Top 5 Weakest V8 Engines of All Time_ When V8s Weren't Powerful!

Well, today we're going to talk about the top five weakest V8 engines produced by domestic automobile manufacturers. And by weakest, I don't mean engines that would blow up in this case, but something different. Instead, the idea here is to discuss V8 engines that really had low specific output per liter or per cubic inch, whatever your preferred measure of displacement is, that they were not very powerful or certainly not as powerful as you would have thought given their relative size. So we won't be discussing four cylinders here or six cylinders, some of which were pretty asthmatic, particularly during this timeframe. But instead, we're going to concentrate on V8s and ones that you would think should have been more powerful, at least a bit more powerful or significantly more powerful than they ended up being during this timeframe. And at number five, we have the base L48 Chevrolet Corvette engine from 1975. Now Corvettes were known for their horsepower, at least ever since a V8 was added to the lineup in 1955. Before that, there was the Blue Flame 6 that wasn't an entirely bad engine, just wasn't overly sporty and the car needed a bit more horsepower, hence it got the V8 in 1955. And from 1955 kind of until, let's say, 1970, the Corvette was known as a relatively good performer, even when you ordered the base engine. But as the 70s went on in 1971, General Motors had an edict that all vehicles, including Corvettes, had to run on low lead or unleaded fuel, and that meant the compression ratios were depressed pretty significantly versus the prior year's versions. Now 1971 horsepower was down over 1970, but as the 70s would go on, emission standards would continue to choke down the overall horsepower output of the V8 engines from General Motors, and 1975 was the inaugural year for the catalytic converter. Now remember that horsepower ratings at this point were executed with all of the accessories on the engine as well as the exhaust, so putting those pellet-style catalytic converters on the engines made them have less horsepower, less net horsepower. And 1975 was really the nadir for Corvette horsepower, because in that particular model year, the base L48 engine made, can you guess, 165 horsepower. That's right, just 165 horsepower. Now before you go saying, well, it was the 1970s and you had emission standards, that's absolutely true, but 1975 was a specially bad year for the Corvette, would have made 165 horsepower just one year earlier. 1974, the base engine was 195 horsepower, the L48 from that year, and one year afterward the L48 made 180 horsepower. 1975 was just unfortunately a bad, bad year for the Corvette, and it's even worse than, some people may or may not know, in 1980, if you got a Corvette in California, it came standard with a five liter V8, a 305, not a 350, and that even made 180 horsepower. So this was worse than the 305 Corvette engine that came out for 1980 in California, just kind of pathetically bad. And at number four, we have the 1975 to 1976 Oldsmobile 455. Now you're probably noticing a pattern here that there's a lot of 1975 era V8s on here, and that's because the catalytic converter was first introduced in that particular model year. And in 1975, the Oldsmobile 455 was really just a shadow of its former self. Remember that just a few years prior, in 1970, there was an optional engine in Tornadoes that would make 400 gross horsepower, or about 260, I would say, 270 net horsepower in that zip code. And here we are in 1975 and 1976, and the Olds 455 is making all of 190 horsepower. That's right, 190 horsepower. So imagine if this were a four-cylinder engine, you cut it in half, it were 227.5 cubic inches and 3.75 liters, it would make 90 horsepower. That's just so pathetic. Many two liter four-cylinder engines today that are naturally aspirated make close to 200 horsepower. And so you've got something that is almost akin to three and a half of those, actually even more, running at the same time, and yet it just still can't make the regular horsepower that well you'd expect. And perhaps it was appropriate that the Olds 455 would be discontinued after the 1976 model year. It was probably time to put it out to pasture because it just wasn't happy as an engine, let's say, that made this horsepower. You know, just unfortunate. I will say I own a 75 Oldsville 88 Royale with this 455, and people will say, oh, it's got a lot of torque, etc. Not really. You know, under 400 pound-feet of torque, and it's kind of hard to break the tires loose, even without a positive traction rear end. You can do it, but you really have to stomp on the pedal, whereas a 455 from earlier years didn't take much. I mean, you kind of scooted or depressed the pedal halfway or something and did it quickly, and you get some tires chirping. Not so with this, and it's pretty asthmatic as well when you floor it. It does not feel like a four-barrel carbureted 455. It almost feels like it's a two-barrel 455 because the heads don't flow that well, the camshaft is pretty wheezy, and there's not much that you can do. This engine doesn't wake up really with extra ignition timing either, unlike some other engines that are going to be on this list, so stay tuned for the rest of those. But the 1975 Oldsmobile 455 makes it to this list. 76 would be the last year for the old 455, by the way, and, well, maybe it was right to put it out to pasture at that time. Let's move on to number three. And at number three, we're going to go to the FOMO co-stable and talk about the 1975, yes again, Ford 351 cubic inch M engine that was in a lot of different Fords, full-size vehicles in particular during this time. Now, as I mentioned, this was the 351 modified engine, and Ford had three 351s. Most people know about the Cleveland versus the Windsor, but there really were three different 351s. There was the Cleveland, the Windsor, and then there was the modified engine, which was effectively a 400 Cleveland that had a shorter stroke associated with it. So it had the same deck height as the 400, different from the 351 Cleveland. It was a taller engine overall, but it did have a shorter stroke than the 400 Cleveland. So you didn't know that Ford had three 351 cubic inch engines. Well, now you know. And which was, I think my least favorite of the three, the modified engine for a number of reasons. Sometimes on some of these engines, the lower end, they lose oil pressure. I would say at relatively lower mileage, 70, 80,000 miles in some cases, if the oil wasn't changed that often, but I have seen some that lasts a long time and, you know, that's just kind of how it is. But for 1975, the 351 modified engine made just 148 horsepower. Well, maybe for the era that doesn't sound absolutely horrible, I can tell you having owned a 1975 LTD with this engine, it was a total wheezer. It was almost borderline undrivable because it was so slow. That's an exaggeration, but I would say zero to 60 in 15 seconds, maybe, maybe a little over 15 seconds. Now, one of the things that I did do that really woke up my 351 modified engine was I put jets in the carburetor that were, I believe, four thousandths richer than what it originally came with. And that improved the throttle response and the power tremendously. It also stopped the kind of start, stall, stop nature of the car when it was cold. On cars and Fords in particular this era, you'd start the car up when cold, it would start up and after about two seconds it would stall out and you have to restart it again. Well, by doing that, that stopped it. And the carburetor was clean. This was just how these cars were from the factory because they're trying to meet emission standards. That was typical. And as a consequence, it was jetted very lean and it didn't have much throttle response. You really had to step on the accelerator to get into the power pistons travel to really move the car with any sort of authority. But by richening the jets, it actually made it pretty drivable and it was relatively pleasant, but it was still low on power. If you floored it, it just didn't have anything. If you drove it normally, it was just fine. But before that, it was not the most fun ride. So if you've got one of these 351 modifies, that's what I suggest. Very easy to change the jets out in an auto like 2100 carburetor. Just pop the top, I think it's four screws and you take a screwdriver, you take the jets out, put new jets in, don't even have to take the carburetor off and you're good to go. So there's a little tip for you if you have one of these asthmatic 351 modified engines. Let's move on to number two. And at number two, we have an engine that I would say is pretty durable, but the horsepower is terrible. The 1975 and 1976 Cadillac 500 cubic inch V8. Now the big block Cadillac engine really started off with, I would say, being great and reliable and powerful and smooth, everything you'd want in a Cadillac V8. And it was introduced in 1968 as a 472 cubic inch V8. It made 365 gross horsepower. So probably somewhere around 240, 250 net, I would say. And it was plenty peppy in the cars that it was in, extremely smooth and again, quite reliable. But as the years would go on and by 1975, this engine had fallen to 190 horsepower and it had been enlarged. It started out as a 472. The first year of the 500 cubic inch V8 was 1970 and it made 400 horsepower and it was an Eldorado exclusive at that time. Then by 1975, the 500 became standard across all Cadillacs. The 472 was dropped after the 1974 model year. And the 500 in 1975 and 6 made just 190 horsepower from 8.2 liters and 190 horsepower. That is pathetic. I mean, most naturally aspirated two liter engines now can crank out something like that. And this engine is four times that size and it could muster up 190 horsepower. And again, you say, well, it's got a lot of torque. Well, not really 360 pound feet. You know, uh, I would say not, not small, but not super torquey either. I will say the engine was smooth and unlike the Ozilbeal V8 that I mentioned before, that just doesn't wake up because the heads are Weezers and the cam is a Weezer. There is a difference here. The Cadillac engine will actually wake up. If you put dual exhaust on your 75 or 76 DeVille Eldorado and you advance the stock ignition timing from six degrees, which is the factory spec to 12 degrees, you'll probably pick up, I would say about 40 horsepower combined between those two modifications. So you'll at least go from 190 to 230, maybe a little bit more. I had a 76 Eldorado. I actually had three 76 Eldorados at one point in time. And it was amazing. I kind of did the same thing to all of them and they all just woke up and they were quite peppy, you know, relatively speaking for their size. Once I had put the dual exhaust on and advanced the ignition timing. In fact, the fuel injected versions of these 500 cubic inch V8s that were offered made 215 horsepower. So you did get 25 more horsepower and 400 pound feet of torque. So 40 more pound feet of torque versus the carbureted version. And guess what the factory spec ignition timing was for base timing, 12 degrees versus six on the carbureted car. I believe that was because of emissions, higher ignition timing at this time tended to mean more emissions. And so often the timing was relatively retarded, but that's my tip. If you've got one of these Cadillac 500 cubic inch V8s from that era, get yourself some dual exhaust. I won't encourage you to take off the catalytic converter or not. That's not what I'm here for, but I will say, get yourself some dual exhaust and you may have to remove the catalytic converter to do that. Or you can put dual catalysts on and then just, you know, I would say advance the ignition timing. You're going to be much happier with the performance of your Cadillac. Once I did this, my 76 Eldorados, I would say were pretty peppy. And you know, with the dual exhaust, I was probably making somewhere around 235 horsepower in that zip code. I actually had at the time a G-Tech that I used. And before I did these modifications, the car was about a close to 13 second, you know, kind of 12 second to 13 seconds, zero to 60 car. And after the modifications I did, it was closer to a 10 second, could even break 10 seconds, zero to 60. So much peppier. And yeah, you know, it was a pleasant ride overall. Let's move on to number one. And here we do truly have a weak engine, weak in the sense that it wasn't durable and it was weak in terms of low horsepower. And that is the one year only 1979 Oldsmobile 4.3 liter diesel V8. Now for those car aficionados, you're saying Oldsmobile diesel, I know those, the 5.7 liter 350 cubic inch diesel that was produced from 1978 to 1985. No. And there was also a 4.3 liter V6 diesel, but many people don't know there was a one year only 4.3 liter V8 diesel in Oldsmobile's only, and it was offered for 1979. And that was it. It was so bad. It made 90 horsepower, 90. That's it. And it was just so asthmatic and so terrible that Oldsmobile dropped it after the one model year. You could get it in your Aero Fastback Cutlass as an example in 1979, and nobody wanted it. It just had no demand. They had tons of issues. They suffered from the same issues that the Oldsmobile 350 diesels did with inadequate head clamping force, head bolts that would stretch, head gaskets that would blow, injection pumps that would require rebuilding, just really weren't great until the 350 cubic inch Olds diesels, the latter ones, when they went to the DX block in the early eighties were actually a bit better. And I've owned them. I actually never had any problem with them, but that's because in the cold winter, I would let them warm up for about five minutes before I drove off. I would drive gingerly until they were fully warm. And if you do that, they'll last. If you don't do that, they're not going to last. But this Oldsmobile 4.3 liter V8 diesel, yeah, it just was terrible. And that's why it lasted one year. Put a comment in the comment section of what you think are the weakest engines, whether they're eight, six, four cylinders, whatever they may be, and hope you enjoyed this video. Put a comment. Thank you. And until next time, take care.