TeamSwift

[ EDIT: whoops, just noticed there's already a thread on this topic in the fuel economy forum, found here (for people searching for this kind of info): http://www.teamswift.net/viewtopic.php?t=23838 ]

A friend in the States gave me an XFi cam, which I'd like to put in my garden variety 98 1.0. Couple of questions for those of you who've monkeyed around in this area...

1) First I want to confirm it's an XFi cam (never know if the engine was swapped, or if the hatchback with the XFi sticker was a swap ). Any easy way to check this - e.g. is a caliper reading of lobe height compared to my stock cam lobe height valid? (I understand the XFi has lower lift.)

2) Is the swap a straightforward job? Any secrets I need to know in advance? Haven't been in a head for a while (and never in a G10 head).

3) About how long will/should it take to do?

I'd really like to do an A-B-A mpg comparison to OEM - but it'll have to wait until the return of warm weather, and I'll only do it if the swap is quick 'n' easy.

I may also play with cam advance, but first I just want to put it in at the OEM position to see what it feels like.

should be like 30 min to swap it

line up the factory cam timing marks before taking the valve cover off, take off the distributor, valve cover, upper cam sprocket, 6 bearing cap bolts and swap cams and put it back together.


When you look at the xfi cam you can see the lobes are not as big as the stock cam so you don't really have to measure it unless you really want to

Thanks for that info Coyote.

Its about time
Take the measurements, and let me know.
I'll tell you if you have an xfi, or regular Metro cam.
Put it in straight up.
Any advance more than +4(I can tell you how), will probably be too much.

One other thing, make sure to coat the bearing surfaces and lobes with break in grease or something to keep it from being dry on first start. Wheel bearing grease can work if you don't have anything else, I have used it before. Just don't put it on real thick and clog up your oil drains with it.

The following is from my 1994 metro service manual:

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).

Thanks for all the info.

I may do this next week. Will post back.

Another question:

Is the timing belt sprocket on the end of the XFi cam the same as the one on the regular engine?

I noticed that the one I've got is a little off kilter. The guy who got it for me told me he had trouble getting the valve cover off the XFi engine, and it looks like he pried hard against the sprocket for leverage.

Do I need to true it, or can I swap the one from the Firefly?

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EDIT: think I found my answer in the other thread: http://www.teamswift.net/viewtopic.php?t=23838

suprf1y, you told the guy to use his non-XFi sprocket with his XFi cam due to belt differences (and it's cast vs stamped). I assume I'm also going to see belt differences between the XFi sprocket I've got and the one in my '98.

Just use your stock one.
It will be different than the one you have on the xfi cam.
If you want a little more power on the bottom, use an GT sprocket, and the E setting.
What will you run for ignition timing with this cam?

Thanks for the tips.

Timing: I'll probably back it off a bit from where it is now, and then start bumping it up a little bit at a time to find where the pinging starts (then go back a step). I tend to do timing by ear.

cant wait to see your results. I've had a bent valve for some time now, but am a tech, so i am constantly working on other people's cars! I have the xfi head and cam assembly and the computer. I want to do it all at once. I know when it was warm out-a good wek for me was 50mpg, so i'll hopefully get better than that when summer rolls around again. Should get to this in a couple weeks-FINALLY!

Did the XFi cam swap this afternoon. (Been waiting for a warm day for a long time!)

It took me maybe 2 hours. (It'd take me 30 minutes to do again though. )

1. I cut my timing belt cover with a dremel so I could remove just the top portion (the part that covers the cam sprocket). If you don't do this, i think you have to remove both the water pump pulley and the crank pulley to get the cover off (careful you don't cut the timing belt too!).

2. I was prepared for the challenge of getting the valve cover off. There are some spacer/gasket-y things under the nuts. They need to be spun off or the cover won't budge.

3. I had to go to a friend's house to use his vice (to hold the cam sprocket so I could get the bolt out and back in, tight enough). Need to buy a vice. Can't believe I've gotten away without one for so long.

Having said that...

WOW! I like it.

---- I was worried I wouldn't be able to detect a difference, or it would so small that I wouldn't be sure if I was just imagining it.

---- But the car definitely has more low end cojones. (Maybe more accurate to say it has "a cojone" now, because it had none before and I'm still not going to sign up for any tractor pull competitions)

---- I can shift at least 5 km/h sooner than I used to, and the engine just pulls smooth smooth smooth.

---- I'll have to back off the timing. I was hearing some ping, and on my test drive I couldn't open the throttle as much as I usually do.

---- There's a tiny amount of lifter tap that wasn't there before, but hey, what could I expect from swapping out a cam with 12,000 kms on it for one from a car that is at least 4 years older, with who knows how many more miles on it (obviously enough that it was ready for the junk yard)!

It's certainly got to help fuel economy because I can shift sooner, so I reduce losses to internal friction & I get to open the throttle further and reduce pumping losses (once I get the timing sorted out).

My thought is when summer's here I'll do an actual before/after comparison in one afternoon to get some hard numbers on the steady speed MPG improvement (I'll reinstall the original cam to do the test).

I think it's safe to say this cam is a perfect match for the taller final drive Swift tranny I put in last year. Peanut butter and jelly!

Did your timing sprocket have 2 positions?
If so, which one did you use?

No, my car's sprocket has just one position. The XFi sprocket that came attached to the cam also has 1 position.

If you get your hands on a GT (and some of the 95+)dual position sprockets, you can use the E setting to give you 4 degrees more advance.
Its about as much as you'd want with the xfi cam.

I've got the cam in, but i still have a problem of breaking up. Seems to be mainly when cold or when i let off the gas, make a turn, then het back on. I think the temp sensor is ok, so im gonna have to keep looking. Seems to run well when i nail the throttle, so i dont think it is the fuel filter, but im gonna replace it anyway. Plus, i just did the headgasket and new valves all at once with the cam. 96k and no burnt valves though! Are there any scan tools that will show data for a 91 metro?
Well, main reason to respond since i haven't really done any testing yet is this:
I have a 91 Metro that has a vacuum advance distributor, so, if i am correct; i cannot use the XFi ECU, right? I believe they used the elctronic distributor advance.....?

Tough to call, but sounds like a vac leak.

Thanks for the tip.

No problem, but it has to be the 30mm wide sprocket, not the narrower 25mm cast one.

suprf1y, in the other XFi cam swap thread, you say:



Pardon the stupid question, but does "ground on a different centerline" mean that the XFi cam is already further advanced than stock?

If so, do you know the difference in degrees?

Just curious.

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BTW - I really like this cam. I've only gone about 50 km since I put it in, but it seems to suit my econo-driving style way more than the stock unit. The engine is so much more laid back - perfect for short-shifting, no muss, no fuss. Seems quieter, too, with a deeper sound. (I could be imagining that part - it's pretty subjective.)

I'm looking forward to even warmer weather - I'll do that before/after comparo with the stock cam and get some hard numbers. Even if the difference isn't huge (which I'm not expecting it to be - my guess is it's under 5 percent), I'd opt for this profile just for the way it's changed the engine's character. Much more enjoyable to drive.

If I recall, its 6 degrees advanced from the stock cam, based on measurements of intake centerline.

Nice to hear you took your time and did it correctly!

Didn't the 95+ have round teeth on the belt and the 94 and earlier have square teeth?

some 94/95 cars had the round tooth sprockets, with narrow belts.

In December of 2006 during the cool weather here in Tucson, Arizona I finally got around to installing the Economy Camshaft that I had purchased from Mike at 3TECH PERFORMANCE along with a set of valves and guides from him, and new rings from the PARTS DINOSAUR.

The old parts were not in bad enough shape to have had much effect on performance so the MPG improvement is really due to the camshaft change.

Prior to installing the cam from 4-13-2006 thru 6-7-2006 I burned 27.365 gal of gas over 1339.1 miles for an average of 48.935 MPG.

After installing the cam from 4-19-07 thru 6-11-2007 I burned 24.335 gal of gas over 1246.1 miles for an average of 51.206 MPG.

An improvement of 4.64% in MPG under similar heavy traffic city driving around Tucson, during the same time of year, NOT using the air conditioner, and staying with the flow of traffic.

Not bad at all in my opinion. I would also echo the comments by Darrin at his website http://www.metrompg.com/posts/xfi-cam-swap.htm about the much improved low end performance for his XFI cam.

I did add holes to my sprocket to allow adjusting cam advance from stock to 10 degree in 2 degree increments, and some seat of the pants performance testing resulted in my using a 4 crank degree advance.

I am glad I did it.