Early 70's Cadillacs and fuel efficiency.

In reply to wawazat :

So you've made a 25% improvement in fuel usage without trying to optimize it fully for fuel economy? No changes to the timing? I'd say that's pretty good! And better than a lot of what I've seen reported for sniper and fitech installs. Of course most of those guys have made no effort to tune for economy. 

In reply to Nick Comstock :

i literally just finished a Sniper installation, about a half hour ago. For the target audience, it seems hard to beat.  Five wires, plumb in a fuel pump (the most time consuming part, for this install), add in the O2 sensor, enter in the engine displacement, and with very little drama it will start and run just fine.  Closed loop operation as soon as the engine fires.

The as-delivered fuel ratio targets are quite a bit richer than I'd want to see for economy.  Clearly the base settings err to the side of great drivability.  I don't know yet if you can go more in depth than the handset's idle/cruise/power targets using the optional laptop software

Cadillac did over a optional bendix electronic fuel injection on the later years of the 500 and its successor the 425. It increased hp on the 500 from 190 to 215 and on the 425 180 to 195.

In reply to Knurled. :

I believe you can. I've read of people making small changes in the idle and cruise maps.

The fuel plumbing took the longest time for me too.  I replaced the fuel tank after adding a EFI rated pump.  When I replaced the exhaust system I installed collectors with bungs and plugs.  The first start up was cool. 

On the FiTech you can play with maps, A/F ratio at various temps and throttle positions, rev limit, idle speed, electric fan temp settings, fuel pump PWM, and others as well as ignition settings.  I have not enabled that feature yet though I do intend to.  I do agree that they seem rich as I play with settings.  

As I said I'm more concerned with driveability than fuel consumption.  It's a top down, wind in my remaining hair, make me feel good about life kind of car.  I can deal with higher fuel consumption than a new car when I'm driving it.

Do whatever you like with it, part of the thrill of modding stuff is to do something no one has done, electric conversation could be cool.

If it was me I would lean more towards diesel and rat rod land, like this guy did because.....why the berkeley not?

I got a pretty consistent 18 mpg from a Caddy 500 with 4.10 rear and a Gear Vendors OD in a 66 Bonneville.

Caddys are part of the smog malaise of the early 70s, but with 8:1 or 8.5:1, they weren't quite as bad as the late 80s, small-displacement offerings like the Olds 307 with 7.8:1 and tiny bores.

Caddys make a crapload of torque and they're all done by 4500 rpms.  Seriously... pair one with a TH400 and 2.73 gears, roast tires, and you'll get much better mileage than a 454 or 455.

In reply to Curtis :

That's encouraging too. Were you running a Q-Jet? Being in a Bonnie I'm assuming things weren't exactly stock?

Just my .02 cents.  Test drive one of these cars, to see if you even like it.  Sometimes an idea/desire and reality don't coincide.  My preference is the 77-79 versions.  If you like them, get the best one you can for the money.  (This is old news)  Next, would be to set up a ground zero with a proper tune up.  Next, possibly, newer alloy wheels and a little narrower tire, better exhaust.  Get it running good.  Someone mentioned a 93-96 Fleetwood drive train swap.  A quick mpg check revealed a 15 mpg average. Another mentioned option is a GM truck/suv swap ..They also get 15 mpg and up on average.  They all weigh about the same, and have roughly the same aerodynamics.  I'm enjoying the ideas being tossed around.

When all hyper-miling tricks were employed (80 psi in tires, radiator tapped up mostly, 50 mph max) my great aunt’s ‘74 DeVille once recorded a hand calculated 14 mpg.

Knurled. said:

The 472 wasn't even designed with power in mind.  Just smoothness.  Any power it made was purely accidental.

 

As for economy, even after 1973... who cared?  You had a Cadillac.  You could afford it.  Or at least, you wanted the image that you were rich enough that you could afford it.

 

Nowadays you can buy a 2 liter turbo Cadillac that makes twice the power, weighs half as much, and gets four times the fuel economy, and doesn't drive like an old truck that is both drunk and stoned.  But our priorities are different today.

 

 

You, sir, are a god*amned communist 

:-)

The FiTech system has a separate pressure tank the eliminates the need to change the fuel tank, lines, and pump. 

The pressure tank is installed under the hood.  Low pressure fuel from the stock tank is pressurized, and delivers high pressure fuel to the TBI. System includes both low and high pressure gauges. 

SVreX said:

The FiTech system has a separate pressure tank the eliminates the need to change the fuel tank, lines, and pump. 

The pressure tank is installed under the hood.  Low pressure fuel from the stock tank is pressurized, and delivers high pressure fuel to the TBI. System includes both low and high pressure gauges. 

Those pressure tanks are plagued with problems.  You’re better off going ahead and doing the tank/pump/lines imo.  For my 75 k10,  with Holley Sniper system,  I went with a factory style tank setup for an in tank pump with a walbro pump installed.  I got the complete setup from Tanks inc.  Its a very nice and quieter than an external pump.  It will of course also work with the FiTech setup,  which is what a lot of people do after fighting with the pressure tank.

In reply to Dirtydog :

I've driven a couple. It's exactly what I'm looking for. I've owned a 64 Electra 225 and the driving experience is very similar. I don't know what it's called but I know it when I feel it and I've not driven any car newer than the eighties that have even a hint of it. 

I appreciate all the other suggestions throughout this thread but I know what I want. 

I'd be looking for a car with good chrome and a good interior. I can handle getting everything else up to my standards. 

Ultimately, it IS your car to do with what you want.

Personally, engine swaps don't bug me, but I kinda recoil at the thought of trying to make the column shifter work with a 6L80 and spending big $$$ for a hokey electronic-to-mechanical speedometer drive adaptor that works about as well as you'd expect one to.  Bolting the engine and trans in is the super easy part, it's the little details that make up 95% of the work and take 99% of the talent.

(Mind you, I'm the guy who swapped a Ford 9" into an RX-7 only after ascertaining a way to continue to be able to use a stock Mazda driveshaft, because one-off drivetrain bits suck.  Also stock Mazda e-brake cables with all manner of mismatched brake hardware)

You might be able to adapt the column linkage to a 4L80, given that it's a TH400 with some extra junk inside.  Length may not work out well for existing driveshaft depending on if the Cad in question used a long or short tailshaft, and I can never rememeber the whichs and whats for that, I just get out the tape measure.

In reply to Knurled. :

Column shifter??

I say paddle shifters!!

In reply to Nick Comstock :

There you go. That's a good start. I agree with you on the ride of that era (and prior).  A nice canvas allows you to concentrate on the mechanicals. It allows you to focus on performance with a hint of green. Following with interest.

SVreX said:

In reply to Knurled. :

Column shifter??

I say paddle shifters!!

The wife's Lincoln has me spoiled, I'm thinking push buttons 

In reply to Nick Comstock :

That would work!

SVreX said:

The FiTech system has a separate pressure tank the eliminates the need to change the fuel tank, lines, and pump. 

The pressure tank is installed under the hood.  Low pressure fuel from the stock tank is pressurized, and delivers high pressure fuel to the TBI. System includes both low and high pressure gauges. 

That's an option Paul it is not required.  I looked at it and didn't want that under the hood so, like Cotton, I replaced the tank with a Tanks Inc sumped EFI tank with their pump and a new Classic Industries sender unit.  Cleaner engine bay as I don't have the tank nor do I have the stock mechanical fuel pump.  The FiTech PWM pump control didn't agree with the Tanks Inc pump Summit Racing recommended and it failed after about 3 months.  Summit advised me on it's purchase and gave me full credit for a new pump from FiTech.  Top mounted pump was a quick change and I was back in business.     

In reply to wawazat :

Tiny hole in tank meant in tank pump not an option.  Modified the sending unit for 3/8" line, used some Hydramat, and brazed a return line into the tank since my fingers are not 8 inches long with six joints, so installing the -AN contraption of a return line supplied with the Sniper was not happening.

Oh that's cool Knurled!  Where is the pump mounted?  Frame rail?  Sadly I don't have the fab skills I admire so much from a lot of you guys.   

The new tank took away concerns of corrosion in the 50 year old stock tank plus being the Mustang's hotter cousin, it shares some DNA and parts so it wasn't too expensive.  Return line connects to top of pump flange.  I used the stock delivery line (with some slight mods as the return and ran a new delivery line.    

Nick Comstock said:

SVreX said:

In reply to Knurled. :

Column shifter??

I say paddle shifters!!

The wife's Lincoln has me spoiled, I'm thinking push buttons 

I was going to suggest push buttons.  There got to be a fairly simple way to do it by now.  I'm glad to see people having good luck with TBI kits.  one of the reasons i stopped driving my Monte Carlo was the carburetor was giving me problems but i don't have the time or ambition for anything to involved to replace it.  These seem simple enough for me to do. 

In reply to wawazat :

Frame rail, yes.  All of the pump and filter paraphernalia was as supplied in the remarkably all-inclusive Sniper kit.

Earlier this year I did a bunch of work on a Torino, and part of that was installing a Holley in tank fuel pump.  The kit came with a nice big section of Hydramat and merely required that you drill a 4" (IIRC) hole in the top of the tank.  Being a Torino, this meant the trunk floor, because that's how Ford rolled.  THAT was a really nice setup.  Expensive as hell, but really nice.

Wally said:

Nick Comstock said:

SVreX said:

In reply to Knurled. :

Column shifter??

I say paddle shifters!!

The wife's Lincoln has me spoiled, I'm thinking push buttons 

I was going to suggest push buttons.  There got to be a fairly simple way to do it by now.  I'm glad to see people having good luck with TBI kits.  one of the reasons i stopped driving my Monte Carlo was the carburetor was giving me problems but i don't have the time or ambition for anything to involved to replace it.  These seem simple enough for me to do. 

Do it Wally!  Not a bad job at all.  I never learned how to adjust carbs growing up.  Now I have pages of things I can screw up on a computer!