HorsePower Boost?

Modified FSJ Tech Area
Post Reply
User avatar

Topic author
Fast79Chief
Posts: 449
Joined: Wed May 09, 2018 7:10 am
Location: Eastern Pennsylvania

HorsePower Boost?

Post by Fast79Chief »

Hey members, so here we are 2021 and good to see we're still into these Full Sizes. So at this point in this process have we found what the ultimate swap or engine upgrade is to maybe double the factory 360 horsepower? I'm kicking around my options to bring my 79 Chief up to 365-385 horsepower and 400-435 ft.lbs of torque. I know that you guys have the formula by this time, so I thought I'd check with the pros.

Have you guys determined that the factory 360 is or isn't worth the cost to get that much HP out of it? Is there a common wrecking yard engine swap out there that can be done for less than what it would cost to warm up the AMC 360?

Then of course that brings us to the transmission and transfer case. As much as I would like to keep the Quadratrac TC, I need a 4th gear for the transmission too. Have you guys worked out a solution for this problem?

Thanks very much for the info, I'm trying to go in the direction that gives me the most bang for the buck.

Appreciate your help,
Fast
1979 Cherokee Chief S, V8, MSD Pro Billet Distributor with New Factory Ignition Box (are these 2 even supposed to work together?), HEI Wires, Edelbrock 1406, Edelbrock Performer manifold, 3.54 gears, Tru-Trac Locker in the rear, Turbo 400, New Quadratrac, Dual gas tanks, new 32 x 11.50's, Big 9000 winch, Homemade 2.5" full length exhaust, Custom Headlight Harness, Custom front bumper working, Custom Rear Swing-out Bumper, Class V receiver hitch ... and a lot of work to do yet. :)

will e
Posts: 5096
Joined: Sat Aug 18, 2012 8:21 am

Re: HorsePower Boost?

Post by will e »

Still here! What are your plans for the jeep? A daily driver would probably do best with a LS swap. If it's an occasional weekend rig the building up the 360 might be the way to go. The difference is technology. You can get 360HP out of a 360 but to do so you have to cam it in a way that it's going to be a bit thumpy at idle and may be a bit more temperamental than a stock 360. An LS will give a much smoother driving experience but still be able to deliver the numbers you are looking for.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
User avatar

fulsizjeep
Moderator
Posts: 5012
Joined: Sun Nov 06, 2011 7:21 am
Location: Fruitville, FL
Contact:

Re: HorsePower Boost?

Post by fulsizjeep »

Oye, I'm still here and will go with will e on feed back. By the time you bump a 360 to 360 HP, it will probably not be suited well for off-road use. And it won't be cheap.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
User avatar

Topic author
Fast79Chief
Posts: 449
Joined: Wed May 09, 2018 7:10 am
Location: Eastern Pennsylvania

Re: HorsePower Boost?

Post by Fast79Chief »

Yes, reliability is the most important need. I would like to be able to not only drive down to the grocery store but also drive up to the mountains and get to a hunting cabin back in the woods or drive to another state and not have to worry about overheating on the highway or the trail. We know that these 'breadboxes' are heavy and not so aerodynamic, so putting together a combo that has power on tap when needed and can also deliver better fuel economy than a carbureted AMC 360 at highway speeds.

So what combo of engine, TC and transmission has proven to be the simplest to fit into these trucks and be reliable?

Thanks.
1979 Cherokee Chief S, V8, MSD Pro Billet Distributor with New Factory Ignition Box (are these 2 even supposed to work together?), HEI Wires, Edelbrock 1406, Edelbrock Performer manifold, 3.54 gears, Tru-Trac Locker in the rear, Turbo 400, New Quadratrac, Dual gas tanks, new 32 x 11.50's, Big 9000 winch, Homemade 2.5" full length exhaust, Custom Headlight Harness, Custom front bumper working, Custom Rear Swing-out Bumper, Class V receiver hitch ... and a lot of work to do yet. :)

will e
Posts: 5096
Joined: Sat Aug 18, 2012 8:21 am

Re: HorsePower Boost?

Post by will e »

Yeah, if you want big horsepower, drivability and reliability then a swap is the way to go. Seems like the LS is a popular swap. Find a wrecked truck and pull the drive train. There is a lot of info in the modified section of the board. This thread has a lot of good info as well:


https://www.fsjnetwork.com/forum/viewtopic.php?t=1850
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
User avatar

Topic author
Fast79Chief
Posts: 449
Joined: Wed May 09, 2018 7:10 am
Location: Eastern Pennsylvania

Re: HorsePower Boost?

Post by Fast79Chief »

You know how these AMC 360's are low compression, I wonder if a 'power adder' would be a cheaper alternative? Has anyone done a SuperCharger on an AMC 360 and would this be a good alternative for needing HP part time?

I'd like to hear your opinions on this.

Thanks
1979 Cherokee Chief S, V8, MSD Pro Billet Distributor with New Factory Ignition Box (are these 2 even supposed to work together?), HEI Wires, Edelbrock 1406, Edelbrock Performer manifold, 3.54 gears, Tru-Trac Locker in the rear, Turbo 400, New Quadratrac, Dual gas tanks, new 32 x 11.50's, Big 9000 winch, Homemade 2.5" full length exhaust, Custom Headlight Harness, Custom front bumper working, Custom Rear Swing-out Bumper, Class V receiver hitch ... and a lot of work to do yet. :)

will e
Posts: 5096
Joined: Sat Aug 18, 2012 8:21 am

Re: HorsePower Boost?

Post by will e »

Super Chargers are not readily available for these motors. A super charger will tend to make the engine run a bit warmer too since you are compressing the air before it goes into the engine.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
User avatar

Topic author
Fast79Chief
Posts: 449
Joined: Wed May 09, 2018 7:10 am
Location: Eastern Pennsylvania

Re: HorsePower Boost?

Post by Fast79Chief »

Ok, so with the 79 I have the passenger side drop front diff and the off-center rear differential. If I go with an LS swap, what trans and TC will allow me to keep my factory axles? I just rebuilt both so I'm not gonna change them.

Let me know what driveline you would look for to allow the factory axles to stay.

Thanks for the ideas guys.
1979 Cherokee Chief S, V8, MSD Pro Billet Distributor with New Factory Ignition Box (are these 2 even supposed to work together?), HEI Wires, Edelbrock 1406, Edelbrock Performer manifold, 3.54 gears, Tru-Trac Locker in the rear, Turbo 400, New Quadratrac, Dual gas tanks, new 32 x 11.50's, Big 9000 winch, Homemade 2.5" full length exhaust, Custom Headlight Harness, Custom front bumper working, Custom Rear Swing-out Bumper, Class V receiver hitch ... and a lot of work to do yet. :)

rocklaurence
Vendor
Posts: 2565
Joined: Sat Mar 30, 2013 6:53 am

Re: HorsePower Boost?

Post by rocklaurence »

Fast79Chief wrote: Tue Jan 19, 2021 5:53 pm You know how these AMC 360's are low compression, I wonder if a 'power adder' would be a cheaper alternative? Has anyone done a SuperCharger on an AMC 360 and would this be a good alternative for needing HP part time?

I'd like to hear your opinions on this.

Thanks
Yes, thats an option but you have to build it. You can get a Universal Centrifical Charger/Paxton and add 6-8 lbs of boost. Or build a turbo system that provides 7-10 lbs of boost. Each of these would add 100-150 HP and would be cheaper than a SWAP. I'd use a Holley/FITEC Boost-ready EFI systems with timing control. With less than 10 psi you dont have to provide a cooler.

chevelleguy
Posts: 379
Joined: Mon Oct 08, 2012 10:11 am
Location: Hughes Springs, TX

Re: HorsePower Boost?

Post by chevelleguy »

There are two centrifugal kits at this time. The supercharger store has procharger based kits from $4500-$7200 and then there is Torqstorm, which I have never heard of before.
https://thesuperchargerstore.com/c-1389 ... 5-amc.html
https://torqstorm.com/product-category/ ... ingle_amc/
David
'83 Wag Limited, 360/727/pinned 229/D44 front/AMC20,lockrite,rear/6" BJ lift w/ 35/12.50/15 M/T Baja MTZ/ Pro-Jection EFI.

'16 Camaro SS
'98 STX1100 Jet ski
'96 ZXi 1100 Jet ski
'90 KDX 200

rocklaurence
Vendor
Posts: 2565
Joined: Sat Mar 30, 2013 6:53 am

Re: HorsePower Boost?

Post by rocklaurence »

Awesome
Post Reply