430's gas milage?

[Guest]

I'm curious if anyone out there is driving a fullsize buick of the mid or late 60's that has a 430. I'm curious what kind of gas milage they get in a stock buick. I'm building a 53 bel air and its going to be powered by a 430, the car is much lighter than an electra that the engine came from.........info would be rad.

thanks.

Jessie

[55PackardGuy]

I had a LOT of experience with a '69 Electra that got phenomenal mileage. Our family car when I was a lead-footed teenager. Low to mid 20's on the highway cruising at 70 were the norm--without cruise control. I posted a thread on the General Forum called 430 Gas Mileage and got many responses from others that found this engine remarkably efficient. There's lots of good stories and theories about why on that thread. People also weighed in with similar mileage from some 455's, although I don't see how that lower compression design could have the same potential as the 430 does with 10.5:1. Although, of course, the old '69 has me prejudiced.

[Guest]

Rad, thank you for the info........do you have a packard? I'm looking for 56 packard tail lights.....know of anywhere to find them.....

[55PackardGuy]

Don't presently have a Packard, but I'm a real buff of the'55 and '56 models. We owned two '55 Clippers (one my father bought new and I "grew up" in) and a '55 400. Great cars. As for '56 tail lights, I suppose you're referring to the '56 Clipper "fish mouth" famous for being used in hot rod customs. They are, because of that, a very scarce item as far as originals go. I know a guy over on the Packard forum who has the ones for his project stored safely in a closet in his house! There may be some repros available (I'd STRONGLY recommend going that way if you aren't using them for a restoration--leave the few originals out there for the collectors) or you can look on e-bay for originals if you have a '56 you want to restore. Take a look over on the Packard forum, too. BTW these tail lights were also used on the '56 "Executive" which was built on a Clipper frame with "senior" front end trim and Clipper rear. A very cool car. Just please be mindful of the need for restorers to have these rare pieces. And be ready for some really astounding PRICES!

[rivijimi7178]

A few years back, after I got my '68 Electra's engine (430) rebuilt,I was averaging 15 mpg. all city driving. Couldn't keep my foot out of it though.

[BqUICK]

Jessie,

I probably answered this on other occasions but if you are still out there here is some unofficial data for you.

In the early 1990s I performed 10K+ miles worth of MPG tests on a 1969 Buick Electra 225 Custom Convertible equipped with the non-posi 2.56, radial tires, Good Year Polysteels, and 430 v-8 with stock duals, resonators removed. 60 mph was the highway speed.

A baseline of several thousand miles was done before SLICK 50 was added. The results indicated 15 mpg on a 40 mile daily travel over several weeks which was 25% city and 75% highway. Highway driving indicated 18 mpg with no A/C and cruise control on over a distance of 200 miles.

SLICK 50 only impacted the low end fuel economy. In other words, it enhanced the city driving portion by about 10%, making the combination driving bump up to 16.5 or so MPG.

CITGO Race gas at 100+ octane raised highway MPGs slightly to 20.5 mpg over about 400 miles on the average. I have even run out of gas on the highway trying to squeeze the most out of her and get accurate readings on actual fuel in the tank.

High thermal efficiency, low rotating mass, short stroke, may all be reasons why the BUICK 430 is a great engine in this regard. This car still runs 15.3's at 89mph with 99K miles.

My friend Tom Wagner races an "A Code - Regal Black" 1969 Wildcat with a FORD 9" and 455 STAGE I, It runs 11.7s. Tom visited a couple of months ago to help me tune my 455 STAGE I powered Electra GSX road racer.

Tom said that 430s have trouble because there is a bushing in the distributor that sometimes falls out and ignition induced damage can occur. Based on my time slips, the car was running as it should, he noted. We confirmed that the bushing was still securely in place under the distributor. I keep her in good tune and now run a 2.73 posi which has changed my MPGs some but I do not know how much yet.

[55PackardGuy]

BqUICK,

I'm surprised you have time to cruise the message boards, given your Faithful Pursuit project. Are you taking a break?

I think the '69 carb setup may have had something to do with the 430 gas mileage that year as well. Looking through an old Chilton's, I discovered that the '69 was set up to run extra lean--and it was for that year only. I know that our '69 Electra had plenty of additional spark timing, too (my dad favored that) and pinged like a sonofagun under acceleration. But it regularly got over 20 mpg on freeway driving at 70 mph. It was easy to verify, 'cuz with a 25 gallon tank you could cruise over 400 miles between fillups (and I've done that without stopping). You kind of get stuck to the seat, though. And don't drink too much coffee!

Also, it actually seemed to get a little better mileage on regular octane than "premium." I've read that there's acutally more btu's in regular, and depending on how you drive it can deliver better mileage. Any truth to that?

[Pontiac59]

I know a guy who has at least a half dozen PAIR of those lights on a shelf in his garage. No, he will not sell any - has turned down $1200 for a set.

If no one reproduces them I'm amazed given the demand.

As for fuel milage, I've run both a '70 Gran Prix with a 4-speed and a couple of 455 Grand Villes. 15 is about average, either way. My '60 Pontiac would get 18-20 on the highway out of a 2bbl 389, though - a big motor can still do it, it's all in having torque enough to make acceleration very easy.

[55PackardGuy]

That's great for a big 2-barrel carbureted engine. The 4-barrel primaries are smaller and typically more miserly for cruising. Anyone sitting on that many original Clipper tail-lights has got to be allergic to easy money. Or else they're his retirement savings plan.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">it's all in having torque enough to make acceleration very easy</div></div>

"Thermal effciency" (how much of the heat energy available in the fuel that actually gets converted into power, as opposed to waste heat) friction and inertia of moving parts, rolling resistance, wind resistance, and final drive ratio all contribute to the potential fuel economy as well.

[Guest my3buicks]

For an another example, my 69 Electra Convert averages 18 on the highway doing around 70 - top up or top donwn doesn't seem to make much difference.

[Pontiac59]

Thats why in the late 70s GM developed a carb that basically was the primary section of a Rochester 4bbl - in fact the early ones use the same casting with the secondary section blanked out.

What I thought was more amusing is the big 389 giving better milage than an '87 full size wagon with a 307 and 200R4. Even babied it was lucky to get 17 or so. Weight not much different, rear gears were close too. But that Olds-based 307 was a dog of an engine anyhow, why they produced that instead of the Pontiac block is something I think no one will ever comprehend. The Buick block was better too and the newest designed, and we're reading here how well the 430 performed, yet they dropped it in 81.

[55PackardGuy]

I b'lieve that was '71 you mean, there. But drop it (the 430) they did, at the time that they were dropping compression to meet emissions and increasing cid to sort of, I guess, even out the power loss. This seemed to play havoc with efficiency in many engines, although some say the venerable Buick 455 was still quite good. Since you're a Pontiac fan, do you know the differences between the Buick and Pontiac 455? For all I know, there were few similarities, but I'm curious.

I imagine that by "the Pontiac block" you mean the 301. I had some second-hand experience with that in my brother's Grand Prix. I don't know how efficient it was for him, but it certainly seemed capable of taking a lot of hard use. This is also the engine they turbocharged for the Trans Am, correct?

[Pontiac59]

Late Buick motors use the same basic block and head design, 430 and 455 spawned the 350 as well, which is a stout enough motor I sold one to a guy to replace one in his Jeep pickup someone had installed years ago. I guess it was parked so long it had stuck and was cheaper to put my $150 engine in it than fix it. They were designed about 1965, replacing the "Nailhead" 425 in 1967. Said to be the stoutest lower end of all the GM engines, the heads have rockers on shafts instead of push in studs. Distributor is in the front for easy tuning, too.

The Pontiac 301 is a garbage motor, a thinwall casting that can't be rebuilt and so far the only motor I've ever had break on me - one morning it started to knock and I made it 7 miles before it threw both rods on the journal it wiped the bearings out of. The heads and intake are junk, too, late 70's economy stuff. When I say Pontiac, I mean the previous incarnation, which was available as a 350, 400 or 455, as well as a dozen other displacements depending on year and even as a 4-cylinder for a couple years in the Tempest. This same basic block was used from '55 on to the point where the front motor mounts will swap from a '59 389 up through the last 301's (TA/Firebird mount differently). It was the high compression 389 that ran near 20 MPG in a 4000 lb car -

The Pontiac and Chevy V8 designs were both based to some degree on the Cadillac OHV V8s, particularly the Chevy - the Pontiac shares mainly the design of the stamped rockers on push in studs (and even the rocker itself being stamped is a Pontiac innovation), which was cheaper to produce than the long shaft setup but weaker in performance applications.

[BqUICK]

55PackardGuy,

The Buick 430 is perhaps the most under rated of the "modern" V-8s . There is no other big block in that range as cubes that is as versatile. 20+ mpg is not uncommon as you well know.

Back in the 70's I remember the raging controversy about which motor, the 430 or the 455 was actually more powerful! The 430 develops its max HP at 5000 rpm and the 455 did it at 4600 rpm. Was it possible that top end was actually where the 430 could beat a 455? The factory numbers are probably wrong but we do know that many racers used a 430 STAGE I and 430 STAGE II, as amazing as that may sound! (STAGE II cam & dealer add ons, STAGE II heads were not available until after the intro of the 455.)

As far as regular fuel having more BTU's than premium, I really do not remember the details from thermodynamics class. I do know that at higher compression ratios, more energy can be released with the appropriate high octane fuel. Remember that the 430 is actually a higher compression engine than the 455. We like to think that the 455 is just a bigger version of the 430, but it is not. The bore to stroke ratio, compression ratio, torque and horsepower curves are different.

My stock 430 powered 4,700 lb. convertible runs 15.35 at 90mph. It has 99K miles and has a 2.73 posi and dual exhaust. Do you think a 427 Chevy, 427 Ford, or even a 426 Hemi could push 4,700 lbs that fast and still get great gas mileage to and from the track? No way, those blocks are obselete 1950's technology with big advertising campaigns and scores of power adder options to prop them up. The humble 430 beats them all!

My dream car is a Regal Black (A-CODE COLOR) factory "PX" Code 1969 Buick Electra 225 Sport Coupe with A/C Delete, PW Delete, Power Seat Delete, and a dealer optioned 430 STAGE II. (Mickey Thompson Super Competition headers, Edelbrock B4B Aluminum Intake, TRW 11 to 1 Forged Pistons, and more came with the STAGE II dealer option) A 2 door coupe optioned in that way would be a high 13 second to low 14 second car with the specially optioned PX 3.91 positraction!

This nostalgia factory hot rod would outrun any luxury/performance car made in that period, including the 454 Monte Carlo SS with a 4 speed! MPGs would go out the window but think of the fun you'd have! The Electra GSX "Faithful Pursuit" is based on the "PX" Code Electra that was available for 1969. I do not know if any were actually built the way I described.

God Speed!

[55PackardGuy]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Remember that the 430 is actually a higher compression engine than the 455. We like to think that the 455 is just a bigger version of the 430, but it is not.</div></div>

Exactly! I think the stroke was the same, as the 455 was a "bored out" 430. Definitely lower compression. As I recall, this was to lower the "oxides of nitrogen" pollutants that were emitted, especially on deceleration. I could never figure out how this gained anything, since the decreased efficiency of the engine would result in MORE pollutants overall such as unburned hydrocarbons, just due to the fact that more fuel was burned per mile. Oh well, whaddoIknow?

But, the upshot of the legislation was, lower compression pretty much across the board, and usually accompanied by higher cid. Heck, the sbc went all the way to 400 cid, and I remember it being touted as God's gift to cleaner air. Go figure.

Looking at them from just about any angle; power-to-weight, thermal efficiency, durability... the 430 is a very hard standard to beat. Sure would've been interesting to see them raced more.

Now why the heck did you go with a 455 in the Faithful Pursuit!?

[BqUICK]

Guy,

Ok, OK, you have a good point! If I had to choose between a STOCK 455 and a 430 for a good all around street and track motor, I'd choose the 430! I performed some timing trials on the 1970 455 "SF" CODE BLOCK, after a ignition timing and distributer check by Tom Wagner of the 11.70 sec. 455 STAGE I '69 Wildcat Wagners!

The short answer is that my 455 is not as fast as my 430 in an Electra. The 455 car get about 17mpg while the 430 got 19+.

Here is the long answer! Hang on! Last Friday, 100 Octane Aviation low lead and fresh tune was good for a couple of tenths on average. Last year I ran mid 16s and my best on Friday night was 16.2 @ 85. Single wheel peel, single exhaust. This is a young 20k mile original 455 car that still has the original brake shoes, shocks, top, and paint! She even still smells new! Had to granny her off the line, but it was enough to take out a 5.0 fuel Injected Lincoln Mark VII on Mustang night. That was fun! I "Romanced the tree" with a .510 R/T Holeshot!

The fact is that the 455 '70 coupe weighs 100 lbs less, has 35 more cubes, is a fresher car but still cannot match the 430 1969 convertible's 15.5s with single wheel 2.56 mileage gear! At 97K miles the 430 is truely amazing! I run AC R45TS plugs at .035 in the 430.

Now...as to why I did not go to a 430 for the Faithful Pursuit...! Scotty Guadagno, Faithful Pursuit's engine builder, knows more about making Electras go fast than anyone other than the famed "Uncle Buddy" or "Pop" Kennedy or even Jim Bell for that matter. Uncle Buddy is probably dead by now, no one knows; Pop passed a couple of years ago. When I call Cali to ask Pop's old partner at Kenne/Bell and I ask about Buick Electras, Jim Bell says "talk to Scotty Guadagno!"

Based on Scotty's say so I used a 455! It has 11:1 CR, Forged Pistons, Balanced, severely worked heads and carb, Blueprinted to Scotty's own special recipe for performance in the 500 HP range. The bigger STAGE 1 valves are more effective in the bigger bore 455 in Scott'y s "Intimidator Motor". Scotty now works for Pat Musi in Jersey and is their top Dyno Man.

A reworked 455 can out power a 430 with little work. Its just a question of gearing it for the 455's fatter low RPM torque curve. With the wimpy 2.56 or 2.73 and no traction the 455 cannot use its torque. You wind up getting a better launch form a 430 motor because it wont break loose as easily off the line. A big car 3.23 gear posi and slicks would probably have the 455 beating the 430 every time!

Also, you can build a 455 to even more HP than a worked 430, Chevy 454 RAT, 440, 426 HEMI, for less money, up to about $8,000. After that we dont have the blocks, heads, and the thousands of add on part to match the Chevy and the others. (We are working on it however, word on the street is there is a totally new Buick 455 block being developed. PAE Enterprises confimed this to me and I have seen photos of the new prototype)

My dream motorcar is the fabled 1969 Electra 225 Sport Coupe with "PX CODE ELECTRA PERFORMANCE OPTION" 3.91 posi A/C DELETE. There is no substitute. Arguably, this PX code Electra and a 430 STAGE II dealer option is the fastest American luxury sedan ever built. I do not know if one exists but the paperwork indicates it was possible to order one. You could had a "HONO-DRIVE" overdrive installed back in 1969, like the Baldwin Motion 427 powered 4.88 geared Camaros, bring your ratio back down to about 3.0.

A 430 powered Buick with such options could blow away most other "factory" muscle in the quarter mile and up to 145 mph on the open road including 427 Chevelle SS, 426 Hemi Belvederes, any 440 big body, and 454 big body, and still get 20 mpg to the track and back!

[55PackardGuy]

I was just teasing about the 455 in your Faithful Pursuit. The old saying "there ain't no substitute for cubic inches" is somewhat true, especially if you're talking about making ultimate horsepower. I just find it interesting that, when they hit upon a stock combination that worked as well as the 430, they only had it a couple of years. This just gives them more "mystique" though. Like your hunt for the ultimate PX Code Electra. I suppose it's possible that they sold one or two to some ranchers who wanted to get from one end to the other of their Texas spread faster than their neighbor in his Cadillac! But I wonder if there are any records left at Buick on how many were produced, if any. At one time I tried to find out how many '84 Mercury Capri RS models with 5.0 4bbl 5-speed with no AC were built. I bought one brand new off the lot in '84, black over silver. It was a "found treasure" and my first new car (yeah, I know, shoulda kept it). I tried everything up to and including writing FoMoCo about production numbers, but no luck. Although I've often seen cars referred to as "one of only 800 built" or whatever. Maybe sometimes they're easier to account for the company has purposely limited production.

Hope you find the one you're looking for. Meanwhile, what do you tweak when you run at the track (if it's not a secret). Like, do you crank up the initial spark timing when you run the 100 octane?

Thanks for the conversation on this thread. I don't like to clutter up your Faithful Pursuit one with my musings. Although I read it!

Also, on a sad note, a P-51 went down in our area over Memorial Day weekend. The pilot radioed that his controls were out and he made a heroic and successful effort to crash away from populated areas. I heard he survived the crash but died later at the hospital. It's a sad loss of human life and a piece of history. Makes you recall that the guys who flew them risked there lives just taking them up in the air, let alone doing battle.

[Guest imported_DaveZZZ]

I'll just chime in here-

I have had both a 79 Pontiac 301 and an 84 Olds 307- both were worthless dogs.

On the other hand, both survived incidents of severe overheating.

-Dave

[ducenqtr69]

hi all been driven my 69 duce stock 430cid/ auto trans400,full power, she's got 122000, mils, only did 5 things changed the ign to(1) Pertronics(II)Got rid of the Ping octain (2) with rapid fire plugs,gaped at.038 ths (3)hot coil, (4)went with a 73 Q Jet (5) bigger single exh pipe, other wise NO major changes , she gets around 18mpg Maybe 20 on good road conditions, but all around 16/18 mpg avg, as I still Have to pass SMOG emissions here in Nevada,,,,,, keep the tires at 33/34 psi , , keep the Timming Stock, u should get oprox same , but with a 53 body be sure u use the subframe from the 69 don't think the weight & Torque will work any other way ,,,,,,,, Good Luck TEC