Don't laugh at my 25MPG ('65 Mustang 6-cyl auto)
 

Considering I am an OLD Hot Rodder and custom car builder, my friends were shocked when I sold a 1940 Ford Hot Rod coupe I drove for 12 years with a V8, and purchased a 1965 Mustang SIX CYLINDER AUTOMATIC. I bored it to the max, changed the cam, removed the 1-barrel and installed a 2-barrel, built a hotter ignition, opened up the exhaust, and installed taller tires. I totally rebuilt the car inside and out, and built it for highway driving on long trips. With Me driving and my wife riding shotgun (2 cornfed old folks), 15" radials, 2.83 rearend, using the air conditioning, running with the truckers in the NASCAR lane (70 to 75+MPH), hauling a weeks luggage, 2 lawn chairs, 2 umbrellas, tools, and my favorite vino, 25 MPG seemed okay. The car does NOT have overdrive but has undercoating, extra foam insulation, sound deadening material, a full size spare, and last year at 76 I weighed 216 and the wife didn't. After 54 years I am a lot smarter. Two months ago I sold the Mustang to build my 1967 Sunbeam Alpine with a Ford 1985 2.3 and A4LD overdrive. Using basic MPG tricks I expect mid to high 30's if I keep my foot under control. I will post my mods as I build.

[Admin note for Charlie - FYI, it looks like some of your posts went into the "moderation" queue for some reason. Apologies for their delayed appearance.]


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Help out a young guy who's never had the chance to drive a first generation Mustang with some context: what MPG would an unmodified Mustang expect to see in that kind of driving?

MPG mustang
 

A first generation Mustang six with standard 3-speed got about 21 to 22 HWY...actual not hyped. The automatic C-4 running the air conditioner, hauling 2 adults with a weeks luggage got about 20 MPG. My 65 AS MODIFIED got 24 to 25 normal highway driving at normal speeds, using the AC, and sometimes doing 75+...just to stay with traffic. My 65 had much added undercoating, extra foam insulation, the AC compressor was switched from the old York (Hi drag) to a modern Sanden, with an aluminum radiator, fan shroud and flex-fan. Very seldom did I punch the gas because I got into a MPG habit, but it would do well over 100 MPH...DON'T ASK. The 6 was bored to the max at .060", with a new street cam, stock valve job, 2-barrel carb adapted, home built points ignition, 2.83 rear gears driving 15" radials (205x70-15). The C-4 did not have a lockup converter so it probably had between 3 and 5% slippage. My Sunbeam will have a lockup converter and Overdrive transmission with taller than stock tires in the rear. I was proud of my Mustang SIX and put it on the hood.

Nice!

The cam: was that for added power, or to shift the torque curve down to make highway cruising more efficient?

Oldsmobile offered (or at least tested) such a cam in the 60's:

Unfortunately, the source web page is now offline. But it referenced a magazine article about the engine.


Lower lift & duration is the design of the special economy cam in the Geo Metro XFi as well.

Better MPG than I get...

cam
 

MetroMPG, the cam specs are more important than most realize. Lift and duration seems to be the BIG info most understand, but OVERLAP and when the Intake Closes make a big difference. Think of it this way; if the intake is still open as the piston moves UP the cylinder, pressure drops lowering compression. The valve needs to be open long enough to fill the cylinder with fuel/air before it closes. Also, with a lot of overlap vacuum suffers, which is used to advance the timing on my points dizzy. I used a TRUCK cam used for pulling in pickups and Vans, putting the maximum torque in the 2000 to 3500 RPM range. I don't remember the duration, lift, overlap, etc. but it worked. The cool-air intake I made pulled air from in front of the radiator, which is about 50 degrees cooler. Say 90 outside, 140 under the hood over the exhaust. Notice I cut an eyebrow-opening on that side of the hood to vent heat also. This is TEXAS so "cold-air intakes do not exist...just cool-air. A denser air charge burns better and Hot Rod magazine proved it even on a stock motor. I make mine out of PVC because metal holds heat. Why pull in cooler air then heat it on the way to the carb? I am an ASE certified mechanic who retired from a city shop as superintendent and was charter president of the Dallas Area Street Rods. Much of my engine knowledge came from being a motorcycle nut for 2 decades as I studied the internal combustion engine.

Last year while walking the dog in a street where I usually see some interesting rides, I had a chat with the owner of a 6-cyl early Mustang about how they are quite underrated, as most folks seem to be more overwhelmed about the V8.


My first opportunity to study internal-combustion engines involved motorcycles too.

Studying the internal combustion engine
 

I got serious about engine study as a young teen, and worked on my own motors from age 18. I built V8's for decades then bought a 6-cylinder for a daily driver. That motor was not a power house but was economical and moved the little Mustang well. It was a 67 with auto but no air. After selling my V8 powered 1940 Ford coupe I bought a 65 Mustang 6-cylinder with automatic and air to begin my study of smaller automotive engines in MY cars. The Ford 200" motor has the intake manifold cast into the head, making any intake mods a problem. My understanding of horsepower and torque gave me the knowledge to modify the little 6 for better economy AND HORSEPOWER. Matching parts is the trick, after deciding what one wants to do with the motor. Basically, building for torque in the rpm range expected. If a car turns 3000 rpm at 75 mph, then the cam needs to make it's torque in that range. Making a good hot-long spark in that range is also important. Allowing the engine to breathe better helps both HP and TQ. Matching transmission gearing, rear axle, and tire size makes a major difference in overall performance. Tuning also helps.

Sometimes there are interesting setups matching parts from engines of different automakers. I remember some folks using Volkswagen conrods on modded Renault engines for example.

Getting better MPG
 

Rooster, I mix-matched parts to save money but also to get more MPG.
1. Reduce Drag...Lower the car and remove any "hang-on items." Narrow front wheels reduce friction/drag. The radiator fan causes engine drag, so use an electric fan, fan clutch, or flex-fan. The AC compressor hurts, so upgrade to a more modern Sanden if your car has an old Ford York. If using AC, once car is cool, cut the AC a little...higher temp. Actually open car windows cause a lot of drag, so using AC on a mild setting can be helpful...really. DO NOT hang mufflers or any under car parts lower than the body line. Bonneville cars often use a full belly-pan, and modern factory cars have partial pans up front under the engine. Air Dams help do the same thing...there is a lot of turbulence under there. 2. Weight...is a big MPG killer. DO NOT haul a lot of tools around in the trunk, or lawn chairs, ice chest, laundry, Beer, laptop, clothes, the kids toys, etc. and MPG will go up. If you never use the back seat (not talking Love Life)...remove it. Replace the spare tire and jack with tire sealer/foot pump/tire plugs. I used plugs in 120 MPH cop cars for over 10 years. Install as recommended. If you do 90% in town driving with gas easy to get...fill the tank half full. Half a tank of gas is heavy. If you want engine building tips...ask. I have done this for decades with cars that were 1948 or older (Street Rods) and later cars are much easier.

I love your Pony, Charlie. I modded a slant six in my Dodge Demon back in the 70s.
-Did you machine the intake manifold to accept the 2 bbl carb, or use a bolt-on adaptor?
-Did you use a vari-jet type of carb? The Jeep guys like to use these Vari-jet Webbers on their straight sixes. The second barrell only opens when extra power is needed, sort of the way a 4 bbl works. I think Ford made something similar to the Webber and used it on 4 cyl mustangs.

carbs and sixes
 

Wheelbender6, I did not machine the intake but used an adaptor. I have the later head that has the larger intake opening but same valves I planned to machine when I built the 73 Maverick 200 motor. The carb was an Autolite 2100 287 cfm 2-barrel with annular atomization I explained on an earlier post. In my thinking it is the best carb ever built for economy, HP, and Torque. Since I am not rich I had to sell the 65 to build my present Sunbeam...which also uses an Autolite 2150 later version of the 2100. I think I posted a pix of the 65.

That Sunbeam holds a lot of promise, Charlie. I like the looks of the 2.3 you've built to go into it, too.

I've always been a fan of fours, especially the larger ones. I like when someone takes a more pedestrian motor and optimizes it and shows the "V8 or nothing!" crowd what they're missing.

The Sunbeam looks like a great project, Charlie.

Saw this:

https://1.bp.blogspot.com/-aaRV7hX2k...19-h424/20.jpg
https://1.bp.blogspot.com/-6Vhoi_qkM...16-h425/21.jpg
http://justacarguy.blogspot.com: Arf... Sunbeam Tiger

"When I grow up I'm going to be a T-Bird". :)

Four Bangers
 

ElHigh, I am a recent convert to the smaller engines from the Street Rodding hobby. Even with V8s I built for economy. My wife is an orphan and I started life's journey in the Dallas housing projects. Neither of us had $$$. Now 54 years later we own everything, and have far more than we need, and I still try to build something challenging. The Sunbeam with an old 2.3 running points and a carb, seemed perfect. If I can make 110 plus HP, 130+ lbs. ft. torque, get mid 30's MPG, and do it in comfort, I will be happy. I have seen most of the United States from an old car(32 Ford coupe, 4 1940 Ford coupes, a corvette powered 35 Ford pickup, a chopped Pontiac tri-powered 34 Ford pickup, and a 1965 Mustang SIX), except the North West. We are retired and in decent health, so why not? The little four built for MPG and comfort, should keep 2 old corn-fed 70's plus folks (I may be 80) cruising in style. I witnessed true poverty from the flight deck of 3 carriers in the 1960's and know this is a blessed nation I want to see more of. I can think of no better way than driving a sportscar I built that runs clean, has plenty of HP, and is economical. And I still say my prayers at night.

This doesn't work out so well in Brazil. A few days ago I was with my mother and grandmother, and my grandmother got shocked to find out some crazy guys lower their cars to the point it drags to the pavement, damaging not only the car but also the pavement which becomes a PITA for everyone else :mad:


Even though 13" tyres became less usual recently, last year my mother considered switching from stock 14" to 13" due to the taller sidewalls for improved comfort. Well, 13" tyres as narrow as 145 became quite rare now, but the more common 165 and 175 are still not bad at all for that matter.


Nowdays I see no reason for anything other than an electric fan to be used in a vehicle. Or even in a farm tractor.


Now that many cars are switching to 48-volt electrical systems and start-stop is also increasingly common, it's quite surprising that all-electric AC systems are not so widespread for cars as they are for RVs, and for big rigs too as it allows the driver to sleep with the engine turned off.


More often the only cars I see with parts lower than the body line are either converted to CNG or wheelchair-accessible minivans.


This is another deal I'd be unlikely to try due to local riding conditions :turtle:

I got halfway around the World once, and I'd point to a picture of the Columbia River Gorge and say I lived not so far from there.

Maybe a little teardrop trailer?

Last time I saw a teardrop trailer, it was coupled to a Volkswagen-engined tricycle. Too bad I wasn't quick enough to at least try to take a picture, and I can blame it at least partially on the dog...

MPG mods
 

Rooster, the reason for going to higher voltage electrical systems is the use of electrical power steering, larger computers, electronic ignitions that are heavy electrical drains, and computer shifted automatic transmissions. Add electric torque converter lockup, bigger computer screens, and on-board TV for passengers, and electric demand goes way up. It sells cars/SUV's but I think we have forgotten the purpose of a car...getting us from A to B as efficiently as possible. When I sold my 1965 Mustang SIX, I mentioned to the possible buyer he would need to get use to people honking at him with a "thumbs-up." Just a minute later a car of teens pulled along side and did that very thing. He bought the Mustang. My Sunbeam will have an automatic overdrive A4LD with a lock-up torque converter that is controlled by a simple button. I am sure I could get 40 MPG if that was my goal, but sacrificing drivability would be compromised for other drivers not familiar with the car's unique driving needs. My cars can be driven by ANY normal driver without special training.

Charlie, I like your taste in cars. Thank you for sharing this!

We certainly have it easy today with electronic control of so many factors. I can tell it was more of an art in the past.

Rooster and others, here in the U.S. wide tires means W-I-D-E TIRES...like 13" wide tread and wider. My Sunbeam with 5" rims and 175x70R-14 on front and 185x70R-14 on the rear are almost skinny here in Texas. I am not an engineer but I read their books when building so I have a good idea why things are done. Fuel Injection is better in a modern car because they have computers that read sensors that tell what the motor is doing internally. Higher fuel pressure atomizes the fuel better for FI, but a good carb can do almost as good with 1/10 the pressure. A points system works fine but is not as accurate once above 5000 rpm...though a 4-cylinder with only 4 lobes on the distributor cam can go well above 7000 rpm with good spark. The points can also be updated with a hotter coil, lower ohms ignition resistor, the best available condenser, brass contacts cap, copper wires, and Iridium sparkplugs gapped a little wider. This makes a good long and hot spark. If one understands them, carbs, points, and matching all the pieces for economy can make a nice car even better. Maybe late next summer I will know. The motor is my 2.3 without boring or using high compression pistons. The back yard pix is my shop shot from the patio I built for the wife. She loves to sit in the shade in the summer and by a fire in winter and read...preferably with a glass of wine. I may do that if I ever stop building things.

It's either going higher-voltage or oversizing the alternator and then increasing its drag. Same reason why military vehicles usually resort to a 24-volt system for a long time. BTW a few years ago a friend told me about some Nissan Patrol 160 and Y60 models he have seen in Europe, and got impressed by the 24-volt system fitted to them.


When it comes to efficiency, no wonder sometimes it seems like the only way to go from an economical standpoint is to switch from appliance-cars to tricycles. It had been quite common in Uruguay.
https://2.bp.blogspot.com/-MoIeL0jMz...%2Buruguai.jpg

The Sunbeam is what Don Adams drove in "Get Smart"?
https://i.pinimg.com/originals/d6/78...75faf803d0.jpg

Sunbeam
 

Yes it was but a Tiger not an Alpine. The Tiger had a Ford v8 and 4-speed, while the Alpine had a 1725cc 4-cylinder with 4-speed. Mine now has a 2301cc Ford 4-cylinder with auto overdrive with lockup torque converter. Hoping for a realistic mid 30's MPG highway with 2 people on board and luggage.

They used to make a manifold for mounting a 390cfm 4bbl on a for 2.3 liter Ford. It may be tough to find now.
Just because your Sunbeam is an Alpine doesn't mean you can't mount a machine gun under the hood like Get Smart.

Sunbeam
 

Maxwell Smart had a machine gun on his hood because he chased bad guys. I am a bad guy! Okay, a 77 year old bad guy who has lost a lot of his BAD, but I still try. These days I prefer comfort over power, so I have a 4-cylinder rather than a V8, and overdrive automatic with lockup converter for max MPG.

Vacuum-controlled lockup?

Very nice projects Sir Cheap! I like cut of your jib.

I'm currently working my way through a love affair with inline sixes. I highly recommend the BMW N52 as a source of educational joy. I've had two and they have both been splendid. Although they do tend to leak over time due to variances in coefficients of expansion. Not the end of the world but not exactly Japanese level "reliability".

Anyway I'm following your Alpine project with great interest. They are fun little cars.