73' Olds 455.

[Droolguy]

Hello everyone I have been lurking around for a while and I am getting ready to start slowly building on my rust bucket 72'.

One of the previous owners swapped in a 73' 455 Rocket motor, which is great for torque but really bad for MPG.

I am looking to get rid of it but I have no idea what they are worth, anyone have any ideas?

[cadillac_al]

Without knowing all the details I would say $500.

[Droolguy]

$500 for a running engine with good compression?

Ebay has people selling the heads, and nothing else, for $400+.

[Backpayne]

More than likely the heads are J heads which are the most restrictive. I am currently rebuilding a '72 Olds 455 for my '64. Which headers/exhaust manifolds do you have?

$500 would be a steal for a running/good condition 455.

[Droolguy]

I will pull the valve covers tomorrow and check the codes.

[Killer Bee]

had a couple of 455 Olds engines, real torquers.. two in my '74 Cutless, the second stolen in my '71 Chevelle

a useless nugget of info I haven't seemed to have forgotten 30 years later is the block casting code 396021F.. guess I'm going to remember that forever lol..

[cadillac_al]

You can always start high and see where the offers come in. I have a couple 472's for $500 with no takers. I have an Olds 425 that I don't want to sell but a guy inquired about it and when I said $500 he lost interest. I'm in the market for a 454 and see a bunch in the $500 area. I'm waiting to steal a nice running one for $500. $500 is always the magic number lol.

[Droolguy]

$500 plus running is the kicker, you can get BB's for $500 and not running all day.

Heads look to be original to the engine. CFD, J, 73.

After wiping some grime off it apparently has a Edelbrock Performer manifold, no idea on the carb.

[Backpayne]

On Facebook I am in two groups: Oldsmobile Performance Engines and Oldsmobile Hardcore Racers. You can post questions and sell Olds items. People are always looking for 455s.

[Coley]

If you want to get more money for it...then do a compression test and post up the numbers in the sales ad. (ie: everything 140psi or 150 psi, etc)
That goes a long way for a potential, interested buyer.
Nothing worse than buying a motor that has one or two pooched cylinders and low compression....the 'boat anchor' philosophy.
So you need to invest time (in a compression test).....to get money....pretty simple lesson.
....with out this kind of info, I regard everything as a project or 'rebuild' motor....so not worth much.
All good and good luck

Coley

[crazy longhorn]

455+ 030....trw/speed pro slugs, rod polished & shot peened, 943 forged crank (.010/.010), balanced assembly, with a Toro pan/Melling hy vol pump. The top was a set of C casting (big valve ) heads, with a bit of Mill, & a 3 angle grind/ Engal cam (.496/ .512 lift & 230 @ .050 on duration). Topped with an Edelbrock torker/ 800 dp Holley. She would flash a said 2300 verter to 3200 Fun to play with, but not very fuel freindly (6/7 mpg cruising).....yes, that ran in my longhorn.

[Boog]

Don't sell the 455 short on mpg. They were known to achieve 18-20 mpg in a stock big olds 98 with a high geared rear ratio in the 2.73 to 3.07 range.
But since you are looking to sell your engine I suggest a compression test as said plus an oil pressure test. These two items will help determine a solid engine. Also include a running video if possible. Everyone would like to hear an engine run before purchasing.

[Droolguy]

If it got 18-20mpg I would keep it, but with a 350 and a 2k stall it gets under 15.

Suppose I could get a doubler or do a tranny swap instead.

[Pyrotechnic]

Honestly, if a 455 got about 12 MPG at all times I'd consider that about right in a truck and I would be happy to have even double digit gas mileage.

The best way to make these trucks get better gas mileage is to park them. Buy a cheap fuel efficient car, and drive that during the week. Fire up the truck on the weekends and have fun.

[Clyde65]

I've had three 455's and I got 10mpg once....long drive, 55mph and I baby'd it to 55.

The others would not have gotten 10mph in the bed of a Datsun truck going down hill for 100 miles!!

[Droolguy]

It's for sure not going to be a daily, I have a beater Honda that fills that role.

The issue is that fuel efficiency right now is so low that it significantly effects range, and if I feel like dissapearing into the back country for a few days or the desert I dont want to have to drag a fuel tanker behind the truck.

Over 15 is not unreasonable, i've seen 700ci+ BBCs get 15+ on the highway with reasonable gear and stall selections, Been doing research into the BBOs and I might keep it, parts are pretty easy to come by which surprised me.

Still undecided.

[Pyrotechnic]

Have you tuned your carburetor to adjust the air/fuel ratios at idle/cruise/power/WOT? Did you use a wide band oxygen sensor and a vacuum gauge to do it? Can you tell me the air/fuel ratio's under all those conditions?

Can you describe to me the exact timing curve, static, mechanical and vacuum in your distributor? Not what the manufacturer paper says, but what has actually been verified in real life with a timing light or distributor machine.

Is your cruise RPM at highway speed optimal for your engine?

Those guys with the 700 cubic inch big blocks getting great gas mileage you describe will definitely answer YES to all those questions. Or at least the engine builder or tuner will be able to.

If the answer is NO, you can swap in whatever engine you want but it won't help, you will get less than optimal fuel mileage and performance.

I don't know if your engine has been modified at all or fine tuned, but fuel economy is the product of a well thought out engine/drivetrain combination that has been fine tuned to run efficiently as it possibly can. You can apply these principals to your engine to make sure it is giving all that it possibly can.

The easy way out is the ever popular LS swap. The engine/transmission is already very efficient with zero modification. As long as your rear gear ratio and tire size is within range to work, no problem. Pay a tuner to program in the last extra bits of power/efficiency with a few mouse clicks and it's done.

[Killer Bee]

big blocks make good smiles-per-gallon.. if you're looking for mpg, buy a prius

[Droolguy]

Having perfect everything for gas mileage is not a requirement to get those numbers, the vast majority of it comes from proper carb adjustments and cam selection on the engine, and stalling/gearing on the transmission.

If you get sub 10mpg in *any* big block on the highway then something is either wrong, the engine/tranny is just built and tuned for max power and nothing else, or you physically don't have a tall enough highway gear.

[DieselSJ]

Originally Posted by Droolguy

Having perfect everything for gas mileage is not a requirement to get those numbers, the vast majority of it comes from proper carb adjustments and cam selection on the engine, and stalling/gearing on the transmission.

If you get sub 10mpg in *any* big block on the highway then something is either wrong, the engine/tranny is just built and tuned for max power and nothing else, or you physically don't have a tall enough highway gear.

LOL...so I should expect my 454/TH400 combo in my 87 CC Dually to get better than 10 on the highway?

[Droolguy]

A TH400 has over 30% more transmission loss than a TH350, on a good day.

It's actually one of the least efficient transmissions in existence.

But yes, 10mpg in your exact combo with proper tuning should not be a problem.