Exhaust headers

[TVRmuppet]

I had an exhaust blow on the offside. I have just got the header from this side off. Is it easier or harder to do the near side? 4.0 1994.

I did think of de-precatting,but discretion may be the better part of valour and I may just fix the blow. I am concerned about taking out the precats anyway as I might take it on a track day when we take up our hill climb mini and 100Db is hard enough to get. As you can see trying to decide what to do...

Any tips on refitting the header, the back bolt is a b*****d.

Steve

[spend]

Remove starter / afm ... & they are pretty much the same I reckon. Copper slip & make sure nuts & washers go on studs nicely before you start reassembly. Not sure pre-cats decrease volume, removal changes the note a bit tho. Go on get em out, 1 less thing to go wrong and a bit more grunt into the bargain.

Dave

[GreenV8S]

spend said:

Remove starter / afm ... & they are pretty much the same I reckon. Copper slip & make sure nuts & washers go on studs nicely before you start reassembly. Not sure pre-cats decrease volume, removal changes the note a bit tho. Go on get em out, 1 less thing to go wrong and a bit more grunt into the bargain.

Dave

Would he be using studs? They are fitted with bolts as standard. On the V8S the manifolds are fitted and removed from above, can't you do that on the Chimaera? I would recommend some new K-head ARP bolts and a good ratchet ring spanner when you come to refit it, it makes a world of difference. Also make sure you have the metal composite gaskets ready.

[spend]

Dohhh recently did the LR manifold ~ it was a clear picture in my clouded mind :-) , still applies clean the threads first its a tad easier if you can spin them in (and every little helps unless you are an octopus to hold the gaskets / wiggle the manifolds / tighten up 8 bolts all at once / collect lock washers/bolts from floor / play Yankee Doodle Dandy / scratch nose ... & still have hands/tentacles to spare ).

Apologies Dave

[shpub]

A half moon obstruction spanner will work wonders, especially on the back bolts.

[victormeldrew]

GreenV8S said:

spend said:

Remove starter / afm ... & they are pretty much the same I reckon. Copper slip & make sure nuts & washers go on studs nicely before you start reassembly. Not sure pre-cats decrease volume, removal changes the note a bit tho. Go on get em out, 1 less thing to go wrong and a bit more grunt into the bargain.

Dave

Would he be using studs? They are fitted with bolts as standard. On the V8S the manifolds are fitted and removed from above, can't you do that on the Chimaera? I would recommend some new K-head ARP bolts and a good ratchet ring spanner when you come to refit it, it makes a world of difference. Also make sure you have the metal composite gaskets ready.

It's practically impossible to get a spanner onto the bolts and apply any leverage at all from above on some of them, even with the ARP bolts (which I have fitted). It is a LOT easier with the ARP bolts, but there are still a couple of bolts each side that you have to do from underneath, unless you are graced with the hands of a babboon. I don't find the starter to be a problem (other than avoiding the connections with the spanner ), but the exhaust side is a PITA.

[victormeldrew]

shpub said:

A half moon obstruction spanner will work wonders, especially on the back bolts.

- esp a ratchet one! Except for the middle headers where the bottom bolt is too close to the pipe to get a ring spanner over - or do you have a half moon open ended? I'd kill for a 3/8 one of those!

[TVRmuppet]

Thanks all, I'm just off to get the gaskets. Looking forward to having no skin on my knuckles.

Decided to leave the precats in, they look in good nick.

Let you know if it goes in ok

Steve

[-JUT-]

TVRmuppet said:

Thanks all, I'm just off to get the gaskets. Looking forward to having no skin on my knuckles.

Decided to leave the precats in, they look in good nick.

Let you know if it goes in ok

Steve

Why leave them in, even if they are in good nick? You don't need them for the MOT, and removing them gives you a considerable reduction in under-bonnet temps. I'm actually planning on taking my headers off in the next couple of months, purely for the purpose of removing the pre-cats.

[That Daddy]

-JUT- said:

TVRmuppet said:

Thanks all, I'm just off to get the gaskets. Looking forward to having no skin on my knuckles.

Decided to leave the precats in, they look in good nick.

Let you know if it goes in ok

Steve

Why leave them in, even if they are in good nick? You don't need them for the MOT, and removing them gives you a considerable reduction in under-bonnet ,temps. I'm actually planning on taking my headers off in the next couple of months, purely for the purpose of removing the pre-cats.

yes same here JUT,TvrMuppet just do it you know it makes sense,you be glad you did.

[TVRmuppet]

Put back the header with a new gasket. Went back much easier than I thought. I left the precat in and the car runs as silky as silky the silkworm. The tappet noise that was diagnosed by the local engine shop wasn't at all.

I left them in as I don't need the car to go faster or be louder. To put things into perspective I am now on 9 points and have to keep to the speed limit :-( Our mini which is for track days and sprints accelorates faster, so that will have to do for speed at the moment.

[pic] www.locostbuilders.co.uk/upload/minitwincam.JPG [/pic]