6.0 368 pros and cons
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500, 472, 425, 368 Discussion, 6.0 368 pros and cons in Cadillac Engine Technical Discussion; Been looking for a coupe for some time now. I got a 90 Brougham and want a coupe to do ...
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    6.0 368 pros and cons

    Been looking for a coupe for some time now. I got a 90 Brougham and want a coupe to do a 90 nose on. whell i dont want a 4.100.... ha...4100 LOL. But a 6.0... cast iron... NICE.

    IN a 80 fleetwood brougham coupe.

    Just wondering the pros and cons on it.

    Thnaks guys!

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    Re: 6.0 368 pros and cons

    con: its slow
    pro: its not an HT4100!

    it sort of goes on from there...

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    Re: 6.0 368 pros and cons

    If you're gonna bother with a big block just go for the gusto, 472/500!

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    Re: 6.0 368 pros and cons

    great engine, typical big block Cad fare.... just... smaller and less powerful.

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    Re: 6.0 368 pros and cons

    Also, the aftermarket for it is bone dry.

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    Re: 6.0 368 pros and cons

    But its better than the HT4100! never forget that... ever.

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    Re: 6.0 368 pros and cons

    I wouldn't say there is no aftermarket for it... its a BB Cad... there are lots of BB Cad parts out.... not all are compatible with the 368, but some are.

    The 368.... is a great daily driver, it'll go where you need to go with enough power to not feel like you are driving a sick dog. Its a Big block Cadillac, meaning it is nearly bullet proof and will keep running, for the era, its one of the best engines to have.

    If you really want to start talking performance, then I would honestly swap it out, a 472 or 500..... and even a 425 is a direct bolt in, all 3 will net you more power out of the box, but you can easily go up from there.... its all bolt in.

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    Re: 6.0 368 pros and cons

    Thats another thing I love about these cars, you can swap stuff!

    can somebody please tell me why I would put a 500 where a 425 was, and not just build up the 425 since its like - the same engine?

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    Re: 6.0 368 pros and cons

    Because more displacement = more power?

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    Re: 6.0 368 pros and cons

    stock, the 500 had 180, so did the 425.

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    Re: 6.0 368 pros and cons

    Quote Originally Posted by Benzilla
    Thats another thing I love about these cars, you can swap stuff!

    can somebody please tell me why I would put a 500 where a 425 was, and not just build up the 425 since its like - the same engine?
    Yeah. The car rides better with more weight under the hood.

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    Re: 6.0 368 pros and cons

    Quote Originally Posted by Benzilla
    Thats another thing I love about these cars, you can swap stuff!

    can somebody please tell me why I would put a 500 where a 425 was, and not just build up the 425 since its like - the same engine?
    Well, you get more power out of the box, it has a slightly stronger crank shaft (honestly unless you are pushing 500+ hp, not a big deal) and you get to say 500CID.... the largest production V8 ever made in a car.

    Otherwise, if you have a 425 already, its a solid start, it really is. 7.0L is nothing to laugh at.... more then a Frod 400 or Pontiac 400, slightly less then a Chevy 454 and the Dodge 440, nearly the same as the 426 Hemi and the 427..... There is alot that can be done to the 425 to wake it up, and for cheap, you can really boost the power alot.

    Some areas where the 425 excels over the 472/500.... its lighter... both the block and the crank... if weight is an issue, this is a good thing. Also, she'll spin faster and at a higher RPM.... it has a huge bore and stroke, but not as massive as the 500.... shorter stroke = rev faster and higher.... not that either are something you really want in a BB Cad, but still. Plus, most the cars the 425 was in ('77-'79 DeVille) is alot lighter then the cars the 500 was in (~1975 DeVille) lighter car = faster.... so, the same work on the 425 in the organal car will make it faster..... although the 425 was stuck with 2.28 gears while the 472 and 500 got 2.73-3.08.....

    Basically, if having a 500, just to have a 500 dosn't mean anything.... then go for the 425, its a great engine and you can really get some killer numbers from it. I wanted a 500 in my '79.....just to have a 500.... just so I woudln't have to ever hear "well, my Chevy 454 is bigger" and for my plans, the 425 would be getting a total rebuild anyway, so I may as well spend 300 bucks or so for a 500 core and build that..... but that 425 had some really nice potential.

    Oh, keep in mind too... the 425 *IS* better on gas then the 500.... I know, I know... these things are gas guzzlers... but... really, a big block Cad is pretty fuel efficent for what it is.... my 425 was netting me 13mpg town and 17mpg highway.... not THAT bad considering.... if I did the minor performance mods for it, not only would she have more power, but it would most likely help fuel mileage since air flow in general would be better.

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    Re: 6.0 368 pros and cons

    Quote Originally Posted by Night Wolf
    Some areas where the 425 excels over the 472/500.... its lighter... both the block and the crank... if weight is an issue, this is a good thing.
    Do you have any data on that? How much lighter than a 472/500? Makes me think again about putting a 425 in my Camaro (didn't want the extra 60# of a 472 in the nose)

    BTW: the 500 is only the largest POST-WAR production engine. Before WWII, there were MUCH larger engines than the 500. But, low compression (think 6 or 7:1) and side-valve technology (although some had overhead valves) made for pretty low torque & hp numbers.

    I saw someone mentioned that a 500 and a 425 had the same HP. Don't forget that the 500 will make loads more torque. Another 75ci tends to do that.
    Factory ratings from this era should also be taken with a grain of salt. Lots of other things going on with the emissions side of things that influenced the ratings. If you have a healthy 8.5:1 500ci motor with a freely flowing exhaust, you should honestly be getting somewhere around 300hp, 490lb-ft at the crank, stock. All at LOW rpm of course, shift before 4000rpm...

    The only bad side to the 368 is really that it is overshadowed by the larger versions of the Cad big block. Honestly, 6L is alot of motor, even in a relatively heavy car. It's just that 7L+ is just that much more

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    Re: 6.0 368 pros and cons

    Quote Originally Posted by BluEyes
    Do you have any data on that? How much lighter than a 472/500? Makes me think again about putting a 425 in my Camaro (didn't want the extra 60# of a 472 in the nose)

    BTW: the 500 is only the largest POST-WAR production engine. Before WWII, there were MUCH larger engines than the 500. But, low compression (think 6 or 7:1) and side-valve technology (although some had overhead valves) made for pretty low torque & hp numbers.

    I saw someone mentioned that a 500 and a 425 had the same HP. Don't forget that the 500 will make loads more torque. Another 75ci tends to do that.
    Factory ratings from this era should also be taken with a grain of salt. Lots of other things going on with the emissions side of things that influenced the ratings. If you have a healthy 8.5:1 500ci motor with a freely flowing exhaust, you should honestly be getting somewhere around 300hp, 490lb-ft at the crank, stock. All at LOW rpm of course, shift before 4000rpm...

    The only bad side to the 368 is really that it is overshadowed by the larger versions of the Cad big block. Honestly, 6L is alot of motor, even in a relatively heavy car. It's just that 7L+ is just that much more
    The weight difference... I don't want to say for sure, but its somewhere around 40lbs between the block and crank.... in the world of things, its not THAT much... but.... if you start with a 425 that weighs less then a 500 and add an Edelbrock intake manifold (22lbs instead of 45lbs) then you are now running a big block Cad for nearly the same weight as an SBC..... if your pockets are bottomless and you get aluninum heads, you have a massive enigne with very little weight.

    Which pre-war production engines for cars are bigger then the 500? One of the largest that come to mind is the Cadillac V16 from the 30's.... but even then, that beast was 7.3L.... produced a smooth 165hp @ 3,000RPM and 320ft-lbs torque @ 1,200RPM IIRC.

    Also, keep in mind the 425, while choked back with emmissions... isn't AS bad as the 472 and 500.... reason being... no AIR pump at all.... loose the origanal cat tho, thats a must (I drained the beads from mine)..... shes got EGR, but that is actually a good thing (and I ended up dumping EGR with the modified '68 472 intake manifold) and the carb is slightly lean (that was corrected with the performance rebuild) so that left the lack luster 8.2:1 compression as the only thing left, besides the smogger cam.... but because of that, I could run 87 and she'd never blink..... 87 will actually give it a little more power for the fact that it'll burn more easily.

    The worst case 500 was making 180hp, the 425 makes 180hp...both these numbers do not reflect real world numbers, in general, the 500 was making more power, especially early versions of the 500 and the hi-po 472. But again, keep in mind, for what the 425 is, its making ecent power, and has some awesome potential too.... the 425 just dosn't get much credit because.... well... why get a 425 when you can have a 500, ya know? but she is a gem of an engine.... 1,400 miles in 36 hours without even flinching..... she would cruise at 75 all day and the only way I knew it was still running was the slight exhaust leak form the left manifold, the indication on the tach... and the fact that the car maintained its speed and the AC did its job.... and in the world of things, the 17mpg wasn't horrible either, cause if I was driving a gasoline pickup, thats what I'd be getting too.

    a 500 is making around 300hp and 450ft-lbs torque.... even the smogger ones. I know I haven't updated it in ages, but take a look at the database thread (stickey at the stop) there are 2 articals of a BB Cad build up in there, and in the one, they throw a stock 500 on a dyno and they coudln't believe the numbers.

    today, 6.0L is a big engine.... but the 368, wasn't making THAT much power not to say its a bad thing, but honestly, trying to make a 368 into a 1/4 mile beast woudln't be very sensable, it was at a bad era, cause the HT4100 was coming out which had what people wanted at the time..... The thing i like most about the 368, is the fact that the V8-6-4 stuff was slapped onto that thing.... I want a V8-6-4 368, and boost the power slightly... then wire up the solenoids manually (easy to do) to only have V8/V4 mode.... I think low-mid 20's would be possible for fuel mileage, and that'd be pretty sweet. if I had a 368, I would run it as is, if I had plans for hi-po, I'd step up to atleast the 425..... but thats not to say the 368 is left out.... AFAIK, she still has the claim of the smallest big block made .

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    Re: 6.0 368 pros and cons

    How much will draining the cat do for power? also, how did the modified '68 472 intake manifold help?

    sorry for the dumb questions, but I'm just getting into engine modding.

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