(reground) cam went flat?
 

Pete's comment about wiping a cam lobe sent a shiver up my spine - as I'm considering a regrind next year...

What I know about metallurgy you could stick in a thimble and it would still rattle around. So, it occurred to me that when a cam is reground, certainly the case hardening is removed and the surface hardening has to be redone or the opportunity to wipe a lobe comes to mind.

Well, Comp Cams provides an additive to replace the "good stuff" (zinc, etc) left out of today's oils - I buy it over the counter at "Winner's Circle" in Joliet. Having just replaced a "wiped" cam in my wife's 69 Vette I rather think it might be a good idea to start putting it in the Z, in addition to the AMO 10W-40 recommended by Marc, especially if running a reground cam to the rpm Pete does.

All that said, I'm reminded too of the advantages some claim by using tungsten disulphide (WS2) coatings on some parts. (More research in indicated, methinks.)

But, I leave the discussion of lubrication to the experts, except to say I don't see how adding the additive would hoit!

What say U?

P.

Re: (reground) cam went flat?
 

Hmmmmm.....never had any problems with the Crower re-grounds.....wierd!?!?;)

Re: (reground) cam went flat?
 

i wonder who pete had do his reground cams ? what can one do to assure that a reground cam lives a long and uneventfull life ? is there a coating that would help here .?

Re: (reground) cam went flat?
 

Pete's comment about wiping a cam lobe sent a shiver up my spine - as I'm considering a regrind next year...

What I know about metallurgy you could stick in a thimble and it would still rattle around. So, it occurred to me that when a cam is reground, certainly the case hardening is removed and the surface hardening has to be redone or the opportunity to wipe a lobe comes to mind.





A few years I took A bad cam cause I was looking to regrind A set.I removed .010 to .15 off the every lobe even with about .100 removed the cam still rockwell 45c scale.So it's safe to say that it's not the regrinding of the camshafts.
As soon as my 441 is done which looks mighty sweet I should add.My regrinds are going in,along with alot of ZDDP.

AL.

Re: (reground) cam went flat?
 

What size regrinds are you putting in the 441 Al ? :mrgreen::mrgreen:

Re: (reground) cam went flat?
 

239/440 intakes for now
224/430 exhaust

maybe in about A year i'll move to some big cams like yours Frank.



AL.

Re: (reground) cam went flat?
 

I had a stock lifter tested, and it showed 62, if I remember correctly. The key, as explained to me, is the depth of the hardening in the cams. I had a scrapped Jeal 470 billet cam that I sent off for testing. At the surface, it was compatible with the 62 of the lifters, however the hardness layer was exceptionally thin and the base metal was quite a bit softer. Any piece of metallic debris would break right through the surface layer and wipe out the lobe. At least that's how it was explained to me.

Re: (reground) cam went flat?
 

WTF.

Paul why did your wifes cam wipe out?

Now for all the smart guys out there that know it all.

Answer me this.

The last time i had my motor apart about 2 months ago i put 4 brand new GM lifters in the right side intake.(the side went bad)

Why only the new lifters went bad but my old 65k mile lifters are still good and i will be reusing them.

I've had my intake cams for over 2 years with no issues till lifter change.

Reason for changing lifters had a nosey one i had to hold 2k rpm for it to load up.

Two of the new lifters have started to show cracks the cam lobes look fine so basicly took out 3 out of 4 new lifters.

So please all you smart guys answer me the above question why they held up for 2 years but as soon as i put new lifters it breaks??


:happy1:
Pete

Re: (reground) cam went flat?
 

I have a broken cam in 1992 ZR1, does anyone know of a custom cam grinder that has billets for custom grinding.

Jerry

Re: (reground) cam went flat?
 

Todd stock cams measure 55 to 56 rockwell and lifters measure anywhere
from 62 to 65 rockwell the difference being if you measuring on the outside
of the lifter or the inside of the lifter respectively.
If the cam was as hard as the lifter I think it would not last that long.That's why when you have billet cams made which measure around 62 rockwell the lifters need to be DLC'D (Diamond like coating) to make the
surface even harder.So the hardness of the cams and the lifter need to be
dissimiliar in order to work without failures,That's the idea is what was told to me.


AL.

Re: (reground) cam went flat?
 

DLC stand's for 'Diamond like Carbon'. Trade name is Casidium.

Re: (reground) cam went flat?
 

Thanks for clearing that up.


AL.

Re: (reground) cam went flat?
 

My cams suck Al !
I .468 L 246 D
E .444 L 239 D

Don't need cams that big in a 4 valve per cyl. engine.

Your good Ryan, I can't even pronounce Casidium.

Re: (reground) cam went flat?
 

Hey...wow, my wrist pins are coated with that crazy casidium stuff.....wierd!:dontknow:;)

Re: (reground) cam went flat?
 

I'm still waiting for an answer

:happy1:

Frank why do you say your cams suck.
What's the problem.

My opinion your exhaust cams are too big.

I think you'll make more power with .228-.230 exhaust duration.

Pete
"Broken lifter Guy" :razz:

Re: (reground) cam went flat?
 

Pete,

Do you recall the worst oil tested in that article Marc wrote for "HOTB" about oil for our Zs a year ago? Well, guess what we were runnin' in Ami's flat tappet SBC? Yep!!

Ami had put over 3500 miles on that car since she bought it, and who knows how many miles were on that cam. So, when if wiped, "WTF!?" was my exact reaction too!

Making a long story short, I'm running Rotella in it now with a bottle of "the good stuff" from Crane to make sure the cam has what it needs to keep from wiping (again).

Question: Are you putting that additive you mentioned in your Z along with the AMO 10W-40 recommended by Marc, or have you been using some other oil?

TIA,

P.

PS. Flatout has our gaskets ready. I'll bring 'em w/ me to pizza nite on Friday.;)

P.

Re: (reground) cam went flat?
 

They must be good pins then, Destroyer. All my Titanium pins i have made are coated. on those...they have steel wear 'end caps', the steel end caps aren't coated, just the main part of the pin itself. i can post pics if anybody is interested. not trying to sidetrack this thread:blahblah:

Re: (reground) cam went flat?
 

Stange how only one side got wiped out, have no explanation for that??? Dont kinow why that would happen.
Id be curious to what spring rates are anyway.

Re: (reground) cam went flat?
 

There is no need for cams that big , especially in a 4 valve per cyl engine.
My opinion FWIW.

Marc did a super job on that engine. Those are MY cams.... That I wanted him to install , and they :thumbsdo:
I would have been much happier with smaller cams.

100 % correct Pete more power and better drivability :thumbsup::thumbsup:
I'd bet the car on the above statement.
--------------------------------------------------------------------------

Back on thread........if done PROPERLY a regrind cam is fine.

Re: (reground) cam went flat?
 

Just proves out the old adage even with DOHC motors.
Better small cam with big heads than vice versa. I have an excellent article on cam selection discussing the really critical parameters for deciding on cam specs. There was also a software application that calculated those parameters for you based on primarily low lift air flow. I used it to spec a cam for my 350 SBC using TFS23d heads. I'll try posting the article when I get to my laptop.

Re: (reground) cam went flat?
 

stk spring pressures are76-84 closed and 194-206 open .just another reason our engines rev fast . alot easier controlling 4 small valves than 2 big sobs

Re: (reground) cam went flat?
 

They were pricey, but weren't as bad as the million dollar rings I had to run with the pistons. It's amazing how much a guy can spend on just setting up some pistons! We just went to Pattersons shop in Kansas a few weeks back to pick up a few parts(lol) and wow......splayed valve and sb2 drag race heaven there!:worship:

Re: (reground) cam went flat?
 

:blahblah:Sorry for the thread highjack, but I think ryan will appreciate this pic of n20 junkies latest all motor addiction! I'll try to get some video of this little chevy 2 testing in late march.....should be fun!:dancing
http://i42.photobucket.com/albums/e3...E/DSC00915.jpg

Re: (reground) cam went flat?
 

Patterson's are definatly on the leading edge of SB-2/SB-2.2 stuff. engine pic looks good, MBE intake...good guys.

Re: (reground) cam went flat?
 

Yep....should fly for sure! MBE also updated his heads.....I'll let ya know what she runs this year!

Re: (reground) cam went flat?
 

Hi Paul,

I'm just tossing this out on the wipped sbc C3 cam in your lady's car. If I remember the time correctly, back in 03 to 05 Comp Cams had some trouble with getting bad blanks. The had a bunch of High Energy cams wipe lobes.

jafwiw:o

:cheers:

Re: (reground) cam went flat?
 

Paul and Domonic are suspended from coming to my garage 1 year.

What you see in my garage stays in my garage.

No Gararge for you 1 year.:razz:

Pete

Garage...GARAGE???
 

WHAT GARAGE? I thought it was the Lockheed "Skunkworks" shop, or mebby a satellite of "Area 51" or something! :rolleyes::mrgreen:

P.

Comp Cams
 

Interesting... However, the maker of the cam that wiped is unknown - Ami bought it in 04, and the engine had been rebuilt at least once at that time, so who knows?? But, the curious thing is, the damn thing ran for 4 summers for a total of about 3500 miles. So, it isn't like it was infant mortality, I wouldn't think. Ah...Who knows. (Did GM supply the cam blanks to Crane?? :rolleyes:)

The new cam has been run in and little else, as we're now having a fuel pressure issue (did I mention the fire?), which was on my "todo" list, until one day suddenly WINTER arrived with a vengeance and hasn't let go in almost 2 months.

More on that later.

P.

Re: (reground) cam went flat?
 

Attachment 446
Click :
http://www.youtube.com/watch?v=kNwbjcuQUv8#

Re: (reground) cam went flat?
 

FU,

You mean CAM NAZI! :sign10::sign10::sign10:

Pete,

OK, OK. I'll buy you pizza Friday.

Re: (reground) cam went flat?
 

Dom...

I think we just got sent to Ban Camp...by none other than the Ban Camp King hisself!:sign10:

P.

Re: (reground) cam went flat?
 

NNOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!

:sign10::sign10:

Re: (reground) cam went flat?
 

Never seen a flow sheet on the LT5 heads before only heard one rough figure before. At some point this year Ill be making a fixture for one and flowing a stock one just to see, maybe some work will follow, see how things go.

Re: (reground) cam went flat?
 

There is a difference between the 90-92 lifters and the 93+. Do not remember exactly what but I think the new ones are slightly higher and to use them in an earlier engine Geoff cut the valves down .001. You can use the older lifters in a later engine but using the later in a earlier engine may cause sealing problems.

Tyler

PS Acording to what I know about spring pressures the LT 5 should be ok without the additive. If you use Red Line it still has the older additive package.

Re: (reground) cam went flat?
 

Lifters are the same, the valve length is longer in the 93+ motors.

Re: (reground) cam went flat?
 

:iamwithst

Re: (reground) cam went flat?
 

Really? Good to know. Wouldja happen to know the API rating?? Rotella T has the good stuff in it as well, but it is actually a Diesel motor oil, and has (I'm told) more detergent in it - perhaps more than necessary to be used in a gas engine, as a rule. Having said that, Comp Cams listed the Rotella as one of the oils recommended as a break-in lube for a new flat tappet cam (along with their break-in additive).

Dayam! I'm not a chemist, and lubrication is a complicated topic. Make a mistake, and it becomes $$$ very quickly! It is hard to pick out the truth from all the hype the oil companies use without a good understanding of the chemistry involved. So, for now I'll go with Marc's recommendation for the Z (AMO 10W-40). The science he used to make that determination makes far more sense that trying to sift thru the oil BS w/o the right tools to assess the distinctions between them. I don't know 'bout you, but of all the products I buy, I'm hard pressed to think of any product that is surrounded with more advertising hype and pure BS than automotive oils...:mad:

Whatever oil Marc H. says to use, is good as gold for me.

P.

Re: (reground) cam went flat?
 

http://www.joegibbsracingoil.com/


^^^:dancingGoooood stuff! I gave the rest of my grape juice to my neighbor.

Re: (reground) cam went flat?
 

I don't know if i mentioned it on here before or not, but i went to a seminar last Sept. put on by Joe Gibbs Driven oil & hosted by Lake Speed Jr. was very, very good. even before the seminar we were using J.G. BR/XP-4 (same thing). only thing we could get some flat tappet stuff to live on, during break in. helps not only cams but ring seal a bunch too. i'm not getting into great detail...don't have time, sorry. quickly...as for API ratings & whatnot, since Joe Gibbs oil is not on the retail market, (never will be acording to them), Wal-Mart etc. they don't have to adhere to government standards (for emisions, detergents etc.) so they can build the oil how they want too. as for Rottella T. yes it's diesel oil but what it has is more Zinc & Moly, that's the key to that stuff. the government ratings for diesel oil changed a few years ago & i think it's set to change again in 2010, getting worse each time. by the next change, 2010, there won't be really any benifits to using it any more:dontknow:. could go on & on & on...gotta go. hope this helps some of you...a little.