I plan the same mod on my forged 1.6 Rotrex. New ported head is already finished. But I have a set of Mazda 323 Turbo cams. I plan to use the 323 exhaust cam and the NB 1.6 exhaust cam as Intake. I'm running already a 36-2 wheel at the crank. But it's not the best solution for me to run solid lifters on the intake and hydro exhaust. I've been noticed that high oil temperatures reduced the lift of my stock NA cams... Thus results in less power. I ran into trouble with this setup because the intake with the solid lifters should be stable and the exhaust side is reducing the lift when it's hot. And I don't know the best setup for Rotrex.. cams with more duration and overlap or less. It seems that dynamic compression is the important thing. But I have no clue..
Great vid lads, great content. And as ever Awesome to see people utilizing the 1.6 unit. I visit forums over the pond, and if it's not 1.8 base, its dog shit.!???. Kudos to you lads. Keep up the good work. Subs with bells on.
I head a valve problem on cyl 4 recently and i was contemplating doing a 1.8 swap but i changed my mind when i opened up my engine. It is in very good condition and i'll put a SC kit from Bofi soon. I am few hundred pounds away from that moment :D and i just can't wait for it
I have a Mazda mx3 exhaust cam in my 1.6 NA Engine because the mx3 have the CAS on the exhaust Side. But it seems to be the better option using NB cams because of the higher lift. What a lucky day i have 2 or 3 pair of them. Btw my Car is Rotrex c30-74 driven. I want to convert it to 36-2 trigger with Cam Signal because its fully sequential wired. I want to use the FM 37-2 Mode. But i think i have to Test the durations with my Rotrex what its the best for it.
The 1.6 also disappeared from the miata in US models starting in 1994 so they are a minority engine across the NA/NB production run. The early NAs with the 1.6 are prized as the lightest miata and gets lots of love but its almost comical how quickly people start down the path of making up that weight difference and then some. Many getting the full 1.8 swap including the heavier driveteain parts, upsized brakes wheels tires, thicker sway bars, chassis bracing, roll hoops, hard tops etc.
Alex Strömberg The K series engines are roller rocker design and valve clearance can be adjusted by undoing a nut and tightening / loosening a screw. No hydraulic lifters.
Hi I'm thinking about doing the same on my 1.6NB with the exception of using 2 exh NB camshafts. The stock exhaust and intake timing are 110° b/a tdc. Is it possible to use the stock cam angle sensor at the 180° offset that will be achieved by just swapping it in? I'm running a MS3 and really hope I could make this work. If anyone knows something about that I'd love to hear that :) Great work, I really think this is my favourite Miata shop
So I’m curious how the cam angle sensor communicates with the NA ecu, please and thank you. Love this stuff, been trying to find a 94-95 MX3 1.6 exhaust cam for what feels like forever. I think this head swap is fun and I’d like to do it here in the states, excited to see this whole setup running.
BOFI Racing - thanks for the reply. I’m currently on a speeduino based setup from Speedyefi, talking with them last night they suggested I run the whole NB long block and swap to the protege 36-1 crank sensor in place of the CAS. We’re pretty sure the usdm 99-00 nb 1.8 ran the 36-1 and should already have a decoder in tunerstudio settings.
Tell me about it... We need to change the oil pump to an NB one we have so we can mount the crank sensor on it, but then it shouldn't be much longer we hope. The supercharger kits are flying out! Keep an eye on our Facebook for any sales
The main difference between hydraulic and solid cams is the RAMP design. Hydraulic lifters take up all the slack in the valve train by .004"-.005", and have the valve about .001" off the seat at that ramp height. Generally by .015" or so, hydraulic cams have reached PEAK acceleration. This is about equal to .022" valve lash. Set the valve lash at .024", and you've put ALL the cam acceleration into the rocker arm BEFORE it contacts the valve. OUCH!!! Talk about slamming a valve open! If you want to run solids on a hydraulic cam, you have to set the lash at .004" to .006", never looser than .008". copy pasted from google but seems accurate
The best way is to make a piston stopper using an old spark plug that is drilled out and tapped to take a threaded rod. Then make a note on the degree wheel where the piston stops both clockwise and counter clockwise, and true TDC is halfway between the two
Have both heads Side by Side on the bench. Its the same head Same diameter of intake and exhaust ports. NB Heads are structured oudside from the cast. NA heads are smooth, NB Heads are ruff like a waffle structure .The only differences that can ne influce the output are the cams and Solid lifters.
You can get away with gigantic skims on the heads before they become interference engines. We haven't changed the valves, so the diameter of the recess is unaffected. The increase in lift is pretty small at 0.4mm and the head was only faced. Many racers skim 1.5mm off the heads so we've got plenty of wiggle room.
Are you sure your ADV and RET reference to more or less rpm for peak power was correct? I thought the exhaust cam was what you said, but inlet is the opposite, ADV gives more overlap and works more efficiently at higher rpm??
Great comment. With the intake you are correct that you would advance the intake for more overlap as it would be opening sooner. However, that would bring the power band down the RPM range. If we retard the intake, it reduces overlap but moves the power band up. We can then increase the overlap and scavenging for NA applications by then also retarding the exhaust. In this case, we may choose to retard the intake to move the power band up, which will then reduce overlap slightly. We can then dial the overlap out further by advancing the exhaust, so both cams are moved in the opposite. In an NA application we would often move both cams in the same direction but by different amounts.
Yes, although we'd probably swap the cams round to put the one with more lift in the exhaust. We will get a bunch of cams and test them all on a HLA car when our dyno turns up to show what actually happens
I'm so confused, is this a 1.6 block with a 1.8 head? This was my first thought when it came to making the 1.6 flow better but every forum I asked on told me it wasn't possible. If this is true, the cheapest and most effective path to boost would be a NA6 on a Arduino based ECU; cast Mani, etc.
That "perfect" in the beat was actually at perfect timing.
😉
Great vid.
A mix of MCM and Engineering Explained in one show.
Thanks 😊
BLOWN MY MIND WITH THIS !!!! DOPE UPGRADE
Thanks ☺️
Surprisingly good content and production guys! You deserve many more subscribers!
Thanks! We're still a new channel. Hopefully we can feature some cool customer cars soon!
Great content and editing 👌
I've only been watching you for a few weeks now but I actually thought you were both one person and just grew a beard and changed your hair 😂
We're like Jekyll and Hyde
I plan the same mod on my forged 1.6 Rotrex. New ported head is already finished. But I have a set of Mazda 323 Turbo cams. I plan to use the 323 exhaust cam and the NB 1.6 exhaust cam as Intake. I'm running already a 36-2 wheel at the crank.
But it's not the best solution for me to run solid lifters on the intake and hydro exhaust. I've been noticed that high oil temperatures reduced the lift of my stock NA cams... Thus results in less power. I ran into trouble with this setup because the intake with the solid lifters should be stable and the exhaust side is reducing the lift when it's hot.
And I don't know the best setup for Rotrex.. cams with more duration and overlap or less. It seems that dynamic compression is the important thing. But I have no clue..
Great vid lads, great content. And as ever Awesome to see people utilizing the 1.6 unit. I visit forums over the pond, and if it's not 1.8 base, its dog shit.!???. Kudos to you lads. Keep up the good work. Subs with bells on.
🔔 Thanks! There is no argument against the extra displacement... All the race series here use the 1.6 though so that make us feel better 😂
I head a valve problem on cyl 4 recently and i was contemplating doing a 1.8 swap but i changed my mind when i opened up my engine. It is in very good condition and i'll put a SC kit from Bofi soon. I am few hundred pounds away from that moment :D and i just can't wait for it
I have a Mazda mx3 exhaust cam in my 1.6 NA Engine because the mx3 have the CAS on the exhaust Side. But it seems to be the better option using NB cams because of the higher lift. What a lucky day i have 2 or 3 pair of them. Btw my Car is Rotrex c30-74 driven. I want to convert it to 36-2 trigger with Cam Signal because its fully sequential wired. I want to use the FM 37-2 Mode. But i think i have to Test the durations with my Rotrex what its the best for it.
The 1.6 also disappeared from the miata in US models starting in 1994 so they are a minority engine across the NA/NB production run.
The early NAs with the 1.6 are prized as the lightest miata and gets lots of love but its almost comical how quickly people start down the path of making up that weight difference and then some.
Many getting the full 1.8 swap including the heavier driveteain parts, upsized brakes wheels tires, thicker sway bars, chassis bracing, roll hoops, hard tops etc.
I see those superchargers behind you! Hopefully ones of those is mine. :)
Yep! There are more waiting to be prepared too 😁
Sorry to say adjusting the valve clearance on a Honda is piss easy, no messing round either with shims or gunk in the hydraulic lifters
Yet another reason Mary needs a K20 😅
No modern Honda has solid lifters
Alex Strömberg The K series engines are roller rocker design and valve clearance can be adjusted by undoing a nut and tightening / loosening a screw. No hydraulic lifters.
@@seany8787 i know what adjusting valves is, I do it almost every day at work. Why do they not just have hydraulic lifters
Alex Strömberg because they arent as good as solid lifters for high RPM applications. Valve bounce
I need to hang out with u guys!! I want some of this knowledge👌!!
Hi I'm thinking about doing the same on my 1.6NB with the exception of using 2 exh NB camshafts. The stock exhaust and intake timing are 110° b/a tdc. Is it possible to use the stock cam angle sensor at the 180° offset that will be achieved by just swapping it in? I'm running a MS3 and really hope I could make this work. If anyone knows something about that I'd love to hear that :)
Great work, I really think this is my favourite Miata shop
So I’m curious how the cam angle sensor communicates with the NA ecu, please and thank you. Love this stuff, been trying to find a 94-95 MX3 1.6 exhaust cam for what feels like forever. I think this head swap is fun and I’d like to do it here in the states, excited to see this whole setup running.
This car will be getting an ME442, so we are able to use different sensors. Sounds like a fun experiment, let us know how you get on!
BOFI Racing - thanks for the reply. I’m currently on a speeduino based setup from Speedyefi, talking with them last night they suggested I run the whole NB long block and swap to the protege 36-1 crank sensor in place of the CAS. We’re pretty sure the usdm 99-00 nb 1.8 ran the 36-1 and should already have a decoder in tunerstudio settings.
@@MonkeyWrenching no na/nb ever came with 36-1 but as you said you can use the protege wheel.
Put back that engine ffs, i wanna see how it works, i can't wait! I'm also hunting for a nice sale or something to get a supercharger kit from you :D
Tell me about it... We need to change the oil pump to an NB one we have so we can mount the crank sensor on it, but then it shouldn't be much longer we hope. The supercharger kits are flying out! Keep an eye on our Facebook for any sales
Yeah, i'm all eyes anyway :))
Hi, does a 1.8 non vvt oil pump fit a 1.6?
please tell me where you got the intake manifold!! PLease!!
So is this 2 nb 1.6 exhaust cams? Any template for cam drilling?
Pretty sure the NA cams have a different profile to NB cams to accommodate for The HLAs......
There are much more aggressive cams out there for the HLAs than the NB cams, but that difference in cams from Mazda should hopefully benefit us
The main difference between hydraulic and solid cams is the RAMP design. Hydraulic lifters take up all the slack in the valve train by .004"-.005", and have the valve about .001" off the seat at that ramp height. Generally by .015" or so, hydraulic cams have reached PEAK acceleration. This is about equal to .022" valve lash. Set the valve lash at .024", and you've put ALL the cam acceleration into the rocker arm BEFORE it contacts the valve. OUCH!!! Talk about slamming a valve open! If you want to run solids on a hydraulic cam, you have to set the lash at .004" to .006", never looser than .008".
copy pasted from google but seems accurate
@@Nebbia_affaraccimiei there is no rocker arm on these engines .... Don't believe everything on interweb ....;-)
do the nb 1.6s across the pond have vvt? never really thought about it till now🤷♂️
No VVT, just a cam angle sensor on the front and a crank angle sensor.
What work have you had done to the valves? Re-cut old or new and cut? Are the springs new too?
Recut the old valves and seats, new guides, upgraded springs sold on the website
What is the specific tool you used to find true tdc? Need to degree my cams on my mx5!
The best way is to make a piston stopper using an old spark plug that is drilled out and tapped to take a threaded rod. Then make a note on the degree wheel where the piston stops both clockwise and counter clockwise, and true TDC is halfway between the two
What are the benefits to nb head on na, apart from cam mod? Does nb head flow better?
Supposedly, we'd need to get them on a flow bench though to confirm
Have both heads Side by Side on the bench. Its the same head Same diameter of intake and exhaust ports. NB Heads are structured oudside from the cast. NA heads are smooth, NB Heads are ruff like a waffle structure .The only differences that can ne influce the output are the cams and Solid lifters.
@@BOFIRacingTV Did you ever find out if it flows better? Am I right in thinking the NB 1.6 takes the same manifold/header as a NA 1.6?
I hope this things got some chop
Choppy cams are a function of lots of overlap/low lobe separation angle, which is good for NA but not for forced induction. We want a smooth idle 😊
@@BOFIRacingTV I think he means power.
Does this turn the engine into an interference engine? I'm pretty sure the recess in the piston is smaller on that side.
You can get away with gigantic skims on the heads before they become interference engines. We haven't changed the valves, so the diameter of the recess is unaffected. The increase in lift is pretty small at 0.4mm and the head was only faced. Many racers skim 1.5mm off the heads so we've got plenty of wiggle room.
@@BOFIRacingTV awesome, thanks! I'll add this to the list of things to mess with.
great sleeping material.
How was your nap?
1 question i have is where i can get one of those exhaust cams from an nb? would like a seller that is in EU. regards, regular customer
We'd look on eBay or Facebook market place
Are you sure your ADV and RET reference to more or less rpm for peak power was correct? I thought the exhaust cam was what you said, but inlet is the opposite, ADV gives more overlap and works more efficiently at higher rpm??
Great comment. With the intake you are correct that you would advance the intake for more overlap as it would be opening sooner. However, that would bring the power band down the RPM range. If we retard the intake, it reduces overlap but moves the power band up. We can then increase the overlap and scavenging for NA applications by then also retarding the exhaust. In this case, we may choose to retard the intake to move the power band up, which will then reduce overlap slightly. We can then dial the overlap out further by advancing the exhaust, so both cams are moved in the opposite. In an NA application we would often move both cams in the same direction but by different amounts.
Can you perform the swap on a 1.8 NA head?
You sure can
would this work on a supercharged setup?
Yes, although we'd probably swap the cams round to put the one with more lift in the exhaust. We will get a bunch of cams and test them all on a HLA car when our dyno turns up to show what actually happens
Hi, what intake manifold do you have on it now?
It's a hand made one-off 😵
BOFI Racing I thought it looked different, from the usual.
I’m thinking of fabricating one myself but I lack plenum design knowledge.
less overlap = higher compression?
Higher dynamic compression, in theory, which is related to how much air can be sealed in, but not a higher compression ratio
I'm so confused, is this a 1.6 block with a 1.8 head? This was my first thought when it came to making the 1.6 flow better but every forum I asked on told me it wasn't possible.
If this is true, the cheapest and most effective path to boost would be a NA6 on a Arduino based ECU; cast Mani, etc.
Nvm, figured it out. Had no clue NB's had a 1.6 option out there, your screwed emission standards have potentially helped my old 1.6 spool faster!
Could I do this on my 99 1.8?
Yes, the hardest part is redrilling the pulley which would need to be done very accurately if you were to use the original ones and not adjustables
This thumbnail is just begging to be a soy boy meme.