361 CI Motor Opinions

Engine, Transmission & Driveline

  1. Catfish-65

    Catfish-65 Member

    Messages:
    72
    Likes Received:
    24
    Joined:
    Feb 6, 2015
    Location:
    Fort Erie Ontario Canada
    Have a friend that has a chance to acquire a strong running 361 CI motor and trans,, He,s not real familiar nor am I with this particular engine,, Any input would be welcomed, ie. comparisons to 383,s and 400,s interchangeable parts etc, Have seen the 361ci listed on line with the other big blocks Thanks in advance Catfish 65
     
  2. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

    Messages:
    7,397
    Likes Received:
    1966
    Joined:
    Mar 27, 2017
    Location:
    Cornelius Or
    361 and 383 both share the same block, heads, manifolds and crank shafts. The only significant difference is the cylinder bore size. A word of caution because the '61 and older 361 and 383 engines will not accept an aluminum cased A-727 transmission as the crank flange is different. The two engines will interchange readily as long as you keep that in mind, but you may need custom mounts for some applications. Both the 361 and 383 are excellent, reliable engines. The 400 will fit anywhere a '62 and later will fit. The 400 block is an updated block, but the bolt on stuff like manifolds and heads will still fit. The 400 has a nodular iron crank for most applications but the forged steel 383 crank can be substituted as long as the 383 harmonic balancer and torque convertor are used. Police, high performance and some truck applications retained the forged steel crank, so a crank number check is advised. The 400 is not a good choice as a stock performance engine unless you plan to do a lot of work on it.

    Dave
     
    Last edited: Nov 23, 2019
    • Like Like x 1
  3. Lefty71

    Lefty71 Active Member

    Messages:
    255
    Likes Received:
    98
    Joined:
    Mar 17, 2018
    Location:
    Ohio
    Replacement piston choices are limited on 361, 413, and 426 wedge engines. Custom can be had, but would be expensive. Egge still has stock type cast units, available at Hughes Engines.
     
  4. 1970FuryConv

    1970FuryConv Senior Member

    Messages:
    1,894
    Likes Received:
    1597
    Joined:
    Aug 8, 2014
    Location:
    Richmond, VA
    Would the 361 have more torque than 383 with smaller cylinder bores?
    If 400 is not a good choice, what is a good choice and why?
     
  5. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

    Messages:
    7,397
    Likes Received:
    1966
    Joined:
    Mar 27, 2017
    Location:
    Cornelius Or
    In factory form, the 361 was a 400 pound torque engine, the 383 was about 420. This was with a 4BBl carb on both engines. Usually more cubic inches will equate to more horsepower and more torque if everything else is equal. In most cases the type and duration of the camshaft will be the main element that determines engine torque and at what RPMs the torque curve will peak. The size of the carb is also important in that a smaller carb will equate to more torque at low RPMs and a larger carb will give more torque at higher RPMs.
    The 400 was not a good choice in stock form for a performance engine because it was a de-tuned smog motor with a low compression ratio of only 8.2-1 and in most cases a nodular iron crank that was not suitable for use over about 4500 RPMs. In addition, the factory had installed advance limiters, leaned out carbs and EGR valves that further limited performance. This engine has a lot of inherent potential if one gets rid of the stock iron crankshaft, pistons, manifolds and heads.(aftermarket intake with updated performance carb and headers or stock high performance exhaust from an earlier engine)
    If I had a choice of the 3 engines to build for performance, I would choose a 383 mostly because of the better stock heads, and higher stock compression ratio coupled with a forged steel crank and the lack of any significant pollution equipment. Many choices for high performance pistons also in much greater supply. If cost is no object, build a 400 (or a 440) for the increased displacement, otherwise build a 383.

    Dave
     
    • Like Like x 1
  6. pomonamissel

    pomonamissel Senior Member

    Messages:
    2,896
    Likes Received:
    1418
    Joined:
    Oct 20, 2016
    Location:
    san jose california
    the b361 and the rb413 shear the same bore size , the 383b and the 426rb shear there bore size , 440rb by iits self , 400b by its self , just bigger then 440 bore . stroke is the same for these engines are b's or low deck 350 351 383 400 shear a 3.38 stroke , and these rb's or raised deck 383 413 426 440 shear a 3.75 stroke . the 350 b and the 383 rb are early wedges that lived in the beginning days of production . oh ya there are no common blocks between those b's or rb's , but the rb 413 /426 industrial block . this was just a bore resize .and these engines sheared other parts inside and out , but mama mopar has done raised deck low deck from the beginning of these v8 engines . note 301 331 354 low decks 392 raised deck chryslers , 241 259 270 low deck 315 325 raised deck dodges , 276 291 low deck 330 345 rased deck desotos , plymouth sheared poly headed dodge motors and 392 chrysler as special package one year . also 354 chrysler in dodge trucks . and a slue of industrial engines .
     
    Last edited: Nov 23, 2019
    • Like Like x 1
  7. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

    Messages:
    7,397
    Likes Received:
    1966
    Joined:
    Mar 27, 2017
    Location:
    Cornelius Or
    There are a couple of typos . b250 should be 350, rb 425 should be 426.

    Dave
     
    • Thanks! Thanks! x 1
  8. pomonamissel

    pomonamissel Senior Member

    Messages:
    2,896
    Likes Received:
    1418
    Joined:
    Oct 20, 2016
    Location:
    san jose california
    yes dave i've corrected my type o's
     
  9. CBODY67

    CBODY67 Senior Member

    Messages:
    4,825
    Likes Received:
    1099
    Joined:
    Mar 27, 2011
    With the 361, it'll be easier to over-cam it due to its smaller size. The stock cams were quite tame, by modern standards. The heads on the 400s, being updated 906s, have been proven to flow the same as the 906s, after a small bit of porting (as in the Mopar Perf porting templates' use). Looking at the distributor specs (initial base timing and the mechanical advance totals), total timing was still past 35 degrees btdc, which is just shy of the allegedly optimum 38 degrees btdc, even with the 7.5 degrees btdc base timing on the '72 400 2bbls.

    To me, the main issue with the cylinder heads would be if they were 4-bolt or 6-bolt hold-downs. Which would mean that matching valve covers would be needed. Don't recall when that change was made in the earlier '60s, though.

    The smaller cylinder bores of the 413s and 361s could mean that the "smaller than 2.08" intake valves are possibly on the 361s. Still sized proportionately to the engine size, though. The larger valves could become shrouded easier by the larger valves, which could negatively affect ultimate port flow. But using "under-cut stem" valves might be a good option, past basic port clean-up on the heads.

    Many people perceived the 400s to be "dogs", when the specs were somewhat the opposite--except for the 1.0+ lower compression ratio. Cam specs had a slight bit more lift and duration, with the duration being there for a little bit more residual EGR in the cylinders at lower rpms, but would also help power on the top end. Ford did that trick on their '74 351-C HO motors, too. Carbs were a bit leaner on the lower rpm areas, too, but the cruise mixture should have still been 14.7 a/f ratio as it had been for decades prior. Base timing was a bit lower, but that's easy to change in order to get to the 38 degrees level (either with a bit more initial lead and/or with the Mopar Peft advance curve kit.

    The OTHER observed issue with the pre-66 B/RB motors was the very restrictive factory log exhaust manifolds! With an outlet hole of 2.0" at best. So an upgrade there would be good to do, with ANY of the earlier B/RB engines. Then following that with a good under-car exhaust system of at least 2.25" mufflers and pipe.

    Any rebuild will probably need .030+ pistons and new rings, by observation, in order to get to "fresh metal" in the cylinder bores. So any of them would need new pistons, as a general rule. It might also be that any cast pistons will not be the factory 10.0 cr piston equivalents, possibly more like the 9.2 cr 2bbl pistons (piston crown height would be the key thing to look at). But the 400s would be an issue as they only came with 8.2 cr, which can be compensated for by milling the later heads to the 73.5 cc specs of the earlier castings (which then makes them look suspiciously like small block Chevy heads, especially if angle-milled). Using thinner head gaskets is another trick to boost the 400s resultant compression ratio. Using forged pistons, "close fit" if possible, can possibly be an easier route to higher compression, but with more expense than the cast pistons. Other than the lower compression ratio, the Data Book for the 400 HO showed it to still have the "guts of a Road Runner" with a lower compression ratio Upgraded material bearings, "more" cam, double-roller timing chain, etc. FWIW

    The 361 might be an interesting build with something like the Chry 256/260 cam, cleaned-up power cylinder heads, later model exhaust manifolds (or headers) with the bigger pipe exhaust system, something like the MP electronic ignition kit, a 650cfm carb and later model intake manifold. In other words, basically what you'd do with a 383 but with one-notch lower on the cam specs.

    Several possibilities to consider. Thank Davea for pointing out the issues with the earlier TF mounting issues.

    Just some thoughts,
    CBODY67
     
    • Like Like x 1
  10. Gerald Morris

    Gerald Morris Well-Known Member

    Messages:
    999
    Likes Received:
    231
    Joined:
    Mar 9, 2016
    Location:
    Tucson
    One advantage to the 400 block I intend to use is the larger coolant ports to the heads. I'm planning to pull the forged steel crank (w the damper) from my 383 shortblock this winter for the 400, along with all other salvageables, as a Step 0.0.0.1-a sort of operation. With a little blessing here and there, I pray to get that 400 ready by 2021. Having another 383 handy won't be bad either.... If somebody offered me a running or easily reparable 361, I'd snap it up for the right price.
     
  11. pomonamissel

    pomonamissel Senior Member

    Messages:
    2,896
    Likes Received:
    1418
    Joined:
    Oct 20, 2016
    Location:
    san jose california
    the 413 heads are better than 361 better chamber size than 906's or later heads . i think some small chambered alum heads would wake it up , yes cam would be smaller for low end but its not much smaller than a 383 or 400 . and the 383 can see 8k on the modified stock low end . 361 is just a 4.18 bore verses the 383 at 4.25 bore , both with a 3.38 stroke , not to say any about the chey 327 was 4.0 bore n 3.25 stroke , ever see a 10k one . i have . so no reason that 361 properly built making hp and rpm . hell my 63 sfgc in all steel went 10.73 with a 8k 383 n auto . note that a rb would cost the same to build and make more power .

    Fury.png
     
    • Like Like x 1
  12. twostick

    twostick Senior Member

    Messages:
    2,110
    Likes Received:
    927
    Joined:
    Dec 13, 2012
    Location:
    Beautiful Downtown Roebuck Ont.
    Nothing wrong with a stock 400 that advancing the camshaft 4 degrees won't fix. If you are doing a stock type rebuild, new pistons that aren't 140" down in the hole will get the compression ratio over 7.5:1 and really wake it up.

    Kevin
     
    • Agree Agree x 1
  13. MoPar Maniac

    MoPar Maniac Well-Known Member

    Messages:
    670
    Likes Received:
    183
    Joined:
    Dec 8, 2016
    Location:
    St. Charles county, MO
    Every 361 I ever drove ran really well. They were al 4 speeds so back then they had a different cam than the autos.

    I had a 72 400 Polara cop car and that was a darn good running car. They weren't dogs by any means. Had a 72 400 2bbl Monaco that was no slouch but it liked gas stations.
     
  14. furious70

    furious70 Well-Known Member

    Messages:
    726
    Likes Received:
    246
    Joined:
    Aug 18, 2018
    Location:
    Chitown
    If I had the choice of a stock 361 or stock 400 to start with to do some bolt ons I'd pick the 400. No fear of the cast crank for me. Bigger bore is going to help any bolt on you might do and 361 small bore can't use a better head because of the valve issue listed above.
     
    • Agree Agree x 1
  15. BTO440

    BTO440 New Member

    Messages:
    6
    Likes Received:
    3
    Joined:
    Jan 1, 2020
    Location:
    Bakersfield, CA
    I have a complete 361 out of a 64 Newport that's available really really cheap
     
  16. Gerald Morris

    Gerald Morris Well-Known Member

    Messages:
    999
    Likes Received:
    231
    Joined:
    Mar 9, 2016
    Location:
    Tucson
    Oooooh! You're in Bakersfield, right? TEMPTING! Must count pennies .....
     
  17. BTO440

    BTO440 New Member

    Messages:
    6
    Likes Received:
    3
    Joined:
    Jan 1, 2020
    Location:
    Bakersfield, CA
    Yep, Bakersfield. Got the transmission too. I think the motor was supposedly a runner. I've had it in dry storage since pulled
     
  18. 70bigblockdodge

    70bigblockdodge Old Man with a Hat FCBO Gold Member

    Messages:
    12,262
    Likes Received:
    5190
    Joined:
    Jan 19, 2013
    Location:
    Avonmore Pa.
    It's fine just don't try to build it for rpms, the bore size does not work for breathing and non custom piston choices limit compression to use a large duration cam.
     
  19. Gerald Morris

    Gerald Morris Well-Known Member

    Messages:
    999
    Likes Received:
    231
    Joined:
    Mar 9, 2016
    Location:
    Tucson
    I wouldn't dream of building a 361 into an overbored, high revving engine beyond Mopar's OEM performance specs, though they did fire these blocks up a bit circa 1960 or so. I would build a 361 for "truck duty" with LOW rev high torque on the bottom of the curve as much as can be contrived. If I wanted a high revving, free breathing B block, I would opt for a 383 or a 400, fitted with heads that would permit ample flow to get that max performance at the upper end of the angular velocity vs power/torque curves.

    Since I have 2 non running B blocks already, needing much attention and investment before transplanting either of them into Mathilda, I don't foresee me running to Bakersfield to get a 3rd, no matter how tempting a deal it may be, unless I had another body into which I could drop it, and easily get it running.
     
  20. BTO440

    BTO440 New Member

    Messages:
    6
    Likes Received:
    3
    Joined:
    Jan 1, 2020
    Location:
    Bakersfield, CA
    Ok thanks Gerald, now you got the right side of my brain telling the left side to go get that 64 dodge shortbox stepside pickup from my friend, yank the straight 6 and put that 361 in it! See the trouble you started, LOL!