Cam lobes new yzooom
#62
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#63
LiLJayV10,
Who is THIS Tony Mamo you are referring to?
Who is THIS Tony Mamo you are referring to?
#65
TECH Apprentice
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#66
Sorry I know nothing about XE-R lobes. I see the cam you are running here the question is how does it run? What would you want it to do that it is not doing now? More on top more on the bottom? Why are you running more EX lift than intake lift?
Question I have after looking at your specs are.
How much compression do you have?
Stick? automatic? Stall?
How much lift can your heads handle?
How do you want it to run?
I see it is street driven mostly if it is do you want the best cam for the street? Or one for the best ET at the track?
Question I have after looking at your specs are.
How much compression do you have?
Stick? automatic? Stall?
How much lift can your heads handle?
How do you want it to run?
I see it is street driven mostly if it is do you want the best cam for the street? Or one for the best ET at the track?
Can I PM or call you when I have my heads flowed and can relay the cylinder head data?
#67
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My understanding is that XE-R lobes offer higher ramp rates, and as a result, are considerably more unforgiving on the valvetrain. I've spoken to guys that only get 6-8K miles out of their springs as a result of the aggressive nature of the XE-R lobe profile. I purchased the heads/cam setup used in the classifieds section, so I didn't personally spec the cam, but the deal was too good to pass up. I'm definitely planning on keeping the cylinder heads and having them milled and inspected, but I'm nervous about running an XE-R lobed cam as I'd like something that'd be significantly easier on my valvetrain. I'd like to go with a similarly sized cam, but on a cam motion or bullet core, and a more street friendly lobe.
Can I PM or call you when I have my heads flowed and can relay the cylinder head data?
Can I PM or call you when I have my heads flowed and can relay the cylinder head data?
#70
Kip, would the street Morel link bar lifters hold up ok with a 6800 shift point? What about 7k?
With the following:
-BTR Dual springs, steel retainers
-2.08/1.57 stainless solid ferrea valves
-thick 3/8" pushrods
-ati balancer
-your cam
With the following:
-BTR Dual springs, steel retainers
-2.08/1.57 stainless solid ferrea valves
-thick 3/8" pushrods
-ati balancer
-your cam
#71
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I will hang in I am not going anywhere. If you have cam questions I will try to answer them. I will be trying to clear up myths about cam design and application on this thread.
#73
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You should not have any problems with 7k at all.
#75
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All lobes are designed for a loft profile let’s say I make a Hyd Roller lobe for your SBC I want 230 @.05 with 350 lobe lift and we are using a .842 lifter with a .750 wheel. In the old days and still now when we made a lobe like this it was made on a mill by hand it was call a model lobe now after making it you have to make a master for the grinding machine and it worked fine for a designed base circle size. This lobe for a SBC would be made on a 1.158 base circle. If we ground the new cam with this base circle it would come out with the correct specs. If we used the same master for a LS1 cam the base circle would be 1.455 now if you measure the dur @.05 with this big base circle it will come out to be about 6 degrees larger 236@.05 because of the geometry. Now all of our lobe are made on the computer and feed into the CNC grinding machine. So this lobe file is just a lift data file before we grind the cam we need to tell the grinding program or machine what we want to end up with. For a lobe to come out what we want like a 230/350 we program 1 Base circle finish size 2 roller wheel diameter and grinding wheel size. If we grind a cam lobe that is 230/350 for a roller lifter with a .700 wheel and you put in lifters with a wheel size of .750 the duration will be a little bigger. Going from .700 to .750 is not much difference but going from .700 to .850 is a fair amount. Now for the week pushrods & spring pressers. No one can made a valve train to stiff the larger the cam core the stiffer the pushrods the most sturdy the rocker stands the lighter the valve retainers the better the system will work and live. On spring presser you only need as much as it takes to not have valve float for your RPM range. Most drag racers over spring because they think more is better. Rockers can fool you. A good expensive set of rockers may work as well as stock or another set that are not expensive. On components like springs and valve spring Frequency can get complicated because a spring can be good for this engine and not for this one so if they work use them if they done try some others there is a lot more to this but I will leave it for now.
Why not make a components specific lobes for the public?
Do you vary the actual lobe LSA between cyllenders/Ports like split LSA with Intake design and bad cyllenders with Cam twist for P to V on a real race motor?
With the .006 to .050 difference number is there a way to set up preaload correctly to use the lobe accell/velocity better as the lifter bleeds down with oil pressure?
What about the .050 to .200 ect.. numbers is there a specific travel by Degree you look for in all lobe designs? Is constant velocity bad?
What about your hardening and core material,how deep do you keep it and where is the limits of your cores for Advance and LSA? Is there a diff in Hyd and Solid cores? are they ground down from a 60mm and can you regrind your cams again after being used?
#76
TECH Apprentice
Thread Starter
OK burnt up lobes are caused by a few different reasons not lobe design. Bad lobe design can beat up and brake parts. The reason lobes brake down and look burned up is because 1 bad material 2 bad heat treat 3 bad surface finish on the cam or lifter wheel 4 Heat treat not deep enough. The main reason I think after dealing with this a long time is the surface finish. When you have a bad finish on cam lobes the lifter roller wheel rides on high points on the surface causing high Hertzian stress . The high concentrated load will start work the steel then small cracks will form after time the surface will start to flake off. All of the cores that are manufactured today should work fine for street use provider the finish is good.
Question do we very lobe LSA between cylinders? Yes on Pro Stocks and Top Fuel we did on some engines having different LS on different cylinders and also different durations on different cylinders. It’s a real pain but it works.
Question on preload .006 and .05 difference? I set preload with the minimum amount but that me.
Question about material for cores. On a 55mm (2.165) we start with bar stock 2.315 and turn it down to size. Our cores are 8620 AQ we can heat treat .110 deep so we can only change the rough out core so far before we cut away to much of the hardeing so we have to make 16 different core to meet the demand. We also make special cores for a certain profile that will not fit on a core we have. The 5160 core that other company’s make are about .200 deep so you have more room to move a profile. Both cores 8620 and 5160 are about 57 to 62 Rockwell C hardness.
Question do we very lobe LSA between cylinders? Yes on Pro Stocks and Top Fuel we did on some engines having different LS on different cylinders and also different durations on different cylinders. It’s a real pain but it works.
Question on preload .006 and .05 difference? I set preload with the minimum amount but that me.
Question about material for cores. On a 55mm (2.165) we start with bar stock 2.315 and turn it down to size. Our cores are 8620 AQ we can heat treat .110 deep so we can only change the rough out core so far before we cut away to much of the hardeing so we have to make 16 different core to meet the demand. We also make special cores for a certain profile that will not fit on a core we have. The 5160 core that other company’s make are about .200 deep so you have more room to move a profile. Both cores 8620 and 5160 are about 57 to 62 Rockwell C hardness.
Thanks for replying,i know that was a loaded question but the reason why i ask is because of burnt up lobes from Comp Cams that people think they have core problems when its component selection,is that one of the reasons that CM dose not offer hard lobes to the public?
Why not make a components specific lobes for the public?
Do you vary the actual lobe LSA between cyllenders/Ports like split LSA with Intake design and bad cyllenders with Cam twist for P to V on a real race motor?
With the .006 to .050 difference number is there a way to set up preaload correctly to use the lobe accell/velocity better as the lifter bleeds down with oil pressure?
What about the .050 to .200 ect.. numbers is there a specific travel by Degree you look for in all lobe designs? Is constant velocity bad?
What about your hardening and core material,how deep do you keep it and where is the limits of your cores for Advance and LSA? Is there a diff in Hyd and Solid cores? are they ground down from a 60mm and can you regrind your cams again after being used?
Why not make a components specific lobes for the public?
Do you vary the actual lobe LSA between cyllenders/Ports like split LSA with Intake design and bad cyllenders with Cam twist for P to V on a real race motor?
With the .006 to .050 difference number is there a way to set up preaload correctly to use the lobe accell/velocity better as the lifter bleeds down with oil pressure?
What about the .050 to .200 ect.. numbers is there a specific travel by Degree you look for in all lobe designs? Is constant velocity bad?
What about your hardening and core material,how deep do you keep it and where is the limits of your cores for Advance and LSA? Is there a diff in Hyd and Solid cores? are they ground down from a 60mm and can you regrind your cams again after being used?
#77
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#79
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#80
TECH Senior Member