Mod's for a 360

[prariepunk]

Does any body know if they make a supercharger for a 360? What mod's would you suggest for low-end torque? I don't like the "screamer" engines. Also, what exhaust sounds good, I want a real low "lug lug lug lug lug lug lug" sound. any help? I know there are some pretty serious gear-heads here!

 

[Junkpile]

RE: headers

What kind of supercharger? There are parts out there to use Roots style blower on it. You could fab a blow-through turbo setup for it, but that's alot easier said than done.

For a good low-rpm 360:
1. The factory heads are all you need, so don't waste money there
2. A good short rise dual plane intake manifold, like the Edlebrock Performer
3. Headers, pretty much any set that bolts up will do the job. 2.5" dual exhaust
4. Use a camshaft along the lines of Comps 260H grind.
5. Any electronic ignition that you can get to work.

An AMC 360 is an easy one. It's a great engine after you rip all of the emissions crap off of them and perform a few basic mods. I'd step it up a little bit if I were you. That combo above will be easy to live with and pull hard in the low-mid range, but in a light little SWB you can safely step it up a little and make lots more power. Especially now, before you have built the rest of the truck. Things like camshaft selection depend heavily on the rest of the vehicle setup. You can build the engine any way you want(to a certain degree), and then setup the Jeep to best utilize the engine.

 

[LBR]

Yep......what Junkpile asked.......which type of supercharger are you wanting...roots or centrifugal? LBR

 

[prariepunk]

carb mounting studs on manifold help swapping carbs

Eh? Um.... uh......... hmmmm......... I dunno, the SC was more of a standard performance add-on, I know nothing about them...... Do they offer them for a 360? As I said before I know NOTHING about them!

 

[Junkpile]

RE: jacking points

A supercharger is mechanically driven by the engine. There are two basic types in the automotive world. The old school Roots style blower and the centrifugal types. The Roots blowers are the ones that have that classic look where it pokes through the hood. The blower itself sits on top of a special intake manifold and the carb(s) sits on top of the blower. The centrifugal style are the ones like are common on late model cars. They mount in front of the engine and are plumbed into the air intake system. With a carb, a centrifugal would be used as a blow through design where the boost is introduced before the carb. A roots is the way to go here. The newer mini-blowers that are on the market are not available for the AMCs as far as I know, which REALLY sucks. It shouldn't be hard to find a used 6-71 blower and intake for an AMC V8 if you are really seroius about it.

A turbo system isn't an impossibility. Instead of being driven by the engine's crankshaft, they are driven by the exhaust gasses. It's a more efficient way of making boost, but it's just different than a SC. The SC makes power in a linear fashion from idle to red line, where the turbo has to build boost and then comes in harder in a narrower rpm range. The SC is more inline and well suited for offroading activities.

How much power do you want? :shock: What are you using this Jeep for again?

 

[prariepunk]

TB help please

I wouldn't want a blower incase I happen to find mud....... while looking for mud :twisted: I'm not sure what my 360 dyno's @ right now, but I'd like it to be over 300hp..... what's the performance differance between HP and Foot Pounds of Torque? I'd like to be (oh god, hit me now) "a little bit country" and "a little bit rock 'n roll", I am so sorry for... [shudders]that[/shudders], what I mean is I love mud (I just like "mud" on jeepz) but I also want to try rock crawling. I have a good gusse that a CJ-5 is a little too short for rocks, oh darn, now I have to talk Mrs. Punk into a CJ-7 or wrangler :twisted: As you already know I plan to run 39" Boggers under it and after much evaluation just a "K.I.S.S." SOA. Woud an FI system be a good investment.... do they sell 'em under $1000? Keep in mind I'd like to be emmissions legal..... that kinda sucks horses outta the motor...... I ran across some picture I took of the Jeep when I first brought it home and it was kinda like looking back on an old girlfriend (the good looking back that is)...... man, I damn near cried! I miss driving her on the road.........

 

[Junkpile]

what's the performance differance between HP and Foot Pounds of Torque?

Two different measurements that depend on each other to do the job of moving the vehicle. Torque is a measurement of force. The twisting force on the crankshaft.....and in turn the drive wheels. Torque is the measurement of force that the engine can apply towards turning the wheels. Horsepower is the measurement of how much work it's doing with that force.

To find the power of an engine just takes a simple math equation using a few known variables. The formula is: Horsepower= (torque*RPM) / 5252

Let's take the old 258 for an example. We know it produced 210# of torque at 1800 rpm. So to find horsepower at 1800 rpm simply takes:
(210*1800)/5252 = 72(rounded) Horsepower@1800rpm

To dispell the theory that torque does it all, lets modify that torque curve a little. Let's say that 258 still makes a peak torque of 210#, but now it does it at 4200rpm. If you plug those into the equation:
(210*4200)/5252 = 168(rounded) Horsepower@4200rpm

Peak torque stayed the same, but horsepower jumped dramatically by raising the rpm at which that torque peaks. The second example would be a much faster Jeep than the first, even though torque output didn't change.

The perfect setup would seem to be where you shift at the rpm immediately after peak horsepower is produced, and the next gear starts pulling right as the engine drops to the rpm at which it produces peak torque.


I don't think anyone really understands it......I just made all of that up :lol:

 

[prariepunk]

Did you make all that up or is it some mathmatic language that only math geeks understand?......
Go slow, I'm slow......... HP = (TORQUE x RPM) / 5252.........? Where did 5252 come from? or is it some mystery number like pi? (3.14 blah blah blah) Doesn't both torque and HP change from old engine to old engine? Mine is different from let's say my buddy Scott's, smae engine but theoreticly they wouldn't produce the same #'s, right?

 

[Junkpile]

Does anybody know of a 4X4 podcast?

Well, I confused myself before I finished that and forgot to include a couple of key points. Like......Both of the examples would produce peak HP at a higher rpm than used in the example, because the torque curve doesn't immediately drop after it peaks, and HP raises with rpm. Even though the engine only produces 72 horsepower at torque peak, it will more than likely produce more horsepower at higher rpms even though the torque output has dropped.

Lets say the torque drops to 190 at 3000rpm

(190*3000)/5252 = 108.5 horsepower
Lower torque output, but higher HP because of rpm.

The 5252 is just the constant for this particular equation. I'm no math geek either, I just know what to plug into the part of the formula that I deal with. A web search would reveal the process used to reach that number.....

A neat little bit of info is that ALL engines will have a torque output equal to it's HP output at 5252rpm.

 

[prariepunk]

RE: Emmissions for a V8ed CJ

but other than intake mani and cam shaft B.S. is that it? I'll be doing more mud than anything....

 

[Junkpile]

Nah, there's lots of stuff you can do.

My 304 is pretty basic for an entry level mid-high rpm "horsepower" engine. It's got shaved and ported big valve heads with shim style gaskets, converted to screw in studs and guideplates, lightweight valvetrain hardware, Magnum roller rockers, Comp Magnum 280H camshaft with matching lifters and springs, electronic ignition conversion, port matched R4B "group 19" intake manifold, long tube headers, Holley 650(eddy 600 right now :roll: ), and.....well, that's about it for "speed" parts. Some other stuff that relates more to durability, but not really required to make the numbers.

It should produce about 330 lbs/ft @ 4500rpm and in the neighborhood of 320hp @ 6000rpm, and it's got about as flat of a torque curve as a little 304 can have at that power level. I have no dyno numbers for this engine, but it's based on a known example. It actually feels alot stronger. It's got perfect response across the board and will rev to the moon in a second......which isn't good with a factory 304 bottom end and hydraulic lifters :lol:

 

[prariepunk]

RE: Re: RE: What President Bush

Nah, there's lots of stuff you can do.

My 304 is pretty basic for an entry level mid-high rpm "horsepower" engine. It's got shaved and ported big valve heads with shim style gaskets, converted to screw in studs and guideplates, lightweight valvetrain hardware, Magnum roller rockers, Comp Magnum 280H camshaft with matching lifters and springs, electronic ignition conversion, port matched R4B "group 19" intake manifold, long tube headers, Holley 650(eddy 600 right now :roll: ), and.....well, that's about it for "speed" parts. Some other stuff that relates more to durability, but not really required to make the numbers.

I have no dyno numbers for this engine, but it's based on a known example

which isn't good with a factory 304 bottom end and hydraulic lifters :lol:

1: I am "motoriticaly" illiterate.... all the stuff in the first part made me go cross-eyed.... from what you said, I understood: camshaft, lifter & springs, electronic ignition conversion, Holley 650/eddy 600, intake manifold & headers. What are.... shaved and ported big valve heads with shim style gaskets, converted to screw in studs and guideplates, lightweight valvetrain hardware, Magnum roller rockers, Comp Magnum 280H camshaft with matching lifters and springs, port matched R4B "group 19" intake manifold & long tube headers? I'm sorry, I'm not much of a gear head but I'm really interested in learning

2: Do you have a known example for a 360?

3:

which isn't good with a factory 304 bottom end and hydraulic lifters :lol:

what is a bottom end and hydraulic lifters?

 

[Junkpile]

RE: Emmissions for a V8ed CJ

What are.... shaved and ported big valve heads with shim style gaskets, converted to screw in studs and guideplates, lightweight valvetrain hardware, Magnum roller rockers, Comp Magnum 280H camshaft with matching lifters and springs, port matched R4B "group 19" intake manifold & long tube headers? I'm sorry, I'm not much of a gear head but I'm really interested in learning

You already have the same head casting that I do. I'm using 79 360 castings. The shaving and thin headgaskets are to raise the compression. The porting is basically just making the intake and exhaust ports bigger so they flow more. Including the $100 purchase price from the junkyard for the castings, there's right under $1000 invested in the cylinder heads. That's with me doing the port work and assembly, but it's muuuuuch cheaper than aftermarket. The 304 heads have smaller valves and ports and aren't up to making big power.
The screw in studs and guideplates are a pretty common conversion for any engine that sees some rpm or runs a big cam. The factory rocker arms are on a bridged pivot, and are secured with capscrews. The screw in studs provide a more solid anchor point.
Magnum roller rockers are made by Comp Cams. They are roller tipped rocker arms. While they don't have the roller trunnion that full roller rockers have, they still free up some ponies from the reduced friction on the valve tip and guides. The bodies of the rockers are also made from cast chrome-moly, not stamped steel like the factory arms. This makes the rocker more rigid which reduces variations in effective rocker ratio. The Magnum 280H camshaft is just a cam grind offered by Comp Cams. It has 280 degrees of advertised duration, and the "H" means it uses a hydraulic lifter. By "springs", I mean the valve springs
The intake manifold that I have for it is an Edelbrock R4B. It's off the engine right now for cleaning and polishing. I have a regular old Edlebrock performer on it right now. The Edelbrock R4B is an intake design that AMC used in some of it's factory backed racing programs "back in the day". This intake is older than I am, and I'll be 30 next Friday.
I'm just running old cheapo Hedman full length fenderwell headers. I'll be switching to in-frame headers soon, these just went on because I already had them. I want some of the new Edelbrock shorties.

Do you have a known example for a 360?

Yes, but I'll have to find them. I would supposedly be making about 400hp if I switched my combo over to a 360 block.....I don't know though. My engine needs freshening anyway, and there is no way I'm using a 304 block again. I've got a complete 74 401 that I might send to the machine shop and then put my heads on, with a slightly larger cam.....after I get the rest of the POS Jeep back going.

what is a bottom end and hydraulic lifters?

The bottom end, the lower end, the reciprocating assembly.....The crankshaft and rods in a 390 or 401 are forged, which is better for heavy loads and higher rpm. The smaller engines, 290-304-343-360, use lighter duty cast components.
The lifters are what ride along the camshaft lobes and actuate the pushrods, which lift one end of the rocker arm----causing the other end of the arm to open the valve. Hydraulic lifters can't take as much load or rpm as a solid lifter. Hydraulics are easier to live with as they don't require adjustment. I'd really like to go with a roller cam, where the lifters have a roller tip that rides the camshaft lobe, but that's expensive.

 

[prariepunk]

How much would having it ported and polished cost (average)? Would a lifter kit be a good one on its own or do I have to have another mod accompanying it?

 

[judge09]

RE: Headed north

prarie....it sounds like your going to be biting off alot getting into all the mods we are talking about here. Esspecially for a "motoriticaly illiterate" ...hahaha. Looking back at your original post if your looking for a little more torque and the glug glug glug sound you dont need a supercharger or anything crazy. Get a performance intake, some headers and flowmaster mufflers for the sound and for more torque, change your gears out or you can pretty easily add power to your engine with the right cam and lifter set up.

 

[Junkpile]

RE: Power on the 2.5?

How much would having it ported and polished cost (average)? Would a lifter kit be a good one on its own or do I have to have another mod accompanying it?

A mild porting can be accomplished fairly easily if you have a die grinder. Standard Abrasives makes a kit for doing it that includes what you need if you aren't sure. There are several printed and internet resources that explain the process. You can do it in stages sort of. A mild porting would include smoothing the ports and bowls and just cleaning up the castings. The equipment to do it and a spare set of junkyard heads is still going to be cheaper than paying to have it done. I don't even know what someone at a shop would charge but it's so time consuming that it can't be cheap.

There's no point in getting new lifters unless yours are damaged or you do the camshaft swap. When you swap cams, you MUST install new lifters.

 

[prariepunk]

Well I don't have to run cat's on it, [joking]but if I could I'd like to up the HP in a budget-like fashion [/joking]