manifold removal query

[CNHSS1]

I have a spare pair of tubular manifolds to fit and have been liberally soaking the manifold bolts for a couple of weeks. Now, some you can get a 1/2" socket and breaker bar on, all these have cracked nicely, but others you cant use a socket, only an open end spanner.
Issus is i cant get enough leverage with a spanner, and the open end feels like it may round the bolt heads.

So what tips do the collective have for me please? :-)

Cheers in advance, Craig

[Loach1]

Put a second ring spanner end over the open end to increase leverage. Does that make sense?

Like this:

http://memimage.cardomain.com/ride_images/1/1237/9...

[TVR-Stu]

Or try some of these. Not got any myself (yet) but I believe they have been recommended before.
Good luck.

[lewdon]

using an open ended spanner will probably round off the manifold bolt head, it did on my first attempt. but if you grind a little metal off a ring spanner it is possible to get it to fit. Even with some metal ground off the ring was still strong enough to remove the very rusted bolts on my manifold, even using a tube over the spanner to get extra leverage.. I also found that giving the head of the bolt a smack with a hammer, as recommended on this forum,(using a large punch to avoid distorting the hex) helped to break the rust free and let the penetrating oil soak in. Good luck.

[phillpot]

All the above re spanners plus must be good quality brand, and try some of this


"Issue is I cant get enough leverage with a spanner" ......try 3 Weetabix for breakfast

[Maffe]

Try MoS 2 oil wait and apply heat and try again, can take an extra day...
Had a bolt that was not giving in for the big "motivator", took 2-3 days with MoS 2 and heat before it let go.
Aluminum part with iron screw + salty roads= not good

[greymrj]

Had a right b..... job with mine a couple of years ago. No way it was coming off, seen to remember resorting to a long fine drill and then splitting the nut. When I got the manifold off I found a couple of the studs so corroded that I had to change them anyway. Exactly the same on another engine I rebuilt, that one now has high tensile* stainless bolts with plenty of copperslip, a couple of years later they are still tight but 'free'.

• If using stainless you MUST get the higher tensile type, typical stainless bolts will be very significantly less strong than the originals and are almost certain to break.

While we are on the subject, the manifold to exhaust studs are another problem. I eventually drilled mine right out about 4 years ago and fitted high quality stainless socket head screws with double nuts*, the exhaust has been off a couple of times since (!) and the new arrangements have worked perfectly.

• surprisingly a stainless nylock did work, the nylon melted onto the thread but formed a hard ring which kept the nut tight. Proved harder to deal with then the double nut when stripping down.

[phillpot]

greymrj said:

* surprisingly a stainless nylock did work, the nylon melted onto the thread but formed a hard ring which kept the nut tight.

Try Binx nuts for high temperature applications......




Manifold to head is all bolts on mine, no studs 'n nuts. Standard A2 which I believe is stronger but not as "pure" as A4 stainless ?

Don't know of any other generally available grades, ARP bolts possibly but expensive or maybe something used in aeronautics?

[S2Mike]

Dont give in,
I did as the bolt heads were already rounded off and my Tame Mechanic actually had to remove the heads and set to work on the manifold bolts on his bench, with heat and violence.
Means I now have new head gaskets which is one less thing to go wrong in the future....

[Griffinr]

phillpot said:

Manifold to head is all bolts on mine, no studs 'n nuts. Standard A2 which I believe is stronger but not as "pure" as A4 stainless ?

Don't know of any other generally available grades, ARP bolts possibly but expensive or maybe something used in aeronautics?

The A2, A4 indicates the corrosion resistance, it's the second set of digits that denotes the strength.
For example A2-80 which are almost equivalent to standard 8.8 grade bolts.
Rob.

[CNHSS1]

loach
yep, will give the old double spanner trick a try, cheers

tvr stu
will order some of those simply as you can never have too many funky spanners! but as lewdon says, I think its the wall thickness of the ring end which may need tasting with a grinder to slip on.

philpott
whilst brawn is needed, id rather work smarter than harder ;-) imho its the wrong tool and being too aggressive that snaps or rounds stuff off, on the others that a decent socket and breaker bar fitted on, they came undone with a satisfying crack.
I have some Wurth (I think) freeze juice, will give it a try. Have tried heat and so far that's not done the trick (unusual tbh)

will also trick the 'percussive maintenance' with a punch--good idea

[CNHSS1]

as for stainless it has its place, but exh studs/bolts aren't for me. Decent steel studs with stainless nuts maybe, but stainless is less ductile and invariably fails just when you don't want it to...

thanks for all the tips Chaps, glad im on the right track :-)

[glenrobbo]

One other small tip, if you crack It off & it then starts to "bind" on the threads, tighten it up a bit, give a generous squirt of release oil, then try undoing again. Back & forth, perseverance not brute force wins in the end.

[phillpot]

Griffinr said:

The A2, A4 indicates the corrosion resistance, it's the second set of digits that denotes the strength.
For example A2-80 which are almost equivalent to standard 8.8 grade bolts.
Rob.

Thanks Rob, looks like most of my stuff is the more common 70 grade.

Here's a nice straight forward bit of info I found...... clicky

[greymrj]

That is a nice summary of stainless/MS comparisons. Got me worried for a moment but I did 'spec' right, lots of bits are A2-70 but the manifold bolts and the larger skt hd cap screws I have used on the car are A2-80. I will try to source some of those nuts for next time the pipe is off.

[Top Gear TVR]

i used the bendy spanners and sockets. i found soaking in release oil for a few days every day and night and then gingerly doing a robbo on a couple and downright fear on the last one did the job. It was the one under the alternator that had 'machine shop' written all over it. But once again bravery did the job, phew!

[mep12345]

One of my heads had all come out easy. The other I had to drill out 3 studs as even soaking and stud extractors wouldn't remove the studs which snapped under pressure applied to the nuts. This was with the head on a bench and not on the car too. Motto is you may be lucky, you may not. Replaced all of mine with bolts and lock rings and on one where the head thread was badly corroded I over drilled the hole and used a nut bolt and lock washer combination

[CNHSS1]

well 'slowly, slowly, catchy monkey' has worked, nearside manifold off :-)
lots of soaking with penetrating oil, some percussive maintenance with a number 5 'ommer and extra leverage usng a thick wall tube with the end flattened to fit over a std 1/2" spanner

[CNHSS1]

well 'slowly, slowly, catchy monkey' has worked, nearside manifold off :-)
lots of soaking with penetrating oil, some percussive maintenance with a number 5 'ommer and extra leverage usng a thick wall tube with the end flattened to fit over a std 1/2" spanner