AeroSprite! Aero & mechanically modified Austin Healey Sprite: consistent 65 MPG US
 

EcoModder has a longstanding (2011) member, xpedro01, who hasn't posted yet, but who has done (and is still doing) some really interesting things.

Things like this:

http://ecomodder.com/imgs/aero-austin-healey-sprite.jpg

http://ecomodder.com/forum/member-xp...46-trlr07a.jpg

http://ecomodder.com/forum/member-xp...847-trlr07.jpg

Details, from e-mail (posted with permission):

• In the early 1970's I was driving 110 miles per day so I modified an Austin Healy Sprite and doubled its mileage over a period of years to a consistent 65 MPG (unheard of in those days).
• This was a 1960 "Bug Eye" with an 850cc engine. It turned close to 3000 at 60 mph and gave 33mpg on average, originally.
• It wound up with a 1600cc pinto engine (& transmission) with the camshaft retarded 2 notches (poor man's Atkinson cycle)
• Additional (2nd) Buick transmission, reversed, to gain up to a 2.5 overdrive
• The engine cruised at 1100 rpm @ 55MPH (Nixon days).
• A slight incline required downshifting, but I had 12 speeds.
• It was made of junk yard body pieces, pop rivets and bondo. Eye level was 70's skirt level.

Here was the car mid-way through its transformation:

http://ecomodder.com/forum/attachmen...p;d=1391531371

Here's the same Sprite in "33 mpg" form:

http://ecomodder.com/forum/member-xp...te-front-1.jpg

Ultimately (after a 250,000 miles), the modified car was taken off the road & dismantled for safety reasons. A student got the chassis in exchange for destroying the body. He had a Midget and could use the parts.

The builder says he prefers driving his recently acquired 2000 Honda Insight (which he is also modifying with a short aero tail) compared to the Sprite. No kidding!

Hopefully he'll join the conversation, now that the cat is out of the bag. At 87, he's got most of us on seniority (by a significant margin), but I bet he'll figure out this forum-posting business if he wants to!

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Oh: the "secondary transmission mounted backwards" trick reminds me of my friend's dad's 1930's-era aero & mechanically modified Model T.

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UPDATE - Feb 18

Reprinted with permission from April 1975 Kansas State Engineer magazine, an article about the car mid-way through its transformation to 65 mpg...

http://ecomodder.com/imgs/AeroSprite...in-article.JPG

Would love to hear MORE about that BUICK transmission: actually an OPEL manual?

Very cool Darin. Old school modder, I like it!

There are a lot of cobwebs involved here as it was almost 40 years ago. As I recall the reason for choosing Buick was because of its very short output shaft which in this case went forward to connect to the output of the pinto transmission. It must have been from an older enclosed driveshaft Buick. With this type of use it had to withstand the torque of the 1600cc engine multiplied by reduction of the Pinto transmission. More than likely it was from a 1950's 70 series Buick since it was a 3 speed with no syncros in first gear. I had converted a buddies 39 buick and my crosley while in the Air Force back in the early 1950's. Behind this transmission was its clutch shaft that had to be supported. This called for an adapter plate and ball bearing + seal. The clutch hub was used to adapt to the driveshaft which was now only about 18 inches long. It ran in what used to be first gear when cruising. This was a 2.5 to 1 stepup and allowed the engine to run at 1100 rpm at 55MPH. A small incline required shifting the 4 speed down to third. Only about 7 of the 12 gears were really usable because of almost duplicates.

xpedro - nice to see you on the forum, and thanks for sharing the project.

When you think about what was available at that time, 65 mpg is remarkable. (Even though it's a walk in the park for your Insight.)

Car and Driver didn't get anywhere close when they messed around with modifying their '74 Pinto.

I had experience with the 1600cc (FOB) engine & transmission in my 1972 Pinto:

http://ecomodder.com/forum/409028-post35.html

...however, my best was ~ 36 mpg at 55 mph. And, ironically, I'd earlier owned a 1965 MG Midget (bought in Newfoundland) the cousin of the Sprite.

Old Tele Man, that was probably doing pretty good since your engine was probably turning over 3000. With my camshaft retarded 2 notches, the power stroke did not end until almost bottom dead center, and the intake valve stayed open till the piston was almost half way up. The displacement was twice the original (almost) so full throttle did not make it ping because of the Atkinson cycle effect (expansion stroke was much larger than the compression stroke). Mine was a gentle low power engine that operated in the 10 horsepower range.

I think this is the first I've read in the forum of someone doing a "poor man's Atkinson cycle" by monkeying with camshaft timing.

(If someone else has done it, I welcome the correction.)

I wonder how it would impact an OBD-II car that needs to pass emissions testing...

So did it get totalled in a wreck?!? :eek: :p

It probably would not pass emission test, but I don't think they tested in those days. There would be no nitrogen problem as the compression was lowered from 110psi to 75, and full throttle gave a cooler exhaust than before.
We also had a 1968 Cadillac that had the almost unheard of in those days of 10.75 to 1 compression ratio. In later years they dropped back to the industry standard of 8 to 1. It was pre Atkinson. The spec sheet said the intake valve closed 90 degrees after bottom dead center. It still required premium. It would ping at 60mph on regular on a slight hill. ONE cog retard solved that problem. It was happy with regular for the next 50,000 miles that we had it.

HI FRANK LEE. My wife resigned her teaching and got a job teaching at Fort Riley for K.State We moved to Manhattan and the need for a commuting car disappeared. I did not want it to fall into other owners hands for safety reasons, so I had a buddy that owned a midget remove the body and keep the chassis for his trouble. After a quarter million miles it deserved a rest.

Ah Bugeyes. I once drove a friend's Bugeye home with a piece of twine coming out from under the hood and over the windshield. The twine acted as a hand operated throttle cable; the foot-operated cable had broken.

this is my favourite bug eye.
its powered by a 3 rotor mazda engine.
it races at autocross by the Kiesel family.
http://1.bp.blogspot.com/_aQZJZohXcL...0/DSC_0846.JPG

Actually we discussed "Atkinsoning a bike engine" in the bike section.
One of the guys tried it (advancing one tooth on the inlet) but had carb settings issues so we concluded it must be done on par with injection (and obviously DOHC is better suited to the mod)

Do you have any photos showing the front and rear views of your car? I was wondering how you dealt with the radiator air inlet (adjustable radiator doors, if any), the air flow through the radiator, and where you exhausted the radiator air.

Basjoos--I am honored. I have a photo of the front. I am a newbie and have not figured how to get to the address of the pictures yet. I will send you my email address on a PM and if you email me I know that will work.

xpedro - if you're not having any luck with the photo, feel free to email it to me and I'll add it here.

I'm tickled to have an old-school modder on the site. The description of his motor mods -- changing the valve timing to make an ersatz Atkinson and still managing 55mph on what little power was left - is just awesome stuff.

I think, Xpedro, you would have made a decent racer. What with however long it must have taken to build speed in your little Sprite on such modest power, you must have learned some skills at not giving up the speed once you'd acquired it.

Elhigh-I appreciate the kind words. Is that a small (maybe not a cub) IH tractor I see on your avatar? l was a farmer till 1966. I worked with things like a John Deere model D, which was a 2 cylinder with 6.87" pistons and a 7 inch stroke. Compression ratio was 3.97 to 1. It was rated by "Nebraska Tests" as a 15-27. That would be 27 HP on the belt pulley and 15 HP on the drawbar with steel lugs.When rubber tires came along in the mid thirties they got an actual 35 drawbar max HP. I think their 'rating' was 70% of max. RPM was 900. It had water injection available and 2 fuel tanks if you used "fuel oil". The 2 gallon one was for gasoline to start and warm it up, then switch to oil (zero octane or less). The upper tank of the radiator held about 5 gallons of water for the water injection.

It's an A. I have a 1945 parked in the front yard; I won it in a raffle. Not even a Super A, just an A, so no hydraulics are installed. It has some fueling issues and I plan on building a 3-pt hitch for it as no hitch gear was installed when it came to me. I have no time nor will to go looking for an original single-point Fast Hitch as it was equipped from the factory, and of course finding implements that would work with that would be like finding hen's teeth. A Cat 1 3PT will allow me to mount up some smaller implements and get some work out of it, though using a machine of this size for some chores I could do, like mowing my 9,000 sq. ft. yard, would be ridiculous. Three passes and the job would be done.

As far as power output goes, it's modest. VERY modest power ratings, easily eclipsed by a brand-new "garden tractor" from the big box stores. But those big box horsepower ratings aren't sufficient to, for instance, drag an 800-lb stump out of my front yard, which the A has done. And in 70 years I doubt if any of those big box garden "tractors" will still be around, whereas the Farmall might actually still be working.

xpedro Thanks for sharing. What was the inspiration for your body design.

Nemo--I had already spent 40+ years messing up good designs. This just happened to be one that lasted a long time. Driving 2.5 hours every day gave me lots of planning details time. This project needed help on a small budget. My very patient wife said "you just cannot leave anything alone, can you". It is just a weakness.Thanks for your interest.

Holy smokey !

I guess we've found the granddaddy of the AeroCivic :)
Or he has found us ;)

That's some pretty hardcore ecomodding xpedro :thumbup:
Even though the term probably wasn't invented back then :rolleyes:

Pity it's gone, but that's life.

Here's what it reminded me of

http://www.eudrivers.net/wp-content/...coupe_s_51.jpg

Hi Euromodder--There was no internet and only one Porche on campus. It was owned by the head of the phycical plant. K State was heated and cooled with steam and a 175 foot tall smokestack. When I removed the 875cc engine from the sprite, he bought it because his wife raced them. Months later he called and said "l thought you might want to know that your engine went 105 miles an hour yesterday in a race".
Thanks for bringing up the memory.

xpedro: added 3 more of your photos to the first post.

I'll send you a private message tomorrow to explain how I did it.

Basjoos--MetroMPG came to the rescue and put them with the first note on page one. You can now view what I was trying to send. Maybe some day I will learn.

Wow great job! I wanted a 59 bugeye so bad when I was looking for my first car, but the values then were a lot more than I can afford, my mom refused to lend me the extra money so I ended up with the cheaper mini. Very happy with it, if I recall from David Vizards book about tuning the A series engine has a chapter on economy, it's from the 70s so there were other people doing eco modding to those engines, however I recall that the upper limit was shy of 60mpg UK so you definetly surpased the potential of that engine.

Seeing this makes me want to drive the mini, too bad for snow!

Minispeed--I paid $350 for the 1960 bug eye in 1968. It was blue like the one in the picture, but had lots of rust. I remember a hole in the floorboard. It didn't have a top and I drove in the rain a lot that first year.
I now have a 2000 insight that is in the process of being destroyed with new mods. I am 87 and do not plan to sell it. My latest is a 16" tail using a second bumper decreased to .55 the original area. lt appears to have gained from 71 to75MPG at 55Mph@40 degrees F. on my 18mile test track. I love it.

http://ecomodder.com/forum/showthrea...5-a-28088.html

thins like this
 

WOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's like having a second Christmas.Thanks for the heads up and photos.No shortage of hero's out there.:D

I love this adventure !

Wish there was more to read about it :-)

There will be more if I learn how to post pictures. This is my first week.

If you have the picture on your computer, just left click on the photo and drag it to your desktop. On your post at the bottom go "advanced". After that you will see options below your post, left click on "manage attachments". Go to desktop on the selections on the left, find your picture on the desktop, and left click on that photo. The manage attachments section will show the photo as a file atachment. Then click add to post at you should get it to the post.

Use preview option to check your post and to see if the photo has been included.

You can reduce the size of this post to use it as an instruction guide as you progress through the process.

regards
Mech

For old photos take a picture of the photo with a digital camera and download it to your computer, or scan it and dowload it if you have a scanner or printer with that capability.

I am not very computer savvy and those methods work for me.

regards
Mech

and already a legend :thumbup:

midpoint
 

This was 1972 to 1975. Please see page one.

http://ecomodder.com/forum/attachmen...5&d=1391531371

GT6 like hood ?

renault_megane_dci--Yes, the Bug Eye hood hinged at the front, and by unplugging a cable and some simple disconnect, you could remove hood and front fenders from the car to work on the engine. I had forgotten that detail since it was 40 years ago. Thanks for bringing back the memory.

Old Mechanic --You guys confuse me- both you and the guy from France have Suzuki 1994 250's. It really is a small world. See posts above.

I had a 59 Sprite when I was 17 years old, last year of high school 67-68. A penny a mile and I drove it like I stole it. 33 MPG was about right.
I see you got the picture thing down pat xpedro1.
regards
Mech

They were lots of fun. I WILL try to ad a shot back on page 1 to show my justification for poking holes in it. xpedro01.