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Mopar guys--? on 318 horsepower

Discussion in 'The Hokey Ass Message Board' started by Fat47, Nov 26, 2009.

  1. Fat47
    Joined: Nov 10, 2007
    Posts: 1,234


    Picked up a 318 (904 Tranny) in a trade a while back----2 barrel----from a 67-75----and recently acquired a 33 Dodge coupe. Wanting to keep the car all mopar I tore the 318 apart and found it to be OK----my first go round with a mopar engine, so before I go any further I was wondering what horse power rating these engines had originally and solicit any suggestions for the rebuild. I am looking to end up with a good road car, capable of trouble free long trips. Advice and ideas appreciated
  2. There`s nothing exotic about the LA 318. It`s simple engineering and a very good, solid engine, no quirks. It responds to high performance modifications similar to a 350 Chevy.
    Add a nice street cam, free-flowing exhaust, dual-plane intake and a 600 Holley and you`ll have a great 300 hp engine.
    The stock electronic ignition is excellent and reliable. Don`t try to get fancy with anything and you`ll be fine.
    Mopar Performance ( Direct Connection ) offers some nice camshafts for this engine. An Edelbrock Performer intake is a good choice.
    Late-model 360 ( 5.9 liter ) heads are an OK upgrade.

    It all depends upon the power level you`re shooting for.
  3. Good advice from Don Man.

    The 318 is a great engine - a lot of guys rag on em b/c they are cheap, avail and mostly came out in lo perf mopars.

    You could EASILY build a very streetable 400HP 318 from cheap, avail factory parts and it'll go the long haul. Back it with the 904 or for OD run a A518 4 spd OD trans and youre in business.

    While the MP cams are great cams, they are old tech and there are newer more efficient grinds out there for mopar small blocks, Comp Cams make some real nice ones, inc hyd roller grinds which will free up some friction.

    360 J heads work well on the 318...mildly ported, port matched and use the factory 1.88 valves unless you're turning it HARD....which it does'nt sound like that is your plan anyway. 9.5:1 CR will enable you to run of the cheaper gas but provide good TQ.

    A nice Weiand Stealth, MP, or Edelbrock Performer RPM dual plane hi rise, a vac sec 650-700 Holley or Edelbrock 650, the factory elec ign killer....just make sure the dist is OK,curved to suit the cam/combo and add a hot coil and an MP orange or chrome box - its all you will need and super reliable.

    A decent set of tri Y headers or if have have the room, 4-1s with small primaries say 1 5/8" will provide good breathing and not affect lo down TQ too much, just the thing. most header makers have em for SB mopes.

    If you can get your hands on the old DC or MP Engine Manual it will tell you to a tee what you need for the level of HP/TQ your are seeking.

  4. I had one of these, and no other engine I ever owned responded as well to cam/carb upgrades as this one did. Its a great engine!
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  5. LowFat48
    Joined: Aug 28, 2005
    Posts: 911


    As Donman said they are excellent engines , if you can find a set of heads from a 90-91 truck 360 , they are worth the expense to install if you have the $$$ , the casting numbers to look for are 4448308 or 4772576 , you will have to have them milled .060 because of the larger combustion chambers . they have the larger 1.88 1.60 valves and are worth 30-40 horsepower by themselves.
  6. the 360 heads will just cost you more money. go with the original heads.
  7. Go with what these guys have said,,,you won't go wrong.
    The 318 is a great engine to use,,,and yes 400 horse is there if you want it.

  8. George
    Joined: Jan 1, 2005
    Posts: 7,263


    If it's front sump & you need rear sump, they came on vans & pick ups. You'd need the pan, oil pick up, dip stick & tube. The 360 heads have bigger valves & bigger chamber, so a slight loss of comp vs the better flow. Most any 4 bl carb & intake will be a big improvement over OEM carb/intake.
  9. LowFat48
    Joined: Aug 28, 2005
    Posts: 911


  10. I have found it better to pocket port and smooth the runners on the stock 318 heads than take the compression drop with the 360's, but if you want a bolt on get the heads with the heart shape combustion chambers from the 87's up to the magnum heads. J heads are a waste on a mild 318, the 2.02 valves get shrouded by the smaller bores.

    Don't go nuts with a cam (stock 340 cams work well or something around 268 degrees duration).

    The smaller the better on the header primaries - 1 1/2" would be really good but I have only seen them for pickups (hooker made them).

    318's make great torque, try to work with it not against it and you will have a nice street motor, 300-325 or so horsepower and lots of torque.
  11. 53sled
    Joined: Jul 5, 2005
    Posts: 5,819

    from KCMO

    Last edited: Nov 26, 2009
  12. kwoodyh
    Joined: Apr 11, 2006
    Posts: 641


    Looks like they about covered it all! Now get building and post some progress pictures! ;)
  13. Retro Jim
    Joined: May 27, 2007
    Posts: 3,860

    Retro Jim

    A 318 is a great small block that will serve you very well for a long time . They are easy to upgrade with out the big cost . Just don't go over board and it wonk cost you a ton to get some more HP . If you just want a good motor that will last forever , then a good mild cam , headers , 4 bbl and an overdrive trans . You won't be disappointed with a 318 !

  14. 440shawn
    Joined: Sep 25, 2009
    Posts: 1,716


    All great advise, I run a 318 very dependable makes good power.
  15. the motor is like any other v-8 18436572. jokeing aside what is at issue is the starter location, that damn thing is in the way even in a fat body.
    the 318-A- is a great mill but as said you will need a truck pan and pick up.
    find a 273 and get the adj rockers and cam option gets better. if you go with 360 heads then you will need to use a 360 intake. 318s needs 318 intake they do change but the ports on a 360 are much bigger then a 318. also remember a 360 pan wont work on a 318,
  16. Racewriter
    Joined: Nov 14, 2008
    Posts: 780


    Building one right now for my '67 Charger. Most 318s had three problems inhibiting the power - very low compression caused by pistons too far down in the hole (most 318s were somewhere between 7:1 and 8:1 CR from the factory), cams that were damn near flat from stock - low lift, short duration, and heads that strangled the engines. All three are pretty easy to fix.

    Keith Black/Silvolite sells a piston that will zero-deck. It's KB167. That gets the piston flat top all the way to the top of the bore. Once you do that, the larger combustion chambers on a typical 360 head aren't such a problem and will still give you compression somewhere between 9:1 and 9.5:1. So, swap to 360 heads. I bought mine for $50 from a buddy, but they're common and cheap. Don't waste money on going to 2.02 valves, just stick with the stock 1.88/1.60 valves with a good valve job. Some pocket porting is nice if you can do it (I can and will), but it's not a killer if you can't.

    Now you have CR and breathing, so a good cam will help. No specific recommendations here other than to go to a cam manufacturere like Comp that stays up with the times - MP's grinds haven't changed for 15 years.

    Top it with a good intake/carb combo, and you're somewhere between 300 and 400 horses depending on how serious you get with the cam and heads. Tripower setups are easy to come up with, using an Edelbrock intake and Holley carbs. I'm a little weird, so I'm using an Edelbrock intake, making some adapters, and using Rochester carbs like an old GM tripower setup.

    The bore/stroke ratio is a lot like a 327 Chevy. Think of it as a 327 with different valve covers, and you'll be fine.
  17. GTS225
    Joined: Jul 2, 2006
    Posts: 1,167


    I didn't see it covered, with the exception that George almost said. If you do need a different oil pan, make sure you get a 318/340 pan, NOT a 360 pan. There was a change or two in rear seal design, and the pans from a 360 won't work on the other LA engines.

  18. MengesTwinCustoms
    Joined: Oct 16, 2009
    Posts: 279


    since you already have a 318 and want a reliable car why not just leave it all stock? How much does a 33 dodge coupe weigh? You don't need 400 horse power to be the fastest car on the road. Just my 2 cents, thanks for keeping it mopar!
  19. 73RR
    Joined: Jan 29, 2007
    Posts: 6,360


    Yeah, gotta agree with the young man from Idaho^^^^^^

    Considering that the stock rating never exceeded 230hp, a 400hp 318 is not going to be 'stop n go driving' friendly. A decent driving 318 will have a moderate cam (220 @50 x .460 lift) 9:1 cr and 600cfm carb on a performer or torquer intake. If you need 1hp/inch then you will spend alot more money and unless you stroke it it will become less and less street friendly.

    318 are extremely reliable, but never designed for high output, that was the 340's job. Currently, Mopar has put all of its perf focus on the 360 for good reason.

    my .02

  20. 90ssp
    Joined: Jan 3, 2009
    Posts: 400

    from dallas, ga

    keep us updated. I want to see how it turns out. I just got a 69 dodge 383 for my 27 dodge roadster
  21. George
    Joined: Jan 1, 2005
    Posts: 7,263


    Obviously a 360 would be easier to build power with than a 318, & a 440 even easier, but the guy has a 318. 1st thing i do is toss the intake & carb. easy fast & simple. The rest can wait till I want to get nore involved.
  22. Fat47
    Joined: Nov 10, 2007
    Posts: 1,234


    Thanks for the responses and the information. I had figured on a Preformer and 600-650 cmf with a mild cam. I don't need 400 HP----want a street/trip friendly and reliable engine. It appears the stock engines put out somewhere in the vacinity of 200 HP, give or take a little. I will need to buy new pistons anyway, so it appears the 8-1 could be raised to 9-1 with very little extra investment. With this mild build it appears I could be somewhere in the high 200HP range?????????

    I will have to check the oil pan/rear sump issue relative to the front end upgrade I had planned. Any other advice/ideas appreciated.
  23. George
    Joined: Jan 1, 2005
    Posts: 7,263


    Probably a Performer intake, cam & carb 600 CFM would probably do fine from your description.
  24. mbmopar
    Joined: Mar 27, 2006
    Posts: 467

    from Canada

    yeah, pretty much what donman said....basic building block engine, no pun intended
  25. 41 C28
    Joined: Dec 17, 2005
    Posts: 1,770

    41 C28

    I,m running a bone stock 318 2bl with a 904 in my 48 Dodge coupe, only mods are dual exhaust and Pertronix ignition. I would like to have a little more power but the car runs good and is simple. I'm not looking for a race car.
  26. storm king
    Joined: Oct 16, 2007
    Posts: 1,991

    storm king

    Horsepower is not what you should be looking for on a street engine. Torque is what moves you. High winding small blocks can make big H.P., but usually only at very high RPM. The 318 is a good torque motor. Purple cam, good four bbl and aluminum intake and you're set. Screw H.P. #'s.
  27. 6mopar7
    Joined: Aug 7, 2009
    Posts: 38


    I had a 1969 Sport Sat with a 318 & 2-bbl for many years & it had ~230 hp in stock form. I did have trouble with the stock intake's heat runners stopping up twice. The valve guide seals leaked as the miles piled up, be sure & check them if you keep it as is. Loved that car, wish I had keep it.

    I would do as another poster suggested; go with a Performer intake & 600 CFM carb (with electric choke).
    Maybe add an electronic ignition. As I remember the 318's had rear mounted distributor so firewall clearance might be an issue?

    Good luck on your build!

    John :)
  28. this thread comes at a great time for me. I just took my 68 318 into the machine shop to get hot tanked and have the bore checked. it is an original 49k motor. I have a set of 1984 police special heads for it with the police special 4 barrel intake with a quadrajet carb. I will be keeping an eye on this thread to see how this build goes compared to mine. I have both a 904 and a 727 for trans choices, I will probably go with the 727 as it also has 49k on it. Bud
  29. Fat47,

    Here's my LA 318 (out of '74 Dodge Dart) sitting in my '39 Desoto.

    *Stock pistons/crank
    *Summit 360 perf cam/hyd lifters ($100.00 +/-)
    *'98 Magnum big valve heads (Craigslist $100.00, and an impromptu sales pitch on how I could become a distributor for Mona-vie. Heads yes - sales NO.)
    (Note: req's head specific-vert bolt holes-intake, AND, if you don't use roller lifters, you'll need to get longer "Oiler" pushrods-early 318's have solid pushrods)
    *Edelbrock Air Gap dual plane manifold ($350.00) (not cheap- couldn't find a stock one to save my life, so ponied up the dough)
    *Holley 600 ($60.00 - got a good deal on it via Craigslist-newly rebuilt)
    *Block Hugger headers ($75.00)
    *Pair of Speedway glasspacks ($120.00)
    *HD water pump (NAPA $45.00)
    *Stock Mopar electronic Dist
    *Stock A-940 transmission (came w/motor)
    *Custom built driveshaft ($200.00)

    Had the same vision as you did Fat47, driveability-with some kick, keeping it as Mopar as possible (selling point down the road). Best guess HP is about mid-300's. Have not got it out on the road yet, but very soon.

    Attached Files:

  30. Good combo,,,it will run great.
    Did you raise the compression at all,,,,(deck the block or mill the heads)?
    Do you have more pics of your ride,,,looks cool.


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