Improving a 460 (power and mileage)

From what I've read the proper way to do a crossover is the run the car up to temp on a hoist. Take a temperature reading along the exhaust pipes. Where ever the exhaust pulses are backing up will be the hottest part and that's where the crossover goes.

 

I'm not really looking for maximum performance, fuel mileage yes. I'm VERY happy with this engine and its current performance and fuel mileage. Back in 2014 I was doing some construction on my cottage and my truck took a dive on me. While it was in the shop the wagon substituted and pulled an overloaded double axle trailer easier that the dang truck. LOL. I think I would need more than a cam from the 60's to improve the engine. Pistons would be another as they were 10.5-1 vs the 8-1 in there now.

When I bought the car from the original owner in 2013 he told me he had the heads shaved on the advice of the shop that replaced the valve seals and put on a NOS carburetor. It suposidly was done to increase compression. I couldn't tell you anything other than that. All I can say it's not sluggish like you would think a '77 would be. I know the cam wasn't changed because it still had the original timing set in with that 8* retarded key way.

 

Both go hand in hand, since an efficient engine runs at peak horsepower. Not to say that a radical camshaft will increase milage. Because, the law of physics simply prevent that from happening, during daily use. Track results would, of course, differ. But, that's not what you're using the vehicle for. The lowering of compression, as well as manipulating camshaft timing- and grinding was done for the purpose of lowering emissions. Otherwise, there was nothing to complain about how engines ran before 1968. To compensate for horsepower loss, displacement had to get increased, through lengthening piston stroke. Through raising displacement, more air volume gets exchanged. Of course, the more air to get exchanged would take along with it more fuel. Respectfull of what your exhaust technician claims, for others here, it's safe to say that headers could only increase fuel milage, because the engine breathes better. The same goes for induction alterations. Any decrease in fuel milage, after such alterations, only depend on your ability to resist the temptation of using a lead foot.

 

Keep in mind that this is a mint original unmolested wagon with all its factory emissions in-tacked. Spending five to ten grand building an engine to get more power is possible and I've been doing that for 35 years on different cars and boats. Everyone likes to talk about horsepower but the only thing that moves this 5000 pound wagon is torque. Horsepower is a mathematical figure, it's not real or measurable and it doesn't move a vehicle. Torque does and having a nice flat torque curve is even better. While lengthening the stock stroke length does increase the displacement, if all else remains the same, the main reason this is done is to increase torque.

This motor has tons of torque and gets good fuel mileage on the highway to boot. The simple changing of the timing gear set sufficiently woke the beast up.

I sorry but I'm going to have to disagree on more power equates better fuel mileage. The only way to get more power is to add more fuel and burn it efficiently. I could list all the formulas here to explain it but simply gasoline only has so much energy and you must burn more of it to get more energy out of your engine. Since my plugs read perfectly I'm therefore burning my fuel as efficiently as possible with a carbureted engine.
Unfortunately most of the time we get vehicles from the 70's and 80's and the emissions equipment have been hacked out and modifications has been made to an engine to make it better and it runs like crap, burns fuel and you have soot coming out the exhaust. Most of the reasons people do this is someone told them to get that JUNK off of the engine and or they think they know more than the factory. We also have aftermarket parts sellers claiming huge gains in power and most of the time it's just a copy of a factor part made in aluminum.
My buddy's mustang does 12.5 in the quarter mile with all the emissions equipment and single exhaust. This car is bone stock. There is a ton of aftermarket parts available for this car but why would he mess with it?
My point in all this is that I'm happy with how the engine runs now and if someone were to ask my opinion I would steer them in the same direction to maintain the integrity of what the factory did with small tweaks.

 

Back then, they used all of those add-ons, to stay below EPA radar. Since then, most of those add-ons have been enginered out, given time for research and development. Nowadays, modifications have become engine internal.
You're right to mention that long-strokers are more economical. This has to do with harnessing expanding combustion gases better. Thus, higher torque.

 

So this thread has been about power and fuel mileage. I've got a '64 Cadillac sedan deville that I installed the Fitech fuel injection on and thought I'd share some results. I know it not a wagon but it is useful information.
First a few things, the engine had been rebuilt around 7-8000 miles ago. I wanted to repaint under the hood and rebuild the comfort control system. Well one thing led to the next and installed a Fitech system, electric fans, rebuilt the a/c and comfort control system and installed a transmission cooler with its own fan. Almost immediately after installing the Fitech and buttoning everything up I took off on a day trip of 400 miles. Fuel mileage was terrible at 10 mpg. (Imperial gallons) Took another 150 mile trip after adjusting a few things in the computer and got 16.2 mpg. I leaned it out a bit more and today's trip of 150 miles I got 18.88 mpg. I'm very happy with this. It's a 429 ci original motor and I think I can squeeze out some more mileage.
I highly recommend this system after putting 700 miles on it!!! It's not an easy installation and if you get lost in your own backyard I recommend that you have it professionally installed by a shop that has done this before.
Oh yeah and it kicks ass for power to!!!

 

If I hit twenty mpg, this setup is going on the wagon if I can keep all the emissions intact.

 

Did you have the air conditioner and/or other accessories running, during your trip?

 

The fuel mileage results have all been with the a/c running full time.

 

Would be curious as to what you get with everything unnecessary to the driving of the vehicle turned off, including the cigarette lighter. Hit that 20 m.p.g. mark, please.

 

My a/c compressor is the newer style a6 and is supposed to be a more fuel efficient unit. Who knows but that a/c stays on until fall as I'm surrounded by the Great Lakes and it's hot and humid here now.
Of course as I type this I'm sitting at my cottage surrounded by water and no air! Once the sun goes down its not to bad.

 

Took another trip in the caddy yesterday temps in the high 70's and low 80's. I leaned out the fuel injection .1 and the engine actually ran a bit cooler in both the coolant and cylinder temps.
Fuel mileage was 20.3 mpg imperial. I've got more to lean out but I want to do a little more research on my temps first. Very happy with this so far.