280z and 280zx exhaust manifold

[Dyst]

Hi, so I've found a tubular exhaust manifold for cheap but its listed as "1977 to 1987 280z/280zx non turbo manifold"
It should still fit right?

Thanks

 

[TimFZ]

I would imagine it would fit pretty much any L series engine but the internal diameter of the individual outputs and of the collectors will have a significantly different effect if you are 2 litre or 3 litre. A smaller bore could give more low down torque but stifle higher rpm output in a larger engine due to the higher gas velocity as the exhaust gas travels down the pipe. On the other hand a large bore would reduce low rpm torque in a smaller engine but be less restrictive at high rpm. look for similar length pipes before collectors. If it is a 3 to 2 to 1 type it will offer a wider torque spread than a 6 to 1 type which are really for high output.

I'm guessing as it states 1977 on, it is intended for the 2.8 litre engines as standard but it is not clear if this covers other markets.

 

[Dyst]

Thanks for your input, I have a standard L28 but plan on deleting egr and stuff, maybe mild cam but haven't done enough research on that lol, also read somewhere the original exhaust manifold is garbage so might aswell switch it out, I'm not looking for big power differences anyways. My main concern was just the bolt holes lining up and stuff, really appreciate the help man, thanks again

 

[TimFZ]

Be careful changing cams on an older engine without a rebuilt head. the greater cam lift will push the unworn and possibly carbonised part of the valve stem through the oil seals and you could end up with burning more oil / smoke. Also, old springs could result in high rpm valve bounce. unless you go no higher than "fast road" cams you will lose low down torque which could make it feel less powerful on the road in everyday use.

If you really want power, go for a rebuilt head with the largest valves you can, ported, and then also upgrade manifold and intakes but getting more than 25% more power on an otherwise standard block is pretty unlikely. Also, use higher octane fuel for an additional 5% (ish) power!

 

[jonbills]

Thanks for your input, I have a standard L28 but plan on deleting egr and stuff, maybe mild cam but haven't done enough research on that lol, also read somewhere the original exhaust manifold is garbage so might aswell switch it out, I'm not looking for big power differences anyways. My main concern was just the bolt holes lining up and stuff, really appreciate the help man, thanks again

You also need to check/confirm the bolts and connections at the other end. Unless the manifold is designed to work with the stock exhaust system you're going to have some work connecting it.

 

[Dyst]

Theres a local exhaust shop I can push it to XD
But it should bolt up to the factory system but you know how most "bolt ons" are lol, Never really thought about it, thanks for enlightening me on that fact haha

 

[Mr Tenno]

Theres a local exhaust shop I can push it to XD
But it should bolt up to the factory system but you know how most "bolt ons" are lol, Never really thought about it, thanks for enlightening me on that fact haha

You'd also be bolting on something designed for a '77 onto a '75 - the cars had some significant structural changes in '76 so it may not even be in the same position.

 

[SeanDezart]

I believe 'your' header has round ports, check that that yours will match and in any case, there won't be a compatibility issue - the flange may not be the same thickness as your inlet manifold and check the straightness of the flange against the engine head - thinner flanges may warp under welding (the primary pipes).
Also, the 'gasket' supplied with it is quite useless as you should be using single inlet/outlet version.
I don't believe that the year makes any difference - these could fit on 240Zs but for their round outlet ports !