Mordeth

Excellent post BigVette. Well thought out. Appreciate the time you took to write it. Saved.

sdgearhe

BigVette. Thanks for all the great info. I was having a hard time trying to decide on my heads. You helped make the decision easy. Package 4 with Moldstar 90 guides. Thanks Steve

Too-Fast

Just put AHP heads with Moldstar 90 guides in mine.

Bryan91SE

And as for the AHP powder metal guide owners, I think Steve's post is on point as well. Those AHP PM guides have the same positive attributes Steve mentioned and are considered "top tier" by their creator just like the MS90's. https://www.corvetteforum.com/forums...post1593790198 We will not be on TV running 500 NASCAR laps on a weekly basis, nor do we have NASCAR sponsors and if we were, we would need to upgrade many other drivetrain components; valve guides probably being low on the list.

I think it is a true testament to the quality of a company that AHP has researched this issue so thoroughly to come up with two great options for valve guides; the likes of which have no history of failure (except where lash caps installs were forgotten!). As racebum pointed out above, valve guides are just one component of AHP's successful history of addressing the heads.

I was reading Steve's post about the roller tipped rocker arms, to those in this post that had their heads addressed, did you decide to go with them, or did you feel it was unnecessary and that the stock rockers were fine? I read a post in another thread that the Yellow Terra's seemed to quiet down the drivetrain, but am unclear on the other advantages except maybe the reduction of side loading if you have a softer guide.

BigVette427

Like the trunnion upgrade, not all the roller rocker arm kits are created equal. Some you have to machine your heads to accept the rails that they sit on, and some of those that you don't have to machine are limited in the amount of spring pressure that you can use, which sort of offsets the reason for going to roller rockers, (higher lift cams and in turn, higher pressure valve springs.)

TSP is supposedly working on LS7 roller-tipped rocker arms that will just bolt on, but they have only released LS1/2/6 & LS3 variants thus far. I'm sure if there were an easy solution it would already exist.

Me personally, I didn't think it was worth the cost for existing roller tipped rockers for my build goals. If you otherwise can, I think it's probably wiser to limit your lift to < .650" on LS friendly cam lobes, and use quality lifters, valve springs, P/R's. If you want to go with lifts > .650" or use more aggressive cam lobes, Moldstar 90 valve guides would be a must-have in my opinon.

I certainly like the CHE trunnion kit although there is not a consensus that you even have to replace the OE rocker arms at all. My LS7 runs very quiet and smooth, with virtually no "LS" sewing machine noise.

LT5 John

My heads were done 5 years ago, WCCH...Used CHE bronze guides, and CHE rockers, heads are still fine...Also, using Brodix heads...

fisher auto

Being the Ferrea exhaust valves are used, has anyone used the Ferrea guides?

MTPZ06

Did the MS90 back in 2015 even though it may have been thought of as "overkill" at the time.

Hib Halverson

Actually, the name is neither "Hilburson" nor "Hiberson"; it's Halverson. as for "... not being the most transparent..." in the past I read something like, " I can see right though your bl st , Halverson."

So what is it?

Am I "transparent" or "not transparent"?
OMG, I am...
(sob)
... soooo confused.

Yes, Kohle and I had a difference of opinion several years ago about how he was doing the now discredited "wiggle test". The disagreement began as a public thread, but went to PM when I was penalized by the mods for criticizing a "Supporting Vendor". The PM-ing ended with Kohle stating that, if I was a "real man", I'd come down to his shop in Harbor City and fight him. At that point, recognizing a lack of maturity in such a statement , I wondered: if Kohle was that way in his personal communications, does he run his business in a similar manner?

In fact, the answer is, decidedly "No." Like many of us, Kohle may say stupid stuff when he's angry, but American Heritage Performance provides a useful service to the C6 ZO6 commmunity and has a lot of satisfied customers. That couldn't happen if the guy couldn't run a service shop in a decent manner.

I do not remember writing a PM saying I was going to publicly "bash" Moldstar 90 valve guides just because I didn't like the guy. Reality is, I wouldn't have been able to do that, anyway, because of the Corvette Forum's restrictions on speech, ie: CF members cannot criticize "Supporting Vendors". Nevertheless, If I did write that, Kohle, please post it publicly so everyone can read it and I can refresh my memory.

Another reality is: my LS7 content on the CAC has never "bashed"–as in: groundlessly discredits–Moldstar 90 valve guides.

My position on Moldstar 90 is the same, ie: It is a suitable material for guides, but it's quite costly in comparison to guides made of other materials which, for real world LS7 durability, work quite well in stock, near stock or even significantly modified LS7s. Interestingly, when you look at really severe duty applications, say NASCAR Monster Energy Cup engines in races like 600 at Charlotte where the engines are make around 825-hp and turn 9200 rpm, the two big suppliers of valve guides for Cup motors, Del West and CHE, typically do not sell guides made of Moldstar 90. While that material is often used for valve seats, most Cup team engine shops use manganese-bronze guides from CHE or Del West. In my research I, also, learned that in Top Fuel drag racing, the choice for guides are screw in steel guides with manganese-bronze sleeves. Can you imagine...steel valve guides? But, I guess, when you're making 1200-hp per cylinder, you need that, eh?

Before I wrote about Moldstar 90 guides in the LS7 article which Kohle referenced as being "not transparent", I interviewed persons who are either design engineers or metallurgists at companies which make valve guides. With all due respect to Kohle, I put more faith in the people who gave me that information.

Again, this is not to say that Moldstar 90 is a bad material for guides, but it is to say that it's a very expensive choice and there are guides made of other materials which, in the vast majority of the LS7s we discuss here, will work as well as Moldstar 90 and cost less allowing us to spend some of our "mod money" on other items.

In the end, there is one constant in this guide discussion: if the guide centerlines and valve seat CLs are not concentric within .0010-.0015in., it doesn't matter what guides you use, stock PM, Del West, CHE, AHP MS90 or ones made of Unobtanium by aliens in a galaxy far, far away–they're going to wear at a higher rate than expected.

Bottom line: if money is no object, have Kohle build you a set of heads with Moldstar 90 guides, but if you're like most of us and money is, indeed, an object, know that there are valve guides which are, in a practical sense, just as good, but cost less.

Now, Kohle...take a deep breath.

I know you disagree–but rather than engaging on another round of character assassination or challenges to fist fights , focus your displeasure on posting some credible, scientific durability testing data which conclusively proves me wrong. Do that and I'll eat a big crow and retract my statements. On the other hand, if you PM me saying that, since I wouldn't come to Harbor City to fight, you're coming out to Goleta to beat me to a pulp; I'm likely not going to respond in a positive manner.

American Heritage

From your PM to me 12/19/2014 @ 8:44pm
........................................ ......................
"4)You have picked a fight with me. Bad idea.
5)Previously, in my LS7 coverage, I endorsed your Moldstar90 valve guides. I'm going to delete that content."
........................................ ......................
Not sure of how to quote form a PM so I had to copy and paste.

Anyhow we are not interested in any back and forth in regards to your post but did want to briefly reply to your comments.
Again im not interested in any back and forth bickering. If any one has any question about Hib's PM to us feel free to PM

Dirty Howie

I already said my piece but this I thought was really fvcking funny


DH

Mordeth

Kohle,

No need to explain yourself. $600 is a trivial amount of money on a full build, is NOT a "very expensive choice" and so I have no idea what Hib is talking about, nor why he feels the need to instruct the value of things to grown men. It is for each individual to determine the value of something and what the opportunity cost is. He should simply stick to the facts. I spend far more than $600 on fuel and tires alone on a race weekend.

Your M90 guides and the heads you built for me survived a full season of racing with my car, even though I literally blew up, broke and trashed literally every single other moving part of my car. Your heads were pretty much the only part that survived - and that is due to the quality of the workmanship and the quality of the parts you installed. So thanks much for the excellent work and for providing a reliable, affordable, performance alternative to the community.

Bryan91SE

I think they are both sticking to the facts and it was a fair post. Both of Kohle's valve guides options have a positive proven record and as Hib stated, and most of us agree from the studies done, the valve guide is just one component in the recipe for reliable heads.

Unreal

Hib,

I'll be in Goleta in a few weeks if you want to grab a beer.

Frankie2blue

That’s also what threw me off about the exchange above, was the fact that 600. is very little money in the big picture of getting heads repaired. There is an old saying “If you eat the horse, don’t choke on the tail”. There are a lot more expensive options on repairing heads out there by other companies that make buying a set of MS90 guides cheap. If going through the mess of getting this done, the only thing that would interest me is getting the very best setup I could possibly get and never have to worry about the damn things again.

MTPZ06

MS90 and tumble polish of OE ti intakes is by far cheaper than going with bronze guides and new Ti/Mo intake valves for compatibility reasons.

Hib Halverson

Kohle quotes that PM accurately. I still feel the same way now...his picking a PM fight was a bad idea.

As for my LS7 coverage, The pleasantries Kohle and I exchanged convinced me to better research Moldstar 90 as a valve guide material. As a result of that research, I re-wrote the article's discussion of Moldstar 90 as an LS7 guide material. Here is what the article currently states...

While the above no longer endorses that material for LS7 guides, it doesn't "bash" it...at least not in the sense that most people understand "bashing", ie: attempting to groundlessly discredit it.

My "spin" on Moldstar 90 guides remains the same:
Yes, they are one solution to the LS7 guide problem and, in fact, they might be the optimal solution for a set of heads with guide/seat non-concentricity exceeding .002, however, if guides and seats are concentric within .001, manganese-bronze guides from any of the mainstream manufacturers of guides such as CHE or Del West will get the job done and do it for a lot less money.

Sounds like a plan. Email me at finspeed@netmotive.net. We have almost have a dozen craft breweries in Goleta.

Dirty Howie

Going to be checking my heads soon as my warranty is gone in a couple of months. If I don't need Moldstar90 I would rather spend the money on porting and tuning.

How's your boxing lessons coming along


DH

NVNO1

Does the car feel faster with the ported heads? I'm assuming your car is bone stock other than ported heads?

GA$$MAN

A lot of good info in here.

Kohle, I emailed you about getting a package set up for me.

Thanks