[Z06] •• LS7 - Bronze Guides - Bumped Compression - Results ••
03-23-2013, 03:33 PM
#1
Former Vendor
Thread Starter
•• LS7 - Bronze Guides - Bumped Compression - Results ••
•• Bronze Guides - Bumped Compression - Results ••
Replaced the guides, raised the compression & ran our latest CNC program on the intake side (+ 390 CFM) - tuned..
This is one of our early LS7 track engines that was in for a "freshening"
In addition to our Gen V intake program we changed the guides, did our valve job and milled .030 to 66 cc. -
Replaced the guides, raised the compression & ran our latest CNC program on the intake side (+ 390 CFM) - tuned..
This is one of our early LS7 track engines that was in for a "freshening"
In addition to our Gen V intake program we changed the guides, did our valve job and milled .030 to 66 cc. -
03-23-2013, 04:05 PM
#3
Former Vendor
Thread Starter
When we built the engine we swapped the exhaust valves to SS. At that time the guides were excellent - two years later and after countless track time, the exhaust guides were approaching GM's "out-of-spec" region. There were two "out-of-spec" intake guides.
03-23-2013, 04:09 PM
#4
Were the valves in good shape?
When you say "countless" track time, are you meaning in the neighborhood of 20 track days or more?
Also, the fact that it got along as far as it did, using the "incompatible" titanium intake valves against the bronze guides, says a lot.
03-23-2013, 04:22 PM
#5
Former Vendor
Thread Starter
The SS valves were perfect.
6 of the ti valves showed some wear & tear on the stems (minor) ut we replaced all 8.
I'd say double that -and driven hard enough to win our Corvette Challenge two years.
no, these heads had original guides throughout - they now have bronze guides
6 of the ti valves showed some wear & tear on the stems (minor) ut we replaced all 8.
no, these heads had original guides throughout - they now have bronze guides
03-23-2013, 04:27 PM
#6
Melting Slicks
The SS valves were perfect.
6 of the ti valves showed some wear & tear on the stems (minor) ut we replaced all 8.
I'd say double that -and driven hard enough to win our Corvette Challenge two years.
no, these heads had original guides throughout - they now have bronze guides
6 of the ti valves showed some wear & tear on the stems (minor) ut we replaced all 8.
I'd say double that -and driven hard enough to win our Corvette Challenge two years.
no, these heads had original guides throughout - they now have bronze guides
03-23-2013, 04:34 PM
#7
Wow, that is impressive track time and they're only just getting close to the out of spec range?
With 585~rwhp, I assume this car has quite a few bolts ons and cam? To have that much track time with such an aggressive setup would have been a death sentence on the OE Hollows.
Of course this isn't 100% proof, but I do think this helps validate that Heat is the primary issue with the valvetrain and that SS is much friendlier than the OE Hollows are to the Guides.
With 585~rwhp, I assume this car has quite a few bolts ons and cam? To have that much track time with such an aggressive setup would have been a death sentence on the OE Hollows.
Of course this isn't 100% proof, but I do think this helps validate that Heat is the primary issue with the valvetrain and that SS is much friendlier than the OE Hollows are to the Guides.
03-23-2013, 04:53 PM
#8
Melting Slicks
Wow, that is impressive track time and they're only just getting close to the out of spec range?
With 585~rwhp, I assume this car has quite a few bolts ons and cam? To have that much track time with such an aggressive setup would have been a death sentence on the OE Hollows.
Of course this isn't 100% proof, but I do think this helps validate that Heat is the primary issue with the valvetrain and that SS is much friendlier than the OE Hollows are to the Guides.
With 585~rwhp, I assume this car has quite a few bolts ons and cam? To have that much track time with such an aggressive setup would have been a death sentence on the OE Hollows.
Of course this isn't 100% proof, but I do think this helps validate that Heat is the primary issue with the valvetrain and that SS is much friendlier than the OE Hollows are to the Guides.
03-23-2013, 04:53 PM
#9
The SS valves were perfect.
6 of the ti valves showed some wear & tear on the stems (minor) ut we replaced all 8.
I'd say double that -and driven hard enough to win our Corvette Challenge two years.
no, these heads had original guides throughout - they now have bronze guides
6 of the ti valves showed some wear & tear on the stems (minor) ut we replaced all 8.
I'd say double that -and driven hard enough to win our Corvette Challenge two years.
no, these heads had original guides throughout - they now have bronze guides
Good to see that everything held up as well as it did.
03-23-2013, 04:57 PM
#10
Former Vendor
Thread Starter
Forged pistons
ti Rods (rebuilt with ARP bolts)
CNC’d heads
Balanced & Blue Printed
Track Cam
Ported LS7 intake & TB
Headers
…looks promising..
03-23-2013, 05:03 PM
#11
My very experienced machine shop guru said he thinks its a heat issue too. He showed me dozens and dozens of used exhaust valves from various LS7's compared to LS6's and other LS motors. All the LS7's had serious signs of heat wear(and where broken LS7 valves all broke) compared to the others. He said in his opinion the stock guides were good although I had him do bronze anyway. He said the powered metal is the same as they use in gears and other tried and true applications. He probably had a hundred heads, cranks, dozens of blocks, all LS's all over with 40 years experience so I put stock in his suggestions along with questioning Katech, Texas Speed and WCCH certain constants remain.
Nice numbers, curious of the other mods?
Nice numbers, curious of the other mods?
03-23-2013, 05:07 PM
#12
Interesting though, that Charlie just changed the valves, left the guides alone, and the guides and the engine both have lived as long as they have.
The exhaust valve guides were not quite out of spec, but two of the intake guides were out of spec.
There was talk earlier by someone else, that changing the guides, was the key, and the valves didn't matter.
But here's a case where changing the stock valves, and keeping the stock guides saw this engine get to this point.
I don't want to think what might have happened if the guides had been changed to bronze, back then, and the valves had remained the same considering that Charlie is giving an estimate of some 40 track days and enough duty that it won their Corvette Challenge for the last two years.
The exhaust valve guides were not quite out of spec, but two of the intake guides were out of spec.
There was talk earlier by someone else, that changing the guides, was the key, and the valves didn't matter.
But here's a case where changing the stock valves, and keeping the stock guides saw this engine get to this point.
I don't want to think what might have happened if the guides had been changed to bronze, back then, and the valves had remained the same considering that Charlie is giving an estimate of some 40 track days and enough duty that it won their Corvette Challenge for the last two years.
Last edited by '06 Quicksilver Z06; 03-23-2013 at 08:17 PM.
03-23-2013, 05:42 PM
#13
Former Vendor
Thread Starter
Interesting though, that Charlie just changed the valves, left the guides alone, and the guides and the engine both have lived as long as they have.
The exhaust valve guides were not quite out of spec, but two of the intake guides were out of spec.
There was talk earlier by someone else, that changing the guides, was the key, and the valves didn't matter.
But here's a case where changing the stock valves, and keeping the stock guides saw this engine get to this point.
I don't want to think what would might have happened if the guides had been changed to bronze, back then, and the valves had remained the same considering that Charlie is giving an estimate of some 40 track days and enough duty that it won their Corvette Challenge for the last two years.
The exhaust valve guides were not quite out of spec, but two of the intake guides were out of spec.
There was talk earlier by someone else, that changing the guides, was the key, and the valves didn't matter.
But here's a case where changing the stock valves, and keeping the stock guides saw this engine get to this point.
I don't want to think what would might have happened if the guides had been changed to bronze, back then, and the valves had remained the same considering that Charlie is giving an estimate of some 40 track days and enough duty that it won their Corvette Challenge for the last two years.
- last year it was won by another one of our customers
...and he ran two seasons so far with all bronze guides...
03-23-2013, 06:16 PM
#14
You are definitely carving a niche and doing it one success at a time.
No arguing with your methods. No sir.
I get the impression that your clientele is not the crown prince and the sultan, with pockets deep enough to swim in, but rather the working guy who simply has to have his equipment be as durable as his pockets will allow.
Keep up the good work Charlie.
People are definitely taking notice. You're making it impossible for them not to.
03-23-2013, 06:23 PM
#15
Former Vendor
Thread Starter
thank you...i give a lot of credit to the drivers and my supporting staff...
Well, your reputation in here, for success on the track, is moving right up there with the "big shots" with the big GM contract Charlie.
You are definitely carving a niche and doing it one success at a time.
No arguing with your methods. No sir.
I get the impression that your clientele is not the crown prince and the sultan, with pockets deep enough to swim in, but rather the working guy who simply has to have his equipment be as durable as his pockets will allow.
Keep up the good work Charlie.
People are definitely taking notice. You're making it impossible for them not to.
You are definitely carving a niche and doing it one success at a time.
No arguing with your methods. No sir.
I get the impression that your clientele is not the crown prince and the sultan, with pockets deep enough to swim in, but rather the working guy who simply has to have his equipment be as durable as his pockets will allow.
Keep up the good work Charlie.
People are definitely taking notice. You're making it impossible for them not to.
03-23-2013, 06:41 PM
#16
Drifting
Nice power Charlie.
03-23-2013, 09:56 PM
#17
Burning Brakes
Interesting though, that Charlie just changed the valves, left the guides alone, and the guides and the engine both have lived as long as they have.
The exhaust valve guides were not quite out of spec, but two of the intake guides were out of spec.
There was talk earlier by someone else, that changing the guides, was the key, and the valves didn't matter.
But here's a case where changing the stock valves, and keeping the stock guides saw this engine get to this point.
I don't want to think what might have happened if the guides had been changed to bronze, back then, and the valves had remained the same considering that Charlie is giving an estimate of some 40 track days and enough duty that it won their Corvette Challenge for the last two years.
The exhaust valve guides were not quite out of spec, but two of the intake guides were out of spec.
There was talk earlier by someone else, that changing the guides, was the key, and the valves didn't matter.
But here's a case where changing the stock valves, and keeping the stock guides saw this engine get to this point.
I don't want to think what might have happened if the guides had been changed to bronze, back then, and the valves had remained the same considering that Charlie is giving an estimate of some 40 track days and enough duty that it won their Corvette Challenge for the last two years.
03-30-2013, 08:48 PM
#20
Burning Brakes
My very experienced machine shop guru said he thinks its a heat issue too. He showed me dozens and dozens of used exhaust valves from various LS7's compared to LS6's and other LS motors. All the LS7's had serious signs of heat wear(and where broken LS7 valves all broke) compared to the others. He said in his opinion the stock guides were good although I had him do bronze anyway. He said the powered metal is the same as they use in gears and other tried and true applications. He probably had a hundred heads, cranks, dozens of blocks, all LS's all over with 40 years experience so I put stock in his suggestions along with questioning Katech, Texas Speed and WCCH certain constants remain.
Nice numbers, curious of the other mods?
Nice numbers, curious of the other mods?
