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Camshafts

ssjkakkarotx

NAXJA Forum User
Why do some cams have a polished finish on the lobes where as others have more of a dark matte finish?? I was noticing that on my cam today. Most of the cams I have installed have the nice high polish crome look , but my XJ's cam (Comp 68 232 4) has the dark finish or coating. Why is that?????
 
jeepster09 said:
If you are talking about a new cam, it is coated/impregnated with a lubricant to aid in breakin. After they are run they all should look shiney.

Yep. You should've been given instruction on how to clean the shaft before installing it. That black matte finish is a protective coat to keep it from rusting while sitting around waiting to be installed.
I know comp cams have the finish but also come with cleaning instructions. I have one at home and I'll read the instructions and post them here if you'd like.
 
The black coating on the cam is from Parkerizing....the function of the material is to aid in break-in of the cam and lifters...the parkerizing wears off as the cam breaks in. In NO CASE should the coating be removed. The "shiny" cams are generally for roller lifters in which there is no sliding friction. Make sure your valves are set to the proper install height, make sure you are not getting coil bind, or retainer interference. Get and use a new bronze distributor drive gear and use a STOCK OIL PUMP.

:lecture: It is important to follow the installation instructions provided by the manufacturer TO THE LETTER or your new cam is doomed. Proper prelube and break-in will insure long life....DO NOT use synthetic oil in an engine with a high performance cam....Use Shell Rotella oil with a can of GM E.O.S. (engine oil supplement) available at any GM dealership. New EOS should be used at EVERY oil change.

The problem is modern oils (due to the "treehugger effect") lack the required metallic antiwear compounds needs to properly lubricate a flat tappet cam and lifters.
 
I just pulled the intallation instructions for my Crane camshaft and it says to completely clean the cam of the protective black coating with a strong solvent then apply a thin coat of supplied break in grease.

I guess each cam manufacturer is different.
 
MudDawg said:
Proper prelube and break-in will insure long life....DO NOT use synthetic oil in an engine with a high performance cam....
Don't use synthetic? Just for break in or never use it at all?
Why do you say this, I have seen lots of high performance engines running synthetic oils.
 
Call tech services for Crane or Comp cams about the oil problems they will tell you exactly what I did....as for cleaning off the coating on a new cam....they mean to CLEAN the surfaces to remove the cosmoline or whatever they put on to prevent rust....NOT remove the Parkerized finish.

Regular oils work fine in engines with ROLLER lifters, or Ricer motors that run with light spring pressures because of the weenie little lightweight valvetrain components.

I know of three 4.0 motors that lost cam lobes when the oil was changed from mineral to synthetic....they all had enough miles to be well beyond normal break-in.....the oils simply do not have the aadditive package to stand up to flat tappet pushrod motors....

Read the Sig.
 
:dunce:
MudDawg said:
Call tech services for Crane or Comp cams about the oil problems they will tell you exactly what I did....as for cleaning off the coating on a new cam....they mean to CLEAN the surfaces to remove the cosmoline or whatever they put on to prevent rust....NOT remove the Parkerized finish.

Regular oils work fine in engines with ROLLER lifters, or Ricer motors that run with light spring pressures because of the weenie little lightweight valvetrain components.

I know of three 4.0 motors that lost cam lobes when the oil was changed from mineral to synthetic....they all had enough miles to be well beyond normal break-in.....the oils simply do not have the aadditive package to stand up to flat tappet pushrod motors....

Read the Sig.




I've got 3 4.0s and one Golen stroker. All the stock motors are well past 200k and have been on synthetics since break-in. What kind of problem can a higher performance oil cause? Ok, I'll grant you that they all 3 leak a little at the rear main seal, is that unusual for a Jeep?:looney:
 
MudDawg said:
Call tech services for Crane or Comp cams about the oil problems they will tell you exactly what I did....as for cleaning off the coating on a new cam....they mean to CLEAN the surfaces to remove the cosmoline or whatever they put on to prevent rust....NOT remove the Parkerized finish.

Regular oils work fine in engines with ROLLER lifters, or Ricer motors that run with light spring pressures because of the weenie little lightweight valvetrain components.

I know of three 4.0 motors that lost cam lobes when the oil was changed from mineral to synthetic....they all had enough miles to be well beyond normal break-in.....the oils simply do not have the aadditive package to stand up to flat tappet pushrod motors....

Read the Sig.

Yah - guys like us have a hard time finding oil for "real" vehicles, since they're all being formulated for all the "weenie" lightweight vehicles out there.

Case in point - the decrease in zinc dithiophosphate (ZDP) anti-wear additive in the latest Sx revision. ZDP is an anti-scuff/anti-wear additive that has been used for years. It's not toxic (as I recall...) the main thing is that it adds to the cost of production. Since most vehicles are coming out with rollerised valvetrains and light spring pressures, ZDP isn't as necessary for newer engines as for older ones.

Workaround? Shell Rotella is good stuff, also make sure that your engine oil carries a Diesel rating (Sx/Cx rating - "S" for "Spark Ignition" and "C" for "compression ignition") rather than an Sx rating only - and don't get any oil that sez "energy saving" or whatever they're calling it this week - it's got reduced or eliminated ZDP, and will accelerate cam wear.

Gear oil is another case - they're not using bronze synchronisers much anymore (Gawd, I miss that.) So, API GL-5 gear oil doesn't have as much attention paid to removing sulphur (naturally occurring) from the base oil. Sulphur is not nice to bronze - Hell, it's not good for any copper alloys. Sulphur attacks the bronze and makes it weak, which can cause your synchroniser rings to disintegrate.

GL-3 doesn't have as much sulphur, and is preferred for the AX-15 and older gearboxes (and well-stocked parts houses will still carry it.) GL-4 can be used in a pinch, but GL-5 should be avoided entirely.

Yeah, I'm old too. It's amazing what you can learn in 30 years of swingin' wrenches...

5-90
 
The stock motors run stock valvesprings...and the older the motor gets, the lighter the spring pressure gets....and the parts are well worn together to begin with...Most cam failures are directly related to improper installation and/or improper break-in.....but lately there have been a lot of failures that are due to the oil.

I run Mobil 1 in my dragbike with no problems, but the valvetrain is maybe 1/5th the weight of the valvetrain in a 4.0....the spring pressures are lighter and the contact patch between cam bucket and cam lobe is far larger to spread the load....plus the buckets run immersed in oil...

I am just trying to help others prevent problems....when the Comp cam tech guys say to use Shell Rotella oil AND GM EOS....something is up.
 
I can see a little of what you are saying. It was rebuilding motorcycles that switched me to Mobil 1 in the first place. NO sludge build up even in air cooled dirbtbike motors (HOT!!). I'll grant that Rotella is an excellent oil, but I am happy with M-1 (I don't break in with it) and cannot find a compelling reason to switch.
 
There's an actual warning on my Crane Cam installation sheet that says most damage to cams from improper break-in is in the first few minutes.

Double check all break-in intructions and follow them to a "T." Last thing you want is to fry your new cam and lifters.
 
pabloconrad said:
There's an actual warning on my Crane Cam installation sheet that says most damage to cams from improper break-in is in the first few minutes.

Double check all break-in intructions and follow them to a "T." Last thing you want is to fry your new cam and lifters.

Yep - and DO NOT BE STINGY with the assembly lube! "Too much is almost enough," you can't use too much of the stuff. (OK, six quarts of it is getting silly, but when I assemble an engine, I apply it liberally to bearings, cam lobes, and lifter feet - usually uses up one small bottle - and then I just dump another one in the engine oil.)

5-90
 
5-90 said:
Yep - and DO NOT BE STINGY with the assembly lube! "Too much is almost enough," you can't use too much of the stuff. (OK, six quarts of it is getting silly, but when I assemble an engine, I apply it liberally to bearings, cam lobes, and lifter feet - usually uses up one small bottle - and then I just dump another one in the engine oil.)

5-90

What assembly lube would you recommend. I have some red stuff in a bottle (can't find it to give you the name). All I know is it's sticky.
 
pabloconrad said:
What assembly lube would you recommend. I have some red stuff in a bottle (can't find it to give you the name). All I know is it's sticky.

Most times, I've use Permatex Engine Assembly Lubricant - it's what I can find locally that's worth a damn. I don't trust anything with a brand name I don't recognise - I usually use Permatex, but I think Amsoil and Redline both make good assembly lubes as well.

I don't use anything by Pennzoil, unless I have a need to make candles...

Yes, it's sticky - that's what prevents "dry starting" the first time. It's also oil-soluble, which means that is dissolves in oil after a few minutes anyhow. I've also used it as an "anti-wear" additive for some engines, it serves well (you can also use LSD Friction Modifier as an "anti-wear" additive in axles, transmissions, and transfer cases that take gear oil - I've done that to slow down and extend the break-in process in some cases (this has some benefits for high-endurance applications - it's less stress on the hardware, which allows it to last longer and normalise better from initial stresses. It's yet another trick I learned from a Cessna A&P yonks ago...)

5-90
 
Not to jump on someone elses post, but I just put a crane cam in my 4.0. I didnt know there was a specific way to break in the cam. I thought u just didnt drive like an a##$% for about a 1000 miles. I ran some 10-40 in it for about 30 miles right after and changed it, then put in some 10-30 mobil high mileage (not synthetic) and a teflon additive my work sells. Am I doing something wrong?? Thanks for any help with this guys.
 
play_in_the_mud said:
Not to jump on someone elses post

No problem. That's what these forums are for: to learn and teach.

play_in_the_mud said:
I just put a crane cam in my 4.0. I didnt know there was a specific way to break in the cam. I thought u just didnt drive like an a##$% for about a 1000 miles. I ran some 10-40 in it for about 30 miles right after and changed it, then put in some 10-30 mobil high mileage (not synthetic) and a teflon additive my work sells. Am I doing something wrong?? Thanks for any help with this guys.

Hopefully, your cam isn't wearing down. Dou you know if you have lifter noise? Or any unknow vibrations?
 
Here is Crane cams advice
It seems that the only real concern about synthetic is "it’s too good!
They state is too slippery, just lubricates so dam good the lifters don’t have enough friction to spin on the cam lobes
Guess its time to go to a roller cam setup

"CAUTION: We do not recommend the use of synthetic
oils for “break-in” because they are too slippery. This
characteristic reduces the tendency of the lifter to rotate
on the camshaft lobe and mate properly."

http://www.cranecams.com/pdf/548e.pdf
 
Comanchedude said:
Here is Crane cams advice
It seems that the only real concern about synthetic is "it’s too good!
They state is too slippery, just lubricates so dam good the lifters don’t have enough friction to spin on the cam lobes
Guess its time to go to a roller cam setup

"CAUTION: We do not recommend the use of synthetic
oils for “break-in” because they are too slippery. This
characteristic reduces the tendency of the lifter to rotate
on the camshaft lobe and mate properly."

http://www.cranecams.com/pdf/548e.pdf

Correct - and not just for the cam!

Machining an engine, no matter how smooth you get the finish, involved making a massive number of microscopic "tears" in the metal. That's what "break-in" is - you're smoothing out those tears and burrs from the machining process.

That's why synthetics aren't any damn good for breaking in an engine - they're TOO slick, and the engine can't lap the parts against each other. I usually use 30-weight non-detergent engine oil for "first start" with one small bottle of assembly lube added to the oil change, and then run that for about five hours runtime. Change the oil and filter to 30ND again (but don't add anything this time) and run for a few more hours. Then, you can go to your normal oil.

Oh - and cut open and inspect the second filter - while you may see traces of metal in the media, if you see a lot, you're going to have to figure out what you did wrong... Don't bother with the first filter - you're going to find metal in the media there!

I'll have to dig up notes (and I did write it up in my book,) but the break-in procedure I use is actually for aircraft engines, taught to me by an A&P that worked on Cessna light aircraft out of Aretz field years ago. It's always worked well for me, and it's a bit better (and makes more sense...) than the usual automotive engine break-in procedure... I'll probably put it up on WiP in the Tech section once I get around to writing it up again...

5-90
 
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