mx5cartalk.com

i'm in the process of rebuilding my head, so far the parts i have are:
Custom grind Tighe Cams
Toda camgears
Vition Valve Seals

still need to a few more things like:
Spring kit
Oversized valves

i have been looking at flyin miata for these, but the valves are very pricey, anyone know of other companys producing springs and valves?

with the cams the head has to be shaved to allow the lobes to clear, and laches to be adjusted, something i am not willing to do. So whilst hevn is at the workshop i will be getting a port and polish while i am at it.

the application, i want the engine to be able to rev to 8000rpm happily, i am in the process of building hevn into an N/A screamer that would be seeing regular track/drift/skidpan/drag days.

the other main mod will be a set of individual throttle bodys, and i may rebuild the block but i am thinking of going turbo down the track so the block will not be touched.

anyways, do you think the plans for the head are overkill for the application?

Have i missed something that i should do whilst the head is being worked on?

i'm currently looking for a workshop that would be able to do this, (racers i am looking at you!) in the sydney region. this wont be happening for a while, but still the more i research the better.

Thanks

Belfab racing sells Supertech valves and springs w/ titanium retainers.

But you are still looking at over $500 for a complete set.

They are also available from other sellers through eBay.

I just bought some in for my hi-port head from Belfab, along with some 11:1 pistons for the long nose build and some other bits. They arrived well packed, but the postage cost was excessive. I'm trying to communicate with Jim (the owner) to discuss the OTT shipping charge.

http://www.chikaramotorsports.com

Chikara also sell the Supertech gear. They don't have prices anymore though...and I can't remember how competitive they were.

adamjp wrote:Belfab racing sells Supertech valves and springs w/ titanium retainers.

But you are still looking at over $500 for a complete set.

They are also available from other sellers through eBay.

I just bought some in for my hi-port head from Belfab, along with some 11:1 pistons for the long nose build and some other bits. They arrived well packed, but the postage cost was excessive. I'm trying to communicate with Jim (the owner) to discuss the OTT shipping charge.

hey, i have seen this link before, its not working anymore though. which workshop did your head?

I used a local guy who does alot of work on RB26 and 4G63 engines. Greg from Pro-Engines in Queanbeyan, around 2 1/2 hours south of the M5/M7/Hume intersection.

He has his own flow bench and full workshop. I completely recommend him.

Sasso wrote:Hey, if you're going to go turbo down the track then there's not much point spending money on the head.
And based on the application "track/drift/skidpan/drag days" turbo would be the best.

i may go turbo, the idea of a quad throttle turbo mx-5 makes me drool, it would be costly but it doesnt matter. either way the main goal is a nice n/a mx-5 with some balls behind it, and the fact that not many of these are running around in oz, compared to the bolt on turbo mx-5's. i dare to be different.

Sasso wrote:

MXHEVN wrote:

Sasso wrote: n/a mx-5 with some balls behind it, and the fact that not many of these are running around in oz, compared to the bolt on turbo mx-5's. i dare to be different.

You won't get much torque N/A, take a look at any honda.
There aren't many around for a reason lol. But it would be cool I guess, purely based on noise.

Buy a turbo or super then you can afford to go on holiday with your GF or something.

take a look at honda? you get those k20a civics doing 13's down the strip with the stock engine. theres massive potential behind n/a cars, but it isnt cheap to get right. fuji racings na8 is running low 13's now too, with a set of cams, irtbs, ecu, zorst and a nb8a head, you cant tell me that isnt a good time for an n/a (particualy mx-5 as stock they do 16-17 sec.)

there not around because no one wants to spend the time or money on them, the reason for this is that a turbo or supercharger is cheaper and easier power. just the simple exhaust can give you a massive gain, cant forget that boost controller (turns it up 2psi) easssy power.

yes, the cool factor would be awsome but thats not why i am doing it, thats just a bonus.

another reason why i wont go turbo is because i am on my P's still, wait till i get off them to get one? waiting sucks! and besides i am stuck on n/a. the noise, the throttle response, did i mention the noise?

Sasso wrote:if it floats your boat....
The hondas might do 13's on the drag strip but they still have no torque, you're always at max rpm, it would be a pain to drive on the street, beauty of FI is that the torque is down low and there's more of it to get the same amount of power.
Superchargers have good noise and throttle response too.

Can't wait 'till you build it though, I'd love to see it.

Oh I would have thought to rev to 8000 you'd need to strengthen the rods because the force on them would be huge. You wouldn't want a piston being thrown up through your new head.

in the end, for the applications i would be doing the same thing with a turbocharged 5, i would be stressing the engine more if anything too.
it would be a pain to drive on the street, but by the time this is done it would be a weekend warrior, and garage queen.
yeah supercharges are ok, but like you said, whatever floats your boat.

you'll see it i still want to see yours lol

considering you said that, your probably right, i'll have to do some more research on all of it before hand, to see what would be safe etc.

anyone else have any suggestions/tips/views?

There are two areas in the 1.8s that are bottlenecks in the induction/combustion arena.
They are,
the throttle body,
Mazda really strangled the 1.8s with a 55mm body. It realistically could have done with a 58 or 59 mm and straight up would have produced enough power to keep the critics happy. This is even more relevant for forced induction.

The second area is the next restriction after valve diameters (which you're wise to have already suggested), The ports and chamber.

At the moment I'm looking for people that want more efficiency from their 1.8s to do a group buy on power and torque http://mx5cartalk.com/phpBB-3.0.2/viewtopic.php?f=29&t=32589.

This investment will be the cheapest HP/$$ around. If you were building a 300 HP + motor you would be looking at an additional 50 HP from that $90 investment.

Thats a bang for your buck investment!!!!

Needing 5 people to make it happen, not promising judging by the responses (or lack there of)

Woo wrote:There are two areas in the 1.8s that are bottlenecks in the induction/combustion arena.
They are,
the throttle body,
Mazda really strangled the 1.8s with a 55mm body. It realistically could have done with a 58 or 59 mm and straight up would have produced enough power to keep the critics happy. This is even more relevant for forced induction.

The second area is the next restriction after valve diameters (which you're wise to have already suggested), The ports and chamber.

At the moment I'm looking for people that want more efficiency from their 1.8s to do a group buy on power and torque http://mx5cartalk.com/phpBB-3.0.2/viewtopic.php?f=29&t=32589.

This investment will be the cheapest HP/$$ around. If you were building a 300 HP + motor you would be looking at an additional 50 HP from that $90 investment.

Thats a bang for your buck investment!!!!

Needing 5 people to make it happen, not promising judging by the responses (or lack there of)

I dont quite understand what you mean? we chip in to finalize tests? how much would it cost to do once completed?

throttle body wont be an issue, as i will be running four in the future

Sorry maybe didn't explain it clearly (could be why no takers yet lol)

Porting can be done a few different ways. Usually we match the head port size to be slightly 0.25mm smaller than the gasket opening on the exhaust AND 0.25mm bigger than the gasket on the intake. This ensures that the flow is always from a small cross sectional area to a slightly bigger cross sectional area.
This principle is applied to both the complete inlet and exhaust paths.

Then there is chamber porting. This consists of adjusting the valve seats so that they dont inpede air flow when closed. So thats area 1. The second area is the surface of the chamber and the actual runners, smooth is bad but casting marks are worse. This is where most people take their porting too. It will gain a 60% improvement in flow if you recess the guides and open the runners to induce " Laminar Flow " (area 3). This is called pocket porting

Then we get into the serious stuff
Chamber design is usually intrinsic to the mould that the head has been cast into. The best performance chambers are (and I stress I'm not an expert in this) pent roof chambers. If the head has enough metal then you can turn our head into a pent roof chamber. Another important area is the quench zone which is the flat area around the sides of the chamber that do the final squeeze right at TDC.

The reason we can build a head and do mild porting (areas 1,2,3) is because if you overcut or undercut these areas it doesnt make a lot of difference to the performance. This will cost about $1000 and will give about a 60% improvement in flow.

To get the other 40% (up to its maximum) will cost money for the Research and Developement
The person in Melbourne with the best reputation for getting the maximum is Tony at Speedworks.
Using an old head he will grind and fill and flow till he gets to the 100%
His cost is $90 per hour and has quoted me 10 hours of R&D to do the deed

Dollar wise I'm strapped, the reason is that like you once the R&D is done we still have to replicate his changes to our heads which will cost the $1000. Only difference is this time we know that the changes being made are actually going to give us the edge, power wise.

I'm donating my old head to be sacrificed to do the initial testing (ie cut up with a band saw and ground, filled and flowed) and will also put in 5 hours of R&D

so straight up there is $500 worth of R&D. With another $500 the pattern will be complete and the information will be available to anyone that wants to pay for it.

You could do this R&D yourself (or your head guy could) but it would cost you $1000 plus the $1000 to do your own head (you have to pay that anyway). Doing it this way we all get the result for $90.
$90 vs $1000 ...... I know what I would choose.

I hope that made the situation a bit clearer. It is quite complicated work, but the savings are big if we pool together.

Cheers
Woo

MXHEVN

what track events do you want to run in?? thats the main question.. as if its super sprints theres alot of restrictions depending on the class your going to run in. if its 2f or prod sports or just club days then NA you can go pretty nuts.. but thats just it.. if you want to be competative you will have to go nuts..

the way ive gone is similar to you. im just planning on selling my head in the future when i go turbo and building a replacement turbo topend.

im currently getting a head done to the top of type 2b super sprints regs which basically limits valve sizes no head shaving (for compresion increase reasons) other than that its pretty free other than intake manifolds cant be molestered either i dont think...? nore can flywheels. how ever if you go SVB the only requierment is pretty much it needs rego.. however a honda with similar work will eat you.

the big question to answer is!!
are you after a car your happy with and.. is that a lumpy at idle rev happy NA screamer then ignore what class regs there are build the car you want then see what you can run it in..
but if its about racing it find out what your racing it in then build it to the regs.

if your really after NA power look at a stroker kit aswell and/or raise the compresion ratio.. i hear using NB8C higher comp pistons in an NB8A with a shaved head (20thou) will get you some really nice gains.. and if you've stroked it say with the FM stroker out to 1.99L you will get huge gains down low... nice and torguey. a high quality balance and a 1.6 light as buggery flywheel and clutch setup and you will have a rocket NA that revs like a motor bike.

BUT your looking at well... a very very pricey bit of gear.
stroker kit high comp pistons and all.
4,199 - 4,499
http://www.flyinmiata.com/index.php?deptid=4530&parentid=0&stocknumber=04-66350++A-BEAM

head work
valves, springs, seals, cams, gears, porting and polishing.
for the nb8a you are looking at about 1,400 for tomie pons with a shim kit (mild cam grind really) pluse another 2,000 or so for all the labour and springs etc

quads
1,100-2,000
http://www.efihardware.com/4_cyl.php

ecu
price will vary pending on install, tuning costs aswell as auxiliarys such as wide band oxy and manifold pressure sensors from 2,000 to 3,000

clutch and flywheel
not sure of costs realy but around another 1,000

at the end of it your looking at probably around 10,000 dollars of power mods.. but thats for the BEST NA motor you will get out of an NB8A... id love to see the numbers you'd pull.. let alone sit in it redlining through 1st 2nd and 3rd.

people are going to say thats a race motor and will be crap to drive on the street but thats not true, it all depends on two parts that make the car feel "streetable" and thats the cams and the flywheel/clutch.
if you steer clear of button clutches and dont go to a uber light 1.6 flywheel clutch combo it wont be quiet so revy but it wont feel like stalling so easy, or need to cherp the wheels to take off from standing.
if you choose a cam that will work in a rev range that dosnt need to rev to 10k to work and kills the bottom end, and get the head work done acordingly, it wont need its neck ringed all the time to go anywhere smoothly..

then the next big rectum (but) is thats only the power?? have you got it to turn and stop to its full potential?? woop theres another 10k with out a roll bar!

im no engineer or am i a geneious...so dont take any of this for gospel.. go talk to someone with a flow bench and past experience in motor building.
im just telling you my thoughts as i'm heading down the same road you are and this is what my oppinions are based on at the moment.. please feel free to raise points flame me if you wish but be gentle

thanks for your input irwin, the purpose of the build is to make me happy, i am not going into any competitive racing, just want it set up for the track days, street, basically all round but not a competitive level, just for my own fun, when (if it ever is) it is finished and i feel like being competitive then i'll have a look and see where i can enter. But the main plan is for a nice streetable (different) setup, as i said, it wont be a daily once the power mods come on.

as stated, i already have cams, camgears, valve stem seals and now looking at supertech valves and springs to finish off the head.

i am still tossing around with some ideas for the block, but a stroker kit is on the cards, yes from flyin miata, this wont be for a while though.

i am going to run quad throttles and $1100 is really cheap *clicks link in intrest*

am i only working the motor?

well, no i pretty much have everything to handle the upgraded engine go to myrides section to have a geeze of the mods already on my mx.

ah yes, and i will be running a 6 speed with all this too so that will be the first mod (as its still a fricken auto) then will be the ecu, i have chosen either haltech or the greddy emanage ultimate, along with this i hope to get a rebuilt head so i wont need to retune so much.

as for flaming, i wouldnt do so, i take note of any opinions/tips but if someone comes along and said to me N/A sucks its a waste of money go turbo because its better. then i'd have to flame you

MXHEVN wrote:
as for flaming, i wouldnt do so, i take note of any opinions/tips but if someone comes along and said to me N/A sucks its a waste of money go turbo because its better. then i'd have to flame you

Go on Go Turbo
Only Joking
I have a Turbo Race car and DAMN the cost are HIGH
MY road car will be a NA screamer. have a head with 1mm oversize valves HD springs and 280deg cams with 9.5 lift
Hoping to make 120RW KW. should keep me happy on the road