just kidding 
Cam Talk
TECH Enthusiast
Joined: Jul 2004
Posts: 546
Likes: 1
From: Washington
Originally Posted by 99blancoSS
...although the ls6 cnc'ed by LPE are sweet as well but are 2k....
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
*this is from a cam thread on the main LS1/LS6 intrenal page. Some good reading.
Just a question or two: who told you that these are lazy ramp rates? If you put them on a cam doctor and check them out, you will find that they are quite aggressive. My predecessor at Crane might have had a conservative philosophy, but that changed 3 1/2 years ago when I got here. We are quite aggressive in all design areas. One of the issues that most people on this site don't seem to understand is the design relationship between a lobe and the harmonics of the spring that the lobe was designed for. Our lobes were designed to be compatible with the harmonics of our spring. That enables a long spring life even with very aggressive lobes. There is no one perfect design for any spring. "Spring harmonics vs lobe lift table design" is a very complicated issue and it becomes more complex as the architecture (size limitations) of the spring is reduced. I submit that most of the spring issues that people have with the LSx engine family is not due to "bad" springs, but due to the incompatibility of a given lobe with a given spring. You have to use springs as a tool to an end result. No one has all the answers; we keep working and testing to get as much info as possible, but there is no one out there with all of the answers. I take exception to your comment about Crane lobes not being as aggressive as the competition. We've checked out the competition and know what they are making. Do you seriously believe that we are not making and testing super aggressive lobes? If we expect to stay in business we have to be leaders, not followers. We are testing extremely quick lift rates (faster than any lobes on the market) with various rockers as well. This includes our "quick-lift" rocker bodies and you know what? There is some real bad poop on this site. People are saying that you can't run high ratio rockers with aggressive cams on this site. They obviously haven't tried it. We have, with ratios up to 1.9 to one. Some customers of ours are running 2:1 and we are looking at that in the next two weeks. In short, we are pushing the envelop as far as we can.
Now to address power numbers. We are not going to make specific claims on power numbers on these cams. We have seen power numbers differ as much as 50Hp on vehicles just due to the state of tune! We have people on this site blaming our rockers because they don't have the correct combination or tuning to make the power they want. They have to blame someone or something rather than admit that the combo isn't right. That's just the world and life. We accept that and there is nothing we can do with it. In all honesty, all cam designers are stuck with the same laws of physics given to us by the Almighty. At Crane, we recognize the inherent limitations of the pushrod engine and what can be done by cam lobe design alone. We feel that the most important issue is what the valve is doing. That is fundamental to our reliance on the "Quick-Lift" rocker geometry that we have developed and are improving. To maximize the action of the valve it is the total combination of the lobe and rocker arm that will give you the most power. And you can take that to the bank!!! If you can tune properly, these lobes will run with any lobes in the industry. If you use our "Quick-Lift" rockers they will run even better. It's your money and your choice. I just know we are dedicated to being second to none in the LSx market.
Mark Campbell
VP, Research and Development
Crane Cams, Inc.
Keep in mind that lobe lift has to be reduced with the higher ratios to get a specific valve lift; but what we are concerned about is the valve lift rate not the lifter lift rate. You must keep in mind that we are talking valve lift rate here!!! We have been exploring and testing this whole issue of how to get the quickest/maximum lift and the results so far show that an aggressive rocker body lift profile combined with a aggressive lobe profile works great on LSx engines. This is because the valve train is so lightweight. Spring pressures and inertia loads are much smaller that what was used on traditional engines such as SBC and BBC. This allows everything to be more aggressive and still maintain reliability!!
Just a question or two: who told you that these are lazy ramp rates? If you put them on a cam doctor and check them out, you will find that they are quite aggressive. My predecessor at Crane might have had a conservative philosophy, but that changed 3 1/2 years ago when I got here. We are quite aggressive in all design areas. One of the issues that most people on this site don't seem to understand is the design relationship between a lobe and the harmonics of the spring that the lobe was designed for. Our lobes were designed to be compatible with the harmonics of our spring. That enables a long spring life even with very aggressive lobes. There is no one perfect design for any spring. "Spring harmonics vs lobe lift table design" is a very complicated issue and it becomes more complex as the architecture (size limitations) of the spring is reduced. I submit that most of the spring issues that people have with the LSx engine family is not due to "bad" springs, but due to the incompatibility of a given lobe with a given spring. You have to use springs as a tool to an end result. No one has all the answers; we keep working and testing to get as much info as possible, but there is no one out there with all of the answers. I take exception to your comment about Crane lobes not being as aggressive as the competition. We've checked out the competition and know what they are making. Do you seriously believe that we are not making and testing super aggressive lobes? If we expect to stay in business we have to be leaders, not followers. We are testing extremely quick lift rates (faster than any lobes on the market) with various rockers as well. This includes our "quick-lift" rocker bodies and you know what? There is some real bad poop on this site. People are saying that you can't run high ratio rockers with aggressive cams on this site. They obviously haven't tried it. We have, with ratios up to 1.9 to one. Some customers of ours are running 2:1 and we are looking at that in the next two weeks. In short, we are pushing the envelop as far as we can.
Now to address power numbers. We are not going to make specific claims on power numbers on these cams. We have seen power numbers differ as much as 50Hp on vehicles just due to the state of tune! We have people on this site blaming our rockers because they don't have the correct combination or tuning to make the power they want. They have to blame someone or something rather than admit that the combo isn't right. That's just the world and life. We accept that and there is nothing we can do with it. In all honesty, all cam designers are stuck with the same laws of physics given to us by the Almighty. At Crane, we recognize the inherent limitations of the pushrod engine and what can be done by cam lobe design alone. We feel that the most important issue is what the valve is doing. That is fundamental to our reliance on the "Quick-Lift" rocker geometry that we have developed and are improving. To maximize the action of the valve it is the total combination of the lobe and rocker arm that will give you the most power. And you can take that to the bank!!! If you can tune properly, these lobes will run with any lobes in the industry. If you use our "Quick-Lift" rockers they will run even better. It's your money and your choice. I just know we are dedicated to being second to none in the LSx market.
Mark Campbell
VP, Research and Development
Crane Cams, Inc.
Keep in mind that lobe lift has to be reduced with the higher ratios to get a specific valve lift; but what we are concerned about is the valve lift rate not the lifter lift rate. You must keep in mind that we are talking valve lift rate here!!! We have been exploring and testing this whole issue of how to get the quickest/maximum lift and the results so far show that an aggressive rocker body lift profile combined with a aggressive lobe profile works great on LSx engines. This is because the valve train is so lightweight. Spring pressures and inertia loads are much smaller that what was used on traditional engines such as SBC and BBC. This allows everything to be more aggressive and still maintain reliability!!
Last edited by Rokko; May 17, 2005 at 05:25 PM.
Hey Guys, Thanks for all of the interest in the new products we are making for the LS1. Both of you are right about the products you have discussed. Gold Z is correcct in stating that we have recently released new "long travel" hydraulic roller and mechanical roller lifters for the LS1. (Part # 144510-16 for mechanical rollers and #144535-16 for the hydraulic rollers...both are in stock and ready for shipping). The bodies are made from "carburized" billet steel for strength and the oil band has been relocated and sized to allow up to .700 valve lift (when using 1.7 rockers, more with 1.8s or 1.9s). This relocation of the oiling band prevents the band from dropping out of the bottom of the lifter bore on (small basecircle) high lift camshafts which would result in loss of oil pressure. Of course, these lifters have premium quality wheels, axles and bearings. The hydraulic roller lifter is designed to work with .060"-.100" preload and we know it will be quiet. This lifter incorporates our 4th iteration of internal oiling in a hydraulic roller lifter. It's interesting to note that one of the hydraulic roller lifters that is highly acclaimed on this site is an exact copy of our 1st design. Oops! Maybe I've just given out too much info and they will look at the improvements in these new "long travel" lifters!!
As far as shaft mount rockers go, XTooper is right. Where did you hear that XTrooper? You must have an "in" at "rumor control"!!! We didn't pursue shaft-mounts for the LS1 for quite a while for two reasons:1) for the most part there is no advantage to shaft mounts until you get over 450# open pressure. We have had dozens of field tests showing that our LS1 Gold Race rockers produce more RWHP than what many consider the best shaft mounts. 2) our investigations have shown that there is no reasonable way to make a "bolt on" shaft mount that has proper rocker geometry to provide anything close to what we term "Quick-Lift"... that is why our stud mounts have made more power!! After several design exercises, we have developed a design of shaft mounts using our Polymer Matrix Composite bearings that we feel will be the ultimate in "Quiet, Quick-Lift" design. They will not be bolt ons, but will require removal of the heads, and some elementary machining. They will be available in 1.7, 1.75, 1.8, 1.85, and 1.9 advertised ratios (of course being Quick-Lift designs, they will start the valve off the seat at a ratio of at least .1 higher than advertised) We expect they will be used by people wanting the best and willing to do what is necessary to take advantage of the design. They might fit under stock valve covers, but that can't be promised yet. In all honesty, we are probably 4-6 months from production and I don't have any ballpark price, yet. I can guarantee they will make power and be quieter than stock!! Hope this info helps. I probably will start a thread in the next few days highlighting the new lifters . Again, Thanks for your interest in our products!
Mark Campbell
VP, R&D
Crane Cams, Inc.
The rockers are not sold as a kit with springs and retainers. They are sold as rockers only (#144750A-16 for 1.7, #144759A-16 for 1.8) and as rocker kits that include: screw-in studs, pushrod guide plates, hardened 7.250 heavy wall pushrods for correct geometry...144750-16 for 1.7, and 144759-16 for 1.8). Some people think the kit is a little expensive, but when you compare the total cost of the parts it really isn't. Other people say that for the price of the complete kit you are close to the price of a set of competitors shaft mounts; but those people have not tested our rockers back to back against the most respected shaft mounts. We have and we know our rockers deliver more RWHP. It is all geometry. There is no way(on an LSx head) that a "bolt-on" (no machining) shaft mount can put the rocker in proper geometry to make the most HP with the way the factory LSx head is configured. It can happen on other heads, I won't debate that, but there are definite geometry issues on the LSx head that limit bolt-on shaft mount performance. It is interesting that the new LS7 head has corrected much of this error (it isn't perfect, but it is a lot better than the LS1/6. For more info, go to www.cranecams.com, click on "products" at the top of the page and then "rocker arms"\ "gold race LS1/LS6. Hope this helps!
Mark Campbell
--------------------------------------------------------------------------------
Mark,
Why do you guys not label the Rocker Arms / Shaft Mounts with the higher than normal ratio rockers as such? I'm not the only one to run into this, Jesel does the same thing on shaft mounts too, and when you use the rockers in a application that is lift restricted due to rules or you are pushing the coil bind barrier this can cause issues.
If it's a 1.72, just list it as that. It's simple, causes less issues and I don't think customers will view it as a negaitve since this a industry where the average joe thinks bigger is better. Might be because most of us are men and "average" is just what most guys have.... sorry gotta throw some Freud in there.
Bret
----------------------------------------------------------------------------
The reason we don't is because there is no exact in this business. That is something I have been trying to get across in all of my posts. People want to think that a 1.7 rocker is a 1.7 rocker at all points in the lift profile. It isn't!! It can't be! You can even change the effective ratio of ANY rocker with the pushrod length. Now I know some people who read this will think I'm crazy and it is impossible. All I have to say is put a degree wheel on a crank and a couple of dial indicators on the lifter and retainer and start plotting a bunch of curves. Depending on pushrod length, I can change the effective rocker ratio all over the map. It is just geometry and physics.
The reason we label a 1.7 rocker a 1.7 is that we can guarantee that as a minimum ratio depending on deflection due to spring load or screwed up geometry due to improper pushrod length. If things are right, the customer will probably end up at 1.72-1.74. Because the final ratio (under spring load) is also dependent on pushrod length, it is necessary to physically check clearances as much as possible. And I haven't even begun to discuss valve control issues due to valve "lofting" due to flexible pushrods, lobe design, lobe/spring compatibility, etc. (Most LSx engines running over 5000 RPM are experiencing at least .020" valve loft. The lifter isn't really following the lobe then. Fortunately, for P to v issues this is happening at a point where the piston is pretty far down the hole!)
In closing, as a continuation of my opening point, there are so many variables that affect items that we "assume" to be exact that there is no way to guarantee an exact rocker ratio. This is why some people check things out and are successful and knowledgeable and some people want to believe what they want to believe and have occasional setbacks! At Crane we are trying to put out as much info as we can explaining our "Quick-Lift" geometry. (Much of that info is available at www.cranecams.com). Some people think we are that this "quick-lift" is smoke and mirrors. It isn't, it's applied geometry. We are having tremendous success with this concept and as improved materials permit, we will continue to push accelerated valve lift as far as we can without compromising reliability.
Mark Campbell
As far as shaft mount rockers go, XTooper is right. Where did you hear that XTrooper? You must have an "in" at "rumor control"!!! We didn't pursue shaft-mounts for the LS1 for quite a while for two reasons:1) for the most part there is no advantage to shaft mounts until you get over 450# open pressure. We have had dozens of field tests showing that our LS1 Gold Race rockers produce more RWHP than what many consider the best shaft mounts. 2) our investigations have shown that there is no reasonable way to make a "bolt on" shaft mount that has proper rocker geometry to provide anything close to what we term "Quick-Lift"... that is why our stud mounts have made more power!! After several design exercises, we have developed a design of shaft mounts using our Polymer Matrix Composite bearings that we feel will be the ultimate in "Quiet, Quick-Lift" design. They will not be bolt ons, but will require removal of the heads, and some elementary machining. They will be available in 1.7, 1.75, 1.8, 1.85, and 1.9 advertised ratios (of course being Quick-Lift designs, they will start the valve off the seat at a ratio of at least .1 higher than advertised) We expect they will be used by people wanting the best and willing to do what is necessary to take advantage of the design. They might fit under stock valve covers, but that can't be promised yet. In all honesty, we are probably 4-6 months from production and I don't have any ballpark price, yet. I can guarantee they will make power and be quieter than stock!! Hope this info helps. I probably will start a thread in the next few days highlighting the new lifters . Again, Thanks for your interest in our products!
Mark Campbell
VP, R&D
Crane Cams, Inc.
The rockers are not sold as a kit with springs and retainers. They are sold as rockers only (#144750A-16 for 1.7, #144759A-16 for 1.8) and as rocker kits that include: screw-in studs, pushrod guide plates, hardened 7.250 heavy wall pushrods for correct geometry...144750-16 for 1.7, and 144759-16 for 1.8). Some people think the kit is a little expensive, but when you compare the total cost of the parts it really isn't. Other people say that for the price of the complete kit you are close to the price of a set of competitors shaft mounts; but those people have not tested our rockers back to back against the most respected shaft mounts. We have and we know our rockers deliver more RWHP. It is all geometry. There is no way(on an LSx head) that a "bolt-on" (no machining) shaft mount can put the rocker in proper geometry to make the most HP with the way the factory LSx head is configured. It can happen on other heads, I won't debate that, but there are definite geometry issues on the LSx head that limit bolt-on shaft mount performance. It is interesting that the new LS7 head has corrected much of this error (it isn't perfect, but it is a lot better than the LS1/6. For more info, go to www.cranecams.com, click on "products" at the top of the page and then "rocker arms"\ "gold race LS1/LS6. Hope this helps!
Mark Campbell
--------------------------------------------------------------------------------
Mark,
Why do you guys not label the Rocker Arms / Shaft Mounts with the higher than normal ratio rockers as such? I'm not the only one to run into this, Jesel does the same thing on shaft mounts too, and when you use the rockers in a application that is lift restricted due to rules or you are pushing the coil bind barrier this can cause issues.
If it's a 1.72, just list it as that. It's simple, causes less issues and I don't think customers will view it as a negaitve since this a industry where the average joe thinks bigger is better. Might be because most of us are men and "average" is just what most guys have.... sorry gotta throw some Freud in there.
Bret
----------------------------------------------------------------------------
The reason we don't is because there is no exact in this business. That is something I have been trying to get across in all of my posts. People want to think that a 1.7 rocker is a 1.7 rocker at all points in the lift profile. It isn't!! It can't be! You can even change the effective ratio of ANY rocker with the pushrod length. Now I know some people who read this will think I'm crazy and it is impossible. All I have to say is put a degree wheel on a crank and a couple of dial indicators on the lifter and retainer and start plotting a bunch of curves. Depending on pushrod length, I can change the effective rocker ratio all over the map. It is just geometry and physics.
The reason we label a 1.7 rocker a 1.7 is that we can guarantee that as a minimum ratio depending on deflection due to spring load or screwed up geometry due to improper pushrod length. If things are right, the customer will probably end up at 1.72-1.74. Because the final ratio (under spring load) is also dependent on pushrod length, it is necessary to physically check clearances as much as possible. And I haven't even begun to discuss valve control issues due to valve "lofting" due to flexible pushrods, lobe design, lobe/spring compatibility, etc. (Most LSx engines running over 5000 RPM are experiencing at least .020" valve loft. The lifter isn't really following the lobe then. Fortunately, for P to v issues this is happening at a point where the piston is pretty far down the hole!)
In closing, as a continuation of my opening point, there are so many variables that affect items that we "assume" to be exact that there is no way to guarantee an exact rocker ratio. This is why some people check things out and are successful and knowledgeable and some people want to believe what they want to believe and have occasional setbacks! At Crane we are trying to put out as much info as we can explaining our "Quick-Lift" geometry. (Much of that info is available at www.cranecams.com). Some people think we are that this "quick-lift" is smoke and mirrors. It isn't, it's applied geometry. We are having tremendous success with this concept and as improved materials permit, we will continue to push accelerated valve lift as far as we can without compromising reliability.
Mark Campbell
That's Bret Bauer and Mark Campbell going at it. I am waiting for Mark's response from Bret's last post. It's a good read in the internal section.
https://ls1tech.com/forums/generation-iii-internal-engine/315892-crane-rocker-arms.html
https://ls1tech.com/forums/generation-iii-internal-engine/315892-crane-rocker-arms.html
I am still not sold on super agressive ramp rates. For most people on this site they will be fine. But for me I just dont want to risk it again with a ubber agressive ramp rate. I'll stick to BIG duration, asymetrical lobes and mild lift.
Good info thoug Rokko.
Good info thoug Rokko.
True, I think you proved faster ramp rates don't mix well with long distance races. Hence the longer durations people run. But those cause their own issues that come with the overlap where the efficiency goes down in certain rpm areas. Which kills you if you are trying to develope a broad power band for drag racing. But in reality, they are both trying to accomplish the same thing. More flow baby....opening fast does the same thing as staying open longer.
10 Second Club
Joined: Mar 2004
Posts: 1,491
Likes: 1
From: norfolk va
Originally Posted by Rokko
for all out wide open racing, yeah, i'd stay away from agressive ramp rates. Even for a daily driver im kinda nervous about agressive ramp rates and spring maintenance.
Whatever cam I run I will be running the springs the cam mfg suggests. I emailed cammotion back and threw a few curveballs their way regarding what springs to run, if the varaible ratio or increased ratio rockers are worth it, or is it better to just grind all that into the cam and use 1.7's. Also let them know I'll be running a smallish 2600-2800 converter sometime in the future.
We'll see what they come back with.
We'll see what they come back with.
