Brass nuts and steel bolts for the primaries. Suitable anaerobic threadlock discussion.

[anthony1956]

edit, wait a minute are those steel bolts and not studs at all? now adding a close up:

 

 

So thinking about biting the bullet and undoing these, a good soaking with Plus gas in hand and I spy different nuts in use. My guess is he ran out of brass ones? Does it make any difference? I'm assuming by the colour that means they are brass.

it all looks nice and new including even the studs which is cool and nice to note. I s t r them on the bill. 

What am I nervous? They are very solidly in place with the side exit exhaust and I am wary of screwing that up when I refit them. My hope is that one cannot screw up such a process, right?

Anthony

speaking of brass, far too many brass monkeys hereabouts

Edited November 27 by anthony1956

[OldAndrewE]

Difficult to tell from that photo but is there enough clearance to the chassis tube to allow use of studs and nuts?

Brass nuts on steel studs is a fairly normal thing on exhaust manifolds, I had the same on my Mini (although I have changed them for ARP stainless studs and nuts now)

Edited November 26 by OldAndrewE

[Englishmaninwales]

+1 on studs and brass nuts. As Andrew says maybe there is a clearance issue for studs on the one header, hence the steel bolts. The downside with steel bolts is likely damage to the thread in the aluminium cylinder head each fitting/removal cycle (but one could helicoil these threads as a precaution).

[7 wonders of the world]

If your tight on clearance use flange head bolts the spring washers on the photo are a waste of time.

If your concerned about security use drilled cap heads and lock wire in pairs

 

[anthony1956]

It’s the no 4 : that doesn’t look like any clearance issues does it?

edit is it possible that locating it in the first place is an issue?

 

this must be one of the last Powerspeed works. Nice it is too. 

Edited November 26 by anthony1956

[OldAndrewE]

17 minutes ago, anthony1956 said:

edit is it possible that locating it in the first place is an issue?

That was my thought, i.e. being able to fit/remove it over the studs.  The fitted position is fine

[anthony1956]

And lockwire resurfaces.. good job I am acquiring that kit and skill 

so ideally this sort of thing

 

just googling flange head bolts 

Spoiler

 

Edited November 27 by anthony1956

[anthony1956]

1 hour ago, Englishmaninwales said:

(but one could helicoil these threads as a precaution).

Lost me. ? 
I have helicoils but?

[anthony1956]

ok so the thread, as ever from Burton power https://www.burtonpower.com/inlet-exhaust-manifold-stud-ford-bda-bdg-1-4-unc-unf-fb840.html

so that will be the 1/4" UNC into the head and externally that other one (what's that?) So my bolt will be 1/4" UNC, of course it will like everything else .. wait a minute, it's usually 1/4" UNC in to the STEEL isn't it? And the fine thread in to the alloy..  hmm

feel free to interrupt! 🙂   need to do this when I am awake.

Edited November 26 by anthony1956

[aerobod - near CYYC]

Hi Anthony, normally would put the course steel thread into cast alloy as it gives a bit deeper thread with less likelihood of spalling and stripping out the thread.

[anthony1956]

will these all be threadlocked?

[anthony1956]

ok so removed one bolt; so first off it IS a bolt. Looks to me like a 1/4" UNC thread length 25mm exc head

The head is 7/16 or 11mm i i r c or 10.1 mm ..  no sign of loctite which I guess is no surprise

Edited November 27 by anthony1956

[anthony1956]

so what about using aluminium bolts and not steel? Won't that remove the risk?

[OldAndrewE]

8 minutes ago, anthony1956 said:

so what about using aluminium bolts and not steel? Won't that remove the risk?

What risk is that you are trying to remove?  

[aerobod - near CYYC]

3 minutes ago, anthony1956 said:

so what about using aluminium bolts and not steel? Won't that remove the risk?

Aluminium bolts into aluminium without a coating on them will tend to be not removable, Anthony. Also, unless they are very high strength aerospace alloys, they won’t be very strong for the same size as a grade 5 steel stud (6061-T6 is 240MPa vs 640MPa yield strength).

[anthony1956]

15 hours ago, aerobod - near CYYC said:

less likelihood of spalling and stripping out the thread.

 

1 minute ago, OldAndrewE said:

What risk is that you are trying to remove?  

 

[anthony1956]

I have started exploring possible suppliers but s o far the responses are "oo er what?"

[OldAndrewE]

The risk of stripping the thread must be related to the tension put into the bolt, and this would need to be the same for each option

[aerobod - near CYYC]

Just now, OldAndrewE said:

The risk of stripping the thread must be related to the tension put into the bolt, and this would need to be the same for each option

On insertion, yes. On removal it is more about the interaction of the materials, corrosion and friction. Plated steel with blue thread locker with a course thread is the lowest risk into cast aluminum. Bare aluminium into cast aluminium will have a nice aluminium oxide bond forming between the two component, so a 6061-T6 stud into cast aluminium would probably shear off on removal after being in there for a couple of years.

Also, on an exhaust manifold 6061-T6 probably won’t be T6 for long due to the heat and age hardening, it would have a low fatigue life in that sort of environment.

[OldAndrewE]

So in conclusion Anthony, I think aluminium bolts are a bad idea.

[aerobod - near CYYC]

13 minutes ago, anthony1956 said:

I have started exploring possible suppliers but s o far the responses are "oo er what?"

Wouldn’t you just use the Burton Power steel ones? https://www.burtonpower.com/inlet-exhaust-manifold-stud-ford-bda-bdg-1-4-unc-unf-fb840.html?srsltid=AfmBOopHWOWlbs04GhOhSFuHcZ964wj7LLNXXHOc90jx4ab5dWAn0AFI

[anthony1956]

oh! Has the penny just dropped in so far as you are suggesting insertion of the studs AFTER locating the primary in place?

As opposed to using bolts of any kind?

James the assumption in play is that bolts have been used owing to inability to locate the primary in place when studs are already also in place.

Edited November 27 by anthony1956

[OldAndrewE]

10 minutes ago, anthony1956 said:

the assumption in play is that bolts have been used owing to inability to locate the primary in place when studs are already also in place.

I think that is something you need to test before deciding what to do next Anthony.  Inserting studs with the primary in place may well work for assembly but if ever you need to dismantle it may be more tricky to remove the studs with the primary in place after they have been in a while 

[anthony1956]

aye.. just want to see what James says..

this is interesting " Plated steel with blue thread locker with a course thread is the lowest risk into cast aluminum" - which loctite is that? I seem to think 243?

The one I have removed was not tight at all really and with barely a turn became finger loose.

in fact @aerobod - near CYYC James you seem to be saying I could simply use my existing steel bolts (as pictured above) and add Loctite 243 ? Where it is essentially being used to create an anaerobic environment to avoid corrosion, as well as a thread lock? 

Assuming I have the colour right.

That would be convenient as I just ordered some more 243 on the back of a Loctite 2701 order (for the butterfly brass screws through steel spindle)  order to get over the free delivery threshold.

Edited November 27 by anthony1956

[aerobod - near CYYC]

Blue/medium strength should be Loctite 243, @anthony1956. Yes the idea is to create an anaerobic seal to eliminate corrosion. If the thread is clean and the plating is still good, I would reuse what you have, Anthony.

Edited November 27 by aerobod - near CYYC