Camshaft and camtower alignment

[yusef]

Hi all,

I'm installing a new cam and looking for some guidance on how good is good enough relative to camshaft alignment within the cam towers. Right now the cam rotates freely with TWO HANDS and moderate resistance. Ideally, this thing should probably rotate with zero or minimal resistance with TWO FINGERS. Question: am I chasing my tail?

As far as install procedure, I went about it very methodically, in that I did a star/symmetric pattern and when torquing the fasteners, and also did a gradual torque increase between passes. While doing the latter, I confirmed cam rotation throughout the torquing process. And yes, I used plenty of assembly lube, kept towers and fasteners/nuts with each tower as well.

Are there any other tried and true methods of ensure the optimal alignment?

Thanks,
Joseph

[redroadster]

A engine tech at my Datsun dealer had a system that worked
Coat the cam journals with 90 W lube and slowly tighten them turning the cam to check for tighten ing
If the head got warped it warps the cam stands , if it was milled over .005 then it warped tightening down
This was when new heads were $$$$ and he trying to get it running best possible
I do remember once helping this tech do this because his back was sore....I mostly did the procedure he checked
He would tap strongly on the cam with a big plastic hammer too. The car came back in 6k miles with a cam journal gaulded seized , oil dirty and kinda low... the trouble is they can move in final tightening or at high revs

[Gregs672000]

HI Joseph, im certainly no expert but I've installed several cams over the years. Were the towers removed or just the caps? Your method sounds good. I don't recall my cam turning easily with two fingers, but it shouldn't spin and then bind anywhere. You should be able to turn it one handed. If it were just the caps removed (numbered and returned to their same spot, right?), then I'd slowly loosen them up, noting which one(s) is/are the main culprit and see if you can improve it by slowly tightening while moving the cam back and forth, probably like what you did. If the towers were removed, you may have to play with that some. Though they are pinned it only takes a little movement to cause some slight misalignment. Start with the caps first and only mess with the towers if you have to. The only way I know to get this right is to keep playing with it, and it usually takes some time. Since the cam is different it will not have worn the same pattern as the old one. If you find a spot that is clearly binding after exhausting all adjustment it may be necessary to carefully polish the cap/tower with some emery cloth. Just be as methodical as you can... testing, loosening, wiggling, tightening etc and noting where the trouble is. Hope this helps...

Since you're replacing the cam, I assume you have new or resurfaced rockers (you must). If you went to a significantly different profile and/or the cam was reground, you may need some different lash caps. The way to check is to wipe something on the entire rocker arm pad (they used to use "bluing" but you can use a very thin coat of grease or a dry erase marker). Carefully install the rocker so you don't wipe off your marker, reduce the lash/adjust the valve (does not have to be adjusted to spec, just make it closer so the cam lobe will wipe it, if you slip a feeler gauge in there it will mess up your grease!), spin the cam, reduce the lash so you can remove the rocker arm and see if it's wiping more or less in the middle of the pad. Does not have to be PERFECT but it MUST not be wiping off one end or the other. If it's not where you want it (say, it's not wiping off the pad but it's pretty close) then you will need to obtain different lash caps (likely thicker) to move where it wipes. If you don't know what's been done to the head, then it would be a good idea to do this just in case, especially if you didn't check the old rockers for the wear pattern before or don't have them available now. If the old pattern was good then it's likely the new is ok unless the cam has been cut several times. Nevertheless, be careful of your assumptions and consider that it never hurts to check.

Like I said, I'm not an expert and others here who are may offer different or modified direction, but this has worked well for me for 34 years.

[yusef]

Thanks for the input. I was able to get it to rotate with one hand and slight, but consistent resistance...definite improvement from first iteration. I will try some more.

[martinmmartinezc]

Moderate resistance isn't unusual, but it should still turn smoothly. I have it now and even checked the camshaft bearings for wear.

[david premo]

It may or may not be an alignment issue. I sent you a PM

[redroadster]

You can use bluing to dye the towers and see where it rubs it off.
But a pretty good way is too assemble with Vaseline freeze it which solidifying the the Vaseline , then gently tighten, then blow dryer it to have it drain out ...I saw it done by our engine tech , with success. I've never done it, that's if the heads not warped of course

[Public_Impressor]

When I replaced my camshaft with a model from https://goldfarbinc.com/, I encountered a similar issue. I purchased a Cummins ISX camshaft and during installation, ensuring smooth rotation was key. I applied a methodical approach, using a star pattern for tightening and checking the rotation at each step.

What helped me was double-checking the seating of the cam in the bearings and ensuring there was no debris or misalignment. Sometimes, even small particles can cause resistance. Also, verifying that the camshaft was perfectly straight and not warped was crucial. In my case, achieving minimal resistance with two fingers was possible after carefully reseating the cam and doing a final check on the torque specs. So, you're not chasing your tail; precision here is crucial for optimal performance.