[besserspat]

Far from me the idea to start a war with tech lovers....

In a thread I started on TC about building a fuel miser BBC 454 with a 2004R and mild gears for my 1970 non-Pontiac A-body

Or going with a fresh '07 LS2 out of a TBSS thats been sitting on my shop's shelves for a little while, supposed to go in a Jeep Wrangler project collecting dust.

The idea was to build the said A-body as a simple, long hauler , road tripping machine since it has two comfy bench seats and a large trunk for luggage.

We all agree that the LS has more potential for MPG but at what cost ?

Complexity, expensive and labor extensive swap, mix mash of parts etc etc...

A mild BBC 7.9CR with an economy 220 @ 050 .515 lift HFT 112 Cam, small tube headers, and Qjet with hot HEI would run on 87 cat pee... Same can be done with a Pontiac 455 or else... Using small gears or OD like a 2004R this thing would get 20 MPG hwy for sure...

The question with technology for sake of MPG is :

Is the Juice worth the Squeeze ?

[besserspat]

So lets pretend that our cars depending of the level of tune , 3 speed transmission and medium gears can still "probably" achieve 11 to 13 MPG... if you dont, well im sorry for you...

There is a fun little fuel cost calculator on the EPA site, you can enter most fairly modern car and compare two models.

Just for fun I've compared :

The behemoth-esque 1987 Squarebody Suburban 4x4 350 SBC, EPA Combined: 11 MPG
(city 11 and hwy 13)
***Runs on regular gas

I think its a brave equivalent of our vintage iron 60 years old tech no matter how fast or slow it is...

VS

The mighty 2016 Camaro with 6.2 V8, 8 speed automatic, EPA Combined: 20 MPG
( city 17 and hwy 28 MPG)
***Must run premium gas

The cost difference between the two is 10 cents per mile driven.

So if your drive 10 000 miles a year you basically save 1000$ per year going from your old crappy cast iron gas guzzler to a brand new LSX, or in simple you save a grand for every 10 000 miles you drive...

Peter.

[Scarebird]

I will let you know. I went beyond the LS route and straight to the Gen V architecture. This offers direct injection (allow more compression) and variable valve timing. The current Gen V 5.3's found in trucks dyno at 400+ HP and offer excellent mileage (we will be going where gas is $8/gallon). It runs on 87 octane. Some items are in their infancy, ie. motor mounts, ECM's, etc. Build is located here:

https://forums.maxperformanceinc.com...d.php?t=856636



Article concerning Gen V'd: https://www.motortrend.com/features/...4-868d2dad0e4b

[1965gp]

Another point is that a swapped LS 50 yr old car is probably not going to be as efficient as a factory built 2012 Camaro

[besserspat]

Originally Posted by 1965gp

Another point is that a swapped LS 50 yr old car is probably not going to be as efficient as a factory built 2012 Camaro

Again this is not a stab at them but I have noticed that many people that have swapped LS in their cars magically get way better mileage than what the donor could ever get in a perfect state of tune off the show room floor...

big cams, big tunes, bigger TBs and large tube headers , big tires on their LSX swapped in a 60 year old , brick shaped muscle car with a 12 bolt diff but get 30 MPG hwy and 25 city

[Dragncar]

If all you care about is fuel mileage, drive a Honda.
We like out Pontiacs slightly on the rich side and kind of snotty.

[1965gp]

I didn’t think about it initially but most swaps probably have better intakes and exhaust- along with no emissions controls.

[chiphead]

I was just talking to a guy the other day who did a 6 l LSX swap and 4L80E Ford 9 in 373s into a 67 chevelle. He said he's getting about 16 around town. Which isn't bad. No emissions controls and it definitely smelled rich when he fired it up. Probably if you super tune it without emissions controls and kept your foot out of it I don't see why you couldn't crack 22mpg on a steady cruise.

The other thing about a fuel injected swap is it does the same thing every time all the time. No worries about the carburetors going out of whack or running ethanol gas.

[Formulajones]

You have to ask yourself first how much MPG is enough. Is 25 mpg necessary? Is 20 mpg good enough?? That differs vastly for many people.

I played with LS stuff for years. Had a few LS camaros we daily drove for a few years, a Z06 vette. Light weight and aerodynamic with double overdrives 25-28 mpg was the norm on highway trips, even after cam swaps and headers etc....

Then did an LS2 swap in my 72 blazer and daily drove that for a couple years. 20 mpg highway after some tuning with a 4L60E behind it, 3.73 gears and 33" tires. Not bad for a 5300 lbs 4x4 truck shaped like a brick. I was content with that.

As far as cost goes, that swap just in parts was $7000 including $1500 for the price of the engine/trans. So the swaps are not cheap by any means when they are done correctly.

In the end though, I find I can get very acceptable mileage from the classics with the dinosaur engines, especially when overdrive transmissions are swapped in. So I got away from the LS stuff many years ago and just drive classics. I'll never own another new car again, and highly unlikely I'll ever swap another LS in anything. The old iron gets the job done.

For example, wife daily driving our 69Z, when it had a muncie I knocked the rear gear down to 3.55's. It would get 17 mpg highway. I installed a TKO600 and it now gets 21 mpg. I have the engine running a bit on the fat side of things and have made no attempt to lean things out. There might be a pinch more there but I'm perfectly happy with what it's currently doing. In fact it's our first choice for long road trips, it's that good. Cruises 80 all day long. Speed limit here is 75 so it's nice to have something that scoots along out in the open desert without the need to spin beyond 2200 rpm.

My 70 Formula is my driver. Stock RAIII/400 turbo and 3.31 gear. Even without an overdrive I've tickled 17 mpg regularly on highway trips. An overdrive would certainly put it over 20 but at this point it's pretty good as is and economical enough that it's affordable to daily drive. Still better than most SUV's on the road today with EFI and overdrive so it's already ahead of the game from what most are driving out there.

My 454 Chevelle makes 608 hp and I run a 4.10 gear in it. After the 4L80E install, and a Sniper Stealth EFI allowing me to trim fuel in the cruising areas, it's knocked down 15.8 mpg up and down the I-17 cruising at 2600 rpm (70 mph) I'm happy with that considering the nature of that engine.

The real eye opener for me is dad's GTO. A 571 making 724hp you can imagine it has been a thirsty booger. I installed the Sniper Stealth EFI, a 4L80E trans, and knocked the rear gear down to 3.42. After some tuning this one is also getting a consistent 15 mpg cruising, with a best of 15.89 and I still have some tweaking to do. The big reason it's doing as well as my smaller 454 that is making less HP comes down to the rear gear. He's cruising 70 mph at 2100-ish rpm vs my 2600. We follow each other on the same roads, his ability to cruise at less rpm has a big affect on MPG. Both cars are tuned very similar with the same EFI system.

In a nut shell, you can get great mpg with these classics on a well thought out combination, well enough to satisfy most people. 20 mpg with a good engine combination is pretty simple to do on this old stuff if you use an overdrive and keep the rpm in a reasonable area, and know how to tune the engine. I don't mean slap on a carb, set timing at 12 degrees and go. It takes some distributor modifications to get an advance curve that works right, along with a modified vacuum advance curve on top of that. Then a carb that is dialed in really well.

I've done well enough over the last several years with this old stuff on our own personal vehicles that I really don't have the desire or even see the need to do modern engine swaps anymore.

[besserspat]

Thats exactly what I think...I collect cars and motorcycles and also drive newer vehicles equipped with "fancy" EFI, Overdrives, working A/C and power seats ...lol

But what draws me to old objects including cars is the fact that they feel, smell and look different. I like a fine running well tuned classic. It can be mild geared or with an OD transmission in order to squeeze more MPG in order to drive it more often.

I thought of swapping my 2004r in my 73 Firebird, but I opted for the simpler bulletproof th400, Continental 3200 Stall and 3.08 gears behind the 461.

And I totally understand people that only have one vintage car and like new challenges of swapping the lastest and greatest engine available at the time. Some people love modern tech in old iron.

I always had friends who were the guys who first swapped 700R4 in the early 80s even if the transmissions we're not really tough, then the 5.7L TPIs with computer chips and airfoils, then the LT1s with optispark and heads that fitted on nothing else, then LSX that starts as a "internet says its plug and play" but can nickel and dime you to death to make it run properly.

I like the LS platform otherwise I wouldn't own a 1999 WS6 Formula 6 speed and have "new" LS2 and LS7 engines shrinkwrapped on my shelves waiting for me to start their respective projects.

Most my cars are gas guzzlers like toyota 4runner v8 ( best is 17 mpg), Jeep Wranglers TJs ( best 17 mpg), Ram 1500 sport 4x4 V8 ( best 17 mpg), My LBZ duramax may get around 20-22 but Diesel is expensive.

Besides my motorcycles, the only frugal cars I own are a 1992 LT1 corvette that averages 23 mpg which I love for road trips and an old Mazda Miata that should be around 27 mpg, I never paid attention.

I dont really put mileage on my '99 Formula WS6 since its supposed to be the rarest Formy ever, but its fun to drive with the 6 speed.

Peter

[Formulajones]

Yep, in my eyes, upper teens for MPG is perfectly acceptable and I'll daily drive them like that and be happy. But it's not really hard to reach 20 mpg with them. Case in point is the 69Z my wife daily drives. The engine is still as it was 50 years ago. Still 11:1 compression, still old iron 2.02 heads, factory 254 @ .050 duntov cam, 780 holley on top etc..... All I did was put a good tune in it, and stick a TKO600 behind it.

Something funny, since I drive my 70 Formula most of the time, I find myself at the gas station with it about once a week. When gas prices are high like they are right now, I find more people like to comment while I'm filling the tank. Almost like routine. I almost always have the guy next to me filling up his SUV say something like "that's a nice car" and the usual questions that come along with it. They generally end the conversation with something like "I wish I could drive something like that but I couldn't afford to keep the tank full"

My reply is "it gets 17 mpg" and I watch their jaw hit the ground because the SUV they are filling up is lucky to see 14 on a good day I always get a kick out of that.

The common misconception I've seen for years is that just because it's an old car it has to be a gas guzzler. That couldn't be further from the truth. What people base that on is remembering what these cars were like 50 years ago. Sure when they were new most performance muscle cars were lucky to see 10-12 mpg. We have to remember that's with super lazy timing curves and vacuum advances that in most cases only worked in high gear, and many would just remove that all together because they didn't understand how it worked anyway. Carbs were typically calibrated a bit on the lean side which doesn't always mean MPG either. By the time the gas crisis hit, they were driven hard and put away wet, many times sold for pennies on the dollar as they were just another used up car.
Things have come a long way in 50 years. Surprising to many what a really good distributor and carb tune will do for these cars, not only for performance but economy as well. Toss in an overdrive on top of that and you have something that's now enjoyable to drive that won't cost a fortune on gas.

Don't get me wrong, I do like the LS platform and owned many of them. I just don't see it as necessary if all someone is looking for is MPG. I have to admit though I am getting a little tired of seeing an LS in every damn thing with a hood open. It's getting a little boring. I'd be just as happy if they kept the hood shut and just admire the car itself.

[besserspat]

LS engines is the gift the Marketing Gods made to SEMA ..

The LS saved the dwindling aftermarket business just like the Chevrolet small block made it explode 60 years ago.

LSX aftermarket sure makes lots of people rich... the LS craze is what Fast and The Furious did for the Import market!

As for fine tuning existing set ups, most people dont understand the value of it.

Its more exciting to swap, slap a bunch of shiny parts together in hopes to have big HP dyno sheets to brag about than spending a couple hours changing jets, adjusting floats ,or weights in a dizzy.

People say no need to learn how to tune a carburetor anymore EFI is here to save us , but EFI like carburetors need fine tuning... fine tuning is a nerd's job... nothing super exciting more incremental gains....

Even myself I'm guilty of not having learned how to fully master that lost art and would gladly volunteer some time with guys like Cliff or my transmission builder to pick their brains and learn the ropes before they get fed up and pull the plug...

The industry cares about selling you parts... how they fit or how they perform its not their problem anymore.... just look at reproduction sheetmetal or valvetrain parts...

Peter

[ta man]

My car runs 10's and was achieving 16 to 18mpg with 308 gears and a 466 engine. Higher Compression and a good tune up helps. Its a good feeling when you are at a car show and know that your car gets better mileage than most and can also out run 99 percent of the cars.
I think with what is out there for parts one could build a 400 or a 455 that gets 25 mpg on the highway. High 10's for compression, a cam that allows the engine to cruise without effort or throttle opening at highway speeds, efficient exhaust and a good tune up. Pick the transmission/rear gear of choice to tinker with the mpg more if needed as well.

[Formulajones]

Originally Posted by besserspat

LS engines is the gift the Marketing Gods made to SEMA ..

The LS saved the dwindling aftermarket business just like the Chevrolet small block made it explode 60 years ago.

LSX aftermarket sure makes lots of people rich... the LS craze is what Fast and The Furious did for the Import market!

As for fine tuning existing set ups, most people dont understand the value of it.

Its more exciting to swap, slap a bunch of shiny parts together in hopes to have big HP dyno sheets to brag about than spending a couple hours changing jets, adjusting floats ,or weights in a dizzy.

People say no need to learn how to tune a carburetor anymore EFI is here to save us , but EFI like carburetors need fine tuning... fine tuning is a nerd's job... nothing super exciting more incremental gains....

Even myself I'm guilty of not having learned how to fully master that lost art and would gladly volunteer some time with guys like Cliff or my transmission builder to pick their brains and learn the ropes before they get fed up and pull the plug...

The industry cares about selling you parts... how they fit or how they perform its not their problem anymore.... just look at reproduction sheetmetal or valvetrain parts...

Peter

Don't misunderstand me, I like the LS platform, it's a good foundation, but I wouldn't call it a gift from god.
I guess because as the old saying goes, I've been there and done that. Back when they first hit the scene they were simple to make fast. A common setup on a 4th gen F-body when I was playing with them, stick a cam in it, headers and good exhaust, a Vigilante converter and 3.42-3.73 gears and it was an 11.60-11.70 car at 116 mph and a total ball on the street. It was stupid simple. I had 4 of those things, lol. Done plenty of swaps in later years. Had fun with it all.

Honestly I'm just exhausted with all the LS stuff anymore and got away from it about 10 years ago. It's actually refreshing to me, to see a car with it's OEM engine in it these days. I really do like the simplicity as well which is why our daily drivers have stayed with carbs and points.

[Formulajones]

Originally Posted by ta man

My car runs 10's and was achieving 16 to 18mpg with 308 gears and a 466 engine. Higher Compression and a good tune up helps. Its a good feeling when you are at a car show and know that your car gets better mileage than most and can also out run 99 percent of the cars.
I think with what is out there for parts one could build a 400 or a 455 that gets 25 mpg on the highway. High 10's for compression, a cam that allows the engine to cruise without effort or throttle opening at highway speeds, efficient exhaust and a good tune up. Pick the transmission/rear gear of choice to tinker with the mpg more if needed as well.

I agree it all starts with the engine build itself. If you have an engine that isn't happy with the selection of parts (ie: compression, cam, quench, timing events etc...) then you'll be hard pressed to squeeze optimum mpg out of it, or sometimes even get it to run the way it should.

[Goatracer1]

A swap to a late model drive train for a daily driver is probably a reasonable idea. For a hobby car swapping the drive train for the sake of mileage alone is not worth the expense or trouble. I added just AOD to my supercharged GTO and went from 6mpg to 15mpg on the highway. I would never recuperate the cost if I went the full route and installed a late model engine.

[besserspat]

Originally Posted by Goatracer1

A swap to a late model drive train for a daily driver is probably a reasonable idea. For a hobby car swapping the drive train for the sake of mileage alone is not worth the expense or trouble. I added just AOD to my supercharged GTO and went from 6mpg to 15mpg on the highway. I would never recuperate the cost if I went the full route and installed a late model engine.

Thats my opinion as well, i have a GN BRF 2004R sitting on a shelf, ill probably use it, put 3.31 rear gears in the 12 bolt, 28" tires.

Then refresh the 7.9CR 781 headed, 454 with a fuel miser HFT cam around 215-220 @ 050 and .530 ...Small diameter full lenght headers and top it off with a fine tuned Qjet and aggressive HEI timing advance and run it on paint brush cleaner 87 octane.

Its funny I get as excited to build a fuel miser engine as I am for a high performance build lol!

Peter

[Scarebird]

My Lemans was getting barely 10 MPG. My 2016 Sierra gets 22 on the highway, 17 in town. The cost of this changeover is about $5,000 - including the offsetting sale of the 440 Pontiac and M22Z transmision.

So if the Lemans averages 20 MPG with the L84 5.3, the difference is 10 MPG.
A liter of fuel in Barcelona is around €1.70 currently, 3.8 liters per gallon make that $6.46. $5,000 will buy 773 gallons, times 20, would be about 15,000 miles to recoup my cost of changeover - about 2 summers of driving over there.

That said, I did have at one time a 462/2801/200-4R/3.55 combination that would pull down 17 on the highway and mid 14's at the track. It would have been much less work to have stuck with that. But I am never happy unless trying something...

besserspat: I first had 3.23's with the BRF 200-4R, much happier with 3.55's as the 3.23's would lug at 60 in OD.

[Formulajones]

Originally Posted by besserspat

Thats my opinion as well, i have a GN BRF 2004R sitting on a shelf, ill probably use it, put 3.31 rear gears in the 12 bolt, 28" tires.

Then refresh the 7.9CR 781 headed, 454 with a fuel miser HFT cam around 215-220 @ 050 and .530 ...Small diameter full lenght headers and top it off with a fine tuned Qjet and aggressive HEI timing advance and run it on paint brush cleaner 87 octane.

Its funny I get as excited to build a fuel miser engine as I am for a high performance build lol!

Peter

I think that engine combo you're thinking of will more than satisfy you on MPG. That's a nice mild 454 with plenty of torque.

Just to give you an idea, I had a 79 1 ton pickup with it's original 454. I pocket ported the heads, put a very mild 220 @ .050 Melling flat tappet cam in it, stock intake with some modifications, and the original Q jet. It was still very low compression (original pistons and heads) 400 turbo and 3.73 gears. That thing would get 14 mpg consistently, and weighed 5600 lbs. I'd just put it on 2800 rpm and cruise. Drove it across country a few times like that. It also towed wonderfully. An overdrive would have easily pushed it to upper teens for MPG, and that was the next step before I sold it.

I've never actually tried to build a fuel miser though, like you I'm more high performance minded, but have managed to get respectable mileage out of some of that stuff anyway.