TORQJNKY

I'm getting ready to pull the heads to have Ferrea SS exhaust valves with Ferrea bronze valve guides installed, and an ARP stud kit, more for insurance than anything. I'm going the A&A supercharger route and staying with the stock cam, so I don't think new valve springs, roller rockers or a trunion kit on stock rockers are necessary, but I'd love to hear other opinions.

What would you do to make your heads bulletproof?

z0sicktanner

puts springs in while ur at it...my stock 06 dropped a intake valve broken valve spring...just cruising at 75 on the interstate....got new motor and I'm replacing everthing but intake valves rockers as well

andreas g.

Before RPM motors built my forged LS7. We did the heads a year earlier just to keep the motor safe. They were CNC ported with solid SS exhaust valves, duel extreme patriot springs,and CHE rockers. That"s all you really need. If you're going FI, you had better consider pulling the motor and putting forged 9.1 pistions in at the mininum. Those cast thin ringed pistons will not live a long life
no matter how little boost you run. Also bring some oil with you, because you'll go through it with those rings.

RichieRichZ06

Send them to West Coast Cyl Heads and tell Richard what you want to do with the engine. He will set you up.

Gannet

This.

Don't ask us, ask the guy who sees hundreds of heads and makes his living at it.

TORQJNKY

That's your opinion and not wrong however, companies like A&A and ECS wouldn't be in business if every non-forged supercharged LS7 blew up. As long as you are careful in how you tune it, don't run excessive boost, and maybe add some meth injection to top it off, a supercharged car will be just as reliable and as much fun as a cammed car without the drivability issues.


Thanks guys but I wasn't looking for a, "Just take your car somewhere else so someone else can do the work and you don't learn **** about properly modifying your car", kind of thread.

I realize there are pros in the business that do this everyday and maybe that pro will be the guy that does the work needed. But, there are some very knowledgeable people on this forum who can provide some good insight into what could be done. It would be good to hear those knowlegable opinions about things that can be done to prevent dropped valves, broken valve springs, broken needle bearings, worn valve guides etc... so you can at least speak somewhat intelligently about it when you call the person actually doing the work.

Here's my attempt at actually answering the question:

-Replace OEM exhaust valves with Ferrea or equivalent SS exhaust valves
-Install Ferrea or equivalent bronze exhaust valve guides
-Install a Comp Cams trunion kit on OEM rockers or replace with aftermarket roller rockers like Yella Terra, Harland Sharp or equivalent.
-Replace OEM valve springs with Manley, PAC or equivalent valve springs and titanium retainers (optional with stock cam).
-While you have the heads off, consider port and/or mill work (more for cammed applications).
-Install an ARP head stud kit.
-Optional, but consider bronze valve guides for the intake valves as well while you have the heads off.

I'm not a pro by any means, so the list above is only what I've gathered through a little research. If there are better parts or other recommendations, please feel free to chime in.

whatcop?

I think you covered it all

tjwong

I had LPE do their full meal deal on my heads, added Ferrea valve spring kit, and also added a set of Yella Terra full roller rocker arms to further reduce friction and side loading. Which will hopefully reduce any guide wear. I also added a set of Ferrea super alloy exhaust valves as my engine is supercharged.

TORQJNKY

Thanks for the feedback. Did you have to use a tall valve cover to clear the Yella Terra rockers?

RichieRichZ06

It sounds like you got it all covered. I suggested calling Richard because he sees boat loads of these heads and ia an expert on cylinder heads. The problem with the forum is even though we have a lot of experts, you will get 15 different answers from each of them.

TORQJNKY

I understood why you suggested calling Richard, but I don't think having different options is a bad thing. That's kind of how I formulated my list, by reading many different forum threads and pulling tid bits from each, that's primarily why I asked for other input.

I'm sure Richard is "The Man" when it comes to heads, I see his name and WCCH all over the forum. But, before calling him and wasting his time with a thousand questions (not saying he would mind), I would prefer to have at least an above average knowledge of what work is being done and why a specific componet is being used. I didn't expect this thread to alleviate all questions about modding LS7 heads, just be informative for those considering it. I'm far from a machinist or a performance auto mechanic. I rely on what I can research and educate myself on, so when I finally decide to perform a modification or have someone else perform the mod for me, I feel that I am making the most informed and best educated decision.

I don't know that my parts list is the best in functionality and efficency when assembled together, I just know it's a list that "I" think can get the job done.

mcar00

Well, I took a different approach. I built a motor that only has to rev to around 6,000 rpm to make its power (660 Flywheel HP). Its normally aspirated but at that RPM range with some good PSI double springs and CV retainers the heads should not really be stressed at all. Cam selection is key.

Your screen name is what convinced me to reply!

Mopar Jimmy

There is a lot of good information on this forum and a lot of BAD INFORMATION also, that can easily mislead you. I agree with RichieRich about getting your info from guys who live and breath this for a living such as Richard at West Coast Cylinder Head, or Jason at Katech. Its these guys you want to get your info from and not the forum in general.

These guys are EXPERTS who make a living doing this and 99% of the guys on the forum giving opinions are not. For instance, if you call Jason at Katech, and I know I would if it were me, you may be surprised what he has to say about the sticking with new oem valves vs SS valves, that weight A LOT more than the oem stockers that I believe Katech uses on their engine rebuilds, that are built for track action. You throw the geometry of the engine off if you go with overkill heavier valve train parts, like dual valve springs, heavier valves, etc., and this may actually lead to the EXACT type of problems you are trying to avoid.

Since you sticking with the stock cam but will be running a supercharger, I would defintely be putting in at least new oem valve springs, or a single spring stronger (lightweigt) equivalent that is a direct replacement for the single beehive oem spring, b/c you DO NOT want to put in too heavy of a spring for your application on the LS7 heads, which by nature is a very light weight valve train, and you don't want to throw of that geometry and charecterics of the stock oem heads (depsite the London Bridge is fallling down threads that you see on this forum).

Call the experts who build aftermarket high performance LS7 engines for GM Racing (Jason at Katech), and educate yourself from their knowledge. Guys who see inspect, and build LS7 heads every for a living, on a daily basis. Best of luck to you!

jimman

And then some mix and match the valves intake and exhaust with Titanium and SS, now that is scary.

tjwong

I installed a set of Katech valve covers. They have all the clearances needed.

Rock36

+1 for Richard at WCCH

I called him, told him what I wanted to do, and he set me up with a new set of heads.

TORQJNKY

Explain. I also saw your post in the "Sky is not falling but READ THIS THREAD if you are on stock valves/guides" thread. All you say is SS is bad or "Scary". Support your argument

SS exhaust valves are used in high heat track situations so I am interested to see what your point is. Higher operating temperatures require a tougher alloy. SS has better thermal properties than the OEM valves. Sodium filled hollow valve stems are used to draw heat up through the stems to aid in valve cooling. This transfers the heat directly to the valve guides which can cause increased guide wear. Additionally, if the sodium filled valve does not receive adequate cooling, which seems to be an inherent problem with these cars, along with valve guide wear, it can overheat, burn, break and/or fail.

Katech may still use the OEM exhaust valves but something with the OEM valve train is not the same when they are done. Is it valve guides, roller rockers, springs, improved valve train geometry, better valve cooling? What is it? Is the way to go to simply replace the OEM steel valve guides with bronze valve guides and stay with OEM hollow sodium filled valves?

I understand a lighter weight valve lends to valve train stability. Is the difference in weight of SS exhaust valve enough to make that much of a difference?

ConfusedGarage

When I send my heads to WCCH this winter I am doing new exhaust valves, bronze valve guides, some porting and milling as well while I'm at it with nothing to do with durability however. That should take care of most issues with the least risk of creating new ones.

Six-Gun-Todd

This is not uncommon at all.....I've built hundreds of race engines with titanium intake valves and inconel exhaust valves with no issue. As opposed to looking at the valve train as individual components it's important to think of it as a balanced system. As long as you have eight valves of one weight and eight valves of another weight the system will work just fine. (keep in mind spring pressure needs to differ for the intake verse exhaust valve)

If you want to take it a step farther.....under boost the intake valve needs to actually have more spring pressure to compensate for the increased load on the valve. (valve area x psi boost pressure). For example....my diesel truck runs roughly 80 psi boost pressure and the intake valves (two per cylinder) have 1.72 in surface area. So if 250 lb seat pressure is adequate for 30 psi boost I need significantly more to compensate for the added boost.

jimman

SS has 40% more weight and 40% less strength and thermal characteristics of a Cement Block. You want the heat transfer where do you expect it to go? Also I understand we have a lot of vendors that may use SS and appear to have no problems but they do not have the resources to properly vet this approach. Do you think that GM even with the bad press is going to go with a large displacement motor that can spin to 7K and guarantee it for 100K miles and then do it over 30,000 times? Ask your next builder if he can do that, food for thought. Please don’t kill the messenger just presenting published facts. The balance issue was explained in a later post on this thread, I still don't aggree with mixing the two with the weight differences. Also, no one has actually determined why there is a problem, if there is one. I have 143,000 miles on mine and I frankly have now concidered taking off heads to see how they look after all this talk.