Cams won't turn - HELP!

[hunker7]

I did keep parts from both heads separate. But now I'm not entirely sure if I'm using the correct ones. Exhaust manifold is fine. (One set of caps are cleaned and second set is still dirty with oil so that's how I know them apart)

[steve briance]

I see that the caps being used are from the replacement head so 'in theory' should be right if they are the right way round and in the right place, just playing devils advocate here, but how do you know the caps are from that head? did you take it off a previously running engine yourself? It would only take for the previous owner to have mislaid a cap and found a spare from a different head for it not to work too well.

A bit of a ball ache but i would be tempted to take the cams out, refit the caps and see if you can see down the bore of the bearing surfaces to see if the caps line up with the surfaces in the head. The head and caps are assembled and line bored in the factory, if a 'foreign' cap is put in and is offset by 3-4 thou of an inch, that would make it tight. You shouldn't see any steps at the head/cap mating surfaces.

When the cams are not pushing against tappets, they should spin by hand with no bother. It makes it harder when they are pressing tappets down but it should still turn over by hand with a spanner, that's how you crank things over to set to TDC. Does it go either way? I just typed about TDC and wonder if you somehow have valve hitting piston?

ooopps. I replied after reading only page one of thread, it sounds sorted now?

[newsh]

Cams won't turn - HELP!

If head cams and caps were all kept as a set then the only thing I can think is that something was damaged when the cambelt went. Maybe the cam is bent?
Then fitting the caps from Jannis' head which has 200,000 miles on it, twice the mileage, (and was maybe bored slightly "higher" making the cap deeper) has given it the extra clearance needed to turn.
I guess this could be checked by measuring the cam journals with a vernier and then measuring the internal bores in the head when the caps are torqued down. If clearance is measured but the cam doesn't turn then something is bent. I'm not sure what the correct clearance should be, a few thou at most I would think.