3.8 opinions please

Discussion in 'The "X" bodies' started by Lukey, Jan 10, 2013.

  1. Lukey

    Lukey Member

    I have a 77 skylark with a 3.8...I am looking for opinions here. Is it worth doing an overhaul on this motor or should I just swap it? The car is going to be my wife's daily driver with about 40 miles a day going on it. I am swapping in an overdrive when I build it (the original trans is blown, that's why I got the car so cheap). So as far as reliability and a major emphasis on gas mileage is the 3.8 a keeper? I have a goodrunning small chevy/th700r4 I can use or I can locate a 350 Buick and a 200r4 to swap. Once a year I will be driving this car on an 1800 mile trip also. Thanks guys:)
     
  2. I have a 4.1, which starts as a 3.8 casting with a bigger bore and gets the 3.8 turbo's crankshaft (and maybe a couple other parts) and a Quadrajet. It's essentially the 3.8 for most practical purposes.

    The 3.8 is a classic with a good ancestry (Fireball 198 -> 225 -> Jeep Dauntless 225 -> back to Buick as the 3.8) and extremely successful descendants (the Series II 3800, while not directly a new version of the Buick 3.8, was designed based on the 3.8's success). It's dependable. Parts are cheap and decently available (though an occasional emissions gadget is completely unavailable), I think...not really sure, can't say I've needed many in the past 40,000 miles but I see plenty listed.

    I wouldn't imagine fuel economy will be stellar. My 1980 Lesabre 4.1 with a 5 speed manual gets down to 20 if I beat on it in winter and up to 29 if I baby it in the summer, but an automatic won't do that and nobody can squeeze fuel like I can. Additionally, my ignition timing is advanced to where I have to run premium...if I dialed it back for regular I'd probably lose a little economy.

    On the other hand, my 80 mile per day commute is not highway driving (only about 35% is), the 3.8 is a little smaller, and a 1977 Skylark may be aerodynamically slicker than my car. Slap some good low rolling resistance rubber on instead of the crap rubber I run and you might be looking at similar results as I have with my 5MT and ultra-efficient driving.
     
  3. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Do you know if it's even or odd fire? Personally I wouldn't bother with an odd fire, and only maybe would overhaul an even fire. I'd pass go and proceed directly to a Buick 350 and 2004r.

    With a good small RV cam in a Buick 350 and a 2004r or 700r4 with lockup, you should be able to knock down some serious gas mileage pretty reliably and it'll drop right in like it came from the factory. Would probably see 25mpg on the highway with a set of 2.73 to 3.23 rear gears. I had an RV'd type cam in a Buick 455 and a .64 overdrive, 3.23 rear gears in mine knocking down 23mpg on a regular basis on 1,000+ mile road trips.

    If you go the Chevy route you'll have to deal with frame mount differences (get frame pads from a Nova), wiring harness differences (like the starter being on the opposite side of the engine) and possibly a few other small annoyances, but outside the first two shouldn't be deal breakers.
     
  4. WV-MADMAN

    WV-MADMAN Well-Known Member

    The 350 buick is almost a direct bolt in, and so is the 200r4.

    The brackets, alt., fuel lines, A/C, wiring, engine mounts, starter everything all swap over.

    The only thing is the A/C-heater box on the firewall will probibly have to be notched on the bottom to clear the pass-valve cover.
    Its easy to cut it and epoxy a patch in, but youll want to do it before the engine is in the way.

    The SBC-700r4 would be way more trouble than its worth for what you want.

    Nothing will interchange...Nothing...Nota.

    Not even the driveshaft or trans-crossmember.

    You could swap a ford or mopar with less trouble.
     
  5. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Shouldn't be an issue. My 455 fit under the evaporator box with no problem. The difference in length between the V6 and the Buick 350 is all in the front, and the wiring harness is more than long enough to accomodate the extra length. I still use the OE wiring harness on my 455.
     
  6. WV-MADMAN

    WV-MADMAN Well-Known Member

    Shouldnt be, but can be.

    I dont know about a '77 Skylark, but in a G-body it is a very real problem with a 3.8 to 350 swap.

    Youre right that a SBB is longer than a V6...

    But the 350 SBB is also wider and taller than a V6.

    And the valve-covers dont slope in at the top like a V6.

    Heck, his '77 might not even have A/C and this is all moot point:Dou:
     
  7. Lukey

    Lukey Member

    No a/c on this one, its pretty much bare bones. It's the odd fire v6. As for the chevy route, I've done it...it's easy...very easy! Frame mounts from a Camaro, rear crossmember is easy to modify, shoot even Camaro headers fit. Just don't really want a chevy motor in it. Will probably go the small Buick route, just wanted opinions on the 3.8 since its a motor I have never messed with.
     
  8. WV-MADMAN

    WV-MADMAN Well-Known Member

    By ''easy'' I meant in comparison to the SBB swap.

    SBC/700r4 = Changing frame pads, motor mounts, wiring harness, battery location, fuel lines, trans cross-member modification/replacement, new driveshaft and different acc. brackets and pulleys ect.



    SBB/200r4 = Pull old engine and tranny. Install new engine and tranny. Done.
     
  9. Lukey

    Lukey Member

    If a 350 Buick swap is really as easy as it sounds, you are right...a small chevy in comparison would be a pain. Guess I'm on the look out for a 350 Buick/200-4R:)
     
  10. WV-MADMAN

    WV-MADMAN Well-Known Member

    Ive done several G-body cars and a 350 Buick gos in stupid easy and will look like it came that way.

    Ive also done SBCs and unless you spend alot of extra time and effort, it just looks cobbled together.

    I did an '82 Regal once with a hopped up '69 GS 350 that I painted black, ran a modified stock breather and put a crapload of dummy vaccume lines on.
    It was a real screamer and a heck of a sleeper.
    I would even pop the hood and show people the ''V6'', most took one glance and didnt count the plug wires and would go tell people about the V6 Regal that busted their a$$:laugh:
     
  11. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I ran a 2004r behind my 231 V6 for several years. It was a drop in replacement from when the stock TH200 dynamited spetacularly in front of a police station. I was looking for a Buick 350 when I found a carb to oil pan with accessories 455 for $250, so thats what de-railed my 350 plans, but the Buick 350 uses the same mounts and frame pads as the 231. The only thing you really have to do is remove the staples from the fan shroud extension to make room for the extra length of the 350. That is if you even have the extension still.

    And I'm 100% positive even if you had A/C the evap box would be the same. The Buick 350 was a factory option for the car in '77, and the factory service manual lumps the Buick 350 and 231 together.
     
  12. jamyers

    jamyers 2 gallons of fun

    What tranny, gears, and tires are in the car now?

    While a Buick 350/200R4 would be GREAT in a '77 Skylark, if the goal is a reliable money-saving car, I'd think you'd be ahead in the long run with a well-tuned and free-breathing, de-smogged 3.8 (small 4-bbl or Q-jet, diy-head-porting, recurved HEI and dual exhaust) in front of a 200R4.

    * you already have the 3.8, any 350 that you'd find would either need rebuilding as well or probably cost the same as rebuilding the 3.8.
    * unless you could re-gear or re-tire (spend money) a 350 so that it turned WAY fewer rpms (like 1500 @ 70mph) on the highway AND keep your foot out of it when not on the highway, a bigger engine will use more fuel than a smaller engine (no matter how much I like the Buick 350).

    On the other hand, if you can get a good solid 350/200R4 for little or nothing, and you wanted to add a/c, and the gearing works out...
     
  13. WV-MADMAN

    WV-MADMAN Well-Known Member

    Like I said, my experience is more with Gs not Xs so Ill take your word on that.

    But on a G-body you will have trouble.
     
  14. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I'm guessing he has common 3.23 gears out back, with a lock up converter and 2004r he'd be turning a calculated 1950rpm at 70mph. And though I have done it, I only gained about 3mpg going to the overdrive on the odd fire 3.8L (which was re-ringed and re-stock cammed, and stock heads, etc) and my 455 in current trim makes probably ~5 times the HP and gets exactly the same mpg (@ 1972rpm) and I got even more mpg with a 455 that made ~3 times the power of 231. The odd-fire 231 simply works too hard against the overdrive gear IMO. My 231 engine passed CA smog and was relatively healthy and tuned too. There is like a 15HP gain when GM went to an even-fire setup at the end of '77, and that is why I asked right away as I'd be inclined to see how the even fire variant would work, but in my experience the odd fire 231 works too hard in overdrive to save fuel (when it even has the torque to carry the overdrive). IMO, the 350 with a very mild cam will pull the same or better mpg, with a Q-jet even.

    ---------- Post added at 03:28 PM ---------- Previous post was at 03:25 PM ----------

    And I don't believe the 4.1L Q-jet intake will bolt to the odd-fire heads. Well it'll bolt on, but the ports are mis-aligned.
     
  15. GSXMEN

    GSXMEN Got Jesus?

    Depending on where you are located, I have a more modern option for you.

    Going to be parting out a 2000 Firebird with the series II 3800, 4L60e, etc. It's got the Y87 package...LS1 brakes, steering & rearend.

    That would make a fantastic and reliable daily driver. 205hp stock and should get you near 30 mpg on the highway.

    I think my brother even has a mid 70's Camaro 3.42 8.5" posi that would match up nicely too.
     
  16. Lukey

    Lukey Member

    It has a 3.23 geared 10 bolt. Stock 14" rims and 195/70r14 tires. I have no idea what trans is in it. The car only has 59k miles, no rust, just a blown stock trans which is why it was parked 6 years ago. The reason the small chevy is even considered is because my brother has an 81 Camaro with mild cam, th350 and 3.42 gears with 27" tires and averages 24 mpg daily driving (proven when I've drivin it numerous times) my other brother owns a machine shop with dyno and all, so machine work, assembly, and list cost on all parts is why I don't mind looking for a small Buick ... I'm kinda spoiled, I know:) if I can get the 3.8 to pull 25mpg with tuning and overdrive, I would be happy.
     
  17. TheSilverBuick

    TheSilverBuick In the Middle of No Where


    That'd be way cool if he's comfortable with the wiring and electronics.
     
  18. Lukey

    Lukey Member

    I'm in central Illinois, where you at? I love road trips! And no, wiring doesn't bother me...the challenge is half the fun!

    ---------- Post added at 08:53 PM ---------- Previous post was at 08:36 PM ----------

    Was even AND odd fire both available in 77? If so, how do I tell which it is?
     
  19. urbancowboy0307

    urbancowboy0307 Silver Level contributor

    Sound like some cool Brothers to have!
     
  20. TheSilverBuick

    TheSilverBuick In the Middle of No Where


    Yes. I forget the vin number change over but it was late 77 then all 78's were even fire. The easiest way to tell is to pull off the distributor cap and look in the cap and if the terminals are or aren't evenly spaced is one clue and the other clue is look at the pickup coil under the rotor and see if the reluctor teeth are or aren't evenly spaced. If they are evenly spaced it's even fire, if they aren't it's odd fire.

    ---------- Post added at 07:52 PM ---------- Previous post was at 07:33 PM ----------

    I'm posting this stuff below because a buick 350 should easily be able to match the mpg's of this 455.

    This greasy all iron 455 with 8.5:1 compression and a .450" lift cam with Q-jet, points and a single 2" glass pack exhaust and TKO-600 5-speed (.64 overdrive) regularly got 23mpg going between Ely, NV and Fontana, CA.

    [​IMG]

    [​IMG]


    And was fun to drive!
    [video=youtube;R_CCLSwdLhU]http://www.youtube.com/watch?v=R_CCLSwdLhU[/video]
     

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