You know i was just thinking of different ways to get milage and came up with a thought that with a bit of work one could switch ports in the head. Think of it this way ignore the cam for now. port the heck out of the exhaust and turn them into intakes using offset guides. run fuel injection, this way you would turn the now center intake port into a true 360 degree cycle the exhaust cycle would get weird but with a bit of calculating with the pipe lengths you might get some scavenging. make up a new cam with the correct firing order. just a thought. 28 mpg at 70 plus with the 1275 (1310) now in the 1100. Aaron

http://community.webshots.com/user/66mg1100

Anytime I have ever put on a header or bigger exhaust on other cars at least, I lost a little mpg because it seems to lose low end but improve top end. Does that make sense? More airflow=more fuel?

My Mini's are un-officially sponsored by Coor's brewing company.

It's in Canadian. Got 59 once, but 51 was the norm.

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l0st.              

"if it's gonna be that type of message board, i'm going to stick my mini in the mashed patatoes!!"

 but canadian mpg or american mpg  as the canadian gal is a bit bigger .  now in liters   of cource .

 my old mustang  66  6 cly   gets  32 in canada with the  can gal and 28 in usa  with the smaller usa gal. 

 

The first year of driving my car I had (still have) 1275 metro lump on my 998 mini gearbox with 998 stock manifold, carb and exhaust. On the hwy I was getting 51mpg. I did draft behind alot of big rigs though.

Drove the car to work today for the first time in 5yrs!! So once I'm driving it more I plan on calculating my mpg again, with all the numerous mods I've done since then.

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l0st.              

"if it's gonna be that type of message board, i'm going to stick my mini in the mashed patatoes!!"

Header will give you more hp but not sure about mpg. Did someone mention single carb? Not Weber of course.

Opinions I express here do not reflect my wife's.

Thanks for all the great input guys!  I'm shooting for  the mid-40's as an average.  I'll try the 1000, how about the hader for better breathing? Think that'll help? Or should I stick with the factory exhaust?  I just replaced it before the accident, so I know it's in good shape.

Also, the air dam idea sounds good, years ago I put one on a '73 Celica GT I had, and I remember it helped both mileage and top end....Now just to find one that looks good!

 Thanks again! Mike

 

Thanks for the bulletin. I don't think my twin-point has that problem, because it runs very well (i.e. starts readily. smooth, steady power at all RPMs, no hesitations or glitches.) If the problem would reveal itself though MEMS ECU codes, I hope to be able to check those soon...

 

DLY

My '92-spec carbureted 1275 British Open Mini has gotten 34 and 35 on the last two tanks, respectively.

I drive with mileage in mind: No jack-rabbit starts. Take it out of gear and coast to stops. Drive as much smooth highway as possible-my commute is about 5 miles of two lane blacktop and the rest is 60 MPH max. 4 lane.

I think 35 is about "it" for me. I'm tickled to death with that.

Pick up the newest Consumer Reports with the MPG car test/charts. Glance at the MPG chart; only 4 (if memory serves me right) averaged over 30 MPG and two or those were Prius hybrids! The wee new cars average mid-high 20's. Not very impressive at ALL in my book.

And NONE have the fun factor my Mini does.

Here is the MPI service bulletin I was told about. Never followed through with the dealer to try to get it fixed before it was too late. Anyone know any more?

MODEL/DERIVATIVE: Bull. No: 0018 Mini CDS. ref: R7303bu Issue: 1 All multi point injection vehicles up to engine number 12A2LK70 345346 PROBLEM: ENGINE MISFIRE, HESITATION, ETC - CAM RELUCTOR May also suffer reluctance to rev freely. Condition may be intermittent, i.e. may run normally on some journeys. CAUSE: Camshaft reluctor teeth not to specification resulting in irregular cam sensor pick-up. Since the cam sensor only requires synchronising on start-up, it is likely that some starts will not detect an error resulting in normal running for that journey. ACTION: Condition described above will be apparent from new even though condition may not occur on every journey. If no other faults are apparent, e.g. ignition or fuel related then replace camshaft. If symptoms develop after a period of time suspect causes other than cam reluctor. PARTS INFORMATION: LGC 105380.........Camshaft

I get 32 in town with the SPI auto and 45mpg highway. Granted that was driving very nicely. Getting ready to check my SPI 4 speed car to see how it does after the SW5 and light flywheel and LCB exhaust. I hope performance mods won't kill my mpg too much.

My Mini's are un-officially sponsored by Coor's brewing company.

Recently ran about 370 miles through the country tour with my 1310, twin 1  1/4's, LCB, 266 cam, 3.44 gear etc. and managed 33 mpg.  Suggest a taller final drive if you run the bigger engine.

I would like to hear more about the bad camshaft idea for twin-points. Mine is similar, rich in the mid to high range, black soot (not oily) at the pipe. But on the dyno, power looked really good throughout the range. I got 53hp @ wheels, which, even after a very modest correction for power losses, puts my 50,000 mile motor at close to rated hp of 63. That's why I thought it was healthy.

But if the "mere" 30-32 mpg is a sign of a bad cam, that would explain a lot (as far as why the mileage seems to vary.) What other ways are there to verify that the cam is bad, short of pulling it?

Thinner oil of course can help. I think (but I don't have enough data to prove it to my satisfaction) I lost 1 or so mpg when I switched from the 10-30 oil recommended in the owner's manual to 20-50 oil at my 2nd oil change (8-9000 miles into ownership.) Since most people felt that 10-30 was too thin, I switched. Normally I adhere to manufacturer recommendations, but this is a British car company we're talking about here. (or at least British-managed.) I'm not sure Rover was that concerned about longevity when they were selling the last of the Minis.

 

DLY

When I raced track bicycles, we would use oil in the bearings instead of grease, tires pumped to over 200psi and some guys used helium to pump them up. They would have to be pumped up again before each race. But my first post on here is the most practicable.

--Spank 

 

In the late 60's and early 70's I ran the shell mileage rally in Canada , I had a 998 mini ,  with .02 over pistons  so I was in the over 1 liter class, we would  normally get 100 mpg ( Canadian gal  of gas is bigger )  and would some times exceed 110 mpg.   Won my class more then a few times.  The under 1 liter would be in the 120 mpg range  800 fiats were hard to beat so we moved to over 1 liter .  The tricks were   driving very carefully  no fast starts, long off the gas braking , turn engine off down long hills or  sitting at lights , higher tire pressure  ie 50 lbs and as skinny a tire we could find,  very thin oil  5- 10 weight.    We would back off the rear brakes , loosen up the bearings , put light weight grease in the bearings .  put the toe to almost neutral .  we would lighten up as much as possible ,  put in a 2.7 rear end , carpets and everything we could  throw out ,  the  single 1/14 carb was leaned right out.  kept the windows closed. We put a vac gauge on the manifold  and drove with lowest reading .   and make sure it engine  was tuned right up.   The car was set up for the economy runs and was almost un-drivable in normal traffic.   But you could not drive it in today’s wild fast traffic.  

My 1980 (updated to 2000 specs) has done an average of 32 miles/gal over almost 60k miles now. But this is a good time and forum to ask. It has always run somewhat rich, actually leaving some carbon soot on the back after long runs. I was once told theat many of the MPI's had this problem due to faulty camshafts. There is actually a bit of a miss at idle. I was also once told there was a service bulletin about this. Has anyone else heard this?

Deseam your car and reduce your frontal area.

Nothing is so bad that you can't make it worse by doing something rash or going berserk.

My speedo would have to be off by almost 30% high in order to get the bluedragon average mpg so if I were to take into account the 10-15% error then im still getting high 30s to 40. If I can get ahold of a gps unit I will test how accurate the mini is against it. 

Elvist-p-m-- are you taking into account the likely innacurate odometer as bluedragon is? take 10-15% off and you have very similar numbers.

Alignment and tire size are probably one of the cheapest changes you can make to your mini for better fuel economy (aside from driving habits). Also, take out the tapered roller bearings and put in the ball bearings--they roll with less drag. Check the brake drag and don't be so quick to adjust up the rear shoes.

My vote is a 998. Also, you will want too have the vacuum advance functioning properly for lean-off at cruise.

--Spank 

Hmmm, then I need to check the tuning on my MPI more closely. I would love to be pulling 35-40 mpg (U.S. gallons that is.)

I have a wideband o2 meter - I'll need to hook that up and take some readings over a period of time. My car did run rich at 3-5,000 rpm on the dyno - perhaps if I can lean that out, I can find the lost mileage. Otherwise, I am quite satisfied with how the motor responds. I do have plans for a performance head and rockers - if I can get more power and use the same or less fuel, what more could one ask!

Proper tuneup is important too - check the valve clearances, which are sometimes neglected.

 

DLY