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I would like to know how well everyone's heads are doing that have been fix??
C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I had my heads done at AHP with 7k miles on the clock and went with the BTR stage 2 cam. 2 summers ago, at about 19k miles, I decided to switch to cnc ported WCCH heads and 102mm tb. It picked up a peak of 15hp,10tq but picked up 20hp and 30tq in other areas past 5k RPM. Every titanium intake valve was trashed. The coating was wore off of the face and every single valve tip was indented. I frequently take it on spirited drives 6 months out of the year, never drag race and never take it to redline. I am very OCD and meticulous about how I take care of my car. Currently, there are 28k miles on it and I've done 11 Blackstone oil analyses just to give you an idea.
My heads were done at AHP by the previous owner at 24k mile. Currently with 105k miles on the clock. Stock cam and do not have any issues. so 81k on fixed heads
I had my heads done at AHP with 7k miles on the clock and went with the BTR stage 2 cam. 2 summers ago, at about 19k miles, I decided to switch to cnc ported WCCH heads and 102mm tb. It picked up a peak of 15hp,10tq but picked up 20hp and 30tq in other areas past 5k RPM. Every titanium intake valve was trashed. The coating was wore off of the face and every single valve tip was indented. I frequently take it on spirited drives 6 months out of the year, never drag race and never take it to redline. I am very OCD and meticulous about how I take care of my car. Currently, there are 28k miles on it and I've done 11 Blackstone oil analyses just to give you an idea.
When you had the ahp heads I assume they reused the stock valves? And the wcch heads used stainless? Did you change the heads because of a bad oil analysis?
My heads were done at AHP by the previous owner at 24k mile. Currently with 105k miles on the clock. Stock cam and do not have any issues. so 81k on fixed heads
When you had the ahp heads I assume they reused the stock valves? And the wcch heads used stainless? Did you change the heads because of a bad oil analysis?
They reused the stock intake valves at AHP, aftermarket exhaust valves. WCCH used Manley titanium-molybdenum intake valves. I mainly went to WCCH because I thought I might be leaving some power on the table. I'm glad I did- not sure how much longer the intake valves would have lasted.
Great thread!
Interested in hearing long term feedback on Race Proven Motorsport's 280 cc Advanced Induction heads package as I believe they use the factory titanium intake valves.
I just put this package on my c6z last year but don't do more than maybe 4000 miles per year, hoping I can get many years from them even with 7100 rpm visits and the B3 cam (Btr .660 valve springs).
WCCH did my heads when Cordes Performance Racing did my HCI build at 46K miles in May 2016. All exhaust valve guides and 6 of 8 intake valve guides were out of spec. 12K miles later I had the bottom end forged, heads back to WCCH just to be checked, all guides .0011-.0016" clearance, so great. Car is still running strong with 22K miles on the redone heads.
CHE bronze guides
Katech TiMo intake valves
new OEM exhaust valves
Katech 501K cam
all other appropriate mods
593/513 rwhp/tq
The car sees easy driving on the street, mostly below 3K rpm. Maybe 10 road course days on the build running 4-7K+ rpm in three or four 20-minute sessions. Another half dozen Silver State events with engine running 150 MPH/4700RPM continuous for 36 minutes per run. 1/2, 1, and 1.5Mile straight line runs revving to 7300 RPM FSO.
Texas Speed did mine. Running a cam that perfectly splits their 2.2 and 3.2 with original intake valves, and apparently some new exhaust valves that I only now just read through and learned I have lol. 15k miles on it so far with pretty hard driving, I usually wring out 2nd and 3rd on most drives and it's my daily outside of the winter.
I have about 8k miles total on my AHP pkg 4 heads...including about 10 track days (4 x 20/25min sessions) between 4k-7k rpm.
So far so good...no noises and I guess I'll do oil analysis next oil change
AHP Package 4 Heads, Stage 3 cam, retained intake valves changed exhaust valves; only about 800 miles, however most of it straight line racing, 3800 miles on the motor/car. I am more worried about the rods at this point.
Original fix by GM under warranty at 13k miles, new heads, all new valves, all new springs, etc.
Valve guide wear out of tolerance at 29k miles, so heads, valve guides, exhaust valves. cam and lifters replaced at 29k miles.
Now at 48K miles, the stage IV heads with MS90 valve guides are seriously out of tolerance again, and the intake valve stems are severely damaged, beyond the coating thickness. So all new intake and exhaust valves are required.
All of the above has been fixed at my expense. This includes new Ti intake valves, new exhaust valves, new valve guides, new valve seats, new valve lifters, and new pushrods. Not a minor cost!
After my experiences, I would advise CF users to invest in used oil analysis after the "fix" to make sure that their engine is not shedding excess copper into the engine oil. Moldstar 90 is 90% copper. Just saying.
Original fix by GM under warranty at 13k miles, new heads, all new valves, all new springs, etc.
Valve guide wear out of tolerance at 29k miles, so heads, valve guides, exhaust valves. cam and lifters replaced at 29k miles.
Now at 48K miles, the stage IV heads with MS90 valve guides are seriously out of tolerance again, and the intake valve stems are severely damaged, beyond the coating thickness. So all new intake and exhaust valves are required.
All of the above has been fixed at my expense. This includes new Ti intake valves, new exhaust valves, new valve guides, new valve seats, new valve lifters, and new pushrods. Not a minor cost!
After my experiences, I would advise CF users to invest in used oil analysis after the "fix" to make sure that their engine is not shedding excess copper into the engine oil. Moldstar 90 is 90% copper. Just saying.
Oh man! That stinks. I assume your head are ahp? And are you still using a stock cam?
Original fix by GM under warranty at 13k miles, new heads, all new valves, all new springs, etc.
Valve guide wear out of tolerance at 29k miles, so heads, valve guides, exhaust valves. cam and lifters replaced at 29k miles.
Now at 48K miles, the stage IV heads with MS90 valve guides are seriously out of tolerance again, and the intake valve stems are severely damaged, beyond the coating thickness. So all new intake and exhaust valves are required.
All of the above has been fixed at my expense. This includes new Ti intake valves, new exhaust valves, new valve guides, new valve seats, new valve lifters, and new pushrods. Not a minor cost!
After my experiences, I would advise CF users to invest in used oil analysis after the "fix" to make sure that their engine is not shedding excess copper into the engine oil. Moldstar 90 is 90% copper. Just saying.
In this case, I have to think it's 'what came first, chicken or egg' situation. I've said it before, and IMHO, Ti components seem to be the LS7s Kryptonite. I'd wager that the Ti intakes lost some of their coating, and that's what took out the intake guides, and possibly the exhaust guides, as well. I had all 16 guides junk in less than 20,000 miles, and 7 of 8 Ti intakes were losing coatings. I sent my heads to AHP, they did the valve job, and I bought 8 hollow stem Ferrea stainless intakes. Cam is a Futral, ground by Cam Motion, has stockish lift@.600". 10,000 miles, no issues. FWIW, which probably isn't much......
I was not willing to re-use the OEM Ti valves that had been run in out of spec guides so I went with the Katech TiMo intake valves ($$$) and CHE bronze guides, checked out fine by WCCH (.0011-.0016) after 12K miles and running great 22K miles on the build.
I was not willing to re-use the OEM Ti valves that had been run in out of spec guides so I went with the Katech TiMo intake valves ($$$) and CHE bronze guides, checked out fine by WCCH (.0011-.0016) after 12K miles and running great 22K miles on the build.
This - Had AHP apply Package 4, (cringed at the term “fix”), put another 4K on the engine and had a lifter go. The GM TI valves even tumble polished never sat well with me and I exchanged my heads so I’m not sure if the valves used were <\> the
the 4K valves I sent in. This go round , I sourced New AHP TI valves, Johnson regular travel link bar lifters and K-tech Red pump to compensate for oil axel lifters. This is what I wanted to do first time around and should have. AHP gives you the option, it’s just a $$$ decision. The guides (pm) we’re all good after 4K, the GM/Delwest are good lapping tools or lightweight paper weights now.
This - Had AHP apply Package 4, (cringed at the term “fix”), put another 4K on the engine and had a lifter go. The GM TI valves even tumble polished never sat well with me and I exchanged my heads so I’m not sure if the valves used were <\> the
the 4K valves I sent in. This go round , I sourced New AHP TI valves, Johnson regular travel link bar lifters and K-tech Red pump to compensate for oil axel lifters. This is what I wanted to do first time around and should have. AHP gives you the option, it’s just a $$$ decision. The guides (pm) we’re all good after 4K, the GM/Delwest are good lapping tools or lightweight paper weights now.
Our AHP Ti Moly intake valves are the way to go if you can fit it into your budget.
They work with both PM and MS90 guides and are just superior in every single aspect to the GM CRN coated ti intake valves.
Dont get me wrong though we have had very few issues over the years treating/tumble polishing and reusing the factory GM CRN coated LS7 ti intakes but they are a possible failure point due to GM's poor manufacture specs (penny pinching is actually a much more accurate term) on the factory CRN coating.
You guys are talking about the intake valve coating. So I popped all my valves out of my stock heads real quick. I was wondering how can I tell if there's any coating left on them?
01-04-2022, 12:13 PM
I would like to know how well everyone's heads are doing that have been fix??
