gen 3 hemi swap in a j body?

[MiradaMegacab]

904/727 bolt upto a gen 3 Hemi(5.7 / 6.1) using a Mancini or ATI flexplate

 

[jasperjacko]

That hemi can get way better mpg at the same power level as a carb. I would love to do a efi turbo in the Modoba. Who knows?.....

 

[kkritsilas]

There was a Youtube video of somebody who did that exact change. Fairly involved from last time I watched it. G3 Hemi has much better heads, and many years to experience as to what works and what doesn't on small block V8s, as well as G1/G2 Hemis. However, it remains that there is a substantial amount of work to do to get a G3 Hemi into our cars for the reward to be had. If you want to do it as an exercise, or to investigate the benefits of a Hemi in our cars, then feel free. If there are budgetary constraints though, the Magnum, or Magnum headed LA block, combined with a 4 speed auto, is probably far more cost effective. Jasper Jacko is probably right, the G3 Hemi combined with a 5-6-8 speed automatic will get significantly higher gas mileage compared to a hotted up Magnum/LA and 4 speed. You can add third party fuel injection to the Magnum/LA, and maybe get some of the gas mileage back, and improve the driveability as well, but you probably not get the same mileage and power as a G3 Hemi and its automatic. On the other hand, if you hook up the carbed Hemi to a 4 speed auto, the mileage improvement vs a Magnum/LA will be somewhat reduced, The other point is to see what the powerband of the Hemi is like compared to the Magnum/LA. As many have pointed out, the power band of a lot of modern engines is relatively narrow, and band aided by 5-8 speed automatics.

There are testimonials that say that you can gain some HP with an add on fuel injection, but I think that those are somewhat exaggerated. Even the claims are talking about a 10-20HP gain, and I think that the most would be 5-10 HP (i.e. not really noticeable), if that. I do think that mileage will increast by 1-2 mpg. (vs. a well tuned carb.), and driveability will improve.

My take on this has been stated above. Just talking theory/bench racing here.

Kostas

 

[Joe12459]

The guy you're talking about actually put a Mirada body on a late Charger frame, much more involved than my project. If you search SRT8 Mirada, you'll find that he has documented the whole project. Very detailed and interesting.

You're right, if you just want to increase the performance of an F/M/J body, there are a lot of cheaper and easier ways to do as well or better than a gen 3 Hemi. And obviously, as an investment, the time and money spent on a car worth a few grand makes no sense. But, it will be a really fun, unique car to drive, and it should be as reliable and driver friendly as a new car.

 

[Greg55_99]

A few years ago, a guy from Canada, Woody, had a way to "dumb down" a Hemi for swaps. Don't know what happened.

Greg

 

[kkritsilas]

MSD makes a HEMI 6 ignition box/controller that can fire the coil on plug spark plugs on the Gen 3, no distributor needed. It uses the factory crank position sensor as an input.

Kostas

 

[Mcfly68]

This isnt that hard of a swap. Most of the same things that work on the A bodies work here. All small block trannies bolt on..manual or auto...just the proper flywheel or flex plate required..I have an A500 on mine. There will be issues with the power brake booster-valve cover clearance ( few options...convert to manual, or hydroboost setup..I am sure there might be others..I quit looking after I converted to hydroboost) and there will be exhaust-power steering box clearance issues..the FMJ's have a simple way to overcome that since the K member and suspension is fully self contained...and because of the transverse torsion bars, there is alot more room for exhaust than on an A or B body. With more and more EFI management options now available ( MS3 pro, hemitronics, hptuner now supporting hemis) it is actually cheaper to go EFI depending on how complete a motor you get. My opinion is a truck engine is easier to fit, especially if you want to keep A/C and just modify the front cover to accept a car intake ( mine is an 04 truck motor with eagle heads and an eagle car intake). With the truck timing cover the Alt and A/C compressor are up top. This isnt quite as easy as dropping in a B/RB...but for the same power ( careful part selection even more..not as much torque though...unless you go stroker kit) and new car driveability ( I must be getting old...I just like to hit the key and it runs...no setting the choke, let it warm up a bit, kick off the choke, then feather the throttle to pull away until full warm up...better fuel mileage and self adjusting for weather instead of rejetting) makes it so much worth it

 

[Jack Meoff]

Thanks for that post McFly.

And also for the chuckle.
You just described my every morning scenario in your last sentence.....lol...

A belated welcome aboard.

 

[Joe12459]

Engine/trans in. Now a lot of wiring to follow.

 

[Monkeyed]

View attachment 9639 Engine/trans in. Now a lot of wiring to follow.

That's awesome. :eusa_clap:

 

[Joe12459]

Just finished the underhood wiring and started her for the first time. Runs great, and I love the HID lights. Now on to the body and interior wiring.

 

[Jack Meoff]

Man that front end looks cool.

 

[Joe12459]

Just needs a good washing. Hopefully she'll be on the road soon!

 

[Monkeyed]

View attachment 9953

Just finished the underhood wiring and started her for the first time. Runs great, and I love the HID lights. Now on to the body and interior wiring.

I'd love to see some pics of the interior

 

[Joe12459]

I'll post interior pics as I complete it. Right now the interior is just a dash frame and a mess or wiring. I'll be working on that this weekend.

 

[efriedrich]

I used an AlterKtion K frame

I thought they stopped making them for FMJ bodies.

 

[Joe12459]

They just don't list them on the website. If you call Bill, he'll make you one. Like I said, the Hemi motor mounts will not be welded up, so you can put them where you want, but everything else is a finished, very easy direct bolt in replacement. Very high quality.

 

[Jack Meoff]

They just don't list them on the website. If you call Bill, he'll make you one. Like I said, the Hemi motor mounts will not be welded up, so you can put them where you want, but everything else is a finished, very easy direct bolt in replacement. Very high quality.

Good to know!

 

[Monkeyed]

I'll post interior pics as I complete it. Right now the interior is just a dash frame and a mess or wiring. I'll be working on that this weekend.

It's up to, I'm aa sucker for a good before and after shot, and a junky for everything in between. :toothy10:

 

[Joe12459]

OK. I'll take a few pics this weekend, before I start working on it again.