GM Rocker Arm Material
#2
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you are going to be looking at a high strength low alloy steel most likely one of these alloys: 4140, 4340, 52100, 6150, 8620 and probably heat treated to increase hardness and tensile strength.
If you want to know the actual temper you can do a hardness test and derive the tensile strength to give you a better idea. and if you cant find it on google sent it to a material lab, pay 200 bucks and get a spectum analysis of the rocker make up and they can tell you.
If you want to know the actual temper you can do a hardness test and derive the tensile strength to give you a better idea. and if you cant find it on google sent it to a material lab, pay 200 bucks and get a spectum analysis of the rocker make up and they can tell you.
#3
The OEM rocker arms seem to be pretty strong. I don't recall hearing of any OEM rocker arms failing ... has anyone else seen or heard of them failing? I'm talking about the rocker arm itself, and not the OEM bearings which are known to fail.
OEM rocker arms with the Comp Cams Trunnion/Bearing Upgrade Kit seem to be pretty bullet-proof.
OEM rocker arms with the Comp Cams Trunnion/Bearing Upgrade Kit seem to be pretty bullet-proof.
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#8
I'm looking for the actual grade of material. I know I can send it off to be analyzed but I'm looking for a more affordable option. I did read somewhere that they're investment cast but that just explains how they're made. I hope someone has some info because I could not find it.
#9
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I'm looking for the actual grade of material. I know I can send it off to be analyzed but I'm looking for a more affordable option. I did read somewhere that they're investment cast but that just explains how they're made. I hope someone has some info because I could not find it.
Last edited by SweetS10V8; 12-14-2011 at 08:57 AM.
#11
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Florida.......Scorpion/Crane????
You cant beat a set of stock rockers with a trunion upgrade in most cases! As we all know the stockers are a fairly good design.
#13
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Are you going to machine these or are you going to cast them? If you are going to machine them go with bar stock high strength low alloy carbon steel. Heat treat it to 180ksi-190ksi and you are good to go. If you are going to make 1-5 sets it will be way cheaper just to machine it. There is still a couble $k in NRE for a casting shop just to set up a mold. Sometimes if you have access to a good 3d printer you may be able to get some of the cost out of it depending on the material you use.
and check this out for a start on an FEA. www.rpi.edu/~des/Rocker_Report.pdf
PS
I can help you design these if you are looking to really make a set...i to have resources. Engineering, CAD/CAM, machining, and lots of fab vendors on a speed dial.
and check this out for a start on an FEA. www.rpi.edu/~des/Rocker_Report.pdf
PS
I can help you design these if you are looking to really make a set...i to have resources. Engineering, CAD/CAM, machining, and lots of fab vendors on a speed dial.
#14
Thanks for the offer GNIUS but that's what I do for a living. I had hoped for some info but I can get it from the parts themselves. I'm not trying to make a career out of I just see a shortcoming. The biggest hurdle for me is time to do it. I would machine them as the tooling investment is too large for me.
#19
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well, the springs were specifically built for the "ls" engine, so i figured there would be no problem, my cam is specd at .600 at the valve, and the pushrods are specd to the cam.
no pushrods were bent, but when the rockers broke, they were pushing down on the retainer part of the valvespring hardware, this may have save the pushrods from bending.
the springs i WAS using were rated at 505lbs springs pressure...ive since then downgraded to some pac-1518 springs and havent had a problem in just over 100 miles since the install.
no pushrods were bent, but when the rockers broke, they were pushing down on the retainer part of the valvespring hardware, this may have save the pushrods from bending.
the springs i WAS using were rated at 505lbs springs pressure...ive since then downgraded to some pac-1518 springs and havent had a problem in just over 100 miles since the install.
#20
You still using OEM rockers (with Comp Cams Kit?) with the PAC-1518 springs? Yeah, 505 lb springs seem pretty stiff.