Fitting Aftermarket Exhaust Manifold/Headers

Woody928

Events Officer
Staff member
Club Member
Hi All,

Looking for some inside hints and tips from those of you whole have been there and done it all before. I'm about to take delivery of one of Sean's lovely Racesport Headers and full system for the L26 on my Z. I'm planning on installing this on my driveway at home in the next couple of weeks having put the car on ramps and axle stands.

I'm generally very mechanically minded and pretty good with spanners however having not installed one of these before on an old school engine I wanted to ask if anyone has any inside hints and tips or advise useful hardware or specialist tools that will help and make my life easier?

Planning on removing the air filters, disconnecting the fuel lines from the carbs, throttle cables and then taking the intake manifold straight off with the carbs still fitted to gain access and work from there....

Everything came off last summer for some overhaul work so I'm hoping that nothing should be seized up. The big one that I'll be concerned over will be snapping studs, however any input or advice would be gratefully received!

This is what I'll be working with:
IMG_8977 by Mark Woodrow, on Flickr
 

jonbills

Membership Secretary
Site Administrator
It should all be easy Mark if the old stuff has been off that recently. Sean's stuff fits together nicely. I've done mine a few times, just work front to back nice and steady and don't do anything up proper tight until its all lined up and and in the right place.
 

AliK

Vehicle Dating Officer
Staff member
Club Member
Would exhaust paste be recommended between joints or is that heresy!?
 

Paul_S

Club Member
I didn't use any paste when I fitted mine either.

It sounds like you've got it sussed to me mate :)
 

uk66fastback

Club Member
Have written down somewhere handy a list of the torque specs for everything you can ... when things come off, put nuts back on so as not to lose anything. Take lots of pics before disassembly.
 

SeanDezart

Well-Known Forum User
Some people have used paste, others have replaced the T-bolt clamps with locally sourced 'stronger' versions. Loosely fit the manifold and secondary pipe and then fit from rear to front finally connection up the resonator to the secondary pipe then tighten up. Unless someone has better ideas...:blush:
 

AliK

Vehicle Dating Officer
Staff member
Club Member
So Mr Woods, when I took mine off for the engine transplant. It really was a piece of cake.

My recommendation is to make a cradle for your carbs to sit upright while off the car - as you don't want them to turn upside down. I have read that can do bad things to your floats.

Also a great time to take the domes off and clean the carbon off the inside.

Put something into the intake and exhaust ports to block them off as your manifold gasket may have glued itself on and you may need to scrape off in situ. You don't want bits going into your engine.

This is a good opportunity to clean your intake manifold too. I simonise VHT silvered mine and it looks like new without looking blinged.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/370802664846

Get some heat shield metal and make a proper heat-shield. My ceramic coated MSA headers get pretty hot and so do the carb bottoms. Sean's primaries are much longer and uncoated and therefore more surface area to emanate heat. It is a great shame to cover them up but it's worth it if you like your carbs to suck cool air with those pancakes. Also good for the longevity of your rubber lines to the float chambers and everything in there that will be heat soaking when the engine is off.

I used Loctite green thread-lock on my nuts - it does smart a bit though! ;)

This is also a great time to get new nuts on if your old ones are crusty / rusty.

I hope the studs would be long enough as Sean's header looks beefy!!

When you put your carbs back on, it doesn't matter how careful you are, they will go out of balance. Use a synch tool to re-adjust.

This is what I use and it's worth every penny

ae1c3eaf21c1f1e589416e732d908f82.jpg


https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/272202975686

Drive her and then after a 100 miles or so check all nuts / torques etc as the thermal cycling / expansion may have loosened things off. Also your gasket will settle in and you may get the tiniest of air leaks/loose carbs etc.

That is all I can think of for now. Off to bed but if insomnia says hello, I will terrorise you again!!

Ps. You won't snap studs - they are hardy things and if anything they may be stuck to the nuts and you will end up unscrewing them out of the head.
 
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nospark

Well-Known Forum User
Is the general advise to fit new studs or can the old ones be refitted if they look in good nick . What are the options for sourcing studs and is any particular brand recommended ? (I ask because with head bolts its strongly advised to go for new and get ARP bolts)
 

uk66fastback

Club Member
I've got my intakes/carbs and manifold off atm. All the bolts came off easily except the ones joining the exhaust and manifold where one proved a b*gger and had to be sawn off. I then got all the studs out of the manifold. If Sean's item comes with new studs then I'd fit them. You'll know after the first one or two whether they're going to come out easily ...

xTvgu6oY.jpg
 
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AliK

Vehicle Dating Officer
Staff member
Club Member
Sean's doesn't come with studs.

I bought my studs from MSA and the ones in my old head were a breeze to get out. I didn't have a stud extractor so I tightened 3nuts on against each other and just used a spanner.

Stud removers will kill the thread but it doesn't mater if you plan to renew them.

Edit: the only ones that gave gave me a hard time were around the water outlet that had corrosion - but I wound them in then out and took my time - nothing sheared. Failing that you can just get some heat on and it does wonders. When I help my fast in-law with his farming machinery / rusted on parts, his favourite two tools are his gas torch and sledgehammer!!!! ;)
 
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uk66fastback

Club Member
If after being cleaned up, the threads are okay on the original studs, then I would use them. The old double nut trick worked wonders for me also!
 

Woody928

Events Officer
Staff member
Club Member
It should all be easy Mark

Those famous last words Jon :EXTRAlol: Thanks for the input...

Have written down somewhere handy a list of the torque specs for everything you can ... when things come off, put nuts back on so as not to lose anything. Take lots of pics before disassembly.

Thanks Mike, do you know any torque settings off the top of your head or is that haynes manual territory?

Some people have used paste, others have replaced the T-bolt clamps with locally sourced 'stronger' versions. Loosely fit the manifold and secondary pipe and then fit from rear to front finally connection up the resonator to the secondary pipe then tighten up. Unless someone has better ideas...:blush:

Sounds as good a plan as any I would say!

My recommendation is to make a cradle for your carbs to sit upright while off the car - as you don't want them to turn upside down. I have read that can do bad things to your floats.

Also a great time to take the domes off and clean the carbon off the inside.

Put something into the intake and exhaust ports to block them off as your manifold gasket may have glued itself on and you may need to scrape off in situ. You don't want bits going into your engine.

This is a good opportunity to clean your intake manifold too. I simonise VHT silvered mine and it looks like new without looking blinged.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/370802664846

Get some heat shield metal and make a proper heat-shield. My ceramic coated MSA headers get pretty hot and so do the carb bottoms. Sean's primaries are much longer and uncoated and therefore more surface area to emanate heat. It is a great shame to cover them up but it's worth it if you like your carbs to suck cool air with those pancakes. Also good for the longevity of your rubber lines to the float chambers and everything in there that will be heat soaking when the engine is off.

I used Loctite green thread-lock on my nuts - it does smart a bit though! ;)

This is also a great time to get new nuts on if your old ones are crusty / rusty.

I hope the studs would be long enough as Sean's header looks beefy!!

When you put your carbs back on, it doesn't matter how careful you are, they will go out of balance. Use a synch tool to re-adjust.

Drive her and then after a 100 miles or so check all nuts / torques etc as the thermal cycling / expansion may have loosened things off. Also your gasket will settle in and you may get the tiniest of air leaks/loose carbs etc.

That is all I can think of for now. Off to bed but if insomnia says hello, I will terrorise you again!!

Ps. You won't snap studs - they are hardy things and if anything they may be stuck to the nuts and you will end up unscrewing them out of the head.

Duly noted about the carbs Mr K :)

Fortunately my intake manifold is polished and needs no attention so that's one less job.

For the heat shield, I have a cunning plan! Albeit it won't be quite as glamorous as someone who has access to a metal workshop I'm planning to use some of this material. I'm going to bolt it through the same holes as the stock heat shield to hold the top in place and then use stainless metal cable ties around the headers to stop the bottom flapping in the breeze so to speak. Shoud do the job nicely I hope....

https://www.ebay.co.uk/itm/Nimbus-G...ally-Efficient-Fully-Recyclable-/141220172306

I've had my eye on this one for a while albeit never used one before...

https://www.ebay.co.uk/itm/Dellorto-Weber-genuine-synchrometer-carb-balancer-made-in-Germany-not-China/292619761772?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

Any reccomendations on new studs/bolts and where to get them from? I think I plan to reuse mine however I know if I don't have them then I'll definately want them.....

Thanks for the confidence vote! :D
 

SeanDezart

Well-Known Forum User
For the heat shield, I have a cunning plan! Albeit it won't be quite as glamorous as someone who has access to a metal workshop I'm planning to use some of this material. I'm going to bolt it through the same holes as the stock heat shield to hold the top in place and then use stainless metal cable ties around the headers to stop the bottom flapping in the breeze so to speak. Shoud do the job nicely I hope....

https://www.ebay.co.uk/itm/Nimbus-G...ally-Efficient-Fully-Recyclable-/141220172306

Why not attach it to the LHside chassis rail ?
 

Huw

Club Member
Mike at MJP Eastern Autos (Mr.K) can get the studs, probably has them in stock I would guess. Got them for me to fit my bling header.
 
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