I'm starting this thread because the other one is quite long.

This thread should only be posted in AFTER reading, RE-reading, and understanding the original thread (Click Here), or there are new cams to compare; and should be heavily moderated.

I'm continuing this from the end of the last thread with the specs of the Crower Stage 2 Turbo cam.

Here's a new cam to compare (taken directly off Exiles website):

Stage 2 - Turbo Grind
Grinds designed for use with forced unduction. Upgrading valve springs is highly recommended

Camshaft specifications:

Duration: Lift:
Intake: 249 deg. Intake: .410"
Exhaust: 246 deg. Exhaust: .403"

At .050" Tappet Lift:
Intake: Opens: -16.5 deg. ATDC
Closes: 23.5 degrees ABDC
Exhaust: Opens: 30.5 deg. BBDC
Closes: -25.5 degrees BTDC

Lobe Separation: 114 degrees

Duration At .050" Tappet Lift:
Intake: 187 deg. Exhaust: 185 deg.

Lobe Lift:
Intake: .234" Exhaust: .230"

After doing the math I came up with these seat-to-seat timing specs:
Intake:
Opens: 14.5 deg. BTDC
Closes: 54.5 degrees ABDC

Exhaust:
Opens: 61.0 deg. BBDC
Closes: 5.0 degrees ATDC

They're not far off from the regular Crower Stage 2 specs, but the Turbo cams have 1* more duration on the intake side. These cams also have more lift and less overlap than the original Crower2, which will allow you to get all that boost in there without as much blowing through.

In my opinion, these Crower2-Turbo's are much more suited for a turbo application than the Crane 14's (turbo grind), Crower2's, or Crane10/12's.

The program (DeskTop Dyno2000) shows it to be a little less powerful than the Crower2's or Crane12's NA (which I believe is due to the less overlap):


Figuring in a turbo is strange with this program, but here's what I came up with:


Eventhough they show the same, I think on an actual dyno, the Crower2-Turbo will perform better.

+1* Intake Duration + More Lift + Less Overlap = Greater cylinder pressure when turbo'd.

I've had these cams since they were first released last fall/winter. I'm not sure how they perform due to other problems that occured with a previous set of Crower Stage 3 cams that we TRIED to dial in.

I may have them for sale in the near future after I finish going a different route with the head. My SC-61 flows a shit load of air and the head seems to be my limiting factor.

If one were to get a custom grind set of cams, what would be the ideal specs for a set. Say comparable to the 272/272 cams that the 4g63 guys have. Would it be the same specs as those cams or am I just off.

Originally posted by WIDECLIPSE
If one were to get a custom grind set of cams, what would be the ideal specs for a set. Say comparable to the 272/272 cams that the 4g63 guys have. Would it be the same specs as those cams or am I just off.

I've asked about this before and, from what I hear, it's definitely something people want to do, but it's a big risk, financially. I mean, since we don't have access to a cam R&D facility, we would have to design such a set completely based on what specs would be theoritcally ideal. The closest we could come to "testing" such a cam set would be Luke being generous enough to throw ideas into the Desktop Dyno to show us what they "should/could" do on paper so to speak. What happens when we actually have someone drop $500 or so on this set of untested, completely custom cams and they don't do shit? That's a lot of time and money down the shitter imo.

As for the 4G63 specs, I'm no expert, but considering how different manufacturers use different methods/guidelines for measuring specs, I don't know that just copying the 272s would translate well for the 420A. Besides, those cams were designed for the flow characteristics of the 4G63 head, not ours. Then again, I'm no expert, right? :P

Just my take on the subject. I would love to see some custom cam specs discussed. Something nasty that would work with larger turbos on well ported heads. }(

Originally posted by DeanoD
I've had these cams since they were first released last fall/winter. I'm not sure how they perform due to other problems that occured with a previous set of Crower Stage 3 cams that we TRIED to dial in. I may have them for sale in the near future after I finish going a different route with the head. My SC-61 flows a shit load of air and the head seems to be my limiting factor.

...and that different route would be....?

A properly ported 420A head should flow plenty for a SC-61. I know the manifold is a limiting factor..

why don't the specs from ert match the crower site? I am a new to cams though so maybe I am just missing something, please enlighten me.
http://www.crower.com/cat/import/mitsu/camshafts.shtml
http://catalog.exileracing.com/index.php?cPath=215_248_223&osCsid=a0b4d13fc1f2f38b4ed541b44cfa0a3c

Originally posted by CarbonFiberRST
why don't the specs from ert match the crower site? I am a new to cams though so maybe I am just missing something, please enlighten me. http://www.crower.com/cat/import/mitsu/camshafts.shtml http://catalog.exileracing.com/index.php?cPath=215_248_223&osCsid=a0b4d13fc1f2f38b4ed541b44cfa0a3c

I think crower's site just needs to be updated :shrug

I had the crower 3's and the spec card that came with them matched ERT's website.

forced performance has some new cams that are better than the hks 272s from what I've read over there. "FP3's" or something like that.....

where is the link!

Bleh, those are for the 4g's. We need some specs to make something for the 420a. I don't know if you could just copy some cam specs from a 4g63 or what. Being two completely different engines, I wouldn't think so.

Originally posted by WIDECLIPSE
Bleh, those are for the 4g's. We need some specs to make something for the 420a. I don't know if you could just copy some cam specs from a 4g63 or what. Being two completely different engines, I wouldn't think so.

Why not? The cam specs are just calculations for valve timing. It only defines when the valves open & close, and how much they open. Theoretically, you could use any specs you wanted, as long as they provided the proper environment for the motor to run. You could design one to have a good amount of duration, lots of lift, and greater lobe seperation so there's less overlap.

Unfortunately, there's no real way to know how it will react. You can go on speculation, you can also go by DesktopDyno, but neither are precise. The simulation program's probably your best bet, but like I said, you never know until you actually run them.

You could start with the 4g cams, knowing they're designed for boost, then customize them. It could be a start.

**EDIT**
Anyone know the 4g stock cam specs?

Originally posted by cougar694u
**EDIT** Anyone know the 4g stock cam specs?

Advertised duration: 219/ 210
Duration @ .050": 174/ 165
Gross lift w/ 1.7: .366/ .343

This was taken from Crower's website
http://www.crower.com/cat/import/mitsu/camshafts.shtml

edit: I looked in the service manuals and couldn't find any other specs.

Originally posted by WIDECLIPSE
Advertised duration: 219/ 210
Duration @ .050": 174/ 165
Gross lift w/ 1.7: .366/ .343

This was taken from Crower's website http://www.crower.com/cat/import/mitsu/camshafts.shtml

edit: I looked in the service manuals and couldn't find any other specs.

With that I'd need lobe seperation & intake centerline. Or the actual timing specs (IVO/IVC & EVO/EVC) to test the stock cam in the program.

I was playing with the Desktop Dyno program and the 4g cams offered by Crane seem to do really well. They offer a 10, 12 & 14, and are similare to the 10, 12 & 16 of the 420a. For instance, NA, the #10 cams are closely matched. But when you put boost to it, there's like a 10 HP difference in favor of the 4g cam specs.

The difference in HP increased with each cam. The thing is, the 4g 14's have 0 overlap at .050" lift (40* at .006" lift), while the 420a 16's have -8 (34* at .006" lift). But the 4g 14's have a lot more duration, 224/216 vs the 420a's 16's 208/208 at .050".

They have a lot more duration, more lift, and less overlap, which clearly allows for greater cylinder pressure. We could copy the same specs and have something made the exact same.

So, in theory, we could copy what the 4g guys have and it would produce the same outcome. Because the problem with most 420a aftermarket cams is the overlap with a boosted application, right? So if we just take the specs for the 272/272 cams, it should be about the same.

Originally posted by WIDECLIPSE
So, in theory, we could copy what the 4g guys have and it would produce the same outcome. Because the problem with most 420a aftermarket cams is the overlap with a boosted application, right? So if we just take the specs for the 272/272 cams, it should be about the same.

That should work. However, looking at Crane's cam's offered the (10 vs 10, 12 vs 12, & 4g 14 vs 420a 16), the 4g cams have more overlap. They have a lot more duration & lift, though. Crane's 4g 14 has more overlap than the 420a 18's. But, at 0.050" lift, none of them have any overlap.

I don't know about crowers cams, though.

Someone needs to put their top end setup on a good flow bench. Basing a cam design off of a cam for a completely different top end will not yield good results. Until someone puts at least their intake manifold and their cylinder head on a bench it's a crapshoot.

Originally posted by ner947
Someone needs to put their top end setup on a good flow bench. Basing a cam design off of a cam for a completely different top end will not yield good results. Until someone puts at least their intake manifold and their cylinder head on a bench it's a crapshoot.

You can't mimic cam specs from engine to engine. Flow characteristics of the manifold, head, exhaust, effect output. Bore and stroke not matching the burn speed of the a:f mix is different. Different compression ratios, etc. All engines are different. Add on top of that stock ECU maps effect on the whole package.

The Crower 3's need a high compression NA environment running to high rpm to really be effective.

Exile Racing Technologies
http://www.exileracing.com
Go that way, really fast, if something gets in your way... turn.