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400+ HP 360 Build |
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WhatISit
AMC Addicted Joined: Aug/07/2017 Location: Phoenix, AZ Status: Offline Points: 0 |
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Posted: Jun/15/2018 at 4:52pm |
I'm in the early stages of building a hot 360...
I'm trying to save a little money where I can without hurting the build, but I would really like to get 450 horsepower--on 91 octane pump gas. I have lots of questions and lots of research to do before I start buying parts. Here's a start: -Edelbrock heads--worth the money on a build like this? Or should I just use factory heads with some work done on them? -Hyperuetectic or forged pistons? (I need different options and their parts numbers) -Maximum compression ratio? -Torker or Airgap intake? |
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purple72Gremlin
AMC Addicted Charter Member Joined: Jul/01/2007 Location: Illinois Status: Offline Points: 16614 |
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Forged. Not qualified to say on edelbrock heads, but I would run them....and torker. 450HP? Wont be very street friendly.
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WesternRed
AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Offline Points: 5808 |
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You probably need to work on 3 main factors, compression, cam and heads.
Most 360's are relatively low compression 8.5:1 and for a performance build you really want a bit more. The easiest way to boost compression is to swap out the factory dished pistons for something that generates more compression, however piston choice is a bit limited for AMC engines. It's pretty hard to go past a set of Wiseco forged pistons which offer either a smaller dish for a little bit more compression or a flat top for a lot more compression. The biggest downside with these pistons is that they are only available in +0.030" and +0.045", which may not suit your particular build. You also have the option of 343 flat top pistons, which is one of the oldest AMC hot rodding tips in the book, but that are only available cast and not really that much cheaper than the Wiseco forged pistons. Heads, I'd say that the factory heads are almost capable of supporting 450 HP without being touched, but a good valve job and some mild port work will certainly help your cause. Edelbrock heads are a good way to get something equivalent to a mildly ported factory head and are a great option if you don't have a good set of factory heads to start with. There are plenty of other advantages to the alloy head as well if they are within you budget. Cam basically needs to be matched to the rest of the combo to achieve your goals, probably best to seek expert advice here. I think the Air Gap and Torker are both good for 450 HP, Air Gap will be a little better at low RPM and the Torker will be a little better at high RPM. It goes without saying that you will need a decent exhaust and the right carby to get there.
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WhatISit
AMC Addicted Joined: Aug/07/2017 Location: Phoenix, AZ Status: Offline Points: 0 |
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Yea, I'm thinking Holley 750 carb and Air Gap. 450 might be a little loft of a goal, especially because I don't really want to hit 6500 rpm to get that number. I have a built 998 with a 3000 stall converter right now, so I'll probably be looking at a cam that has a 2000-6000 RPM range.
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6909 |
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Thoughts are budget, compression, cam RPM range and if this is street, drag or both and gearing as stated. Others can input but this is my take-
If you want to use pump gas then 10.5:1 to 11.0:1 would be your maximum compression - but maybe others that can get more. 10.5:1 would be quite street-able. Now after you find the compression that pump gas can achieve you look at the pulse or heart beat - cam. On pump gas near 0.0520" and 108 to 110 duration seem to be the option most are happy with. More lift would be dual springs, Edy heads ... that should not be not required to get 450 HP. The block will take the HP but you will need the pistons to get the compression and then everything else should fall into place. Once the compression and cam are chosen then Carb/EFI and exhaust. Headers add 20 HP over ported/cleaned cast free flows from what I've read. Too big on the headers may actually loose HP. 1-5/8" or 1-3/4" should be very close. Dual 3" H pipe to muffler and 2.5 " from there back should be close. RPM dictates air gap - lower vs torquer -higher. 450 HP the torquer seems the choice with pump gas. It will not idle nice but sounds better then the factory radio. Don't undersized the carburetor - 650 Holley should be in the ball park. Take a look at some Jeep sites and 360 builds, they spec out everything for 450 HP. Edited by Trader - Jun/16/2018 at 6:37am |
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Boris Badanov
AMC Addicted Joined: Dec/14/2013 Location: NH USA Status: Offline Points: 4210 |
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Eddelbrock heads are a cost effective solution.
Get the ones with no manifold heat. Eddys are little more expensive than rebuilding a set of iron heads and save about 40 lbs. That and an aluminum intake save nearly a hundred lbs. I will venture a guess that to do what you want a cam in the 250 deg @ .050 lift range and 11:1 compression will do the trick. A 650 cfm carb and a Torker or a 750+ and a dual plane for an intake. A Quick Fuel "Holley" is my recommendation or an Eddelbrock (or two). Set the quench tight(.035-.040) with a reverse combustion chamber piston will keep the detonation issue under control. Stock rods and crank will do fine with ARP or similar rod bolts. The above list should easily deliver 400+ HP on a dyno. Edited by Boris Badanov - Jun/16/2018 at 12:09pm |
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Gremlin Dreams
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19686 |
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If you're going over 10:1 compression use the Edelbrock heads. The aluminum heads will tolerate at least a half point more compression than iron due to the better heat rejection (run a bit cooler).
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Frank Swygert
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Red Devil
AMC Addicted Joined: Jul/10/2007 Location: Canada Status: Offline Points: 1743 |
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Check this 343 build by jcisworthy:
http://www.theamcforum.com/forum/pump-gas-343-on-dyno-today_topic83434_page1.html 220/232 @ .050, 112LSA in at 109, .568 lift, Doug's headers 1 7/8 primaries, 10.36 compression, Edelbrock air gap intake, ported factory iron heads. 455 HP @ 6K. 446 ft-lbs @ 4K |
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