Head replacement-Cams won't turn!

[merlin's S4]

I've just fitted a rebuilt and modified 7a head to my AAN block and have been trying to fit the cam belt and time it all up this evening but the cams won't move, well not without far too much force.

I've fitted the cams from the old AAN head and used the 7a cam caps. They have all been fitted as per the Bentley manual and torqued up properly. If I loosen the nuts on the cam caps slightly I can get the cams to move but as soon as I try to torque them up the cams get too stiff.

What's going on?? Do I need more lube on the bearing caps? Should I try the caps from the AAN head? I'm pretty stuck so any help would be greatly appreciated!!

[twoqu]

What did the Bentley advise?
I thought its 1 to 5 for exhaust and 6 to 10 for the inlet with all the recesses on the caps pointing towards the inlet side of the head.

[andy10v]

Put the cam caps on the head they came off, the cam caps are line bored and so will not work on another head.

Also the cam caps are numbered, put them back on the same head, in the same location they came from.

[mcandmar]

What did the Bentley advise?
I thought its 1 to 5 for exhaust and 6 to 10 for the inlet with all the recesses on the caps pointing towards the inlet side of the head.

2nd that. Wrong cap in the wrong place would cause it to bind up. Also dont use caps from another head as they wont fit properly.

[merlin's S4]

What did the Bentley advise?
I thought its 1 to 5 for exhaust and 6 to 10 for the inlet with all the recesses on the caps pointing towards the inlet side of the head.

Yes that's right. Bentley says to first tighten caps 1 3 and 5 for exhaust and 6 8 and 10 for inlet. Then fit the rest of the caps. Specified torque for the nuts is 15Nm

[Knight Rider S4]

I know what you have done ...I did this myself ..you have put the caps on the wrong way round ....Stu put picture up for me , looking at it , Its reads 12345 so on from the exhaust side not the inlet I think need to dig out pic

Pic taken from Petes Engine but you can see the cap 10 and how they follow number wise

[merlin's S4]

As stated above all the caps fitted are from the 7a head. I was sure that interchanging caps from different heads was wrong.

I'm sure that all numbers are in the correct places and all recesses are facing the inlet side. I checked this more than once but I'll chack again tomorrow.

[Knight Rider S4]

Oh and easy to get 6 and 9 mixed up

[twoqu]

Its alway better to sleep on it!
One possibility might be that you have mixed up 6 and 9 although the recesses should alert you to that. I can't remember if that skinny one at the front of the inlet is marked for orientation. Again, perhaps if you loosen that and it frees up, that is the culprit. I can check a head tomorrow.
Failing that, you might need to source some plastigauge and methodically check the clearances on all the caps.

[bikerjim]

How tight is your cam chain? I tryed to fit a set of golf KR cams into my coupe 16v and the cam wheels were slightly different which made the chain really tight, this stopped the cams from being able to turn freely as they should.

I found a set of ABF cams and these had the same style of cam wheel as my origional cams, when i fitted these the chain was acceptably tight not over tight and the cams turned fine.

[merlin's S4]

Its alway better to sleep on it!
One possibility might be that you have mixed up 6 and 9 although the recesses should alert you to that. I can't remember if that skinny one at the front of the inlet is marked for orientation. Again, perhaps if you loosen that and it frees up, that is the culprit. I can check a head tomorrow.
Failing that, you might need to source some plastigauge and methodically check the clearances on all the caps.

Yeah I wasn't really in the mood tonight after it didn't work the first time!
I'll give it a proper look tomorrow. I was thinking that it could be the front inlet cap as you suggest as that's the only one I remember looking at and being unsure about. I shall report back tomorrow.

Thanks guys!!

[Billman]

Yeah I wasn't really in the mood tonight after it didn't work the first time!
I'll give it a proper look tomorrow. I was thinking that it could be the front inlet cap as you suggest as that's the only one I remember looking at and being unsure about. I shall report back tomorrow.

Thanks guys!!

The small one also has a notch that point towards inlet manifold like all the caps and I think the torque was higher than 15 but not sure.

[spink]

do you know the 'history' of the cams you are using?i have come across bent cams before that have been stored badly

[twoqu]

Billman is right, see below. It is quite difficult to see, especially in a hurry (lower righthand corner). The temptation is to orient it with the big writing towards the exhaust rather than the inlet as it looks upside down!
Anyway, all the caps appear to orientated as we have already described.