hey guys, i posted this over on my mopar board but i have not gotten any response to speak of, i need advice here, lol. and you guys are the best group of car guys out there... please disregard the car that the engine will be going in, i know its not hamb friendly, but i could really use some sage advice on the engine build. i am needing advice to assist me in building my 360 to get what i want out of it. its a 74 model LA 360. it will be going into a 74 charger w/an a-500 tranny. what i want is to have a street friendly build and i my HP goal is 360-400...dont need more than 400. let's plan around a 4bbl and stock manifolds but i will eventually be going to tbi and headers. i already have a comp ex262 comp cam that i can use in it. i have been told that may be a bit small for my HP goal, so im open to suggestions on that as well. i want a lopey idle, but still need to retain ac, pwr brakes, etc. i need to know what will be needed for this build. i do not want a thirsty beast, or a race build. just enough power to play around with when i push the pedal. where cost is concerned, let's aire on the less expensive side if we can..... can someone, anyone, give me some real world advice on how i can attain my build goals. if i can do it without boost, then i prefer to. i am needing advice on internals. the more opinions the better, some questions i am wondering about are things like... stock dished pistons vs flat what pistons can i use w/o having to worry about hitting the valves. hp capability of stock heads(after porting) i need to know it all, dont leave anything out or take anything for granted. if you say use different pistons, tell em what else i need to change in order to use them... any and all advice is greatly appreciated! i want to learn here as well as getting opinions. thanks in advance guys.
Personally I'd run a set of Edelbrock Heads with a Performer RPM intake (Carb) or a Mopar M1 single plane (TBI or EFI) around 9.5 to 1 with a good split duration cam, if you want to run stock exhaust manifolds. The extra exhaust duration will help make for the lack of headers IMHO. The edelbrock heads are available for around 1200 a pair with new valves springs etc... by the time you add up a valve job, porting and all the parts they are hard to beat. I'd run KB flat top Hypereutectic pistons they are great for a street motor, and pretty cheap. You may also want to look into a 408 stroker kit, especially if your crank needs to be ground, same story, you are already replacing the pistons, and the stroker cranks are pretty damn cheap. A 9.5 to 1 408Cu In motor with the Edelbrock heads and a good cam will probably get you 450 HP pretty easily
You have some conflicting goals, and are unclear on a couple points. Street (no racing) and MPG with a heavy car and an OD trans means keeping it a torque not a HP motor, but you want 400 horses. ??? Clean sheet and a decent budget, I'd get the Edelbrock heads. They are reasonable enough that it is worth the cost. You can also run higher compression, which will help the MPG and the sound you want. I'd really avoid the exhaust manifolds. Even a 2 bbl. 318 will wake up with headers. I'd talk to a good engine builder and find out what your options are with the block you have. Building quench and having a good compression ratio will be the main focus. If the budget allows, a stroker kit will make the task easier. More cubes tames a bigger cam, and also you can move the power range lower (good for the street and MPG). By now, you have spent over 6 grand. If you are on a tighter budget, go with a basic rebuild of the 360, just adding a proven cam, 9-1 compression, and intake, 4bbl and exhaust. BTW, always compare a crate motor. It may not have exactly the parts you would choose, but they are complete, assembled, proven combos. Most have limited warrantys. Here are some, including a 360 crate at 390 horse for 5K. These tend to be a bit radical for the street, and many guys have moved down to a milder cam for street manners. They also have a 406 stroker at 435 horse for 6200. That would NOT be a MPG or daily driver motor. http://www.mopartsracing.com/parts/blocks.html#smallblocks BTW, all these are Magnums, or the later model, roller cam and stud mounted rocker motors. They also have a pre-magnum 360 short block for 1900. The magnum short block is 1600. Can you get your shortblock done for that?
http://www.moparts.org/Tech/Archive/smallblock/8.html http://www.allpar.com/mopar/4bbl.html I'd get both of these books, too. http://www.themotorbookstore.com/9780895861283.html http://www.motorbooks.com/Store/ProductDetails_10476.ncm If you have a buddy that has a desktop dyno program, try out different combos. You will want to figure out what weight, gear ratios and tire size you have, what conditions you will be driving and try to build the torque curve to fit. With a 3800+ pound car, an OD trans and a sane limit on speed, I doubt you will ever see more than 4200 RPM. No need to have any component that has a range much higher than that. Avoid the big cams, big carbs, and big intakes. Try to get velocity up, not huge airflow numbers. Once you have found a good torque curve, try finding a converter that will give you the best street manners.
the charger is the newest car i have, lol, so dont get after me too bad for it, lol. thanks for the advice so far, and if my goals are conflicting or unclear, please let me know, i am totally learning here, so i didnt know i was trying to make gold out of lead, as they say.... any adive adn opinion offered will be greatly appreciated, i want to learn what i do not know, and i dont understand completely what goes into reaching my goal. so keep the info comin, thanks... btw, yeah, 6k is a ways over my budget goal. someone asked, so, i can get the long block, stock build for 1600. bone stock, but i dont want to go bone stock.... i know ill have more in it than 1600 but need to keep it reasonable.
yep... PS... no one needed to know what it was going into, that way you wouldnt be getting your chops busted for an OT car
Budget 360 Stock cast crank and rods 9.5:1 compression Stock volume oil pump unless you're going over 5,500 '92 and up 318 or 360 Magnum heads or if the Magnum head conversion is a little too much, a set of homeported J heads will do Performer RPM intake Speed Demon or Holley 650 Just finished building mine with a stock bottom end for under $2000 with Magnum heads. Is your 360 already all together? If it is just leave the rotating assembly alone and put the Magnums on it. They'll raise the compression ratio and flow better than the factory J heads. You might want to join forbbodiesonly.com too.
that hurts I would address heads first you will need to find a set of cop 360 heads or 73 3/4 ton trk heads they had bigger valves and flow better. 9.1.5.1 pistons will be gas friendly and work well in the heat. spend your money on a good 600/650 holley street avanger and use a mopar dist with a chrome box. the mag heads is a real pain. your hp goals are not very real unless you want to step up to alot of money. the parts list I gave you will give you a real 300 hp and very streetable. another thing to look for is a set of 273 adj rockers they make life with a cam a little easyer. your cam is a little weak look to a 286 . less money and mopar are not in the same book. if your running off the hotrod build of 400 hp that was a pure B.S. build they worked the scope to get the numbers they printed.
All 360 heads are the same until '92. All heads had 1.88 intake and 1.60 exhaust valves. All flow the same. Most 360's you'll find have the J heads. Good factory heads that should make 400 hp with some minor porting. The magnum head swap is not a pain at all, as I said earlier I just did it. Bolt the heads on, buy some pushrods and you're ready to go. The smaller chambers will raise the compression with factory pisons and the exhaust ports flow much better than the J heads.
Easiest way to get you closest to where you want to go (most bang for the buck, too) would be to find a Magnum Motor, fit it with a set of Iron Ram heads (800 to around a grand) and a stouter roller cam. A 500 is too light duty a transmission for what you want, find a lockup converter 518. Either one will cause you to modify the T bar crossmember (both the crossbeam spot welded to the floor and the bolt on mount brace). While all the horsepower and/or torque is in the heads (provided you have enough cam) and while Iron Rams or the new Indy head will help you get the most from any short block, if you're building down to a budget, find a pair of 89-92 308 casting heads from a pickup, clean em up, grind the valves if needed and use em. Pick the right cam and you'll be surprised. Just be careful where you get a cam from, most of the aftermarket ones are just rehashed Chevy grinds and don't take advantage of the larger diameter Mopar lifter.
well, if i had just said it was going in a 4k lb car, everybody would want to knw what it was going in, lol, so i saved the trouble.....lol.. so, then, what determines whether i want a HP build, or a torque build... i was under the impression that HP was what made the motor feel "strong", but someone up above said it was torque. maybe i am using the term HP incorrectly. i am learning here, so with a 4k lb car, do i need to focus more on torque than power? or is there a balance to be found? also, some of you have said that the cam i have on the shelf is too small, what is the difference that the cam makes? what i want is an build that (with a 3.23 rear gear, etc) will MOVE that 4k lb car when i ask it to. Now understand, i am going from a 318 2bbl and 2.76 rear gear to this 360, so anything will be a big difference from what i did have. is torque what gives the push you back in the seat feeling, or hp? can anyone give me more info on a magnum head swap? there are plenty of trucks around here i can get heads off of, and i would likely have to go that route, rather than new mag heads...but i thought i would need to have water or oil passages redrilled or something, or that the bolt angles were different, i thought there was a bigger diff than just pushrods. thanks for all of your time, btw. i appreciate it. i just hope im not asking dumb questions....
Torque is good to have for a street car. If you really want good torque on the street then go for the big block. The cam will decide when your power comes in. Google magnum head swap or magnum head conversion. Better yet, join www.forabodiesonly.com and look for a thread on it there. There is some really, really good small block info on there. Highly advised to check it out. For the magnum heads you need a magnum specific intake and pushrods. Again, check out forabodiesonly.com and look around there.
I hope you take this the right way, but your questions indicate you are new to this and don't have a clear overall picture. Buy and read the books. They will you develop a better understanding of how all the components are related, and what your choices are. For example, if you are using the block you have, you need to know the actual crank stroke, rod length, deck height, bore, head CCs and planned gasket to figure out the best piston. Torque is force, not necessarily work. think of a big guy pushing against a fridge vs a little kid. Once it's moving, either can keep it going. To move it or to accelerate it, you need more force (the big guy). Horsepower is work. It's moving the fridge across the floor a set distance in a set time. In engines, they all develop more at greater RPM. The issue is that a Honda 1.8L may develop 200 HP at 6500 RPM, where your 360 will develop it at 4000 RPM. It's the torque under the curve that you feel, especialy in a heavy car.
I would suggest that you visit the salvage yard and find a pickup 360 from 98 or newer, roller cam, magnum heads, etc. There are several options for cams. You'll need an older ignition system and a single 4 intake and carb. Those are nice setups. In stock form they are rated at 250hp. With the cam change and a different intake, 300 should be easy. The newer stuff is way more efficient than the earlier engines.
RODSTRACE, i didnt take that wrong at all. i completely understand what you meant. i have been raised around cars. i do restorations, and can do all around work. can do plenty of mechanic work even, but where i am at a disadvantage is that though i can work on the engine, even tear it down and put it back together, i DONT understand the ins and outs of the internal workings...the fine details, i dont know where the tradeoffs are between HP and torque are, dont know what quench is, dont know what the critical tolerances are, things like this, i dont know, but would love to learn. i.e. if you change your cam, how do you KNOW if you need to change springs, pushrods, pistons, etc....these things i do not know....so feel free to explain anything you wish, i will soak it up.
Thanks for the info, I don't have a hot lick Mopar body but what should be my tow rig is an 88 Dodge D250 conversion van that I could use a bit more oomph out of. It was cheap and it's comfortable and has a bed in the back what can I say. <input id="gwProxy" type="hidden"><!--Session data--><input onclick="jsCall();" id="jsProxy" type="hidden">
The Jalopy Journal
