308 QV head torque

As I prepare to do the head gaskets on my car I've been reading through the manual and service bulletins and in regards to torquing the heads I'm having a bit of trouble following what they are saying. The procedure is to torque each nut to 33 ft/lbs then using a goniometer turn each nut an additional 120 degrees. The problem, and the part I don't get, is since you're using the AV 1393 adapter and your wrench is fixed to it how can the goniometer measure the angle since the nut and it's rotational center is offset from the wrench by 2 inches?

I suppose I can just mark the nut and rotate the mark 120 degrees or maybe people just go for a specific torque value?

I've done a search here but haven't come up with much.

 

the specs are the specs. How you do it with your tool is what you have to decide. Your suggestion is good. Mark the nuts and then them 120 degrees (that would be 2 complete flats on a 6 sided nut)
There are also these new electronic wrenches that can measure torque angles. You have to do multiple passes to get 120 degrees.

 

I'd just use a torque angle gauge. Also - Don't forget to use NEW bolts.

 

If I remember correctly, they don't use bolts. It's all studs and nuts and the nuts are hidden in the pockets, hence the special tools.

 

Arg, sorry... I was mentally picturing the valve covers, even though you didn't say that.

 

Well that’s the part I don’t get - how you would use an angle gauge when the head of your wrench is offset 2 inches from the axis of the nut you are torquing. The whole assembly of wrench and angle gauge is going to move through an arc. I use a similar adapter for cylinder base nuts on aircraft engines but it has another dogleg at the top end so you have the clearance but the wrench is still in alignment with the nut.

I’ll figure it out one way or another.

 

Perhaps this link will help. And this tool.

 

I have a torque angle gauge, it’s a very simple tool but it needs to be directly in line with the axis of the nut or bolt you are torquing, you then fix the adjustable arm or magnet so that the gauge face remains stationary and the needle rotates as you turn your wrench the specified number of degrees. This isn’t going to work when the head of the wrench is offset from the axis of the nut. The whole thing is going to move through an arc with a 2 inch radius from the nut. I could make another adapter to hook into the Ferrari tool to bring the wrench back to the nut axis (it would look kind of like a c-clamp shape) but maybe it’s just easier to eyeball it or maybe people have just come up with a torque value to use rather than the degrees.

 

Can you determine the completed angle by calculating the distance travelled on the outer arc? IE, basically using trigonometry. Just musing on this...

 

Determining the angle is not really a problem, as yelcab pointed out it’s two flats on the nut. I was just trying to figure out what they are saying and showing in the manual with the angle gauge (goniometer) I notice there is one on Amazon with a flexible cable mount like the one in the illustration shown in the QV manual, maybe that would work. It’s only 30 bucks.

 

Unless I needed a goniometer for regular work, for a one-time Ferrari head installation I'd just mark the nut and turn it 120 degrees.

 

Well there are 20 nuts and if a $30 tool makes it that much easier it's probably worth it. I have an engine I'm building for my Land Rover that has TTY head bolts so I'd probably use it again. What the heck it's only a mouse click away lol.

Image Unavailable, Please Login

 

I don't see how that is going to work? The point where the socket is attached to will not stay stationary.

 

Me neither, that was the whole point of my original post. That tool looks exactly like the one pictured on page B51 of the 308QV Workshop Manual. Also there is no socket, that tool has to snap into the extension that comes off of the adapter tool so the whole thing is offset 2 inches from the nut you are turning and cannot remain stationary in any case.

 

I'm guessing that via the knurled nut on the right you can loosen that dial, and rotate it. So, torque your bolt to the torque spec. Then swap your torque wrench for this tool and a ratchet. Loosen the knurled nut, and rotate the dial until you have it pointed at a reference mark on the head. Tighten the knurled nut so the dial moves with the bolt, and then turn until the right angle is now pointing at your reference mark.

I think the key thing is that the reference mark is not part of the tool - you have to find a reference mark on the head or somewhere stationary against which to gauge the rotation.

 

From the workshop manual:

Image Unavailable, Please Login

 

I would just mark the nuts and read the 2 flats.

 

The angle tool arrived today so I tested it by attaching it to the head nut adapter and just turning it around a wood dowel in my vise and I'll be darned the thing actually works. Basically the flexible arm holds the dial in the same position while allowing it to swing through the arc and the pointer shows the angle. I did a test of 90 and then 180 degrees and it was dead on.

Who'da thunk?

 

Another interesting find - I also have a copy of the Mondial workshop manual in which head nut torque is listed as 10 daNm/Kgm. That would be equal to 74 ft/lbs.

So maybe that's the way to go, it's the same engine.

 

Update - disregard this entire thread as I just realized I had a complete brain-fart. The whole section on using the goniometer is for the F 105 C which is a 328. The workshop manual is a 308QV and 328 combined so you have to very careful and pay mind to what section you are in. The proper torque for a 308QV is 74 ft/lbs.

The manual is a bit tricky, maybe I should print out a hard copy with all of the 328 stuff redacted LoL.

 

That's what I would do for the 328 motor. Fabricate an extension to bring it in line with the nut. I would buy a 1/2 inch short extension and weld a length of rod to it to bring it in line and then weld a 1/2 inch drive female connector for the torque wrench.

 

Afternoon Paul,
QV are torqued at 10Kg/m and the studs are 11mm diameter. They are not torqued in degrees... only the 328 uses that torqueing approach.
Keep in mind that the torque wrench HAS TO BE KEPT at right angles ALWAYS (parallel to the nut), like in the drawing posted.
If not, torque may be increased more than specs, which is a no, no.

John.

 

That post from KCpilot is 2 years old. I think he is done with that project for now.

 

Yes, finished it last summer and have put close to 5,000 miles on it since. All is good.

 

Hello guys,
Didn't check on the dates
Glad all is ok...enjoy the driving, which is the fun of owning these cars.

John.