New cam install... difficult to turn

New cam install... difficult to turn - 03/17/12 07:42 AM

Got almost everything to finish off my 440 build, one of these things being the cam. I got a custom grind from compcams that has been nitrided, specs are similar to the XE285HL. I cleaned off the cam and painted it with that heavy comp assembly lube and installed it into the block. The cam itselfs slid in with relative ease.

Now I'm ready to degree the cam and it seem tough to get it to begin spinning. Once you've got it moving it doesn't feel bad at all. Should I be worried that something is messed up? I had the machine shop install the new cam bearings for me since I didn't have the tool for it.

Posted By: DaytonaTurbo

Re: New cam install... difficult to turn - 03/17/12 08:20 AM

I would be concerned they didn't hone the cam bearings to size. I know what some guys on here said they've done is taken a stock cam, cut grooves in the cam bearing journals and spin it around a few times to true up the cam bearing install job. If you lubed up the cam journals with oil(not lifter lobe paste), it should not be hard to get spinning when there's no load on it from rockers, valve springs, etc.

Posted By: BEINGmeISaCRIME

Re: New cam install... difficult to turn - 03/17/12 08:27 AM

Used that super heavy assembly lube from comp on the lobes and cam bearing surface. Maybe I should take it back out, and use oil instead?

Posted By: BEINGmeISaCRIME

Re: New cam install... difficult to turn - 03/17/12 08:47 AM

Welp I messed up, plain and simple. Got too excited I'd reckon.

Taken from comps installation instructions

Quote:

Step 5: Remove your new COMP Cams� camshaft from its packaging. Inspect all lobes and the
distributor gear, making sure the camshaft was not damaged in shipment. Next, compare the stamped
numbers on the end of the cam with the spec card to make sure this is the correct cam. It is a good idea
at this point to lightly wire brush the distributor gear with mineral spirits or an equivalent solvent.
Remember, during the installation process, the cleaner you keep your new components, the better
chance you have of avoiding failure. Using COMP Cams� Assembly Lube (part #103) supplied with
your cam, coat all lobes and distributor gear. It is important to coat the lobes completely, yet not
excessively. This same rule applies to the distributor gear and fuel pump lobe. Coat the cam bearing
journals with conventional SAE 30 or 40 wt. oil. Note: We do not recommend the use of synthetic
oils with our cam and lifter packages during break-in.

Posted By: DaytonaTurbo

Re: New cam install... difficult to turn - 03/17/12 09:23 AM

Well there you go. Pull it, clean it and relube it. I have a quart of non-detergent 30w oil on the shelf just for lubing stuff up.

Posted By: Clanton

Re: New cam install... difficult to turn - 03/17/12 02:42 PM

when you pull the cam you can look for signs of a tight fit on the cam and bearings.

Posted By: jamesc

Re: New cam install... difficult to turn - 03/17/12 11:49 PM

Quote:

I would be concerned they didn't hone the cam bearings to size.

i would be concerned if they did. these bearings are not meant to be honed. camshaft bore accuracy is a very common problem with BB mopars. in my experience it's unusual to NOT have to scrape bearings to correct a tight cam. normally i will install the bearings one at a time after the first two checking cam fitment after each one. if there is binding it will leave a shiny mark at the high spot that can be scraped with a bearing scraper or by carefully dragging a new razor blade backwards across it. as mentioned only oil is really necessary for installation as the engine should be primed before starting anyhow.

Posted By: RBSat66

Re: New cam install... difficult to turn - 03/18/12 01:45 AM

Is the cam difficult to turn by itself or have you put the timing chain on and are trying to turn it with the complete rotating assembly?

Posted By: BEINGmeISaCRIME

Re: New cam install... difficult to turn - 03/18/12 07:19 AM

Difficult to turn without being attached to the timing chain. I cleaned it all off today and just used 10w 30 oil and it helped but not very much. I'm gonna take the whole thing into the machine shop I go to on Monday and have them take a look at it.

Posted By: Kern Dog

Re: New cam install... difficult to turn - 03/18/12 07:36 AM

The 493 in my Charger had a similar problem.
My machinist said that there were some Chrysler Big Blocks that had improperly machined cam bearing journals. Some came through the factory slightly undersized. ONE fix was to reduce the outside diameter of the cam bearing with sandpaper or Emery cloth, then press it into place. Mine was a little different. The journal had a ridge at one end which pinched the edge of the bearing. He had to file the ridge off and clean the block again. Afterwards, standard bearings fit correctly.

Posted By: MLR426

Re: New cam install... difficult to turn - 03/19/12 07:30 PM

I have ran into several blocks that you can't install the cam due to block stress relieving after welding on it or shot peening etc. I have them set up in a rottler cnc and line bored and install .010 over Durabond cam bearings. I understand the whole scraping thing but thats just a bandaid fix and excessive scraping can lead to other issues.

logan426