Hello All,

I have been diligently looking for a cam core for a MEL that I want to build (can't get teh profile I need out of a re-grind), and I took what I thought was a longshot and called Chet Herbert tonight. Well, at first their cam grinder said that all I can do is a re-grind. However, after I talked with him more and showed that I wasn't just some idiot with an old car and a desire to go fast, he started listening and said that he might have a chome/moly camshaft core for one! He said that he would check for sure tommorrow, and that if he did, that I would just have to find some case hardened lifters. I agreed to call him tommorrow. . .

Now, I know that chrome and moly are two different substances, and that it is either chrome or moly, but nonetheless, I have never heard of such a cam. Is this a billit core? Also, what about these "case hardened lifters"? I guess I am showing my ignorance, but I need a little education here. . .

Also, if there are such things as "case hardened lifters", are there any made for an FE (the MEL and FE lifters will interchange)?

Thanks to any and all that respond,
Nathan

 

I know chrome-moly refers to a steel that has some chromium and molybdinum in it as far as alloying elements. It is a good higher strength steel. I don't know about wear capabilities for chrome-moly though. Case hardening refers to hardening a material to a certain depth. Axle shafts are case hardened. This allows them to remain "soft" in the center and have a hard outside, this prevents them from shattering if they were hardened thruogh. Case hardening may increase the wearability of the lifters. I'll be the first to admit I don't know much about cam shafts, but I have never heard of a chrome-moly one.

 

Chrome moly is generally 4130 or 4140 steel. It has well known material properties and is easily hardenable. It is a good material to use in high fatique applications because of its high strength and endurance limit. Typical cams are cast steel I think. It would be the same as comparing a standard cast crank to a billet crank. The billet being able to take high loads.

 

Here's a listing of common steel compositions, courtesy of a poster on the 385 forum. The 4000 series is actually a percentage of molybdenum, while 5000 numbers have a percentage of chromium. Both, plus nickel would be 8000 or both a letter suffix after the primary ID.

Any cast iron (steel) part is just that, molten iron poured into a mould and then machined to final size. A billet steel part is machined from a forged piece of steel; the forging process eleminates air bubbles and irregularities present in a casting process and offers far greater strength.

Those funny #s that designate steel like 4340,5140
UNS classification[unified numbering system]
steels are assigned a series of 4-5 numbers
the first # is the primary element[s]
the second # tells the percent of the first element[s]
the last #s indicate the amont of carbon content in hundreths of a %
1=plain carbon
2=nickel
3=chromium and nickel
4=molybdenum
5=chromium
6=chromium and vanadium
7=tungsten
8=nickel,chromium,molybdenum
9=silicon,maganese
say you have 5040,the first # shows the main alloying
element is chromium.the second #[i know seems confusing "0"]is gona be less than .5% so it gets rounded to 0 so its low chromium.if the % of chromium were .75% the first 2 #s would be 51
50xx=low chomium
51xx=med chomium
52xx=high chromium
the last 2-3 #s are the approximate carbon content of the steel in hundredths of 1 %
so 4340 would be
molybdenum,with approx. 3% molybdenum element and .40% of carbon
d=die steel.air hardening,high chome
h=hot work,chomium,tungsten,and/or molybdenum
t= tungsten alloy,high speed steel
m=molybdenum alloy,high speed steel
l=low alloy,special purpose
f=carbon-tungsten,special purpose
p=mild steel,low carbon,and other types
if anyone has anything to add have at it

 

The lines through the definitions appeared when the message posted.