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look out XFI cam here comes XFIII custom cam pix
Topic Started: Nov 6 2013, 11:56 PM (16,409 Views)
ZXTjato
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bass heads

All this talk on mpg and such....I get 39-40 mpg on a 4:39 trans 12" wheels and driving like it's stolen, shifting at high rpm and 85-90 on the free ways. Makes me wonder if I drove 55 mph could I get 41.5 mpg??? Honestly i want a cam because it sounds fun. Spend money to have fun. Not spend to save....that's just me :)
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Coche Blanco
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Troll Certified

:popcorn
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HelterSkelter
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#1 Pizza Driver

as long as the lobe isn't pointed enough to create enough pressure to break through the oil film the engine will be fine. most good oils are good on film strength up to the 100k psi range, quite a lot of pressure needed to break it.


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3tech
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j63812f
Nov 25 2013, 12:22 PM
For what its worth, I just sent a stock 16 valve cam and paid to have it evaulated by crower, and here are the specs right from their machine.

Intake Duration 173 Degs, Lift 206
Exhaust Duration 177 Degs, Lift 195
Lobe separation 110 Degs

The factory did a dual profile on this one. I use this cam with a 4 deg advance and feel a noticeable difference in low end response.
You could have saved your money. I've posted the specs on that cam a number of times. Free.
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Johnny Mullet
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Kim John Mu

Mike knows his shit. He has been in this game for a long time.
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Geo Glenn
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What's in your engine?

.
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3tech
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It's none of those things. It's specialization.

The problem is that they measured that cam the same way that they would measure a small block chevy cam, and different applications require different methods.
There is no way that they can know how every cam will be installed, nor is there any reasonable way that they can measure it in it's final application, and provide the real numbers.

Yes, that is what the lobe is showing on their equipment, but there's a reason why OHC and OHV cams are measured and reported differently, and this is it. What the lobe is, and how it degrees out on a test jig, or cam doctor and how it degrees out installed are two completely different things. I could write a whole page on the geometries of a G series valvetrain and how it affects lobe requirements and measurements. It's critically important on an OHC. If you used those numbers and tried to spec out a custom grind based on them, you'd be chasing your tail. I've spent a lot of development time on this particular application, and done a lot of business with race teams in India who have been down this road with a few of the large custom grinders.

I've been saying it for a long time because it's important. When we develop something, it's 100% application specific. With OHC, there is no other way to do it properly.

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clarkdw


Not very often have I seen a cam with less than 180 duration and I think that I can be pretty sure that less than 200 thou lift would be rather unusual as well. Those numbers are wonky for sure.
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j63812f
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J R

.
Edited by j63812f, Sep 13 2014, 10:26 AM.
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dalebolger
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[ *  *  * ]
This spring when I rebuilt my 93 1.0 I am using this cam for my hill runner my goal is a 70 MPG car. When we start the rebuild/restore the photos will start. I will be working with mike on the parts and specs, the car will be built at my shop in Fontana, CA.

Dale
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3tech
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j63812f
Nov 26 2013, 02:30 PM
Here it is. Stock 16 valve 1.3 cam specs direct from Crower. No guessing or reading posts with differing numbers.


You should have saved your money. For the reasons listed above, those numbers (with the exception of the lobe lift) are essentially meaningless. There are also a few mistakes on the sheet as well.

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Coyote X


What is wrong with the numbers and what are the mistakes?
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z34-5speed
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Formerly "Tech Certified"

I believe Mike was saying that they measured the cam as if it were for an OHV configuration when in fact it's an OHC setup.

Not talking for Mike, that's just how I read what he was saying.
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socal geo garage
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We have cams in .. here are two of them xfIII stage two and super eco cam II they made a few changes to the intake of the xfIII rounded the intake lobe more.

Posted Image

Posted Image
Edited by socal geo garage, Nov 27 2013, 01:04 AM.
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Coche Blanco
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The bullshit is getting deep in this thread. No one is going to get rich on anything Metro related, why are we even bothering with this debate? Spill the beans already.
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