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Because the other brand engines were set up more for low rpm torque from the factory which is what moves you...most sbcs with the exception of maybe the 400 were not all that torquey from the factory. Of course I keep seeing you mention 305's in your posts so it comes as no surprise why you wonder why an economy engine isn't a performer. Overrated? Maybe but the SBC is far from a pos otherwise no one would be building them.
My opinion of any of the sbc's under a 400 is the same as the 305!
I have one in a 1978 Bonneville. So far , it serves me well , albeit with a noise like the lifters are bad. According to the owner's manual , these were placed into a small percentage of these cars.
I have one in a 1978 Bonneville. So far , it serves me well , albeit with a noise like the lifters are bad. According to the owner's manual , these were placed into a small percentage of these cars.
Then you have a towing package on it? Also a later in the model year production number as they ran the 400 Pontiacs then as I understand it after they stopped the production of the Pontiac 400, filled remaining orders with the 403.
M3 MitchQuote:
Originally Posted by 12GO The 403 Olds is a desent engine. Thye make good power and torque & with a few mods, they are easy 12 second 1/4 mile capable engines.
What do you do about the "weak" bottom end, or is this really a problem?
It isn't an issue in stock or near stock engines. It's when guys turn up the rpm and compression they broke the main webbing that goes to the side of the block. I've heard that there were a handful of soild main webbing blocks too, but I've never seen one. I do know that if you let it preignition,("ping") you'll break it too.
I would like to put in a more fuel efficient engine into my 78 cadillac eldorado. I have know idea what would work. any help would be awesome.
There is no reason to spend thousands of dollars to get a few mpg. Doesn't pay off. What you need to do is a cam swap to an aftermarket cam, and change the stock intake for a aftermarket one. The 403 has alot of good stuff avalible. A cam with a 204/ 208 degrees duration at .050' lift on a 112 lobe seperation works well. The Edelbrock performer rpm intake is the best for these engines. These 2 things will boost power and mpg. Next is a true dual exhaust system with 2 1/2" diameter pipes. Use either Magnaflow or Walker super turbo mufflers, they will sound good but not loud. This combo in my 403 powered 85 Delta 88 gets over 20 mpg. And it isn't lacking power either. I have 3.08 rear gears, with 275-60-15" rear tires and 255-60-15" tires on front.
Assuming your 78 Eldo is in good shape otherwise, (and, big, probably inaccurate assumption: nothing is truly "wrong" with the car - no vacuum leaks, etc.) and worth spending say $700 on, you could in no particular order (brands are just my personal favorites) put in a set of NGK spark plugs, if you are in a warm climate you could gap them a little wider than the factory recommendation, plug wires, cap, and rotor if you need them, fresh air and fuel filters, (my big assumption above means the carb does not need work, if the carb isn't right, get it right) synthetic lube in engine and tranny, set of low-rolling-resistance tires all round like the Michelin Green-X Hydroedge.
The above "super tuneup" might get you a couple more MPG. The 78 Eldo is the last year of the big Eldo, like 3-steps says it weighs damn near 3 tons, anything better than 20 MPG is just not in the cards, and if you got to 20 you would be doing better than I really think is possible.
These big old cars are very dependant on driver technique to get best possible MPG.
If you want a car that can be called "economical" you would be light years ahead to start with, for example, a 1980s VW watercooled, you can still find them around if you look, dedicated user base on the web to help you with repair/maintenance, they are economical and fun to drive, reasonably sporty for what they are.
By all means get something with a stickshift if you want to save gas.
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