Mystery Metro Camshaft Grind

[War_Wagon]

I don't know about the rest of the world, but here in Vancouver there is only one place left that custom grinds camshafts. I was trying to figure out what I was going to do with my 3 cylinder car, and started looking into the differences between a regular Metro and an Xfi (Xfi's weren't sold in Canada). I emailed the cam grinder and asked if they had a profile for the Xfi cam. He left a message on my phone saying he would be unavailable until Monday, but that he had done a custom grind for someone at one of the local technical colleges that had been "phenomenal" for low end torque and mileage, and to call him next week for the details.

Now really, how can I not follow up on that? Once I get the info from him I will post it here. I don't know if I will have to buy one off of him in order to get the specs, but can anyone post the Xfi cam specs here for me? Maybe he just copied the Xfi grind, or maybe he came up with something new? Either way it should be interesting!

[gone-ot]

...sounds like he's a phenomenal salesman as well as being a one-of-one cam grinder (wink,wink)!

[MetroMPG]

The differences in numbers (from a 1994 service manual, for those who like the nitty-gritty):

XFI Model
Standard camshaft lobe height is 39.628 to 39.788 mm
(1.5602 to 1.5665 inches).
Wear limit 39.528 (1.5562 inches).

Base and LSI Models
Standard camshaft lobe height is 40.415 to 40.575 mm
(1.5911 to 1.5974 inches).
Wear limit 40.315 mm (1.5872 inches).


International heart transplant: the Blackfly gets an XFi cam - MetroMPG.com

[War_Wagon]

Thanks Metro, but does anyone have the full specs with duration etc? I realize this post is close to being in the Unicorn corral, but for what it's worth I will yack with this guy on Monday and see what he has to say.

[Gasoline Fumes]

302 lift/182 duration are the XFi cam numbers I got from 3tech. His economy cam is very similar.
3 Tech Performance
3tech

[arcosine]

Looks like the stock cam has 192 degrees duration, 330 lift and the econo grind has 184 degrees, 305 lift:

TeamSwift • View topic - Cam profiles for all models [3 Tech]


Saturn s series dual cam, 4 valve engine has 200 degrees intake and 180 degrees exhaust duration, intake opens 7.5 degrees btdc. Max hp at 5600 rpm.

[metromizer]

Originally Posted by War_Wagon

I realize this post is close to being in the Unicorn corral...

Why would you say that? A fuel economy camshaft isn't exactly a Pogue 200mpg carburetor or anything.

I've worked with a local cam grinder on several projects. I'll say this; of all the engine guys I've encountered, it's usually the cam grinder that understands the internal combustion engine the best.

However, they are no magicians, I've never had a camshaft turn chicken $hit into chicken soup. Like any businessman, they do have sales to make, door to keep open, and can typically do a much better job in tailoring a grind for a specific use, where the OEM's have to come up with a grind that is used over a broad spectrum. I wouldn't expect him to improve on a 3tech or Xfi grind, without several test cams being tried (some may be worse, some may work a tiny bit better).

When you talk with him, make sure to tell him GM offered a fuel mileage version of the metro, with a different cam, be sure to share both standard and Xfi specs with him. He might be able to offer something with closer seat timing and a somewhat faster ramp, that might increase cranking compression without loosing much higher rpm torque. Maybe. But we aren't talking 'phenomenal results', here.

[War_Wagon]

Originally Posted by metromizer

However, they are no magicians, I've never had a camshaft turn chicken $hit into chicken soup.

This. Also, I am totally stealing that line and passing it off as my own from now on ha ha. Once I hear what his version of phenomenal is, I'll go from there. It'll probably turn out to be the Xfi grind or very similar, but I'd like to find out. Did the Xfi have a different ECU than a regular Metro, or were the differences all mechanical?

[MetroMPG]

Different ECU as well is my understanding.

[War_Wagon]

Well I spoke to the gentleman about his cam. I told him about the Xfi, he didn't know such a thing existed. He asked me to not put up his camshaft specs, but he did tell me what they were, and they are not similar to an Xfi or the 3Tech copy. Hmmm. I must say I am interested to see what his can do, the only problem is I would have to baseline my Metro for a while before I did the cam swap, and I had planned on driving the Acura for the winter. I know what my Firefly got for an average MPG on the routes I usually drive, but the Metro has twice the KMs on it, so in order to give even a rough idea of a before and after comparison, I'd have to put some miles on the Metro as it sits first. If I decide to sell the Acura and get stuck in a ratty Metro for the winter, this cam better work!!