A-series fuel mileage record holder?

[blownb310]

Hi Guys,

 

Some of you may have seen this on the 1200 forums, but for those who haven't, here's the story about how I decided to go for setting a record for the best fuel mileage ever recorded for a Datsun A-series powered car. I am using my '77 B210 for this exercise. Before this I had modified the car for performance as seen THIS thread. When my car club decided to hold an Economy Run [fuel mileage contest] event, I accepted the new challenge of modifying my B210 for maximum fuel efficiency.

 

Here's a recap of how I prepared my car for this event.

 

Previously the car was modified for speed and power. I used it for hillclimbs and such. I built and modified the 1397cc engine to 1608cc's complete with twin 40mm Dellortos...

 

It ran terrific but only got 25 mpg. I needed a much more stock type engine for economy run events.

 

So I removed this original 1397cc engine from my '76 B210 parts car. It sat outside in a field for the last 15 years. It needed some work!

 

I tore it down and freshened it up.

 

I used an '80 Datsun 210 "mpg" cylinder head [casting number 990] with it's smaller round intake ports and small combustion chambers. This head, on the B210 block [with it's flat top pistons] yields about 10.5 to 1 compression ratio. High compression is one of the keys for improving gas mileage.

 

Other than the Pacesetter header and 2" mandrel bent exhaust system, the reast of the drivetrain is stock.

 

The big engine comes out, the little one goes in....

 

After bolting it all together, I fine tuned it with an Innovate LM1 wide band oxygen sensor setup. After rejetting the stock Hitachi carburetor for between 14.6 and 15.0 to 1 A/F ratio, I took the car out on a 64 mile test loop the afternoon before the big event. I slowly filled the fuel tank right to the rim and then carefully drove a 64 mile loop. I then refilled the tank [right to the rim again] and it took 1.1 gallons of gas. I was very happy to have gotten 56 mpg in this initial test! B210's sit quite high off of the ground and this brings a poor drag coefficient, so I went home that night and tried to help the poor aerodynamics. I added a makeshift front chin spoiler, clear plexiglass headlight covers [not visible in the picture- because they are clear], and blocked off half of the grill to reduce wind drag.

 

 

The next I morning I competed in the A.M.E.C. Economy Run event and carefully drove the 118.7 mile distance. During the post event refill it took only 1.91 gallons of fuel. This equates to 61.53 miles per gallon!

 

 

I think we have a new record for the B210 chassis folks!

 

This was not my absolute best attempt at fuel mileage for these cars. I would have needed much more time to prepare. There are many other things I can and will try in the future but I don't want to do this with my B210 though. My plan is to take this to the next level with my '81 210 sedan instead. Then I will get into lowering the car for aerodynamics and such.

 

Full results for this event are HERE.

 

More pics can be seen HERE.

 

Has anyone else ever tried to maximize the fuel efficiency of their Datsun?

 

Mike

[datzenmike]

I had a new '76 B-210 and drove to BC from Ontario and back. Hit over 40 MPG without even trying while carrying a roof rack and full trunk. Averaged in the high 30s most of the time. At home mid 30s but I drove the shit out of it and twice managed to get into the 20s. Great little car, fun to drive.

[b210in]

congrats man, home run for us bee guys.

[DRIVEN]

Once again proving the flexibility of the Datsun brand. Well done. Promise me you'll be giving the finger to every Prius and Smartcar you pass.

[INDY510]

:eek:Damm... dude that is awesome

I want a A12 motor with a motorcycle head, it has been talked about on the 1200 forums, but I never saw it finished. A dual cam FJR 1300 head would probably get good gas milage. but a ZX12r head would sound cooler.

 

I got 42mpg in my 1972 Datsun 510 with the stock L16 and stock carb. It had a 5 speed and I was driving mellow, but it would still get over 30mpg no matter how heavy my foot was.

 

I still have plans for a CA16de 510, but it will be after a couple other projects get finished: like a AC propulsion powered 510:DI wish

[blownb310]

Thanks guys,

 

There is still room for improvement. The 120 mile course we used for this event was in a very hilly area. Take a look at one of the competitor's graph of elevation changes we traversed during the economy run....

 

 

I will continue to tweak the car a bit more in the Spring. I hope to get into the mid-60 mpg range then. I bought a 3.54 H150 differential to swap out for my standard 3.70. This, combined with the five speed, will drop the revs even more on the highway. I will go to narrower 155/80R13 tires too. Right now I have 175/70's. I use 50 psi air pressure in the tires.

[FJDatto]

Outstanding!

 

In the early 80's, I drove a 72 1200 to Spokane with 2 friends. Car had a weber dgv, with electronic ignition, pacesetter header, and 2" pacesetter exhaust. Achieved 52.7 mpg averaging 67 mph with only a 4-speed. Never came close after that as the engine was usually sitting between 6000 and 7300 rpm while being driven. :rolleyes:

[blownb310]

Outstanding!

Achieved 52.7 mpg averaging 67 mph with only a 4-speed.

That is outstanding. The B110 chassis with an A12 is the way to go for the ultimate mileage in one of these Datsuns.

[ppeters914]

50+ MPG? I could talk the wife into that. :D

Trouble is, only if I get rid of one of the other cars. :(

 

Nicely done, sir.

[mikko1200]

61.53 mpg ,that

[blownb310]

BTW, I really like your B210 "blownb310". Nice period color and no foolish modifications. It

[Guest jaimesix]

Very nice job, congratulations Blownb310.

That is an astonishing endeavor, lots of gumption and dilligence to achieve it.

I second Mikko's comment, your B210 is got to be one if not the best B210 exponent I have seen . No foolish mods, just good taste, good performance, and now the ability to swap engines according to the plan of the day, from super mileage to ultra performance.

 

Jaime.______________________________________________________

[blownb310]

Thanks for the kudos Jaime.

 

Here's what I'm up to this week. I want to replace the standard 3.70 final drive with a 3.54 from a later 210. I found this one in an old junkyard in the woods.

 

This place is up on a mountain and you can only get in there by foot. It isn't fun to carry everything you need for a job like this up that hill. But I am serious about improving mpg's so I rise to the occasion.

 

Pulling the axles......

 

I brought a come-a-long and other paraphernalia to get the job done, as this place is up a steep hill and you don't want to be short any tools once you finally get up there.

 

It was easy to get the differential carrier out at this point. ;)

 

Now my B210 is utilizing a B310 "mpg" head, 5 speed transmission, and final drive too.

 

Mike

[blownb310]

Just installed the taller 3.54 diff today. Freed up one of the parking brake pivots while I had the axles out too. Ever notice how those darn things always seem to get tight after a while? Oiling them with a squirt can and working them free by hand does not last very long, so this time I took them apart and packed them with wheel bearing grease. It's good to stay on top of little things like that. You definately don't want the brakes dragging when you're out for best mpg's.

 

I will finish up tomorrow morning with filling the diff with synthetic gear oil and mounting four narrow 155/80R13's on standard wheels. I am entering a new and different fuel economy contest coming up this weekend and want to do well. I also plan to lower the car some to improve the aerodynamics a bit. I will cut a half of a coil off of the front springs and make some aluminum spacer blocks to lower the rear to match. Just have to find some longer leaf spring U-bolts to do so.

 

Mike

[datzenmike]

Have you thought of a more restrictive exhaust? Headers tend to reduce bottom end torque. Perhaps a stock manifold at least. A before and after to see if headers do indeed affect economy at low speed/throttle.

[blownb310]

Have you thought of a more restrictive exhaust? Headers tend to reduce bottom end torque. Perhaps a stock manifold at least. A before and after to see if headers do indeed affect economy at low speed/throttle.

Thanks Mike, that's an interesting thought. Might be worth a try at some point. I'd have to weld up a connector pipe to join the manifold with my header back system.

 

I have to admit that I am enjoying the substantial weight savings the header's giving me though. I read that the factory curb weight for a B210 is 2000 lbs. Mine weighs 1,860 as it sits now with the lighter header, bumpers and such.

[b210in]

stock b210's come with a 3.70 rear gear?

[blownb310]

stock b210's come with a 3.70 rear gear?

In the US market and with a manual trans, yes. I *think* the automatics had 3.90's. I know that was true with the B310's.

[datzenmike]

Up to Aug '74 the H-145 rear with 39/10 (3:90) ratio was used with standard and automatic. After Aug. '74 The H-150 rear was used and 35/9 (3:889) ratio with automatics and 37/10 (3.70) ratio with standards was used.

 

I can only find the MPG optional 37/11 (3.545) ratio on the first year '80 and '81 210. This was an option and not on all cars so I hope you checked the numbers stamped on the crown gear... 37/11. Also grab the speedo drive out of that tranny and put in yours to keep the speedometer accurate.

Edited April 30, 2009 by datzenmike

[blownb310]

Thanks for the clarification Mike. Yes indeed, my newly aquired diff is a genuine 3:54. I am looking forward to having them as now I can stay in 4th gear when cruising under 50 mph and really going for the big mpg numbers. You see, in our transmissions 4th gear is not really a gear. You are simply locking the mainshaft for a straight 1 to 1 ratio and sending the power flow straight through the transmission. In 5th [or any other gear], there is a bit more drag because the power flow through the trans is has to go through both the main and countershafts, and through the gearsets themsleves.

[Guest jaimesix]

Man!

 

That poor 210 had a slow death in the woods. Glad to see its legacy will be alive in those parts you are taking from it.

 

When your project fuel mileage record finishes, are you going to restore your B210 to its glory??? That B210 with the sidedraugths and worked engine is a delight. On part of me longs to see your project mileage make it, but another side tells me say no, stop it:eek:

 

It will be restored I am sure.

 

Jaime.__________________________________________________________

[Duke]

I must say, I am loving the mpg project you have going. Very cool. I'm almost inspired to find a 1200 and do something similar. It would make a great daily driver. Keep up the good work.

[Icehouse]

Yeah awesome thread! I like most of us gear heads like to read anything about cars. Well I stumbled across a Prius chart on Wikipedia that had all the numbers we like to read. The weird thing I noticed was that the newest Prius is getting a bigger engine! They say the added torque will help more than the extra displacement will hurt.... Just thought it was weird and I should share that small bit of information :D

[ggzilla]

Same with Datsun. The A14 got better fuel economy than A12 engine. By fitting an A12-type cylinder head to the A14, top end power (and max fuel usage) was limited to same as A12. But low-RPM power was better. Add higher final gear (differential gear) and overdrive and it was a winner.

[blownb310]

Man!

 

That poor 210 had a slow death in the woods. Glad to see its legacy will be alive in those parts you are taking from it.

 

When your project fuel mileage record finishes, are you going to restore your B210 to its glory???

Don't worry Jamie, the twin carbed 1608 is sealed in a clear plastic bag on an engine stand and will go back in as soon as I feel I've maxed out the current combination and can't get any better mpg's because of aerodynamics.

 

Then I'll transplant the mpg engine, trans, and diff combination into my '81 B310 2-door sedan [which has been sitting in dry storage for 10 years now] and try to take it even further. Then I can go wild and get into areodynamics and such.

 

Mike