triblk6spd

In a nut shell I have the car pretty much the way I want it in regards to the looks AND performance. I am now set on tackling the LS7 specific problems in regards to head problems and valve/guide issues. Here is my plan...

-Remove the heads
-Replace valve guides with bronze (what brand??)

-Check stock valves and guides for wear...replace any worn valves (OEM or other??)
-Obviously post any findings here.

-Reinstall heads with new ARP hardware and gaskets (OEM or something better *Cometic*)??


Other random questions:
-Will this address the weak link AT my current power level..640 rwhp?

-Should I replace my valve springs that came with my LPE GT19 cam with 689 lift!!...they have ~15,000 miles and ~4 years on them?

-Is there anything else you would consider attending to..keeping in mind I'm not trying to make more power..just make the power I do have more reliable.

1320IN9

my opinion if it's not broke dont fix it, in the future if it does break then build it better stronger and faster.

screaminchevy

Since you have an 07 (as do I) I think it's a good idea to do all of the above and have your needle bearings/rocker arms checked. My heads are getting cnc'd right now and I'm swapping out exhaust valves, guides, and rocker arm upgrade. It just gives me peace knowing that's not a weak point anymore more since I like to drive it hard!

Dirty Howie

Good luck and waiting to hear about guide wear


DH

triblk6spd

Right! The trunion upgrade was one of the first mods I did. What did you use (brands) for guides, seals, lash caps, valves and where did you source them?

Mopar Jimmy

Sounds like good preventive maintenance idea on your part, especially on a forced induction application.

Make sure you get a good 5 angle valve job and I would use the same bronze guides as WCCH, and may as well just send your heads to Richard at WCCH, and tell him what you have in mind. You can also contact Carlos at Vette Air, as he is offering a complete upgrade on heads for a good price, and you can't go wrong with him either (he really knows these LS7s).

And while your doing all this, CERTAINLY, replace your valve springs, its just good cheap insurance, and since your approaching 20,000 miles on them makes A LOT of sense (and its inexpensive).

0Cunningham Motorsports

send your heads to Richard at WCCH, he works these heads all the time, i wouldnt bother porting them being your supercharged, but definitely upgrade the guides and exh valves... i can almost guarantee you that your guides are already worn out of spec, its very common on all ls7 heads... replace the springs cheap insurance

triblk6spd

Ok good advice. Since Im not porting or polishing do I NEED to send them out or could a good head guy here in Austin do the guides and whatnot?

Also, the spring set that LPE put (and sells) for my GT19 cam is over $$1100! http://www.lingenfelter.com/mm5/merc...gory_Code=P016

0Cunningham Motorsports

a good cylinder guy should be able to take care of you... just make sure they dont screw up the valve job, had a machine shop do that once.... texas-speed has springs that will work just fine for your cam for half the cost, but the same quality

triblk6spd

Texas Speed offers two set of 700 lift springs...both have to have the head modified for them to fit. Seems maybe I should just do the damn LPE spring kit and save the hassle of modding the heads. ???

AirBusPilot

Wow, those are some high dollar springs. I'd first have the open and closed spring pressures checked and see if they are still in spec. Might call LPE too and see what kind of life they are getting.

Wulverine

I'd replace the GT19 cam with a blower cam and save some money and probably make more power.

screaminchevy

I went thru Richard at WCCH. Not sure what brand he uses for the hardware. If I had a larger budget, I'd have sent them to Larry Widmer at ENDYN. If you've never heard of him, he was the guy that created the badass super swirl heads that Bob Gliden used to set all the pro stock dragster records in the 70s. His shop is in Fort Worth and he's been known to get his custom head design to run 17.1 compression on 93 octane...

Michael_D

I'm still not convinced there is an inherent "problem" with LS7 guides, all guides wear. It's just the nature of the beast. But, there is enough chatter to motivate me to pull mine and inspect them. And while I have them off, might as well have them worked....it never ends.

LSK lobes (which is what the GT19 uses) have very aggressive opening / closing ramps. They are hard on valve train components, especially springs. The Ferrea spring is a very good spring, which is why LPE recommends them with these cams. I doubt you will find its equal for much less. PAC might have a set, I dunno... I suspect you will also find the guide clearance is in the weeds. The OEM rockers have a fairly small sweep up till about .620 lift, then they start to migrate from center and start side loading the guide. I'd be hesitant to run that much lift without moving to an adjustable rail system with roller tips, but they aren't exactly cheap and require the pedestals to be machined down and re-tapped. Then of course the other big consideration is valve weight running those lobes. If you move to a solid SS valve, you'll need more spring and that in itself has its own can of worms. LPE will tell you to run oem (or comparable) sodium filled valves to keep weight down. Personally, I think Ti is the way to go and think of sodium filled valves as hand grenades with the pin half pulled jsut waiting for an opertunity to pop out the rest of the way, but this adds another $600 or so to the bill.

This is just a thought, but you might be better off going with a new cam, verses dumping the coin on new Ferrea's and dealing with the headaches that GT19 brings. That cam wasn't really intended to be for boost anyway. I suspect that Geoff at EPS could grind you a custom stick with less lift that would make more power and add a bit more reliability. I like his lobes. They gently set the valve down on the seat to keep it from bouncing, but yet still have fairly aggressive off seat ramps between .50 and .200 for better under curve performance. Sometimes less equals more when you have more stable valve events.

I would not send your heads to just anyone for guide replacement and seat / valve work, especially when working with Ti. Seeing how you aren't terribly far away from Arlington, you might want to pay Darin Morgan at Rehre Morrison a visit. I've had several conversations with him about working my heads, and he's been very forthcoming with details and recommendations. He’s a straight shooter who won’t try and baffle you with BS. You might be surprised to hear what he has to say. He also has different port designs for these heads depending on what your goals are. You don't hear much about R-M in on the forums as they stay plenty busy with pro-stock builds, but they do plenty of street / strip builds and are very familiar with LS engines. Just a thought...not a sales pitch.

I prefer the oem gaskets. I also have a preference for studs over bolts, but they can make in-car head swaps a bit more challenging. ARP is good, but not the best. Definitely good enough for these power levels.

Valve guide brands are all over the place... each shop will have their favorite supplier and they'll use the most appropriate alloy for the intended use (there's many different bronze alloy's and each have pro's / con's). I have had good luck with SI and Rev guides. I've also heard good things about CHE, but have no personal experience with them.

Watch your boost if the short block is stock. Get much over 6 with the OEM pistons and cylinder sleeves and you may regret it.

triblk6spd

Wow thats a lot of info! I had to read it twice. Thanks for the good read. Im hoping I can have the heads gone thru and continue to run the same cam with a new set of springs..prob use the same Ferrea stuff LPE put on back on day one. Like I said I dont plan on making more power and I dont feel like the power I do make is out of safe territory.
Where would I find a good set of Ti. valves to replace my OEM ones?

0C_Williams@RPM

We do a fair amount of LS7 heads and the typical upgrade and reliabilty options looks like this...

LS7 Cylinder Head Reliability & Upgrades

Cylinder Head Components
• Phosphorous bronze valve guides (CHE)
• Stainless steel, one-piece Exhaust Valves
• Upgraded rocker arm trunions
• Competition dual valve springs

Cylinder Head Labor
• Competition Multi-Angle Valve Job
• Install guides and hone to size
• Bowl Porting and Blending
• Mill & CC Combustion Chambers

Additional Cylinder Head Options
Complete CNC cylinder head porting
Intake manifold & throttle body porting
Titanium exhaust valves
Head studs

Also - the GM intake valves are generally great (Del West) but occasionally the coating will wear and they need to be replaced. Two of the best are Del West and Xceldyne - links below

www.delwestengineering.com

www.xceldyne.com

Mopar Jimmy

Great stuff William (RPM),

Out of curiousity what is basic cost for a customer to send in their stock LS7 heads and have the first 2 categories done (basic reliability upgrades and labor)?

Thanks in advance.

Random84

That's a new one....

0C_Williams@RPM

$1295 - includes all parts, machining & labor - customer needs to send the heads and rocker arms - we will take it from there.


Cylinder Head Components
• Phosphorous bronze valve guides
• Stainless steel, one-piece Exhaust Valves
• Upgraded rocker arm trunions
• Competition dual valve springs


Cylinder Head Labor
• Disassemble,clean inspect and reassemble
• Competition Multi-Angle Valve Job
• Install guides and hone to size
• Bowl Porting and Blending
• Mill & CC Combustion Chambers

AirBusPilot

http://www.delwestengineering.com/pa...ve_guides.html

Valve Guides
All Del West valve guides are manufactured with the necessary tolerances and high quality level so that they can be installed directly into the cylinder head guide bore without additional work.

Guides are manufactured of several materials depending upon your application. Cross holes for addition valve stem lubrication are also available upon request.
Levels of control on critical dimensions:
• OD Diameter ' 0.005mm ( .0002") ' Tighter control is available upon request or if required
• OD Taper ' 0.005mm ( .0002") ' Tighter control is available upon request or if required
• OD Roundness 0.005mm ( .0002") ' Tighter control is available upon request or if required
• OD-ID Concentricity ' 0.005mm ( .0002") ' Tighter control is available upon request or if required
• OD Surface Finish ' Ra0.20microns' Tighter control is available upon request or if required

Material choices:
• Manganese Bronze
• Beryllium Copper Alloys
• Aluminum
• Sintered Iron

Please speak with a Del West engineer to understand what is right for your application.

Del West. Precisely.