3rz camshaft installation question

I'm installing a rebuilt cylinder head on a 3rz and have gotten to the point where I need to install the camshafts. The manual indicates the the intake camshaft should be installed with the knock pin facing upwards, however, this results in the back two cam lobes sitting on the valve lifters so that the cam is not resting level on the head. The manual also states that the camshaft must be installed level on the head or else the thrust surfaces could become damaged.

What am I missing here? I don't seem to be able to accomplish both a level cam and an upward facing knock pin. I could tighten the the cam down until it is level and compress the valve springs in the process but it would not start out level and I would expect that the compression of the valve springs would effect the torque readings.

 

I should mention that the cam is sitting about a 1-2mm above the back journal, so it's not that far out of level and I don't think the thrust surfaces would be damaged by tightening it down where it is. I'm just concerned that there is a problem with the rebuilt head and that the valves/lifters are too high in the head.

 

Hey deepee i ran into the same exact problem with a rebuilt head yesterday on my 3rz. I ended up just compressing some of the valve springs while installing the exhaust camshaft. Haven't started it up yet... waiting on ignition cups in the mail. I'm curious how it turned out for you?

 

4banga, I just compressed them. I don't think it effected the torque all that much, but I seems to me that the manual shouldn't tell you to install the camshaft level if that's physically impossible, so I'm a little baffled. I just got the truck running today and it runs just fine, so far. The quality of the rebuilt head is questionable, so we'll see how it goes.

 

It's literally not possible to install the cams without using the bolts to suck them into place, just be careful going together and they won't give you any issues. Done it more times than I can count now.

 

Thanks for the advice. I also have a rebuilt head of "questionable" (chinese) quality. After bolting down the camshafts, I checked the valve lash with feeler gauges to see if it was in spec... and to my disappointment, most of them weren't within spec (too tight). I'm not sure if I should be concerned.

 

Yes you should be concerned if they are too tight!! These valve tighten up over time, and will cause burnt valves if the get too tight. If you are close to the bottom of spec you might be ok, but when it's all apart I would adjust the shims.

 

I think I'm just in denial after spending $600 on a remanufactured complete head, I expected everything to be within spec.

 

Haha yeah, I went through the same thing with a reman head. The valves are mostly all in spec but some barely. Gonna keep an eye on them, it does take a while to tighten up. Wish they would check this stuff before you buy, or include a notice that valves need to be checked. Oh well.

 

'Install level with head' is apparently Toyota-speak for 'draw the camshaft down evenly using the bolts'. Standard practice common with all camshafts- if you bolt one end down completely it cocks the cam and then tightening down the other end can damage things.

 

Paetersen, the manual is very specific about the tightening sequence on the camshaft which starts in the middle, not on an end, so there shouldn't be any concern about someone who is following the manual suddenly tightening down one end of the cam. It's just a wild guess, but perhaps they were re-using some instructions from another model and neglected to realize that on this particular head the camshaft cannot be placed level to the head.

I guess I should have checked that all of my valves were within tolerance. I just checked a couple and figured the rest would be ok. I noticed other crappy craftsmanship on the head. I found quite a few large bits of metal debris and the distributor drive gear that was extremely poorly built - like I think a lego would have lasted longer. I ended up just taking the gears off the old cams and returning the new ones with the core since they were such poor quality. The head I got was built by ATK who are notoriously bad. Unfortunately, it was the only head I could get in my location.

 

Make sure you reset the preload on the exhaust cam gear spring.

I used cylinderhead.com for my reman. $455 shipped to my door, ready to bolt on. Cams, calves, etc all included