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[grifter]

Hi

Does anyone have the torque wrench settings for later senator 3.0 12v head bolts?

Had a look on net, ABS, can't see anything and my autodata books are not with me at the moment!

There was a guide for the early senator/monza on ABS but not sure if it is the same - 74 Lb/ft tightening in a spiral outwards from centre.

Cheers

G

[Steve Brookman]

This is from ABS (from the excellent Derek)

"Anyway I've used 74 lb/ft (100 Nm) and used head bolts all these years and never had any problems. There is no mention of any angle tightening. Just do them up in three equal stages, 25, 50 and 74 lb ft. make sure the two locating studs in the top of the block haven't fallen out or rusted away. Ideally you should use new bolts (I wouldn't use old bolts on alloy heads such as the 24v) but the big cast iron 12v head seems to be pretty robust, the bolts too, and the biggest problem when working on these engines is being careful not to mess up the splines on the torx headed bolts. Even with the hex headed bolts it is a good idea to clean crud out before undoing them, especially on an engine that hasn't seen many oil changes. If you balls one of the bolts up it is a major drama trying to extract it, and i've seen a few of those."

I used the later method (I had a later Senator Haynes manual) where you torque up the bolts then rotate by so many degrees wait and repeat rotation. I think this may be one of the reasons my head gasket let go.

I'm going to use Dereks method above-I also read the 1978-1984 Carlton Haynes manual and it mirrors what Derek says.

Chris (CIH) will be along soon-he is an expert on these engines.

Steve

[grifter]

This is from ABS (from the excellent Derek)

"Anyway I've used 74 lb/ft (100 Nm) and used head bolts all these years and never had any problems. There is no mention of any angle tightening. Just do them up in three equal stages, 25, 50 and 74 lb ft. make sure the two locating studs in the top of the block haven't fallen out or rusted away. Ideally you should use new bolts (I wouldn't use old bolts on alloy heads such as the 24v) but the big cast iron 12v head seems to be pretty robust, the bolts too, and the biggest problem when working on these engines is being careful not to mess up the splines on the torx headed bolts. Even with the hex headed bolts it is a good idea to clean crud out before undoing them, especially on an engine that hasn't seen many oil changes. If you balls one of the bolts up it is a major drama trying to extract it, and i've seen a few of those."

I used the later method (I had a later Senator Haynes manual) where you torque up the bolts then rotate by so many degrees wait and repeat rotation. I think this may be one of the reasons my head gasket let go.

I'm going to use Dereks method above-I also read the 1978-1984 Carlton Haynes manual and it mirrors what Derek says.

Chris (CIH) will be along soon-he is an expert on these engines.

Steve

Cheers Steve, I also asked on ABS too and seen that what you quoted on there, but was more thinking about the process for the later cars.

For the purpose of sharing this for anyone else involved in this engine I also had quite a problem with the short head bolts on the N/S. I never had the cam at the right position and the bolts jammed against the side of cam when I plopped them in the hole. The cam has an indent to allow the bolts to fall in to bolt hole. luckily it's not something that hides itself until you try and start, although potentially it could be if you don't do an engine spin test first with a ratchet. It partially seizes up the cam as the head bolts are rubbing against the cam, i.e. they are not seated home properly because the bolt head hits the cam and leaves about a 1/2 inch gap between the bolt head and the seat.

It feels like it is tightening too when you are turning it 

See where it has been rubbing?

[Steve Brookman]

I'll dig out the process on later cars-on my way!

Steve

[Steve Brookman]

This is out of a later Senator Haynes manual-E to L reg.

Stage 1
60 Nm  45 lb foot

Stage 2
angle tighten a further 90 to 100 degrees

Step 3
wait 10 mins

angle tighten to a further 30 to 40 degrees.

When I lined up the timing marks, the cam was in the correct position for the bolts to go in and out.
The major problem I have is access to the two rear bolts-very tight against the bulkhead.

I'm going to try Derek's version as my car is a 1983.

Hope this helps

Steve

[cam.in.head]

hi steve. yes the earlier engines like yours can have the head bolts re used many times. i have never had a problem with doing this and torqued them all up in stages as suggested in the excellent post further up saying torque to 25 then 50 then 75 lbs .see the bit mentioned about the bolts fitting in by the cam through the recessed section. no doubt that will have confused a few people on those engines .

[cam.in.head]

there are also different length head bolts that were fitted too and i dont mean left hand side and right hand side.as far as i know early engines up to approx 82/83 had the splined head ,later engines went onto a socket head type and im pretty sure they had deeper heads and deeper recess into the head and therefore slightly shorter in length overall. if you fitted wrong ones you could either have bolts that bottom out ,bolts that dont go in far enough or bolt heads that can rub the cam whilst its rotating. all issues to be avoided at all costs so always use the same bolts that came out or identical replacements. now the very late senator engines 87-94 did recommend new bolts and an initial torque setting of 45lbs thrn angle tighten 95 deg then angle tighten 35 deg. this is detailed in the later haynes book no,1469

[grifter]

there are also different length head bolts that were fitted too and i dont mean left hand side and right hand side.as far as i know early engines up to approx 82/83 had the splined head ,later engines went onto a socket head type and im pretty sure they had deeper heads and deeper recess into the head and therefore slightly shorter in length overall. if you fitted wrong ones you could either have bolts that bottom out ,bolts that dont go in far enough or bolt heads that can rub the cam whilst its rotating. all issues to be avoided at all costs so always use the same bolts that came out or identical replacements. now the very late senator engines 87-94 did recommend new bolts and an initial torque setting of 45lbs thrn angle tighten 95 deg then angle tighten 35 deg. this is detailed in the later haynes book no,1469

Will double check old bolts against new again but I think they were the same. The front RH bolt went straight in but the others ones going progressively back didn't. Think that the cam is 180 and the indents are on the other side to allow the bolt to go past, although that doesn't explain the first one going in ok.

Do you know what that O ring is actually sealing off at the front of the block as I pushed a screwdriver down both openings (in head and block) and they seem to go nowhere? The seal on mine was brick hard so I replaced with the new one given in head set, the new one looked like a collar but the old one was flattened, obviously by the head pressing it down. Just as a precaution should the new o ring be doughnut or flat edged? Mine was flat edged so I wondered if this was right. It was the only O ring seal in the pack so assumed that is it.

Finally what is that daft plastic nut thing in the middle of the cam sprocket? What use is that?

[cam.in.head]

the o ring at the front of the head is a water feed or at least it is on all the early engines i have worked on. if yours goes nowhere maybee the very late engines used a different channel. and the plastic screw bolt thing at the front is an endfloat nylon bearing. it must be screwed fully into the cam(not too tight to snap it !)then you measure the endfloat / gap between it and the domed 3 bolt plate on the front. approx 0.1 - 0.2 mm feeler guage.if the gaps too large the front plate may nip up a bit or you gently tap the centre inwards to create less gap.if the gaps too small remove cover and tap centre back to create more gap.its a very crude system but it works and all the cam in head engines have this. do not be tempted to try to adjust it by screwing the nylon bolt in or out !

[grifter]

the o ring at the front of the head is a water feed or at least it is on all the early engines i have worked on. if yours goes nowhere maybee the very late engines used a different channel. and the plastic screw bolt thing at the front is an endfloat nylon bearing. it must be screwed fully into the cam(not too tight to snap it !)then you measure the endfloat / gap between it and the domed 3 bolt plate on the front. approx 0.1 - 0.2 mm feeler guage.if the gaps too large the front plate may nip up a bit or you gently tap the centre inwards to create less gap.if the gaps too small remove cover and tap centre back to create more gap.its a very crude system but it works and all the cam in head engines have this. do not be tempted to try to adjust it by screwing the nylon bolt in or out !

Ok that makes sense will check that once the domed plate is on.

Cheers

Andrew

[cam.in.head]

make sure cam sprocket is pushed back as far as it will go so as not to give a false reading.easier to do before followers are in or loaded

[grifter]

Bit of a confusing one with the head bolts. The original head bolts were Allen key type but the new ones were T55 Torx. However originally I had ordered a "ribe" socket set. I think the description was misleading as it said torx otherwise I wouldn't have bought them.

Strangely enough one of the ribe sockets slots nicely in to the T55 torx bolt. So away I went tightening the bolts down. Luckily the ribe I was using was too long to get into the back left hand bolt on the head. I could get it on - just - but any serious torque was not viable on the ratchet anyway and I was not willing to risk rounding the new bolt internals until I got the smaller length socket.

Anyways I popped into my local hardware store and he did have lots of torxs but not the ribe socket. Stupidly I had taken the socket not the bolt. I went back home, looked at the bolt very carefully and realised it was actually a torx. I was also in halfords and the guy showed me the socket set they had, this was when I discovered it was called a ribe socket set.

So back to my local hardware store with the bolt this time and tried a T55 torx, which fitted snugly. I had to buy a full socket set as they were the only ones that were small enough to go under the bulkhead, the loose T55 torx was long socket. The ribe socket looks exactly like the pattern of a torx except that the points are square rather than rounded. On some of the bolts the ribe square edges had slightly nipped the inside of the torx hole so I had to push them in with a little force, with some wiggling, to get past the "slag" from the ribe making it's mark.

After that I gingerly tightened the back bolts down and that was that. Here's pics of some of work done, head now tightened and manifolds/water pump on etc.

Primered chassis leg


Painted chassis leg


Water pump on - just after this I put on that tight elbow pipe from pump to stat housing


Water pump/casing view


Inlet manifold and injector rail stripped & cleaned


Both manifolds and new exhaust shield on

[grifter]

Does anyone happen to know what this valve is:



It sits at front of engine, on top, just behind thermostat housing, and secures with 2 allen bolts onto a plate?

I appear to have broken the plastic collar on one or two of the vac pipes on it. Not sure if it was a push in bit to the pipe that broke or a bit on the actual valve itself. This can be seen in the pic below