Manifold studs

[Bambikiller240]

Originally posted by Bambikiller240

That is the "normal", "stock" from Nissan situation on 240Z's. One can convert to all studs if they wish, but from the factory they came with studs for the lower row of manifold attachment, and with bolts for the top row of manifold attachment.

8mm X 1.25 bolts, studs, nuts.

Length is the same for all studs. (EDIT: within 3/16" or 4-5mm)

See quoted text for where studs and bolts go.

My Bolts also had a 7 on the head.

[240 in OZ]

Thanks Carl

What about the two attachments on either extremity, one that is common with the bracket that holds the heater by pass hose and the one on the other end under the thermostat housing. These are neither an upper row or a lower row, more a mid level row.

Able to help out?

Thanks

Joseph

[Bambikiller240]

Hi Joseph!

Those two are studs as well. You are talking about the first and last exhaust manifold mounting points, right? If so, STUDS.

[Ed]

Here is a picture of a head (N42) for reference. As far as I know and someone please correct me if I'm wrong, numbers 1-11 red are all studs. And numbers 12-17 blue are all bolts.

Which ones are supposed to be the long studs I don't know. Maybe someone else knows?

[Zedrally]

Does anyone now why there is a combination of studs and bolts?

[Victor Laury]

Does anyone now why there is a combination of studs and bolts?

It eases assembly and disassmbly. With the bolts out, you set the exhaust manifold on the studs, set up the bridge washers, start the nuts, then you slide the intake manifold down under the bridge washers and install the bolts. This saves serveral minutes of dropped nuts trying to install them on the bridge washers while reach under and around the intake manifold.

It's a common modification we do on the roadsters, but stock on the 240.

BTW all the 240's I've worked on had the same "TR" "7" bolts.

[240 in OZ]

Ease of installation/removal I would guess. I assume that having some fixing points that are totally removable would make this easier.

Just a guess. Interesting to note that the parts book calls up the part numbers for the studs only, and doesnt even mention the bolts.

Joseph

[Victor Laury]

Joseph! we were simultaneous

[240 in OZ]

Hey Victor

Yeah, I noticed that. We must have been typing our responses at the same time!

Lucky we came out with the same outcome, albeit a guess on my part!

Joseph

[Zedrally]

FWIW, I've always replaced all the bolts with head studs, just curious if there was any technical reason not to?

Never had a problem losing nuts as Victor does, actually found it easier!