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Discussion Starter #1
Decided it may well be time to drop in a new set of camshafts, so time for some stupid questions....

First off, how big a job is a camshaft change? I presume you need the correct kit and its not a job to be doing at home?
How long does it take? Whats it gonna cost me (not including the cams)?

Here's what I am looking at:

HKS Intake & Exhaust. 256 degrees, 8.8mm lift,

OR

HKS Intake & Exhaust, 264 degrees, 9.0mm lift,

OR

Tomei Intake & Exhaust, 260 degrees, 9.25mm lift...

Now, will I notice any difference between the 3? WHat are the respective benefits of different durations and lifts (I know bigger lift + more open valves, and I presume the rotational duration is how long the ports are open, and overlap etc)?

WHat do you guys think is the best set to go for?

Do I need to change both int and exh at the same time?

Will I need to remap the car or will the ECU adjust?

HELP! Only time I have ever played with cams was on an old mini... Hardly the same methinks.....
 

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I would change the cams in the engine when they become the limiting factor.

Higher lift is definitely better. I think you can use the std ECU if the cams are dialled in correctly, but I dont think you'd get the benefit of being able to push more fuel and air in (and out of) there then, would you?
 

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Jock Alert said:
Whee.. at last a reply! Think you have a good point there, was just judging on the fact that my motor seems a bit lazy when I rev it compared to others....
LOL

I kept it short, thinking that you had already chosen and installed them anyway and expected you to say what you think about them.

Let me see what you said in more detail.

Jock Alert said:
First off, how big a job is a camshaft change? I presume you need the correct kit and its not a job to be doing at home?
How long does it take? Whats it gonna cost me (not including the cams)?
I dont know about the RB engine, but I'd imagine that it's pretty similar to any DOHC engine and that you can replace them in situ without removing the head. The problem you'll face when doing it that way is that you cant dial them in as easily, although the position of the engine should make it easier than on a transversally mounted engine.

COst would depend on labour. I would guess it can be done in an afternoon?


Jock Alert said:
Now, will I notice any difference between the 3? WHat are the respective benefits of different durations and lifts (I know bigger lift + more open valves, and I presume the rotational duration is how long the ports are open, and overlap etc)?
That's it.


Jock Alert said:
WHat do you guys think is the best set to go for?
I think that depends on the turbo(s) you hgave in there, but generally higher lift is better than higher duration (unless it's a drag car).


Jock Alert said:
Do I need to change both int and exh at the same time?
Unless there is a basic design fault there (which I doubt), I would say yes. An engine is a fuel and air burning machine. Why should you let more in and less out or vice versa?

An interesting thing I learned from a friend's experience (with his 4G63 :eek:) is that higher lift exhaust cams reduce exhaust backpressure and that the engine can make more power that way.

TOMEI are highly regarded in the Jap performance market; I would assume their stuff is excellent. Myself, not knowing crap about the liner engines, would take a look at what turbo setup they run these cams with on their demo car to get an indication of what purpose they are designed for. Also, what other cam specs do TOMEI make? Are these the most aggressive ones or the medium ones? That sort of stuff... Oh, and I'd email a few tuners as well. Did you do that?
 

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Jock,

If the main thing concerning you is speed of engine pickup then it might be worth considering a lightened flywheel.
 

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How much does the standard flywheel weigh?
 

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Jock,
Some of the tomei cams with higher lift require a conversion to solid lifters and different springs etc. Im currrently weighing up the virtues of a set of 256's for my R33 GTSt

http://www.tomei-p.co.jp/

Paul
 

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make sure your car can deal with high lift mate. are you planning to rev byour engine Jock this is a factor I would look at , as most cams in the skyline range seem to work well under extended rev range.

Additional lift might mean hitting the pistons ensure you have ie solid lifters etc!
 

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Discussion Starter #9
Roger all that! Cheers guys.

Like my other car plans, its kinda sat on the back burner for the next month or so now I am having to disappear for a month.....

Might look into the flywheel though when I get back.
 

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Flywheel weight I think I have seen is abour 11-14Kgs ? Leightweight ones are usually around the 5-7Kgs I think.
 

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Sarky_FCUK said:
Flywheel weight I think I have seen is abour 11-14Kgs ?
I think R34 flywheels are heavier than R33 flywheels?

Sarky_FCUK said:
Leightweight ones are usually around the 5-7Kgs I think.
That's what I have seen, too.
 

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You have me at a loss with regards to the two flywheels on the different models ie R33 & R34.

You would have to speak to a tuner for that type of information.
 
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