jansolo

iTrader: (2)

Revolver Cams:

Duration / Intake: 262º
Duration / Exhaust: 264º

Valve Lift / Intake: 11.4 mm
Valve Lift / Exhaust: 11.5 mm

Link:
http://www.revolvercams.com/mitsubishi.html

GokuSSj4

iTrader: (7)

once i have the chance to get my hands on piper cams , i will compare how much of a difference they make .
dyno 264/272 vs pipe rally 265/265 11.5mm lift with ferrera valve springs and reving to 8,000rpms. see what results are accomplish.

Guack007

That would be sweet. Thnx for offering to do the Research for us

ShapeGSX

I'm not so sure about the whole idea of using a larger exhaust cam than intake cam.

I have some airflow data now in an excel spreadsheet, but I should have some better data tomorrow, assuming the track doesn't get rained out tonight.

Basically, I think I lost a lot of airflow and power when I swapped in my HKS 272 exhaust cam in place of the 264 I used to have in there. Now I am back to 264/264. I'll see if I got anything back. I may even try the 272I/264E setup.

Fenris Ulf

iTrader: (-1)

As I have said a hundred times before, a 272 exhaust cam is not a good idea. Almost every single turbocharged vehicle runs more intake duration from the factory for a reason. The exhaust does not need extra duration to push out all of the spent exhaust gasses which are under extreme thermal loads and pressure. In fact, too much exhaust duration will increase the overlap period (time when the intake valve is starting to open and the exhaust valve is closing) and allow the intake charge, which is under a large positive pressure from the boost, to be pushed into the combustion chamber and then right back out the exhaust! This means a portion of the intake charge is not even being combusted and thus decreases power output, efficiency, time to full boost etc.

Fenris Ulf

iTrader: (-1)

I have built a twin turbo Viper, several single and twin turbo LS1s with Incon or Lingenfelter kits and worked on dozens of 2JZs, 4G63s, EJ20s etc and every single one of those cars runs better with more intake duration than exhaust and retarded exhaust timing to further decrease the area of lift during the overlap period....

TampaTurbo

iTrader: (7)

This could be a very huge debate if there were to be some highly tuned evos from tuners who have played with the various cam set ups/gears etc.

en1gma19

iTrader: (23)

it will be interesting to see where this thread goes.....

TampaTurbo

iTrader: (7)

I think Boost Solutions was working with the 272i/264e setup and was making good results. We are waiting on a comparison of dyno charts right now.

Ted B

iTrader: (6)

Oops, be careful...

The exhaust cam lobe immediately precedes the intake cam lobe, not the other way around. If the exhaust cam is retarded, it reduces the lobe separation angle and increases valve overlap.

Cam design is dependent upon many variables, some of which include the flow characteristics of the intake ports, the same for the exhaust ports, and how these two sets of numbers flow with respect to each other.

Because the exhaust gas is energized by its heat, the static port flow for the exhaust can be about 75% of that of the intake to give relatively equal real world numbers. Therefore, if a particular cam setup gives balanced flow, upsetting the balance by making one cam larger may not be to our benefit. Of course, we are speaking in generalities here.

In short, static cam specs do not tell us enough about what is really going on for us to make arbitrary determinations. All we can do by looking at cam specs is compare them on paper and judge how one set should behave in comparison to another.

megatron

iTrader: (6)

quick question. which hks setup would give me a better 1/4 mile time??? im leaning towards a mix setup of either 264/272 or 272/264 but still seeing which one works best.

boomn29

iTrader: (47)

272's overall are built for high end hp.
264's overall are built for lower end hp.

People do the combo to try and get the best of both.

mayhem

iTrader: (9)

How do you properly measure cams? Can it be done at home with simple tools? I have a set of WORKS 269 cams sitting in my dining room right now.

JustDSM

iTrader: (28)

Depends on what you want to measure. Give us an idea of what you want to know and I can better help you.

[EDIT] Forgive me, I wasnt thinking about what I was saying.

I think its quite obvious your looking for the specs relavent to this post.. In order to do so they must be installed and degreed accordingly.
[/EDIT]

Wangan_X

ok not sound like a newbie... as i have helped build plenty of engines... but why is lift important... i realize the wider a valve opens the more room, but wouldn't duration be more important on the HP side of things. Also... not that i would ever do this, but can you mix brands of cams to create more HP or a better power curve