Exhaust manifold bolts

[Graham]

I need to get a set of exhaust manifold bolts, and knowing what a pain it can be to get a spanner or socket on them to get at them with the engine on the car, has anyone tried cap heads rather than hex heads?

is it easier or indeed possible to get an allen key in to them in situ?


Cheers

G

[Bassfiend]

Now, I bought a set of "Allen" cap head bolts for mine and my guys that did my manifolds recommended that I didn't use them as - apparently - they're an absolute bugger to get access to and the hex head bolts are easier so I just stuck with them.

[ctsdave]

G, we use allen head bolts on the racer. Some are much easier with it and some are a pita! I've got a cut down allen key that I can use with a spanner on some... When the time comes to rebuild the engine though I may well mix and match to make spanner checks easier!

[Graham]

hi dave its for the chim road car so hopefully fit and forget, but it is a tvr. is the engine bay on the chim the same as the griff.

[locodude]

ARP do a set with smaller heads that allow you more room to get a spanner on.

[Pupp]

The ARP stainless screws with the smaller 3/8" heads are all possible (if tight) to get to from the top on a Chim, especially if the Serp heater circuit rail is done away with. Usual selection of sockets/ring spanners needed mind.

[Discopotatoes]

Pupp said:

The ARP stainless screws with the smaller 3/8" heads are all possible (if tight) to get to from the top on a Chim, especially if the Serp heater circuit rail is done away with. Usual selection of sockets/ring spanners needed mind.

^^^^ this ^^^^ and a set of nordlock washers, I can't recommend them highly enough, one of the mods to my manifolds were to slot the bottom holes, originally to fit studs but that was a wk idea, bolt and washers throughout then when undoing just loosen the bottoms and remove the tops and with the 3/8 heads and a small spanner makes the job a doodle, (you may need to nip the bolts up after a few heat cycles but then they are solid)

[chris1972]

This is an interesting thread. I was thinking of getting my manifolds out so I could remove the pre-cats, but looked at it and couldn't understand how to get it out!? It all seems so tight? How do you get the bottom bolts off? Do you use a normal ratchet and socket?

[Discopotatoes]

chris1972 said:

This is an interesting thread. I was thinking of getting my manifolds out so I could remove the pre-cats, but looked at it and couldn't understand how to get it out!? It all seems so tight? How do you get the bottom bolts off? Do you use a normal ratchet and socket?

No a spanner, the original bolts will probably need access from top and bottom

[chris1972]

Discopotatoes said:

No a spanner, the original bolts will probably need access from top and bottom

Thanks for that. How do you get access to the lower bolts? Do you have to get under the car? Do you need to remove anything to facilitate access first?

Cheers!

[Pupp]

Yes, from under the car, all pretty straight forward but, on the driver's side, remember the starter lives right underneath where you are working with the potential for fireworks if you drop tools onto the solenoid if the battery remains connected. If you do it 'live' and have the rear wheels on the ground or ramps, I'd leave it in neutral too...

[phazed]

Have the car in the air and front wheels off.
Remove the starter and pull all the gubbins out the way.
I ditched the heater pipe rail some time ago, this makes the operation a tad easier.
ARP bolts and Nordlock washers are best.
You will find out from experience what spanners are best, believe me the first time is a right royal pita!

[Russell Mc]

I took the exhaust off to but it's possible with it on just harder

[stumpage]

I have just taken my manifolds off and changed the gaskets. I did it all from the top. I found when removing the bolts 9/16" spanners make the job easier than 14mm. I know there is not much diffence but the extra slack that the 9/16" has makes it easier to get the spanner on the awkward bolts. I also used a small stubby spanner for the rear most bottom bolts and a 9/16" cranked spanner like this for the top drivers side avoiding the need to remove the heater rail pipes.



The bottom bolts on 3 and 4 as well as the top bolts on 7 and 8 (If I remember correctly) can only come all the way out as the manifold is moved away from the block. When putting them back on make sure you remember this as these bolts will need to be put in first.

[Dickie Dastardly]

I had the manifolds off mine to replace the gaskets and weld up the 4-branch splitter which is very prone to cracking. As mentioned in some of the other replies I also re-fitted using the ARP bolts and nordlock washers - without doubt that's the sensible way to go.

I didn't remove the exhaust but would probably recommend it, particularly if you’re doing the job for the first time; it gives easier access to the n/s/r lower bolts.

The job is straight forward enough but can be fiddly and frustrating at times - be patient and take your time would be my main advice.

Cheers

Richard

[spend]

Soak in penetrating fluid (even brake fluid!) for a period before hand, and go round loosening & tightening whatever you can reach for a week beforehand... Makes it a lot easier than fighting all 16 at once.

Slotting is king IMHO, but I'd always use studs over bolts ~ far less likely to damage the precious heads (doesn't matter too much on 400's I suppose?)

I am certainly not keen on the ARP bolts, they look far too hard to use safely on the soft ally IMO, there are other reduced head 3/8UNC manifold bolts available, as well as studs with wasted stems for smaller UNF nuts (even ARP make some)....

[pbaker43]

My manifold removal was just to replace a gasket that was blowing. Since I removed them the pre-cats have come out (see pic), I’ve had them grit blasted and painted with high temp 900°C silver paint, now they are ready to be mounted with new gaskets.

|http://thumbsnap.com/qUYOkXOI[/url]

Removing them was a PITA, it was a combination from the top and the bottom, took the starter out which helped a lot (I am replacing the main battery cable as the battery is in the boot now) without the removal of the starter the job would have been near to impossible, also removed the exhaust to gain access to the n/s/r, the whole car was raised up to gain full access. See pic





I decided to go with same spec bolts but SS, I know you should use steel in alloy but I am hoping that the copious amounts of copper grease I have used on the thread cleaning tool, plus the grease on the actual bolts will keep the little buggers from seizing.
I also used Nordlock washers as suggested by Chimpjunkie, all my bolts and gaskets were supplied by ACT.[url]

[v8sag]

Hi Graham, I swore by cap screws. On the pita ones I coupled a good quality ratchet ring spanner on a selection of different lengthed straight shanked bits.

[rev-erend]

ARP bolts here .. much better as the heads are smaller.