Cosworth camshafts for NC

[NC13]

I am an NA engine lover purely because it's more fun to build and harder to make power...
Been looking at some internal bits and found that Cosworth build cams for the NC engines with moderate duration over stock. Anyone with NC that have these installed? What's your take on them?

[NitroDann]

Not trying to be a smartass.. Surely the answer lies in looking at the specs?

Dann

[deanb90]

Not trying to be a smartass.. Surely the answer lies in looking at the specs?

Dann

Some people can't read by the specs.

[NitroDann]

Post em up.

Dann

[NC13]

Not trying to be a smartass.. Surely the answer lies in looking at the specs?

Dann

Not trying to be a smartarse... Surely you would have understood that I'm asking for opinions from fellow members who might already have them on their NC?......

[NitroDann]

Why do you need an opinion when you can look at the specs and know exactly what it will do?

Dann

[Charlie Brown]

Spec as per Good-Win site:

"Intake Duration 264, Lift 9.8mm, Ex Duration 244, Lift 8.5mm. Mazda uses a graded bucket system to adjust valve lash. Mazda offers a range of buckets or tappets in different thicknesses to adjust valve lash. Since our Cosworth MX5 cams are ground to the OE base circle specification, chances are you will not need to change the tappets to adjust lash. However, this is not always the case and the end user should be prepared to perform the task as needed."

The biggest drawback is this note:

"Note you will need our MX5 Sniper Tuning Kit to tune the motor for use of these Cosworth MX5 Cams....as used in our own Cosworth MX5!"

To my knowledge there hasn't been a successful tune using Sniper here in AU. Maybe because of a difference in the ECU, maybe the fuel mix we use. Those who have tried it have lost power.

As sponsorship is virtually non existent in Australia, a number of dedicated track only NC racers have been investigating ways to get more power without throwing buckets of money at the car and stay within class rules. All have come to the same conclusion that the best we can do is to change the intake, header and exhaust system. Play with the diff ratio and lighten the flywheel. None have fitted cams.

There has been a lot of research done by Cosworth to get more power out of the NC motor.
The biggest restriction is the head, which in its stock format is at its limit of development.
The second biggest restriction is the inlet manifold length. It’s too short.
As Cosworth couldn’t get any useful gains out of the stock head, they developed a new big valve head. Problem is that the cost for this is as much as the supercharger.

Back to the cams. You're looking at around $800 landed for the cams, plus fitting, plus “tuning”, so a total around $2,000 for how many kW gain? 10?

So if you are chasing power for the road you should consider a supercharger.

[NitroDann]

Assuming those profiles are measured a .01 lift (ie advertused duration) They will give a stock idle with a big mid range lift and a bit at top. Ive not seen stock NC cams but Id be amazed if they only made 10rwhp more. And I wouldnt bother with a 'tune' at all.

Dann

[deanb90]

OP, try the Tomei cams. There should be specs on sites such as nengun.com or yahoo jp. There are different stages as well.

[wozzah1975]

I have played around with cams alot on the BP engine in N/A form and back to back dyno'd a number of grinds.

I do a cam kit for these on a changeover/DYO basis
Specs are
Inlet
.310" lift (7.874mm)
268 deg adv duration
220 deg @ .050"
Exhaust
.365" lift (9.27mm)
270 deg adv duration
226 deg @ .050"

or
Inlet
.365" lift (9.27mm)
270 deg adv duration
226 deg @ .050"
Exhaust
.365" lift (9.27mm)
270 deg adv duration
226 deg @ .050"
(this is more complicated, done using 2 exhaust cams)

What I have found is:
-The car needs to be fitted with decent extractors and intake system BEFORE you play around with camshafts, otherwise you are wasting your time, there will be little or no gain.
-Any bigger than these grinds requires cylinder head porting also, as there is little or no flow benefit going any bigger on a standard cylinder head.
-Cam timing is absolutely critical, on my engine moving the exhaust cam just 2 deg made a massive amount of difference to mid range power and torque (almost 10rwkw), so cam gears and a good dyno is a MUST.

They're $460 a pair if anyone is interested,

Cheers
Woz

[daffyflyer]

Why do you need an opinion when you can look at the specs and know exactly what it will do?

Dann

So you assume that everyone will be able to look at cam specs and work out a full picture of what it should do, and that the opinions of those people who might be using those cams, and how well they actually work and what they do is therefore of no use? Nice...

[NitroDann]

I figured he could just post specs and have his question answered. We all know no one has an ecu on an NC yet, so chances of cams only...in australia... Doubt it.

Dann

[orx626]

We all know no one has an ecu on an NC yet, so chances of cams only...in australia... Doubt it.

Dann

Sorry Dann I'm not sure what you're saying here Are you saying that no one has put an ECU (piggyback or standalone) on an NC in Australia as yet, or that no one has done both an ECU and camshaft swap?

Because if you remember in that Dynotronics thread I stated that I've had a HKS F-Con IS on my NC for over 18 months whilst I've been developing a supercharger kit and testing exhaust upgrades.

Cheers,
Danny

[NitroDann]

Im saying that so far as I am aware, no one has both cams and an ecu on an NC in australia.

Is this incorrect? Sorry if it is.

Dann

[orx626]

Im saying that so far as I am aware, no one has both cams and an ecu on an NC in australia.

Is this incorrect? Sorry if it is.

Dann

Cool. That's my understanding as well Dann. Would love to know if there is someone outside of the MX5cartalk world (but it Australia) that has done both ECU and cams.

Cheers,
Danny