good replacement for a 360

[sonofasailor19]

ive got a '90 gwag and am looking to replace the engine for better performance/gas mileage. possibly a small-block chevy. anyone have any advice. thx

[Jeepasaurus]

I can't imagine getting better gas milage with better perfomance but maybe a little. The 360 can be done nice and the 401 better. I would put the money into a good rebuild instead of adapters to switch engine brands. Remember Jeep engines for Jeeps. Just my thoughts.

[ January 01, 2004, 03:47 PM: Message edited by: Jeepasaurus ]

[Crazy_Jeepman]

Lots of swaps have been done, with your 90 Mopar would almost be as easy as it gets, no adaptors would be needed, just a matching TF727 to your Chrysler Motor of choice. Motor mounts and Radiator, exaughst ect, would all have to be dealt with. Depending on what performance you are looking for and how much you want to spend would be your only limit. If you plan on this swap to gain MPG, then forget it, you will not see a increase enough if at all to make the swap worth while. Don't worry about Jeep Motors Only in Jeeps.............Jeep could not even decide what motors, or parts of them to use. LOL! Welcome to the Forum by the way! smile.gif

[Elliott]

About the only way to get better mileage is to go diesel and the cost of that negates the gain. Nothing you are going to build in a GM gas engine is going to get you better mileage or performance then what you can build into an AMC motor. The AMC rebuild will cost a little more, but you don't have to modify anything. There are stock to performance AMC crate engines you can pick up starting at ~$1,500.
Jeep dumped the GM products, good move IMO. :D

[Crazy_Jeepman]

Originally posted by Elliott:
Jeep dumped the GM products, good move IMO. :D LOL Yea and look where Jeep is now! Jeep going to AMC was the downfall of Jeep LMAO. tongue.gif

[Elliott]

I wonder if Mark Donahue would agree?

[Elliott]

Oh yeah... welcome aboard sonofasailor19.

[ulm210]

Originally posted by sonofasailor19:
ive got a '90 gwag and am looking to replace the engine for better performance/gas mileage. hahahahahahaha!

[gbarrett]

I stripped my 84 GW of the stock drivetrain and went Ford 351/C6. Easy swap and now I can get parts everywhere. It wired up to the stock Jeep harness since Jeep used Ford sparkboxes.

[Elliott]

7.5 Liter Caddy V-12? The new replacement for displacement.
http://www.trucktrend.com/roadtests/suv/163_0302_cadillac/
http://www.trucktrend.com/truck/roadtests/suv/163_0302_cadillac02_s.jpg

[ January 01, 2004, 05:54 PM: Message edited by: Elliott ]

[Sycho15]

Use www.customefis.com (http://www.customefis.com) Fuel-injection kit on a fresh engine for the best mileage.

Oh and superchargers improve mileage if you can keep your foot out of them.

[gsmikie]

i like the 8.2 caddy

[sonofasailor19]

so there is no way to get over my present 6-8 MPG unless i rebuild the engine?

By the way- I have a fuel projection system on it, but not too sure of the specifics as it was put in before me

[ January 01, 2004, 06:44 PM: Message edited by: sonofasailor19 ]

[Knucklehead]

Originally posted by sonofasailor19:
so there is no way to get over my present 6-8 MPG unless i rebuild the engine?
Something is wrong there. I get between 12 and 19 in my J10 with 33" tires, loaded and driving 70mph. It is rebuilt and a little over stock. But it did on good on mileage before I rebuilt it , and it was way shot.

Is it using oil? Had a tune up? How many miles on the clock? New timing chain?

I love Chevys. But AMC has one of the best flowing stock heads out there in CFM and port velocity. The weakness in the AMC motor is those stupid CAST conecting rods, a lack of a good selection of pistons and that stupid oil system. And the oil system can be modified very easily.

In a wagoneer which is loaded (I assume) I would stick with the 360 and fix it up.

[Jeepasaurus]

I get between 12 and 19 in my J10 with 33" tires, loaded and driving 70mph That must be down hill both ways. lol

[Knucklehead]

[/QUOTE]That must be down hill both ways. lol[/QB][/QUOTE]

That is on I70 between Denver and Rifle with Isenhower tunel and Vail pass (going 70 mph). I have to admit that the thin air up here helps with the wind resistance and I run the carb a bit on the lean side and a lot of timing.

It does use a lot around town where it it is up hill every where I want to go...

What is funny is that the J10 gets better mileage than my wifes 4runner pos. And it will smoke the tires too. the toter couldn't get out of its own way. So I bought her an 79 Chero the other day. When she gets back and sees it, that will be funny. I might have to sleep in the shed for a while...

[Elliott]

Originally posted by 66HD:
</font><blockquote>quote:</font><hr />Originally posted by sonofasailor19:
so there is no way to get over my present 6-8 MPG unless i rebuild the engine?
Something is wrong there. I get between 12 and 19 in my J10 with 33" tires, loaded and driving 70mph.
The weakness in the AMC motor is those stupid CAST conecting rods, a lack of a good selection of pistons and that stupid oil system. And the oil system can be modified very easily.
</font>[/QUOTE]The 401 has forged rods (and crank).
Something is wrong... big time if you are only getting 6mpg. You can get a good 10mpg out of a worn 401 with a 4bbl, 360s run slightly better.
Unless you are dripping fuel past the pistons into the crank case (which you would be aware of pretty quickly) your problem is in that fuel projection system and it's costing you performance as well as mileage.
What manifold do you have on it, stock or Edlebrock?
If you aren't low on compression or blowing oil I'd say swap on another carb. I don't trust the fuel injection systems to give you bottom end torque anyway... maybe Indy has one that works well at low end, but it seems to me that carbs have the advantage down low and so what if they are thirsty... for what a new fuel injection system will set you back you could build a nice motor.

[Knucklehead]

[/qb][/QUOTE]The 401 has forged rods (and crank).
[/QB][/QUOTE]

Yeh, I forgot about the 390 and 401. Wish I had one of those.

I Agree, It is prolly the projection.

[carrotman]

Hot Rod Magazine did a build up of a 401 in their July 1998 issue. They spent $3600 to get 521 HP at 6,500 and 508 lb-ft of torque at 5,500.

Rod & Custom Magazine did a build up of a 360 in their July 1988 issue. They used a PAW rebuild kit and based on the cylinder head flow and cam selection, they estimated 400 HP and 450 lb-ft of torque. The stock 360 head outflowed a stock 1992 Chevy LT-1 aluminum head.

With their engines, little AMC set numerous speed and endurance records, won two Trans-Am championships, won NASCAR, and even ran at Indy.

[Joe J-Truck]

I'd like to suggest a 4.0 injected engine swap... reliability, torque and economy... obviously not as much power as a well built v8, but those use ALOT of gas and there's not much you can do about that.

I always thought it would be cool to do a 258 with the 4.0L injection setup..

[Rick@battlement]

Originally posted by 66HD:
That must be down hill both ways. lol[/QUOTE]

That is on I70 between Denver and Rifle with Isenhower tunel and Vail pass (going 70 mph). I have to admit that the thin air up here helps with the wind resistance and I run the carb a bit on the lean side and a lot of timing.
What Engine is in this 19 MPG FSJ??????

[Crazy_Jeepman]

Yea I been driving FSJ's forever, and I can say you can count on 10 MPG on average. Somedays more some less but when the tank is empty its 10 MPG.

[Brown Bear]

YOU PEOPLE NEED JOBS! GET OUT AND PLAY MORE AND PULL YOUR PANTIES OUT FOR GOD'S SAKE.

[Knucklehead]

[/QUOTE]
What Engine is in this 19 MPG FSJ??????[/QB][/QUOTE]

It is a 360. With edelbrock intake and carb. Mild cam (same spec as performer) which I will replace with a comp cams XE series soon.

The best part is not the MPG but going 70 in high gear between geogetown and the tunel (up hill).

[ January 01, 2004, 09:35 PM: Message edited by: 66HD ]

[Retro93]

Originally posted by gbarrett:
I stripped my 84 GW of the stock drivetrain and went Ford 351/C6. Easy swap and now I can get parts everywhere. It wired up to the stock Jeep harness since Jeep used Ford sparkboxes.Still awaiting picures of your swap. :D We need a look see.

[Crazy_Jeepman]

Originally posted by Elliott:
I wonder if Mark Donahue would agree?Hard telling.........Since he is #1 no longer with us, #2 AMC was not the only car he raced or drove, #3 who cares tongue.gif

[82wagonlimtd]

wow Nate... "For Gods Sake!" I knew you'd come around eventually. tongue.gif tongue.gif

[ January 02, 2004, 05:36 AM: Message edited by: 82wagonlimtd ]

[Lindel]

Another option (one I'm going to be using) would be to use a brand spanking new LS1/4L60E, and using a 4x4 4L60, your NP229 should be a bolt on.

These engines are available from G and R Auto Parts out of OKC. www.gandrautoparts.com (http://www.gandrautoparts.com) for about $3500, including the computer, wiring harness, Fuse block, engine and tranny. Only 4 wires to connect and disabling the anti-theft program in the computer.

That would still leave the motor mounts and exhaust to deal with, but you'd have fuel injection, good power and reliability. BTW, my 03 Silverado avgs about 19.5mpg with a 4.8L LS1, so I would imagine a FSJ with a 5.3L LS1 could net about 18mpg on the highway!

[GWDriver]

Please,..........PLEASE send pics of the swap.

[Elliott]

Originally posted by carrotman:
Hot Rod Magazine did a build up of a 401 in their July 1998 issue. They spent $3600 to get 521 HP at 6,500 and 508 lb-ft of torque at 5,500.

Rod & Custom Magazine did a build up of a 360 in their July 1988 issue. They used a PAW rebuild kit and based on the cylinder head flow and cam selection, they estimated 400 HP and 450 lb-ft of torque. The stock 360 head outflowed a stock 1992 Chevy LT-1 aluminum head.

With their engines, little AMC set numerous speed and endurance records, won two Trans-Am championships, won NASCAR, and even ran at Indy.Yep, and on top of that I don't think you'll ever read about a Ford, Mopar or GM small block doing 192mph normally aspirited or 216mph blown.... That's an AMC thing! ;)
A small block 8.26 1/4mi is the AMC record. :eek:

Now, back to mileage.... that 4.0 injected is not a bad idea for that realm.

[ January 02, 2004, 05:42 PM: Message edited by: Elliott ]