new cams stuck

[jilo]

I just recently bought a used head on here and built it up. I got some tomei 264 cams and solid lash adjusters valvesprings etc.
Now that Its time for me to shim the head, for some reason when I tighten the intake cam down it gets stuck. I'm not forcing it to turn, it should turn fairly easy.

Is It possible that I bought a warped head? I'm going to mic the cam caps today and make sure they're all the same size Id. When tightened.

If anybody has run Into this, shed some light on the situation. I'm not trying to ruin a cylinder head by scoring the cam bearings. Thanks

[Homer_Simpson]

It is possible that the previous owner of the head mixed up the cam caps or used cam caps from another head.

[jilo]

That's pretty much what I've been thinking. It's not possible to warp a head that bad without noticeable evidence from heat Is it?

[mikeroy420]

Make sure your shims and guides are in the proper spots. Guides on the left and shims on the right. If they are not, when you rotate your cam the guide will stick to your rocker and cause the valves to stick open.

[cotbu]

Just to clear things up, you're talking about the cams without the chain, rocker arms and whatever else installed, correct? That would be a bigger problem than just shimming it correctly.

[jilo]

Currently, everything Is assembled. I remember the cam turning freely when there were no rocker arms in the head. I need to go and plastiguage the cams and check all of the clearances today. I'm going to try spinning the cam without rockers installed and see what happens.

[I LUV MY S13]

did you measure for warpage?

[jilo]

when i was assembling the head in my apt, i had the cams in without rockers and the exhaust cam spun, but it was tight. now with rockers in, it dosent want to spin. the head does still need to be shimmed, and im afraid that my clearences are going to be all over the place. i assembled the head in my apartment and wanted to check the clearences and get started ordering shims, but the clearences were all over the place. some were huge, others were very very small. i didnt write them down so thats obviusly a speculative piece of info.

im gonna head up to where i keep my car tonight and take some measurements. ill get back with proper results written down.

[jilo]

so it turns out the front three cam caps were wrong. #1 had .13mm of interference fit, #2 had.12 and three had .04, i ended up using the caps from my old head. thankl god for snap gauges and micrometers!