Blackfly XFi?

[MetroMPG]

http://images.google.com/images?q=tbn:03ZbMoOy-wHz9M:http://www.landroverclub.net/Club/Technic/Worn_cam2.jpg

Thanks to a certain website overlord who shall remain nameless, I now have in my posession a camshaft from a Metro XFi (year and mileage unknown).

This cam will find its way into the Blackfly's engine compartment in the not too distant future, replacing the extravagantly wasteful OEM cam that came with the car. ;)

[Bruce]

Wouldn't you need the ECU as well?

[MetroMPG]

Apparently not.

[Bruce]

I'd really like to do some A-B-A to get an actual number, but cam swaps at the side of the road on a hot engine may be problematic.

Should only be about as tough as changing a flat without stopping. :)

Congratulations. I wish I were able to make some practical tradeoffs of power for efficiency in my car, e.g. a smaller engine, but I haven't seen anything yet that wouldn't require major surgery or drastically impact the reliability.

[MetroMPG]

Thinking more about this.

[DaX]

You can build a DET CAN (http://www.honda-tech.com/zerothread?id=1555006) for detecting knock...it's always amusing when mechanical solutions are better than electronic.

[TomO]

hmm, that sounds like a good and cheap thing to do. Thanks for posting that DaX!

[DaX]

hmm, that sounds like a good and cheap thing to do. Thanks for posting that DaX!

No problem. Just don't let the police see you driving down the road with headphones on! Imagine how strange it would be when a cop looked in the car and saw hoses running from the headphones to the engine!

[MetroMPG]

CoyoteX posted a cheapie microphone-based ping detection method too. One or the other will come in handy, yes.

[Matt Timion]

I would love to see a side-by-side comparison of the two cams. My functional engine knowledge is not the best.

[MetroMPG]

I also found a post that confirmed I may have to watch the ignition timing after the swap.

[Coyote X]

I would set the timing back to 6 degrees advanced like the factory calls for. I don't think you will have any problems with it knocking unless you have really bad gas or something. A knock sensor out of something from a junkyard is pretty cheap but if you have good hearing then you don't really need it.

Also I got better mileage out of my xfi when I have the cam advanced to 11 degrees :)

[MetroMPG]

Do you have to run higher octane with the cam advanced 11 degrees?

[Coyote X]

Nope I am still running 87 with the cam at 11 degrees and .040 shaved off the head so I am at 10.5:1 compression ratio. I am only running 4 degrees of ignition advance but the car seems happy with this combo. I just need to get it to run for 3 weeks or so straight without breaking down to get a good mileage reading.

I would put the cam in straight up with the ignition at 6 degrees and get some time on it before changing the cam/ignition timing just so you get a feel for the mileage with the new cam before changing more variables.

[Ted Hart]

Apparently not. My understanding: the different cam profile - lower lift & duration - raises the cylinder pressure and shifts the torque peak downwards, so less throttle is required at low RPM. It's a mechanical thing.

It lowers the XFi's HP rating from 55 to 49, but the torque value is unchanged (the RPM at which the max occurs is lower). (EDIT: The cam alone may not be the HP limiting factor - it could also be ECU.)

A number of people have done similar swaps including GeoMetry on this forum,

I sense a bit of "misunderstanding" here....
A lower lift and/or duration cam profile (opening the "doors" to gas flow later, closing them earlier, and holding them open for a shorter time) is going to raise the BMEP? ...and shifts the torque peak downward? How so? If gasoline is the source of power (pressure), then how is less of it gonna make more?
Torque is what moves the vehicle. Power is the rate of producing this torque.How is less of it going to move it better? Easier? More efficiently? Are you aware that HP = torque (by definition) at 5252 RPM? The two are tied together so tightly that "nothing moves without them". Check your physics book!

[Gary Palmer]

MetroMPG: I would go ahead and make the cam swap. I would also set your timing up to match whatever the Xfi specification is, certainly to start out with.

The cam basically controls when the valves open and close, relative to the crankshaft and pistons. It won't change the actual compression ratio, but it can change the effective ratio. Additionally, the cam lobes can be ground to have different ratios of opening and closing, how long the valves are open/closed and when they are open and closed. Depending on the engine rpm, they are optimized for a specific rpm, but are generalized at the same time, to allow the engine to operate over a wider rpm range.

It is possible to get cam's set up that are optimized for lower rpm, but they typically run more poorly at higher rpm's. When Honda introduced their VTEC technology, it basically allowed them to have two different cams in the engine, one optimized more towards the low end, one towards the high end.

I would doubt it you will need to change the ecu. To a large extent because of your driving style, I expect the engine is generally in closed loop, so that it is monitoring your O2 and other factors, to control the engine parameters. In open loop mode, the setups in the ecu are probablly already close enough, for what your asking it to do.

I've thought about pulling a camshaft off of a 91-94 CX and putting it into my 89 Wagon, towards the end of improving the fuel economy. However, it's rather far down my list of things to do and preceded by issues of more a more pressing nature, which seems to be the way things go, more often than not.

Make the change and then let us know how it goes, in comparison to your previous mileage.

[MetroMPG]

I'll be the first to admit I'm not a cam expert. You can see I've mostly quoted things I've read elsewhere.

[MetroMPG]

It won't change the actual compression ratio, but it can change the effective ratio.

Yes, I had read this also. Which addresses Ted's question, "If gasoline is the source of power (pressure), then how is less of it gonna make more?"

It is possible to get cam's set up that are optimized for lower rpm, but they typically run more poorly at higher rpm's.

That's true.

It's mentioned in the source I linked in the previous post. The shorter duration on that Olds cam meant a higher lift rate was used, which resulted in a lower red line (the valves would float at a lower RPM because of the higher lift rate).

The same is probably true of the XFi cam - and perhaps that's another difference in the XFi ECU: a lower rev limit.

[Gary Palmer]

One of the items which is on my list of I'd like to do, is to get the HF transmission I have, rebuilt, so I can get it into the Wagon. After I do that, my rpm should come down substantially and then I may try to make a cam swap to more adapt to that change.

In your car, I believe you already made that change?

[MetroMPG]

Yes, I've swapped transmissions and have a much taller final drive. So you're right: the cam swap and lowered torque peak should match the engine better to the gearing I have.

[MetroMPG]

Here's a question: if the cam is going to raise effective compression, would that show up if I did a before & after compression test?

[Gary Palmer]

I am not sure if it would or not. I would expect that if the valve's are opening and closing at different timing, relative to what you currently have, it may.

However, I'm not sure. I've only run a modified cam in one car and in that I had put in domed pistons and raised the regular compression up to 12 or 13:1. However I ended up having about 250/1000's shaved off of the head, which was all I they could take off, before I even got to where I could get the ignition to ping. Once I did, it ran like gangbusters, with probably 30% more power and about 20% better fuel economy. However, I never did a compression test on it, after I finally got the darn thing to run.

My personal conclusion was that you start fiddeling with it and you can either make it better or a lot worse. I decided to opt for what something came with from the factory.

In your circumstance it seems to me like a cam switch would be very likely to show a noticable, significant increase in mileage, on top of what you already got from the transmission change.

Do you know if the XFi has different pistons, or anything, from what you have?

[MetroMPG]

Engine wise, differences I know of on the XFi (besides the cam):

- slightly smaller throttle body,
- 2 rings on the pistons (vs. 3 on the regular) for reduced friction,
- and the different ECU.

[rh77]

I had to check -- thank goodness it's not a pushrod!

At any rate, I think this test may have some potential for members who are stuck with a powerful engine that have access to less-aggressive cam designs for their application.

I'm excited to see the results. If the redline is the only conern, then that's entirely manageable with or without an ECU. Otherwise, cam swaps are fairly common in the horsepower scene -- but to change it for economy is brilliant.

Any concerns with tuning, or will it be install and go?

Keep us posted :thumbup: and good luck!

RH77

[MetroMPG]

The Actual Unit - 6 lobes of fury

[Peakster]

I'm itching to get this done, but it'll have to wait until winter retreats a little. It's -22 C / -7 F outside. That's Peakster weather, not Blackfly fixin' weather.

Ha haha! Thanks :rolleyes: . By the way, it was only -10*C (14*F) in Regina today and it's going to get above freezing this upcoming week :p .

[nathan]

You can build a DET CAN (http://www.honda-tech.com/zerothread?id=1555006) for detecting knock...it's always amusing when mechanical solutions are better than electronic.

thanks for posting that DaX. i made one on the weekend and tested it out.
works pretty good, you can hear everything your engine is doing. quite amusing actually.
anyway, i advanced my timing and went for a drive, i could hear ping from moderate to high load, so i pulled over and retarded it a bit, took a while to find the right spot and im not even sure how much ive actually changed it from where i began. anyway thats enough threadjacking for me, sorry MetroMPG

[MetroMPG]

No that's OK. You're not threadjacking at all - it's relevant.

Question: how much of a difference did using it make? I mean, could you think the timing was OK to the "unaided" ear, but when you used the det can did you discovered it was actually pinging?

[nathan]

nah it actually didnt help me out a whole lot. my car lacks sound deadening and the little bit that it did have (ie carpet.) i removed.
if however you have a car which you cant hear the engine too clearly i can see how it would help. it made it easier to hear the ping but i wouldnt say i needed it. i could however hear other engine sounds which i wouldnt be able to make out without the det-can.
if you have the parts laying around id say go ahead and build it. its worth it in amusement alone

[MetroMPG]

That's funny.

I'm a bit of an automotive hypochondriac (immediately assume the worst whenever some new sound appears, or the car doesn't idle like it normally does...), so maybe I'd be better off not hearing the noises that I couldn't otherwise hear. :D

Here's a serious question though: exactly how bad is pinging? EG: If I have my timing set so that I'm just beneath the ping threshold for 98% of my driving, but it does ping on those rare occasions when I load it up (say on a really steep hill, or to accelerate faster than usual), am I playing with fire? Going to wreck the engine?

[Ryland]

if your engine pings, it's the feeling of your engine getting stressed, insted of doing useable work, it's hard on your bearings, and stresses your pistions, and it has no positive side affects, not even little ones that I know of.

[rh77]

That's funny.

I'm a bit of an automotive hypochondriac (immediately assume the worst whenever some new sound appears, or the car doesn't idle like it normally does...), so maybe I'd be better off not hearing the noises that I couldn't otherwise hear. :D

Here's a serious question though: exactly how bad is pinging? EG: If I have my timing set so that I'm just beneath the ping threshold for 98% of my driving, but it does ping on those rare occasions when I load it up (say on a really steep hill, or to accelerate faster than usual), am I playing with fire? Going to wreck the engine?

The more dramatic term for "ping" is "detonation" -- basically the fuel igniting at the wrong time and not having the piston in the right spot to move (some people call it "spark knock". Constant ping will destroy an engine as Ryland put it: extra, undue forces on internals. Rare ping is normal, but I'm like you -- if the car idles funny or pings, I immediately begin the diagnosis and treatment. A common fix for the troubled pinger, is to do a carbon cleanse, adjust that timing, or go up a grade in octane rating. But if you have it happen occasionally, then that's entirely normal. We're talking over 50,000 miles of serious, constant ping to destroy a well-built engine.

Causes range from poorly tuned timing to a abnormal build-up of carbon or even high intake or coolant temps. Ford Crown Vics/Grand Marqs were notorious for building up so much carbon that the engine would ping itself to death. My Father-in-Law's old G-Mq had so much carbon in the intake manifold that it split, spewing raw fuel all over the engine. No fire was started, but at the time, he did trade it on a new 2005 Civic LX Sedan upon the advice of an unnamed son-in-law ;) (and he loves it). Take a ride in a cab and you'll see what I mean. Law enforcement agencies use seafoam or pure water to clean the carbon out of their Crown-Vic units to get them to last forever, so they ping less commonly.

Moral of the story: unless you experience ping every time you drive the car, then I wouldn't worry about it. Otherwise, perform some of the above maintenance.

Speaking of paranoid, I noticed for the first time ever that a belt is slipping after a FAS startup. It's just a chirp, but it makes me nervous. I hope it's an isolated, weather-related event. All the belts were replaced last year...

RH77

[DaX]

I think the occasional ping is ok. Many street tuners that I spoke with while I was building my turbocharged Civic told me that they will tune the timing maps by adding timing in each RPM/load cell until they detect small amounts of detonation, then back off a few degrees and leave it there. Dyno tuners will do the same but look for a small loss in power, then back off a few degrees. Remember that your engine will continue to make more and more power all the way up to the detonation threshold.

[Silveredwings]

I used to have an MGB that had a vernier timing adjustment knob on the side of the distributor called the "octane selector." It's purpose was to enable you to advance the timing until it pinged when you tromp on the gas in 4th gear at ~20 mph. - and then back it off a little.

[MetroMPG]

Cool. I would like to have a knob like that on the dashboard.

[rh77]

Cool. I would like to have a knob like that on the dashboard.

I'm told that modern engines (at least in Hondas) have an "octane sensor" that sorts this all out automatically -- so if your car requires premium and you put regular in it, it automatically adjusts timing. It could be a fancy name for a knock sensor -- not sure :o

RH77

[DaX]

It could be a fancy name for a knock sensor -- not sure :o

RH77

Yep, it is. Some Hondas have it, many don't.

[Silveredwings]

Old bikes like Indian Chiefs had the throttle control on the left and a timing control on the right.

[MetroMPG]

Swapped cams this afternoon. Warmest day of the year so far: + 6C, sunny & calm. OK for driveway tinkering!

Haven't driven it yet (just started it up - sounded the same). I'll take it for a spin after supper and will report back...

[Peakster]

How difficult was it to install?

[MetroMPG]

Not difficult. CoyoteX suggested it was perhaps a 30 minute job. It took me maybe 2 hours. It'd take me 30 minutes to do again though :)
So it certainly hasn't hurt!

In fact, I think it's safe to say it's a perfect complement to the taller tranny. Like peanut butter and jelly!

[Peakster]

Not difficult. CoyoteX suggested it was perhaps a 30 minute job. It took me maybe 2 hours. It'd take me 30 minutes to do again though :)

Anyway - on the test run, even without being able to use as much throttle as I would have liked, I was able to pull off a 84.8 mpg (US) P&G round trip - 9.8 miles, 1 hr EBH assisted start, 3C temp.

So it certainly hasn't hurt!

In fact, I think it's safe to say it's a perfect complement to the taller tranny. Like peanut butter and jelly!

HOLY SMOKES!!!
How many more gallons do you have left in that tank of yours? I can't wait for your next fill after that!

By the way, if the XFi cam increased low end power, what was the reasoning to why all the Metros didn't have it?

[MetroMPG]

I was going to fill up tomorrow to start the "team challenge" off with a full tank, but the prices are over a buck a liter here. I may wait a week or so to see if they come down before I fill.

(EDIT the refiner who had the fire says they'll be back up to full prod'n this week. So prices should drop.)

[zpiloto]

-6 C that's hardcore. I can't wait to see the results from that. I know it probably buried in the thread but what do you think the FE improvement will be?

[MetroMPG]

Whoops, no it was +6 C. (I'm not that motivated.)

Hard to say how much it'll help. I'm guessing a few percent, but that's just a WAG.

[Silveredwings]

Congrats on the project. :thumbup:

As I recall, you don't heat your garage. Did you have the EBH engaged, or pre-warm the engine?

[MetroMPG]

Thanks. I thought about preheating my "work area" with a little drive, but no, I worked on it cold - but on the driveway, in the warm sunshine.

[brelandt]

NICE.......I was waiting to hear when you was going to do this.

Glad to hear it went well and can't wait to see the numbers come in!

[MetroMPG]

96 mpg (US) round trip, hardcore P&G; 8C; no EBH; 12.4 miles; 47 mph max; 27 mph avg; ideal conditions (traffic wise).

This is the same route I used on Sunday, with a small extra bit tacked on at the end. I probably would have had low 90's if I had stuck to the exact same route.

Even 5 extra degrees C warmer makes all the difference - I came into a few well practised turns/stops too hot and had to brake because the rolling resistance is less than I've been used to for the past 3 months.

I'm liking this cam. To me, the motor seems quieter (could be because I'm shifting a little sooner), and it has a deeper sound.

[Matt Timion]

YAY! I'm glad I could contribute to this project :)

[MetroMPG]

Yes - definitely thanks for spotting that XFi at your junkyard. There ain't any of those cars north of the 49th.

[Peakster]

I was going to fill up tomorrow to start the "team challenge" off with a full tank, but the prices are over a buck a liter here. I may wait a week or so to see if they come down before I fill.

(EDIT the refiner who had the fire says they'll be back up to full prod'n this week. So prices should drop.)

Prices in my parts went up again today (from $0.999 - $1.039 a litre). Gasoline prices dropping? Who ever heard of that :p? Have they dropped in your area MetroMPG?

[MetroMPG]

No, and then I remembered why: it's March Break - the kids are out of school, family trips etc. Prices often go up for holidays & long weekends. :(

I can wait. I've got a couple of gallons left, and I don't have any out of town trips planned until later next week.

And it's warm enough that I've resumed biking for in-town trips, yay.

[zpiloto]

No, and then I remembered why: it's March Break - the kids are out of school, family trips etc. Prices often go up for holidays & long weekends. :(

I can wait. I've got a couple of gallons left, and I don't have any out of town trips planned until later next week.

And it's warm enough that I've resumed biking for in-town trips, yay.

This has got to be a record for time between fills where a car is not up on blocks:). You da man:thumbup:

[MetroMPG]

I think it's the longest I've gone between fills before. Partly it's the car (most efficient I've owned), partly it's because I just didn't go very far this winter, and partly it's because we only got about 8 weeks of winter, so I was able to keep riding the beater 10-speed right into mid January.

---

[MetroMPG]

For anyone following this thread, I've updated MetroMPG.com with a post summarizing the issues, installation, and (predominantly subjective) results of installing the cam in my car. Most of what you've read here is included, with some new bits added:

International heart transplant: the Blackfly gets an XFi cam (http://metrompg.com/posts/xfi-cam-swap.htm) - MetroMPG.com

[ALgeovalley]

sorry about the bump, but i just got myself what auto-zone calls an XFI cam for a 94 metro. it runs about "$157.00", i'll be getting it today or tommorow. i currently have a late 95 metro. i've tried registering over at teamswift with no success yet:(

so, before i get the cam i'm going to make sure i know what i'm doing. could you guys point a few things out to me like, will the cam alone increase my mpg? do i need to have the cam machined in some way, also, i am assuming i will be putting this cam in not monkeying with the timing belt and i'll be good to go. what about the cam pulley, is there any reason for getting one thats adjustable?

just modivate me already:D i'm looking forward to this swap, and to your replies.

[MetroMPG]

Welcome to GS...

before i get the cam i'm going to make sure i know what i'm doing.

Before you start, I'd make sure it's actually an XFi profile. Got some calipers?

I assume you've seen these:

- http://metrompg.com/posts/xfi-cam-swap.htm
- http://www.teamswift.net/viewtopic.php?t=29755
- http://www.teamswift.net/viewtopic.php?t=23838

[ALgeovalley]

4.64%, i think i'm going to sit this one out, i like my car a great bit therfor i dont feel 4.64% is worth the ping. i already am getting results of around 55 mpg just the way it is. what did you get that transmission from, is that an xfi transmission you're running with that cam?

if i happen to run across a transmission and cam together i might consider it. also, everyone says the specks are 6 BTDC with circuit jumped oem. under our hoods out here in bama its labeled 5 BTDC, any reason for this? what would the best mpg setting be for me, 5 or 6? THANKS...

[MetroMPG]

The car won't ping if you re-adjust the timing.

Transmission is from a 93 Swift 1.3L 4-cyl. Much taller final drive than the XFi transmission.

As for timing, generally speaking, I've read that more advance is better. Of course you run the risk of ping under high loads the further forward you go.

[DaX]

More advanced timing is better for FE (more power, etc) but there is a limit you approach where detonation happens and typically tuners approach the detonation limit then back off a few degrees.

[ALgeovalley]

The car won't ping if you re-adjust the timing.

Transmission is from a 93 Swift 1.3L 4-cyl. Much taller final drive than the XFi transmission.

As for timing, generally speaking, I've read that more advance is better. Of course you run the risk of ping under high loads the further forward you go.


What about a transmission From a 95 or 96 4 cyl ("Geo Metro") ? it is a 5 speed transmission, Please comment on this for me, THANKS.

[MetroMPG]

Any of the 4-cyl transmissions will have a taller final drive than the 3-cyl versions. It may vary slightly depending on the model & wheel/tire size.

[ALgeovalley]

well, i got the transmission in today,, also took it to the gas station and filled er up, hit the trip button and away i rode :) love the way it shifts out, it's not what i expected! the rpm's are so laid back just like you said! :thumbup:

i will be driving this car in the country hills only, rarely i'm on the highway...

[MetroMPG]

Congrats! It's quite the difference isn't it? Pleasant surprise.

You should fill in your garage info so we know more details about what you're driving.

Looking forward to your results.