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Nick
Dodge Dakota
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12/25/2003
18:49:22
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 Subject: 360 Heads...?
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I was having a talk with my dad a while back about my r/t. He was telling me that he had an early 70's AMC AMX with a high compression 360. From what he told me, the 360 in my truck is similar to the one in his AMX but doesnt produce power like the older ones because of the 8.9:1 compression compared to his 10:1 compression on the AMX. Is this true? From what he says, it makes sense. If so, are there high compression heads available aftermarket for 5.9's?
Thanks,
-Nick
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miller
Dodge Dakota
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12/25/2003
19:13:51
|  RE: 360 Heads...?
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mill your heads at any good machine shop, and it will increase compression.
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Nick
Dodge Dakota
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12/25/2003
19:18:48
| RE: 360 Heads...?
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Ok, I'll look into that more, but is that really one of the things holding the engine back from performing well...? or do I have this wrong?
Thanks again,
-Nick
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Riv
Dodge Dakota
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12/25/2003
19:37:19
| RE: 360 Heads...?
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Your intake is choking the life out of yor engine as well. remember it was designed to be used as a truck, (lots of low end torque) so it doesn't breath very well above 4500rpm. Same as the exhaust it was designed for bottom end torque as well, and chokes the engine too.
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Riv
Dodge Dakota
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12/25/2003
19:42:00
| RE: 360 Heads...?
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Check out the Hughes engine sight, they explain about the intake pretty well, and as for the exhaust, you can go the cheapo route which is what I did, 92 exhaust manifolds, if u can find them, or headers, my manifolds are fully ported and ceramic coated inside and out, for a smooth polished finish, they flow very, very close to most tube headers and actually better than some tube headers(gibson).
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gen1dak
Dodge Dakota
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12/26/2003
00:49:20
| RE: 360 Heads...?
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Heads, cam, exhaust...it's the whole package. The Magnum heads do flow quite well, but compression will make a difference, all else being equal. However, if you were to advance the ignition timing, it'd also improve power. Two engines, all else equal....one high compression, the other lower. You'll get away with more ignition advance in the lower compression engine before detonation occurs. This means more net power. In other words, you'll have more usable power. Going with a good cam will also increase cylinder pressure to build power. None of this requires pulling the heads. Milling the heads is still part of the plan, and is great if you use a high overlap cam which saps lower rpm power by virtue of reduced cylinder pressure til higher in the rpm range. This setup allows for more ignition advance because the tendency to detonate is inhibited somewhat. Put it this way. You can do all sorts of things to build power, but once the heads are milled, you're stuck with 'em.
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Nick
Dodge Dakota
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12/29/2003
09:19:03
| RE: 360 Heads...?
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OK, I think I understand this more. I'm obviously going to replace the intake on my engine soon. I'm trying to find a good deal on a shaker hood because I love how they look. If that fails, I'll go for 360airintakez or whatever.
As for the 92' exhaust manifolds... In stock condition they are better than the ones I have now...? That just seems sort of odd to me, but if what you said is true about the better flow, that'd be the cheapest way out. Thanks for your help...
-Nick
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gen1dak
Dodge Dakota
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12/30/2003
01:25:46
| RE: 360 Heads...?
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The 92's and early 93's had larger inside diameters in the exhaust manifolds, as well as matching crossover pipe leading to the cat. These flowed better, to the tune of 10-15hp over later units including yours. This puts them in an elite class. They're fairly rare. All later manifolds were somewhat smaller to help lower rpm torque a bit, but at the cost of upper rpm hp. Seems weird, but we're talking about corporate mentality (they claim it was in response to customer feedback---yeah, right). They also made the cams lazier at the same time, but kept lift figures the same. A '92 318 Dak, bone stock with 3.90 gears, would click off 14.90's all day long.
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Nick
Dodge Dakota
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12/30/2003
16:46:22
|  RE: 360 Heads...?
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Sweet, I'll be checking the yards around here in the next few days for 92 or 93 manifolds. Thanks guys, I appreciate the information!
Oh, one more thing... I know this is dumb, but how do I know if the truck is a 92 or 93?
Thanks,
-Nick
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gen1dak
Dodge Dakota
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12/30/2003
22:33:52
| RE: 360 Heads...?
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If the truck is intact at all, it'll have a tag in the engine compartment, and another in the driver door (you'll see it when you open the door). The door tag usually has info about vehicle loading. The engine compartment tag will say the engine size and has a statement that the vehicle meets all emissions requirements "for 1992 vehicles..." Either tag will have the vehicle year on it. That's the easiest way I know of. The inside diameter is something like 1 7/8 inches on later units, but around 2 1/8 inches for the early units. Remember, you need the matching crossover pipe that ties into the cat. converter to get full benefit.
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EBL
Dodge Dakota
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12/31/2003
14:02:24
| RE: 360 Heads...?
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Crossover pipe? I haven't seen one on my 92 that I can remember. My pipes leave the manifold and go straight down to the Y. After the Y they are 3 inches back to the cat. (I believe the newer ones are a smaller diameter.)
Where is the crossover pipe? I don't believe the system was modified since I had the original exhaust system on my truck when I removed it 2 years ago.
Another way to check the year of the truck is to check the date stamped on the block. My engine was made in December 91. If the salvage yard has one that is made later than mid way trough 93 I bet you are looking at a 94.
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gen1dak
Dodge Dakota
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12/31/2003
20:58:30
| RE: 360 Heads...?
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Okay, I'm talking about the pipe(s) that run between the manifolds and the cat. However it's assembled, they/it match the manifolds and should be used. When I stated "crossover" I had the driver side pipe in mind since it "crosses over" to the cat. on the passenger side.
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Jim Z
GenI
1/01/2004
11:06:34
| RE: 360 Heads...?
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"He was telling me that he had an early 70's AMC AMX with a high compression 360. From what he told me, the 360 in my truck is similar to the one in his AMX but doesnt produce power like the older ones because of the 8.9:1 compression compared to his 10:1 compression on the AMX. Is this true?"
They're only similar in that they both displace 360 c.i. The AMC 360 was an entirely different motor than the Chrysler 360.
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R/TBlues
Dodge Dakota
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1/21/2004
21:22:45
| RE: 360 Heads...?
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Thanks Gen1, I always new the 92's & 93's were faster because I owned a 92,93 and 94. The 94's were DOGS! I totaled my 93 jaust after installing a custom made cam from Brown's. The insurance cut me way short on payoff and I got a 94 to replace the 93. I was never so dissapointed in all my life. My 92 was a 4X4 CC 5.2L auto and it would run all day in the high 15's. My 93 was a 2WD CC 5.2L auto and it would run high 14's. The 94 was a 2WD CC 5.2L auto and the best it ever ran was a 16.4sec. It typically ran 16.8's. It SUCKED!!! But it also average 4mpg better than the 93 or 92. I think there is more to that than the exhaust manifolds. That is a good tid bit of information though.
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for jimZ
Dodge Dakota
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1/24/2004
08:13:35
| RE: 360 Heads...?
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hey bonehead he NEVER said they are the same engine only SIMULAR just like the boss 302 and the 302 chevy built for can am and scca racing. same displacement and simular hp and torque, but not the same block, both using pushrods. both of the 360's had the same bore and stroke and cylinder spacing and.......
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R/TBlues
Dodge Dakota
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1/24/2004
21:15:18
| RE: 360 Heads...?
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How many of you here are AMC experts? AMC and Chrysler are more simular than you think. As a matter of fact parts and pieces of the current "Magnum" head design was copied from AMC. The 60's and 70's AMC cars ran TORQUEFLIGHT transmissions! The heads on the small block AMC were nearly identical to the small block Dodge except that the AMC ran Chevy style rocker arms with hollow push rods for the oiling (Walla! 1992 Magnum head). When Dodge developed the Magnum engine they used the AMC small block as their starting point. Anybody who has been a Dodge whore for more than 30 years like myself knows all of this already.
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gen1dak
Dodge Dakota
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1/24/2004
23:26:34
| RE: 360 Heads...?
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R/T, seems to me, they used the LA block as a starting point, and the AMC stuff as their destination. Also, like you said, it was more than just the exhaust. The cams, while retaining the same lift, were less aggressive in the later daks. This roughly coincided with the change in exhaust.
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R/TBlues
Dodge Dakota
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1/24/2004
23:42:16
| RE: 360 Heads...?
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Gen1, I meant to say they adapted some of the AMC'c head/block configuration into the LA block to make the "Maganum".
I figured something like a smaller cam was to blame for the piss poor performance of the 94-96Daks. Why did DC advertise the later models as having the same HP and Torque @ the same RPM as the 93's? The difference was like daylight and dark. I picked up my 94 after totaling my 93 and I pretty much bought it sight unseen. It was supposed to be the same truck right? NOT!!
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Nick
Dodge Dakota
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1/25/2004
09:40:52
| RE: 360 Heads...?
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R/TBlues,
Thats some interesting AMC info. My dad used to love them. I thought he could be right about them being similar engines. Obviously, a design 30 years later isnt going to be identical... but he swears the 360 in my truck 'sounds' and 'feels' like hes back in his old AMX. Thanks for the enlightenment man, I'll pass this info on to my dad.
-Nick
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gen1dak
Dodge Dakota
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1/26/2004
00:50:25
| RE: 360 Heads...?
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R/T, I figured that's what ya meant. Ahh, who knows why they advertised the same numbers. Probably didn't want to look like they were losing ground in the power race. They just had to go and shoot their foot AGAIN!
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