerated wear.



If I was to put on a new set of heads regardless of what heads. First I would have them blue-printed. I would check for valve guide wear after a few thousand miles. If OK... I might check them again at 10K miles. If OK... I would check them again at 20K. At that time I would be replacing the valve springs, retainers and valve seals.

If all checked out up to the first 20K, I would check them again at 20K while replacing the valve springs, retainers and valve seals again.

Extreme ? Most likely but I've always been a maintenance fanatic. I would have changed my oil at least 5 times and all fluids a few times during that first 20K miles.

I still have my 04 C5ZO6 go kart, I change the valve springs, retainers and valve seals every 20K on that.

'06 Quicksilver Z06

Yeah, OK.

MTIRC6Z

While the conflicting experiences between the likes of Katech and Brian Tooley/TFS might leave some perplexed, I guess if you decide whether your car is a race car or a street car it might help lead you in one direction or the other as to which experience is more relevant to your personal requirements. So how many 24 hour races have you competed in lately

Cheers, Paul.

'06 Quicksilver Z06

Thanks for your response Bearcatt.

Yeah, I recall the Castrol situation from a while ago, and I agree with you that it will be difficult to prove how effective oil is at minimizing the wear being discussed here.

As I said earlier though, from my own standpoint, I'm not overly concerned about what Chad says that he found.

But speaking of what he found, you have heard it said in here that since that video that he has inspected 5 sets of heads with the Bronze/SS modification and that all have been out of spec.

That is not what was said.

What was actually said was, since that video, he has examined 2 sets of heads. And that these last two were out of spec.

Two of the total five sets which he speaks of were the Livernois heads that were on his car and Z06POS's car. Both are described in here in the links which I gave you earlier. We in here, also saw what Livernois had to say about the one set belonging to Z06POS, which were being used the same as had been in Chad's own previous combo during a time when Chad was a member here.

There was one other set of heads which Chad had told me about at the time of that video back 9/26 which was out of spec. So I've known of 3 sets, 2 which our membership knows about and are referenced in here, and one other set which he told me about, which he said that he had examined, all were bronze guides SS valves.

Since that video however, he says that he has examined not "5" more sets, but 2 more sets. Both running Torquer cams he says , and while both were not crazy out of spec, they were still out of spec.

One of these two cars was done in 2009 and the other in 2010, so during a time when not as much was known as there is now. He made no mention of mileage in either of those cases.

He mentions that of the 5 total sets, none of them had come from the shop sometimes referred to in here, but of course we already knew that 2 of the 5 were from Livernois.

The other 3 sets could have come from anywhere. He knows, but was not saying.

Lots of variables. From who did the heads, to what other parts were used, etc.

However on another note, I see that you are indeed a maintenance fanatic.

If you were changing valve springs, then you might as well check you guide to stem clearances while you're in there.

That is the only scenario under which I would consider checking my own.

'06 Quicksilver Z06

None. And have no plans to.

But from what I have been able to gather, Katech was using this approach in their packages where stock valve guide wear was discovered, regardless as to whether the owner would or would not compete in such 24hr races.

MTIRC6Z

Yes and this is because, as I mentioned before, they used WCCH for that work and thus did not have any other choice.

They seem to change valve guides like you change your underwear. By buddy who has had a number of engines done by them gets new guides every time he sends it back and they don't even bother to check what the guide wear was before replacement...from what I can tell they simply regard it as a maintenance item because they are race engines

I could say they are vehement about changing guides regularly but that would be my word for it and possibly not theirs

Cheers, Paul.

'06 Quicksilver Z06

I'm thinking that it might be better to let them tell us what it was because of.

And I can understand your caution.

Indeed, while really you would have to ask them to be sure Paul….but I'm not thinking that they've been looking at replacement bronze guides by WCCH, as a "short term solution", or a "band aid", for their customers who would need valve guide replacement in preparation for, or as part of, one of their Stage 1, or Stage 2 packages.

I could be wrong, but somehow I don't think that they would put those guides in those particular customer's cars if they believed that they wouldn't hold up for any real length of time.

But now, to be absolutely positively certain of that, I'd encourage you to ask them if that was the intended approach. In other words, a short term solution for that group of customers.

Let us know what they say Paul. Vehemently, luke warm or otherwise.

MTIRC6Z

WCCH has NOT been offering PM guides so what other guides would they have used???

And YES you could be wrong, that is an absolute

Cheers, Paul.

'06 Quicksilver Z06

It's an absolute for all of us Paul. Including you.

That's why I'm thinking that I'd rather know from them as opposed to you, just why they were apparently comfortable using bronze guides in their Stage 1 and Stage 2 customer packages which needed valve guides.

I've seen no indication in here that they did not have confidence in the long term durability of those guides that they were using on those packages, regardless as to if you perceive that they were somehow forced to use them, but then you may have seen where they didn't have confidence in their long term durability.

Please point me to such.

As always, thanks Paul.

Ricky.

bearcatt

Shortly after that Mobil 1 was no longer a true synthetic.



Excellent, Thanks for setting the record strait on that. It's good to make the best attempt to separate fact from fiction.



Indeed. That's what makes it difficult to get to the root of the problem.


That would most certainly be part of the maintenance schedule.
An ounce of prevention is worth a pound of cure.

.

bearcatt

When the time comes, regardless of what heads I get... I will use PM guides, stock or Katech's Ti-valves, Ferrea hollow competition valves, Fel-Pro viton valve seals, PSI 1511 behive springs. Heads will be blueprinted. I would like all valves tumble polished too.


.

bearcatt

Quote:
Advantages and disadvantages of bronze vs powder metal guides: This is kind of a tricky question to answer since its not as cut and dry as it may seem. There are many different compositions of bronze and powder metal guides. All bronze and powdered metal guides are not made the same. Some lesser expensive bronze guides have horrible wear characteristics and wear out very quickly. Some Poorly manufactured powdered metal guides have very poor wear characteristics and wear out very quickly. With that being said we have used lots of different bronze guide manufactures over the years and in recent years have found a bronze guide that is very high quality, made in American and exhibits exceptional longevity for a bronze guide. A major advantage of bronze guides is bronze's natural lubricating property's. Basically in short a bronze guide self lubes itself. For this matter bronze can help combat poor oiling conditions. A bronze guide can also be installed a little "tighter" (guide to valve clearance) than a Powder metal guide without fear of hanging a valve. The real main disadvantage of bronze is that since it is a softer metal it tends to wear out alot faster than a harder metal composition guide. Alot of high end engine manufactures (Ferrari and others) have started switching from using Bronze guides to using highly developed and engineered powder metal guides. The advantage of powdered metal guides is it can be as good as the engineers want it to be. Unlike bronze, powder metal when correctly composed is a very hard metal that will wear alot slower than a bronze guide. We also experimented over the years with different manufactures of powder metal guides and have found a manufacture that makes powder metal guides of the highest quality and standards. They use a proprietary composition to make their powder metal guides and there powder metal guides are some of the best in the business.
A disadvantage of Bronze is its faster wear rate and in ability to sustain side loading from non true roller rockers (i.e. LS7 rockers). It has been advised for years and years that when switching to a bronze guide one needs to reduce the side loading of the valve to keep the guide from wearing pre maturely. Switching to roller rockers reduces the side loading of the valve and will help keep the bronze guide from wearing.
Our powder metal guides are harder than the bronze guides and can tolerate side loading which means you can run stock LS rockers with our aftermarket PM guides without wearing the guide like you would with bronze.





Interesting...

Is it possible that GM changed suppliers for their PM valve guides thus having lesser quality in some LS7 heads ?

I thought I saw a post somewhere in this thread about Lingenfelter offering PM guides. If that's the case, how would one know if a particular PM guide is of high quality when buying it ?


.

ctsv510

It is certainly possible.

And that's the trouble...how do you know they're high quality and how to you ensure it is installed and machined correctly?

Regarding the psi 1511 springs...it doesn't look like they are sold in a kit. I priced out the parts...springs, ti retainers, seats, seals on the website and it came up to $730. I couldn't even find locks so they weren't included in that but based on the other parts' prices I'm sure that would round out to $800. Am I missing something or is that what they really cost?

Based on that, having the heads done by AH with PM guides, psi springs, ferrea F2042P valves, and the other standard work would put you just above $2000 plus shipping (no porting).

By comparison the same work by AH but with the dual spring kit would put you at around $1528 plus shipping (no porting).

Then the same work by WCCH with bronze guides, rev solid valves and BT dual spring kit with ti retainers is $1170 plus shipping (no porting).

If you are staying with the stock LS7 cam, referring to the valvetrain dynamics testing, it doesn't appear necessary to spend the extra for the PSI springs. If you are running an aftermarket cam then the psi springs do appear to be necessary. So current setup and future plans are very important in deciding these parts.

Mark2009

IMHO you don't want dual springs -- they're heavy and old tech. Use beehives in a light valvetrain. For the Ferrea hollow valve on a stock cam you could probably reuse the GM spring kit, but in a $15K engine I think I'd pop the extra $700 for the PSI 'package' (and I think even that estimated price can be beat).

Mark2009

Anything is possible

Lingenfelter told me those are GM OEM guides, or the same as.

One would not.

'06 Quicksilver Z06

With regard to my setting the record straight on that particular matter, there were in fact a few other points which should have been made, however in the interest of brevity, I left them out of that post, as adding them would have made for a long post even for me.

You see, I left out one other description of a car with worn out guides which was running SS valves and bronze guides.

Forum member Veech, wore his out in less than 3K miles.

http://forums.corvetteforum.com/c6-z...o-the-bml.html

The point which should be made at this time, is that a lot of the time when we refer to "bronze guides", it is not taken into account that there are various bronze alloys used to manufacture bronze guides.

Not all "bronze guides" are the same and depending upon which bronze alloy the head builder selected, this can have a huge impact, a tremendous impact on their longevity.

Now bear in mind, those who don't like "bronze" guides, or who want to make hay in their arguments by pointing to a few instances of "worn bronze guides", probably do not want you to know that the term "bronze guides" is somewhat of a generic term. I'll explain what I mean in the text below, and supported with links and the Ferrari 355 situation.

This takes us back to Chad's findings, and the attempts by some of our membership to offer up that his findings are somehow a black eye for "bronze guides and SS valves".

The problem with that, is that no one has said whether or not the guides in some, or even all of the 5 heads which Chad found to be out of spec were manganese bronze, silicon bronze, phosphor bronze or just which "bronze" alloy.

That's extremely important. Not just important, it's HUGE, because all fall under the generic title "bronze guides", all are currently in use by various machine shops and head builders, and they have wide variation in terms of their durability.

If they were not manganese bronze, and they may not all have been, as it is not said, well then it is conceivable that they would not only have worn out, but worn out in an unexpectedly short period of time.

What Chad does tell you though is which shop those heads which he found to be out of spec, did not come from, and I am glad that he did point this out.

Chad is a standup guy and I have a great deal of respect for him after getting to know him.

As with anyone else, any other person in here, I can both respect and appreciate his change in position on this matter overall, as I did the same thing, and that is his, or anybody else's right as a human being. Irrespective as to if his "current" position is consistent, or inconsistent with my own.

However as he no doubt observes the discussion in here on this matter from afar, I would only say that a few things, such as which bronze guides are being used, the guide supplier and the bronze guide alloy being used, and any other quirks to the guides themselves, or lack thereof, or surface texture of the valve stems, should be taken into account in any evaluation or re evaluation of position on this matter.

If you are going to have "bronze guides" and SS valves done, well then I implore you to have someone do it whose reputation is impeccable, and who is not going to slip some of these cheap "bronze guides" over on you, and have you in here complaining that your bronze guides wore out in short order.

Your neighborhood shop, or some shop which does not do a lot of these LS7 heads, may or may not fit that description, so I advise you to choose wisely.

There are different bronze alloys in use in valve guides used in cylinder heads. "Bronze" is made primarily of tin and copper.

A few years back, Ferrari had a huge issue with valve guide wear in the 355s.

The copper content of the bronze alloy which they were using was the bone of contention in the Ferrari situation.

Bronze alloys that I have heard of "bronze valve guides" being made are:

Manganese Bronze

nickel-aluminum bronze.

aluminum-silicon bronze

phosphor-bronze

All are available.

So if someone tells you that they put "bronze" guides into your heads, or use "bronze" guides in their work, well then they aren't necessarily lying to you if they put cheap bronze guides, or softer alloy bronze guides into your heads which are not going to give you the durability and wear characteristics that you are likely trying to get.

Not all "bronze valve guides" are made of the same bronze alloys. And they vary in thermal conductivity and wear.

CHE, and SiValves both use manganese-bronze.

CHE uses a proprietary method and have had good results thus far.

If you are going with bronze guides, well then ask your head builder which ones he is using. And when evaluating "reports" of "extreme guide wear" in cars running "bronze" guides and SS valves, then among the inquiries you should make are which bronze alloy they were, and how this was confirmed, because all "bronze" guides are not alike. In fact they are significantly different when it comes to their durability.

http://cheprecision.com/CHE_Catalog.pdf
http://www.sivalves.com/ocdomestic_vguides.html

With regard to the Ferrari situation and the early F355s from back in the day, i.e. the '90s, here is some light reading:

http://www.ferrarichat.com/forum/456...-buy-them.html

https://www.ferrarichat.com/forum/34...#post142144920

http://www.ferrarichat.com/forum/348...-guides-2.html

The "bronze" guides in use in the LS7 heads that people are having rebuilt on this forum, are typically, but not always "manganese-bronze".

Phosphur-bronze, or sometimes referred to on the Ferrari boards as "copper" guides because of their higher copper content. And this is what was being replaced in Ferraris.

One other point of extreme interest is below with regard to the Ferrari situation. It is spoken of here.:

This company replaces the stock Ferrari guides with manganese bronze guides.
http://nicksforzaferrari.com/forzafe...bsite1_006.htm

Phosphor bronze guides are referred to as being around 88% copper in the Si Valves information.

However, phosphor bronze can be as high as 93% copper as per the phosphur bronze alloy this company offers:

http://www.concast.com/c51000.php.

Manganese bronze, and there are various types of even manganese bronze, are described at this site.
http://www.nbmmetals.com/products/br...se-bronze.html

If you look at the copper content you can see that it is less than it is for the Phosphor bronze. The same company shows around 55%-66% for the types of manganese bronze they offer.
http://www.concast.com/alloys-manganese-bronze.php

http://www.concast.com/c86200.php
http://www.concast.com/c86500.php
http://www.concast.com/c86300.php

and

http://www.dura-barms.com/bronze/man...nze/c86300.cfm

So the moral of the above story is three fold.

If you hear of someone wearing out their bronze guides, then just as you point to in the writing in your above post about "quality" associated with powdered metal guides, the observer should make the same inquiry with regard to the "bronze guides", which the investigator is pointing to, as well as which bronze alloy the guides were made from.

Secondly, ask your head builder which bronze guides he is using for the rebuild of your heads. Even manganese bronze guides are different.

Finally, there has been a lot of talk about powdered metal guides and their advantages over the "bronze" guides.

Again, this goes right back to quality of the guide as some of these powdered metal guides are wearing out in short order as well.

But the point here is that when we hear "powdered metal guides" we equate that with "stock guides".

As mentioned in your below post, not all powdered metal guides are equal. So people attempting to point out that the "stock guides" are "better" than "bronze" guides, are well, ……... "misguided"

That may not be the case, and at least one of our vendors using a powdered metal guide, is not using the stock powdered metal guide.

Some more light reading for those interested.

http://www.ferrarichat.com/forum/348...ve-guides.html

https://www.ferrarichat.com/forum/142144920-post93.html

https://www.ferrarichat.com/forum/34...fiction-5.html

http://www.ferrarichat.com/forum/74762-post1.html

http://www.the355.com/mambo/content/view/18/27/

'06 Quicksilver Z06

You are absolutely right.

You hear the powdered metal guides being touted in here, and all of the talk about them, but as you can now see, all PM guides, just like all "bronze" guides are not alike.

If I were considering PM guides, well then I certainly would have a hard time even considering the stock ones, taking into account how many of them we have seen wear out in a short period of time, and in cars which were supposedly well outside of the 2008-2011 guide machining issue window referenced in the sticky thread.

Of course these and other parts may have worked in prior LS engines, but this does not necessarily mean that the same parts will enjoy the same success in other LS engines.

No one is more amazed than I that some of the prior parts, hollow stemmed sodium filled valves, stock powdered metal guides, have had a stellar record in other LS engines, the LS6 for example, but a not so great a record in the LS7.

That the LS7 is unique in many aspects, a "one size fits all" approach to the selection of certain parts for it, may not always be the best route of management.

As an important aside to that, excessive wear of these stock PM guides, being passed off as "OK" is also being observed in the LS9 as well.


Of course, if one is a real stickler they would want to know how well those guides referred to above have held up, how many years they have been in use and how many miles.

All legitimate questions.

Very important observations.

propain

All stock GM LS type heads use the same valve guides. Amazing how those guides have no issue in previous LS applications.

Once again, there are those who demonize stock parts without a clue as to why. Your choice to run PM guides seems like the right thing to do considering how much wear is now coming back with bronze guides. Most likely due to sideload from the 1.8 rockers.

All this talk of inferior bronze material being used and putting down other shops while promoting another is fine when you have data to support your argument. So once again, SHOW ME THE MONEY. Without the data its as usual... ALL TALK and some really like to talk on this forum.

The absence of evidence is not evidence of absence.