cam/lifter rockwell ?

rod · 10-26-2012, 09:12 PM

my friend just finished a 496 BBC. had a solid lifter cam. not long after break-in a lobe failure occurred. he had the cam nitrided, so it would last a long time. there is a tech college near him and he had the cam and a lifter checked for hardness. the lifter came in about 54 RC and the cam between 34 and 39.
what we do not know is 1. what is a normal figure for these two pieces, and 2. should the cam be the same hardness as the lifter.

any thoughts will be appreciated.

thanks rod in AZ

Terry Cain · 10-26-2012, 11:22 PM

That sounds about right for lifters but, kinda soft for cam. How much spring pressure, open and seat? High Zinc oil correct? I'm guessing roller rockers?

Marty Buth · 10-28-2012, 12:33 PM

Nitriding usually yields a hardness that you can't dig into with a 62 rockwell C file.

Alan Roehrich · 10-28-2012, 01:38 PM

Where on the cam did they perform the Rockwell test?

Terry Cain · 10-28-2012, 06:27 PM

One more question. Is it a Crane cam?

rod · 10-31-2012, 05:06 PM

I assume the test was on the actual lobes, more than that i was not told. the brake-in was with the single outer spring. [dual spring pressure was in the area of 150 seat. personally i would have used a lower pressure for the brake-in, because the springs had to come off any but.....]
yes roller rockers and it was a lunati [sp] solid lifter.
anyway the cam tested low on the rockwell. so Andy is really ticked off.
thanks for the help.
rod in AZ

Marine One · 11-04-2012, 05:09 PM

Should the cam and lifter be the same? No - never. If you want to see two metals eat each other up (cam to lifter, bearing to race, etc) just make them the same hardness. One of the two has to be a little softer.

Keep in mind that abrasive wear is the fastest growing type of wear you will see. Ever have a bearing go out in a rear end? It starts with a low growl, then just keeps getting louder and louder until it sounds like someone is running a bench grinder. That is a good example of abrasive wear. Once it starts, there is no reversing it. It just keeps getting worse and worse.

Jeff Lee · 11-04-2012, 10:32 PM

MACH Development in Maricopa, AZ has a coating they apply to the cam & lifters that requires no cam / lifter break-in and you can start the engine first time with upwards of 520# spring pressure and let it idle if you want. I believe it's $150 total but contact them and find out for yourself.

10-26-2012, 09:12 PM	#1
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 315 Likes: 0 Liked 20 Times in 15 Posts	cam/lifter rockwell ? my friend just finished a 496 BBC. had a solid lifter cam. not long after break-in a lobe failure occurred. he had the cam nitrided, so it would last a long time. there is a tech college near him and he had the cam and a lifter checked for hardness. the lifter came in about 54 RC and the cam between 34 and 39. what we do not know is 1. what is a normal figure for these two pieces, and 2. should the cam be the same hardness as the lifter. any thoughts will be appreciated. thanks rod in AZ

10-26-2012, 11:22 PM	#2
Terry Cain Senior Member Join Date: Feb 2008 Location: Georgetown, Indiana (close to Louisville, KY) Posts: 776 Likes: 530 Liked 230 Times in 106 Posts	Re: cam/lifter rockwell ? That sounds about right for lifters but, kinda soft for cam. How much spring pressure, open and seat? High Zinc oil correct? I'm guessing roller rockers? __________________ Terry Cain ???? STK tcain19689585@gmail.com

10-28-2012, 12:33 PM	#3
Marty Buth Member Join Date: Nov 2002 Location: Freeport, IL Posts: 467 Likes: 653 Liked 232 Times in 39 Posts	Re: cam/lifter rockwell ? Nitriding usually yields a hardness that you can't dig into with a 62 rockwell C file. __________________ Marty Buth 3657 STK

10-28-2012, 01:38 PM	#4
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,113 Likes: 1,571 Liked 1,821 Times in 413 Posts	Re: cam/lifter rockwell ? Where on the cam did they perform the Rockwell test? __________________ Alan Roehrich 212A G/S

10-28-2012, 06:27 PM	#5
Terry Cain Senior Member Join Date: Feb 2008 Location: Georgetown, Indiana (close to Louisville, KY) Posts: 776 Likes: 530 Liked 230 Times in 106 Posts	Re: cam/lifter rockwell ? One more question. Is it a Crane cam? __________________ Terry Cain ???? STK tcain19689585@gmail.com

10-31-2012, 05:06 PM	#6
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 315 Likes: 0 Liked 20 Times in 15 Posts	Re: cam/lifter rockwell ? I assume the test was on the actual lobes, more than that i was not told. the brake-in was with the single outer spring. [dual spring pressure was in the area of 150 seat. personally i would have used a lower pressure for the brake-in, because the springs had to come off any but.....] yes roller rockers and it was a lunati [sp] solid lifter. anyway the cam tested low on the rockwell. so Andy is really ticked off. thanks for the help. rod in AZ

11-04-2012, 05:09 PM	#7
Marine One Junior Member Join Date: Mar 2010 Location: Indiana Posts: 69 Likes: 2 Liked 0 Times in 0 Posts	Re: cam/lifter rockwell ? Should the cam and lifter be the same? No - never. If you want to see two metals eat each other up (cam to lifter, bearing to race, etc) just make them the same hardness. One of the two has to be a little softer. Keep in mind that abrasive wear is the fastest growing type of wear you will see. Ever have a bearing go out in a rear end? It starts with a low growl, then just keeps getting louder and louder until it sounds like someone is running a bench grinder. That is a good example of abrasive wear. Once it starts, there is no reversing it. It just keeps getting worse and worse. __________________ Chad Sheets \| STK 319 \| 10.69 \| 1.39

11-04-2012, 10:32 PM	#8
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: cam/lifter rockwell ? MACH Development in Maricopa, AZ has a coating they apply to the cam & lifters that requires no cam / lifter break-in and you can start the engine first time with upwards of 520# spring pressure and let it idle if you want. I believe it's $150 total but contact them and find out for yourself. __________________ Jeff Lee 7494 D/S '70 AMX