[Coupes33]

As part of getting a built engine, I have had the head ported to gain some more performance. Mick at North Brisbane Cylinder Heads did the work and the results have been quite pleasing.

[NoGuru]

Nice, thanks for sharing. Hard to say if you will notice the gains but post up if you do.

[jzx_andy]

This looks great. Forgive me but I have very little knowledge, yet have many questions about this sort of stuff. I've read about others swapping to an N53 head and doing other valvetrain modifications to lower the amount of required boost to make the same power, etc.

At what stage does head porting and valvetrain mods become desirable or viable in the world of N54 modding? Is it simply a thing worth considering once the motor is out and you're already invested into a block build, or are there more specific goals that can be achieved with head mods, like safely revving the motor past 7k or so on?

I'd definitely appreciate if you could explain these sorts of things in greater detail, as there aren't many Aussies talking about this sort of stuff in the N54 world.

[NoGuru]

Originally Posted by jzx_andy

This looks great. Forgive me but I have very little knowledge, yet have many questions about this sort of stuff. I've read about others swapping to an N53 head and doing other valvetrain modifications to lower the amount of required boost to make the same power, etc.

At what stage does head porting and valvetrain mods become desirable or viable in the world of N54 modding? Is it simply a thing worth considering once the motor is out and you're already invested into a block build, or are there more specific goals that can be achieved with head mods, like safely revving the motor past 7k or so on?

I'd definitely appreciate if you could explain these sorts of things in greater detail, as there aren't many Aussies talking about this sort of stuff in the N54 world.

It's like everything when it comes to modding, it really depends on your goals.
You could just replace just the head parts for more reliability, or you could upgrade them for more efficiently which can equate to more power and flow.
Upgrading the head usually means higher revs which also equates to more power.

[donR]

Very nice job.

I've never had a close look at an N54 motor but the benefits depend on how well everything is matched up including the inlet and outlet ports to the manifolds. Any edges or obscure castings to obstruct the flow should be removed. Of course enlarging the ports can also help increase air volume and flow which will make more of a difference in an NA engine.

With that said I'd also be checking how well your manifolds line up with your new machined ports, you can use the gaskets as a template and machine right up to the edges.

Back in the day I pulled my old M20 engine apart and I was surprised how poorly the manifolds matched up with the inlet and outlet ports. I machined them up as well as improving the porting. Ran very nice afterwards. A bit like a race engine.

I would also get everything perfectly balanced and blue printed while you are there.

[Aussieatlarge]

Originally Posted by donR

Very nice job.

I've never had a close look at an N54 motor but the benefits depend on how well everything is matched up including the inlet and outlet ports to the manifolds. Any edges or obscure castings to obstruct the flow should be removed. Of course enlarging the ports can also help increase air volume and flow which will make more of a difference in an NA engine.

With that said I'd also be checking how well your manifolds line up with your new machined ports, you can use the gaskets as a template and machine right up to the edges.

Back in the day I pulled my old M20 engine apart and I was surprised how poorly the manifolds matched up with the inlet and outlet ports. I machined them up as well as improving the porting. Ran very nice afterwards. A bit like a race engine.

I would also get everything perfectly balanced and blue printed while you are there.

Originally Posted by donR

Very nice job.

I've never had a close look at an N54 motor but the benefits depend on how well everything is matched up including the inlet and outlet ports to the manifolds. Any edges or obscure castings to obstruct the flow should be removed. Of course enlarging the ports can also help increase air volume and flow which will make more of a difference in an NA engine.

With that said I'd also be checking how well your manifolds line up with your new machined ports, you can use the gaskets as a template and machine right up to the edges.

Back in the day I pulled my old M20 engine apart and I was surprised how poorly the manifolds matched up with the inlet and outlet ports. I machined them up as well as improving the porting. Ran very nice afterwards. A bit like a race engine.

I would also get everything perfectly balanced and blue printed while you are there.

Many eons ago i had a 1600 miata with a twin screw blower on it. One night i got board and ported the crap out of the ports. I don't recall how much better it ran but I could never understand why my maximum boost dropped off after porting. I realised years later that it a good thing. The blower had finite air flow and did not have to create as much pressure to flow that volume of air as before. Those were the days. AFM plus variable rate fuel pressure regulator (controlled by manifold vacuum / boost). It was a fun car. I was living in Colorado at the time. One morning while getting onto the freeway I checked for cops and when all was clear wheel spun through first into second and kept my foot in it About 20 seconds later a cop lit me up. I got off the freeway and pulled into a car park. He asked my why i thought he was pulling me over. I said it depended on how long he had been behind me. He said "since the surface roads". I said "oh shit" he saw my boost gauge and said "i didn't think a stock miata could light up the tires like that". He went on to say that he got up to 100mph and i was still pulling away from him. If you live in Australia like I do now, you won't believe that he let me off with a warning.

[Coupes33]

Originally Posted by jzx_andy

This looks great. Forgive me but I have very little knowledge, yet have many questions about this sort of stuff. I've read about others swapping to an N53 head and doing other valvetrain modifications to lower the amount of required boost to make the same power, etc.

At what stage does head porting and valvetrain mods become desirable or viable in the world of N54 modding? Is it simply a thing worth considering once the motor is out and you're already invested into a block build, or are there more specific goals that can be achieved with head mods, like safely revving the motor past 7k or so on?

I'd definitely appreciate if you could explain these sorts of things in greater detail, as there aren't many Aussies talking about this sort of stuff in the N54 world.

It has been well documented how badly the standard N54 head flows so as I was having my engine built and had to wait months for the JE pistons, I decided to have the head ported. I wasn't after a radical job but the results were quite good. With the head flowing more efficiently, I am hoping for more power at the same boost level or the same power at a lower boost level. I have retained the standard valves and springs so I am not after extra revs. 7,000rpm will suit me. Reliability is my main goal with the built engine with a bit extra hp as a bonus.

[Coupes33]

Originally Posted by donR

Very nice job.

I've never had a close look at an N54 motor but the benefits depend on how well everything is matched up including the inlet and outlet ports to the manifolds. Any edges or obscure castings to obstruct the flow should be removed. Of course enlarging the ports can also help increase air volume and flow which will make more of a difference in an NA engine.

With that said I'd also be checking how well your manifolds line up with your new machined ports, you can use the gaskets as a template and machine right up to the edges.

Back in the day I pulled my old M20 engine apart and I was surprised how poorly the manifolds matched up with the inlet and outlet ports. I machined them up as well as improving the porting. Ran very nice afterwards. A bit like a race engine.

I would also get everything perfectly balanced and blue printed while you are there.

The porting didn't involve widening the entry sizes to the ports. They were well matched to the manifold prior to porting. The engine will be balanced and blueprinted.

[Coupes33]

Originally Posted by Aussieatlarge

Many eons ago i had a 1600 miata with a twin screw blower on it. One night i got board and ported the crap out of the ports. I don't recall how much better it ran but I could never understand why my maximum boost dropped off after porting. I realised years later that it a good thing. The blower had finite air flow and did not have to create as much pressure to flow that volume of air as before. Those were the days. AFM plus variable rate fuel pressure regulator (controlled by manifold vacuum / boost). It was a fun car. I was living in Colorado at the time. One morning while getting onto the freeway I checked for cops and when all was clear wheel spun through first into second and kept my foot in it About 20 seconds later a cop lit me up. I got off the freeway and pulled into a car park. He asked my why i thought he was pulling me over. I said it depended on how long he had been behind me. He said "since the surface roads". I said "oh shit" he saw my boost gauge and said "i didn't think a stock miata could light up the tires like that". He went on to say that he got up to 100mph and i was still pulling away from him. If you live in Australia like I do now, you won't believe that he let me off with a warning.

I agree Aussie that the boost level should be able to be lowered for the same output. A fast Miata you had by the sound of it.