How to fit extractors

harlequin2 · Post by **harlequin2** » Fri Dec 19, 2014 8:04 am

I'd be interested to hear from anyone who has fitted new exhaust headers. I have some and have crawled under the car to see how I might go about removing the old and installing the new, but it looks like a difficult job, so I'd like to hear about problems and pifalls before launching into it.

asyado · Post by **asyado** » Fri Dec 19, 2014 4:09 pm

Hey there,
well you are right, the job ain't an easy one, that is unless you have small Japanese fingers, lol, to reach those inlet/exhaust nuts and bolts.
You will have to check to see if the original heat shield between the carbs and exhaust manifold will still fit up once the new headers are in place, if it doesn't, then it may need some slight modification to be re installed back into place.
Obviously the job is best done with the motor cold and as exhaust nuts are usually the worst to get started in turning without shearing them off from the studs, then I'd be squirting some CRC onto the buggers the previous day to let the slippery stuff do its work all for you in getting off without having to replace head studs. Though you might find the condition of them might warrant a new set while you have both the carbs and exhaust manifold off and can inspect them closer up.
If re using the same gasket, but I would personally get a new one. You will need to apply some kind of sealant to it, as the gasket will have lost its crush up effect and may pose a possible exhaust/ inlet leak when re fitted and everything is tightened up again.
Usually the outflow of the headers will be a larger diameter than the standard exhaust system, so hopefully you have an adaptor to link into the remaining exhaust system and really, if you are fitting headers, then the rest of the exhaust needs to be of the same pipe size as well, to benefit from the better flow of exhaust gases from the motor, as this is what you are trying to achieve in the first place.
Are the headers you have, do they have square or round ports where the flange bolts to the side of the head. If your head exhaust ports are round, but the header flange ports are square, then there will be problems with exhaust gas flow.
Match round to round, or square to square for head and header flange matching.
I'd allow at least half a day to do the job properly and with all things during the job going well.
Catcha,
Nigel aka asyado

djz · Post by **djz** » Fri Dec 19, 2014 5:23 pm

I think he has a 350Z.

agecage · Post by **agecage** » Sat Dec 20, 2014 10:52 am

Lol. There's no easy way. Try remove as many parts as you can to gain better access. It will be tricky, make sure you have a varied range of spanners and crescents.

350ZEB · Post by **350ZEB** » Sat Dec 20, 2014 3:34 pm

As above, heaps of different sockets (especially single hex) if it feels like its going to round off, put a smear of valve grinding paste in the socket, makes a world of difference. You also need a lot of extensions and a good torch for unbolting from the cats and I'd say you'll be in for a bad time if you try and do it without a hoist, those cats are heavy when your lying on your side trying not to drop them on your face.

harlequin2 · Post by **harlequin2** » Sat Dec 20, 2014 7:04 pm

djz wrote:I think he has a 350Z.

Yeah, its a 350Z with the "rev up" engine. I was hoping to hear from someone who had done one and could tell me what major things had to come off, if the engine had to be lifted, etc.
I have lots of sockets! And hammers. And other stuff! But not a hoist, just axle stands.

agecage · Post by **agecage** » Sun Dec 21, 2014 10:21 am

I took the cats of last week in the drive at home. Took me about 3 hours on my back. The extractors looked even harder to get of. Mind you I have a stagea, but I imagine engine baywould be a similar size.

harlequin2 · Post by **harlequin2** » Wed Jan 14, 2015 1:05 pm

Well, I bought a couple of headers a while ago made by DK Sport in the US and we spent a bit of time trying to fit the damn things! I learned that the US makes things for left hand drive cars and if you try to fit them to RHD cars you discover things like the steering column get in the way. What a job that was. Ended up having to cut a small section of pipe out and weld in a piece curved the other way to clear the column. That has put a small restriction in that piece of pipe, but hopefully that will not have any real effect. But a warning to everyone - if you must fit extractors and that seems to be of dubious value - get some made for a RHD car.

BRONZEE · Post by **BRONZEE** » Wed Jan 14, 2015 9:10 pm

harlequin2 wrote:get some made for a RHD car.

Common problem when importing stuff for our cars from the US.