Grinding a new profile onto the stock cams?

[pche059]

We have a profile that we can grind onto you cams and will give you approx 10% more power and about 1000rpm more at the top end.The cost to grind your cams is $250NZD+gst.

I have not seen the computer out of a '99 Primera but if it is the same as the earlier ones we can chip it (actually an external memory board added inside the computer)for $999+gst.We can then program what ever rpm limit you would like and also alter the fuel and ignition maps to suit the cams and any other mods you have done(exhaust etc).

I got offered this.....getting more information on it later...
what do you guys think of this idea anyway?
please do give comments....
don't wanna fucx up my engine..it's still quite new

[T4 Primera]

Who made this offer?? Are they an established and reputable outfit??

I've heard it mentioned before that regrinding cams can be quite risky. You invariably end up with steeper lobe ramps that will put more strain on the valvetrain.

When they said "if it is the same as the earlier ones we can chip it", did they mean P10 pre- '93.5 - as far as I'm aware nobody has cracked the code for the ECUs after that date. For example, Peter Van Brugel only offers a chip for the P10 and not the P11. Prestige only offers the Dastek Unichip for the P11 which is a programmable piggy back computer, not a chip. i.e. Prestige knows that the computers are different on the later cars.

For $817 + GST and about 4 hours labour Peter Van Brugel's outfit can set you up with a programmable piggy back computer. By the time it was installed (4hours labour) the price wouldn't be far off and you'd have a much more flexible, tested and safe system.

Please post the info when you get it.

[pche059]

hehe the place is called " Kelford Camtech"
it's in Christchurch
this is there website

Anyway...do you know if peter has cams avaiable for us?
I mean..to get the entire exhaust from the header to the tip peter is gonna charge me around 1300nzd...then i thought i could probably get more gain for that money getting the cams done...do you agree?
i am sick of loosing to those standard Starlet GTs man...
can't even beat the FX GT until over 140kpm.....
crap

[T4 Primera]

Kelford has been around for quite a while (my chev engine has a Kelford grind in it) so if they'll guarantee it I guess it'd be o.k.

Hmmm... 10%, that's about the difference between the 110kW engines and yours isn't it? (allowing for the different exhaust manifold). Maybe Kelford's is just gonna grind the profile from the higher output SR20s onto your cam. If that is what they do, you'd probably be better off getting another intake cam for the high output motor that corresponds to yours - then at least you know it's gonna be reliable.

Pete V.B. doesn't have any cams listed on his website but it can't hurt to give them a call to check. Maybe he can put you onto some.

As far as the exhaust goes, how about just doing the header? It seems that this would get you most of the power from exhaust mods anyway.

I think you should explore doing a GT upgrade. i.e. getting GT parts of the same model as your car and fitting them to your motor. You've done the intake, right? so you could get the GT exhaust manifold and intake cam. Might save you $$ you can spend elsewhere. Go to this site http://www.primeraweb.co.uk , enter and click on modifications. It covers most of the questions you are asking.

[T4 Primera]

Oh, I forgot, who was offering the chip?

[pche059]

the same people man

hey do you think Peter VB's header will be better than the GT header?
i have been thinking about just doing the extractors....
but was worried that the power gain will not be enough...
altho..everybody on here says that you get over 90% of the gain from the header...and shit all from the actual exhaust?

is this real?

+ i have been wondering...is that extractor 9-13hp significant?
i mean is it like...oh...i have got another 10hp now..i am faster...
or does the car really go harder?

yea i have got the air intake done already..so ....
btw....
a Primera has less power than a dohc Vtec civic aye...?
hm...

[pche059]

oh by the way my sr20 is the new roller rocker type anyway...will in still work with the older model cams?

[T4 Primera]

You'll need a cam for a roller cam motor.

No idea on the gains with the Pete VB header compared with the GT header. All I know is some sportier models came out with a tubular manifold, not the cast iron type.

As for the hp being noticeable, go to a car sales yard and take a 110kW Primera for a drive and see what you think. Compare it with yours. Who knows, you might trade on one.

[P10DET]

Originally posted by T4 Primera
I've heard it mentioned before that regrinding cams can be quite risky. You invariably end up with steeper lobe ramps that will put more strain on the valvetrain.

YES YES YES.

Do not get regrinds! In addition to what Sandy has already mentioned, regrinds change the base circle of the cams, and this leads to other problems and requires some funky shimming usually to get them to work OK.

It is a pretty ghetto way to to produce cams. They usually don't perform worth a shit and some actually hurt performance.

If you want cams, the JWT roller cams are still under development, but should be worth waiting for. Glen "Lumpy" Campbell in OZ is a JWT dealer and can get them for you. JUN also makes excellent cams for the SR20, but I'm not sure they offer roller cams.

[Moppie]

Hey P10det, dont talk Crap!

There is nothing wrong with a good regrind, providing its done correctly.
In fact you have the same risk of faliure in grinding a new billit as you do regrinding an old cam. The ONLY difference is an old cam is cheaper to buy than a new billit.


pche059
Where abouts in NZ are you?
Kelford have a good reputation, and have certainly been around a while, but 10% from new cams is pretty poor, as T4 Primera suggested it sounds like thier just offering the profile from a new model.
Try asking them for a mild street or race cam, go for say an extra 15kw-20kw peak if you really want to make the cost worth while.

If your Auckland or Tauranga based I know some good shops who can do some good custom cams to suit you perferctly.

Other wise have a search of the net, and ask around, the SR20 is a well developed and resuarched engine, so there are plenty of cam Profiles out there. The trick is to find one that will deliver a power increase and power curve you like then get it ground into a set of cams from a wreacker, and fit them to your engine. (that way you can return it to stock if you want to, and the car dosnt have to be off the road for very long). Make sure you use some adjustable cam gears at the same time.

The Guys at Kelford, or someone like Peter VB will be able to tell you at what point you need to change the ECU, or use a piggy back, most factory ECU's will actualy handle mild cams with out any trouble.
I wouldn't worry about an ignition upgrade untill you start adding head work to the equation. (which you need if you want the most from your new cams)

and yes the DOHC VTEC civic's have more power, 117kw for a pre 92, and 125kw for a post 92. Its also only a 1600.

[P10DET]

Originally posted by Moppie
Hey P10det, dont talk Crap!

There is nothing wrong with a good regrind, providing its done correctly.
In fact you have the same risk of faliure in grinding a new billit as you do regrinding an old cam. The ONLY difference is an old cam is cheaper to buy than a new billit.

Now who is talking crap? Oh, of course.... a Honduh driver. I guess it's universal all around the world.

Look, pche059, I've giving you good advice, as is T4. It's your money to waste however. Regrinds suck. The base circle is screwed and has to be compensated for with too much shimming causing stress on the valvetrain that is not good. The geometry of the valvetrain gets screwed around. The only time I might even consider regrinds is if there are no cams ground from billet available.

Originally posted by Moppie
but 10% from new cams is pretty poor

That's actually not too bad for an SR20. I guess Honduhs have shitty cams from the factory.

Originally posted by Moppie
Make sure you use some adjustable cam gears at the same time.

Properly designed and tested cams do not need cam gears. JWT extensively tests their cams and they work best at stock cam timing.

Originally posted by Moppie
I wouldn't worry about an ignition upgrade untill you start adding head work to the equation. (which you need if you want the most from your new cams)

You will not need an ignition upgrade for a NA SR20DE. The stock ignition is extremely good. You will not benefit from an ignition upgrade until running very high levels of boost. This is from a great deal of testing, not some Honduh driver talking shit.

[Moppie]

Once you start flaming people any arguments you may try and make suddenly fall apart very quickly.

Iv used Reground cams in both my own road car (it was a Triumph) and a Race car. I also know plenty of people who have used them in thier own road cars, and in other race cars.

Shimming up a cam is no big deal, if your unable to fit the right sized shims, that isnt a problem with the cam, but your mechanical skills.
I think you fail to realise whats involved with grinding a freash billit or regrinding an old cam.
The same basic process is used for both. The cam lobes are ground to a desired profile. It makes no differnce to the grinding machine if the cam is a new a billit or an old one. Just as long as its the same basic shape.
(although on a new billit, its possible more material may need to be removed).

As for reducing the base circle, well you can take two cams from two different engines and swap them over, and theres a high chance you will have to change the shims. Measure the base circle on a reground cam, and then on one thats done very high milage, you will probobly find the differnce is not much, certainly not enough to as you claim stress the drive train!

Only a VERY mild cam change would not require altering the stock cam timing to get the most out of them, and it would be a grind so mild it would be a waste of money getting it. (unless economy was your goal).
Altering the lift and duration of a cam profile also requires you to alter the cam timing if you want to get the most from it, any engine tunner can tell you this. Its one of those things that affects all engines, regardless of age, displacement, or company of manufactor

As for the only 10% gain.
Unless the head porting and intake and exhaust system on the SR20 is extremly poor then 10kw is not much, and I belive Nissan does make some well designed heads. Also as Primera T4 pointed out, this is an achievable gain just using some bolt on parts from another model. If Im going to buy new cams, I want a worth while power increase, and im sure most people will agree.
Primera T4 has given excellent and unfaultalbe adivce, I was not disagreeing with any of it, just backing most of it up, as the word of two people who do seem to know what thier talking about carrys a lot more weight than the word of one.
While the word of one person who can't even spell Honda and has to resort to insults because he lacks reasoning to back up his false statements carrys very little weight.


And just because I own a Honda dosnt mean I hate or don't know anything about Nissans, my Fisrt car was a Nissan, and im curently building a hybrid kit car that uses some Nissan parts.

[Moppie]

pche059
I just remeber what it cost to get a cam ground for my 6cyl Triumph abuot 4yrs ago. Just the cost of the regrind was about $150.
So $250 for two 4cyl cams is a good price.

[G-Forces]

I wouldn't put reground cams in my car if you paid me. Just my $0.02.

[Moppie]

Originally posted by G-Forces
I wouldn't put reground cams in my car if you paid me. Just my $0.02.

I have to admitt I used to have the same attidute, then I decided to work over an engine that new billits were unavliable for, and the tuner simple recomened a regrind. I was very scepticle at fisrt, but asked around, friends, people in my car club, guys in the service parks, other tuners, and they all said the same thing. Regrinds have a bad reputatin they dont deserve.
The only problems they may have is if a cam from a very high milage engine with a lot of wear on it is reground, there might not be enough meat left to get a good new profile, or if there was heavy pitting from excess wear on the lobes it could weaken the cam.
However a good reliable shop will not even consider doing a regrind to a cam in this condition, as I found out when the fisrt cam I took in had come from a high milage engine, had some sever pitting and was no longer completely straight. (im not kidding!)
But you can get the same problems with a new billit. There might have been a flaw in the casting process, an unknown weak spot may exist that dosnt show up will you hit 6,000rpm. Or it may have been badly ground when its intial shape and bearing surfaces were made.
Iv actualy talked to a guy who only use's regrinds in his race car after a new billit failed and destroyed a new motor during a race. His theory was that a regrind had been tested before, if it was going to break it would have a long time ago, but you can't be so sure with a new billit.
Its a slightly flawed theory, but still isnt totaly stupid.

After doing a little resurch into regrinds and then having experiance using them I dont have a problem with useing them again in the future.