Aluminum Slant 6 engine

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moparblood

moparblood

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besides the head gasket what are the pro's and cons to having 1 of these?
i get the weight reduction. someone told me the 170 was better than 225 as far as better MPG's. is this true?
 
Honestly, dollar for dollar you're better off buying a newer car with a 4cyl/6cyl. While it would be neat, it just not financially viable.
 
got a car yet?

those goals may not be easily met in a 50 year old car
then again, ma mopar set those goals when she made the feather duster

my point is, dont look at just the engine, look at the whole package, every pound f car you have to push will run down your MPG
rolling resistance comes into play aswell, making sure the wheel bearings are in good shape and properly greased, lightweight wheels, light tires...all that
 
dano said:
Honestly, dollar for dollar you're better off buying a newer car with a 4cyl/6cyl. While it would be neat, it just not financially viable.
Click to expand...
Really? No computers or engine lights. Mass wires, tons of electrics to go wrong, tire valve sensorsetc.., the more electrics the More to fail. just My pinion!
 
moparblood said:
besides the head gasket what are the pro's and cons to having 1 of these?
i get the weight reduction. someone told me the 170 was better than 225 as far as better MPG's. is this true?
Click to expand...

I've gotten 30+ on the highway with a souped up 170 in a 4 speed 64 Barracuda.
 
diymirage said:
got a car yet?

those goals may not be easily met in a 50 year old car
then again, ma mopar set those goals when she made the feather duster

my point is, dont look at just the engine, look at the whole package, every pound f car you have to push will run down your MPG
rolling resistance comes into play aswell, making sure the wheel bearings are in good shape and properly greased, lightweight wheels, light tires...all that
Click to expand...
Exactly. You would need to run a narrow tire similar to what was factory on the car.
In the late 60's, early 70's I ran a 700-13 tire on the front with about 50psi - not on long highway trips, but it helped with the manual steering and mileage. Not everybody's cup of tea, but rolling resistance, synthetic lubricants and a good wax job are key to your goals.
 
I completely understand his motivation. Its no different than building horsepower that you really dont need. Just a challenge.
As for the cost... I dont think its will cost anymore than a late model cheap econocar is good shape. And less to repair if it ever needs much.
 
mbaird said:
I completely understand his motivation. Its no different than building horsepower that you really dont need. Just a challenge.
As for the cost... I dont think its will cost anymore than a late model cheap econocar is good shape. And less to repair if it ever needs much.
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I've owned at a dozen Neons my 1st gen got 30+mpg's,lasted over 400Kmiles(hard to believe) the rest good and a few mutts. i figure for bout 10k or less this can be done. changing motors on these are a breeze. i have a chance to get an Alum.motor6, wonder if its worth it? though i ve owned many 6's long time ago never really tuned them. they were so plentiful. easier to change motor.
 
The aluminum Slant-6 is nifty and cool (in that "I have something not many other people have" kind of way), but it's not a hot ticket to awesome MPGs. You save 80 pounds, that's it.

If you're trying to build a max-mileage maker, it'll be much more cost-effective to build a top-notch 170 engine and save the aluminum-block money for an EFI setup instead.
 
slantsixdan said:
The aluminum Slant-6 is nifty and cool (in that "I have something not many other people have" kind of way), but it's not a hot ticket to awesome MPGs. You save 80 pounds, that's it.

If you're trying to build a max-mileage maker, it'll be much more cost-effective to build a top-notch 170 engine and save the aluminum-block money for an EFI setup instead.
Click to expand...
 
If gas mileage is the key goal, and the car you're building isn't too heavy (and you don't live up at elevation), then yeah, build a 170.
 
You know there's no big secret to getting good mileage, right; you just slow the engine down and lean it out until it won't maintain speed, or burns itself up trying.
For a guy who typically drives 12000 mile per year, the savings from 25mpg to 30 mpg is 80 gallons. What's 80 gallons cost down there? Well, at $3.00/g that would represent an annual savings of $240bucks. Over the life of the engine, say 120,000 miles before freshening, you could save $2400 bucks.
I bet you a dollar,an aluminum block is not gonna save you $2400.
What will save you money is an extremely small final-drive ratio, and a well tuned engine......and driving style.
But you'll need a big enough engine to achieve the power, to get up to and maintain your chosen cruising speed, in your chosen chassis. and you will need enough reserve power,to pass and climb hills.
There's no substitute for cylinder pressure. But too much tends to break things, so, sometimes, a little bigger engine,operating at a little lower pressure is a better idea. And some engines do not take kindly to pressure, at all. Some designs do....
 
MOPAROFFICIAL said:
I have one, probably going to block rock it and run an oil cooler.
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Whats block rock it? i must be getting old. At 12k a year i would drive my 440 dart. Now its just a matter of can it be done! Do the ends justify the means?
 
moparblood said:
besides the head gasket what are the pro's and cons to having 1 of these?
i get the weight reduction. someone told me the 170 was better than 225 as far as better MPG's. is this true?
Click to expand...
First, Welcome to FABO!! Second, there is no "G"(short-deck) Slanty block in Al-U-minimum that I'm aware of, so no Al 170's unless You de-stroke an Al 225. Third, the 170
"G" block is Approx. 1&5/8" shorter than the "RG"(Raised G) block the 198 & 225 are based on, so it is a good chunk lighter & still iron. Fourth, under-sizing an under-power
engine for a task will cause it to downshift much more often, & spend more time in the carb's power enrichment circuit....not more efficient.....................
The upshot is if the smaller engine has a high enough output efficiency, and the gears are picked correctly, it will return better MPG. If not, it will disappoint You..........
My opinion is to skip the Al-U-minimum block unless You just want the novelty of it, too many finicky issues possible, and You can find better ways & places to lose 80lbs.
 
Killer6 said:
First, Welcome to FABO!! Second, there is no "G"(short-deck) Slanty block in Al-U-minimum that I'm aware of, so no Al 170's unless You de-stroke an Al 225. Third, the 170
"G" block is Approx. 1&5/8" shorter than the "RG"(Raised G) block the 198 & 225 are based on, so it is a good chunk lighter & still iron. Fourth, under-sizing an under-power
engine for a task will cause it to downshift much more often, & spend more time in the carb's power enrichment circuit....not more efficient.....................
The upshot is if the smaller engine has a high enough output efficiency, and the gears are picked correctly, it will return better MPG. If not, it will disappoint You..........
My opinion is to skip the Al-U-minimum block unless You just want the novelty of it, too many finicky issues possible, and You can find better ways & places to lose 80lbs.
Click to expand...
dually noted! thats why i ask questions. i currently have a 225 cast crank alum. man. 4 speed OD trans. wanted to see if ends justifies means. using all syn. fliuds,alum.wheels etc.. i'll be ready by spring and will post results.
 
AJ/FormS said:
You know there's no big secret to getting good mileage, right; you just slow the engine down and lean it out until it won't maintain speed, or burns itself up trying.
For a guy who typically drives 12000 mile per year, the savings from 25mpg to 30 mpg is 80 gallons. What's 80 gallons cost down there? Well, at $3.00/g that would represent an annual savings of $240bucks. Over the life of the engine, say 120,000 miles before freshening, you could save $2400 bucks.
I bet you a dollar,an aluminum block is not gonna save you $2400.
What will save you money is an extremely small final-drive ratio, and a well tuned engine......and driving style.
But you'll need a big enough engine to achieve the power, to get up to and maintain your chosen cruising speed, in your chosen chassis. and you will need enough reserve power,to pass and climb hills.
There's no substitute for cylinder pressure. But too much tends to break things, so, sometimes, a little bigger engine,operating at a little lower pressure is a better idea. And some engines do not take kindly to pressure, at all. Some designs do....
Click to expand...

The funny thing is I have found the opposite is true for mpg. I have always built for dependable power, the unexpected result is much better mpg if driven sanely. Of course you can go too big or race oriented and go the other way. My 170 was a really nice high winding engine producing plenty of power to pull a 4 speed Barracuda along and get great mileage cruising on the highway. I can't remember if I was running the O/D at the time. No experience with the Al block.
 
In my '64 Dart 170, with the stock 170cuin/3spd manual, 3.23 gear, I'd average 23mpg. When I went to a 4spd OD and 3.55 gear I was averaging 27mpg. Most of my driving is in town too.

Now with a 360/4spd 3.55 I average about 12mpg.
 
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