Mods/Upgrades to our 2003 Dynasty

[rpasetto]

Mike, Just a note; I've been following your thread off and on for a while and see you are taking on some really impressive projects. I also have an 03 Dyn, got it used about 12 years ago, and it's nice to see some of the awesome things you've done to it.

Back about a half century ago, during my pre-motorhome days, I did some heavy shade-tree mechanic work, but not as extensive, nothing that approaches, what you've accomplished. Kudos to you!

[zmotorsports]

Originally Posted by rpasetto

Mike, Just a note; I've been following your thread off and on for a while and see you are taking on some really impressive projects. I also have an 03 Dyn, got it used about 12 years ago, and it's nice to see some of the awesome things you've done to it.

Back about a half century ago, during my pre-motorhome days, I did some heavy shade-tree mechanic work, but not as extensive, nothing that approaches, what you've accomplished. Kudos to you!

Thank you Rick, that is very flattering. I appreciate the comments.

Glad to hear you too have a 2003 Dynasty that you are enjoying.

Thanks for following along on my projects thread.

Mike

[zmotorsports]

I know this isn’t “exactly” RV related, but it kind of is because our Jeep is connected to our coach much of the time.

I’ve been away from the forum for a while as I’ve pretty much built two Jeeps over the past seven months and haven’t done much RV’ing or playing. Both of which I hope to be able to change soon.

We basically built my son’s new Jeep WJ starting in July of 2018 and we finished it up and had it on the road by the first part of December.

I then tore into our Jeep to perform an upgrade that I have been planning in my head for over four years, although life got in the way of actually doing it due to our move, building a new shop and putting a yard in.

Last May~ish I started collecting the pieces and parts a little at a time and by September timeframe I pretty much had everything I needed for my little upgrade. I was hell bent on having my Jeep ready for the 2019 RV’ing and Jeeping season and I think I’m ready.

My upgrade consisted of pulling the body off of the frame, removing the anemic Chrysler 3.8 liter engine and 42RLE transmission and replacing them with a 6.2 liter aluminum GM LS engine with 6L80 transmission.

I also took a couple of weeks in December to regear my Jeep from the 5.38 gears that I had ran for the previous 90k miles/7-years with 35” tires to new 4.56 gears to handle the new powertrain as well as my new 37” tires. I also added hydraulic assist steering. All if that was completed prior to my engine swap which has now been done for about two weeks. I have about 500 trouble free miles on her now and ready to tackle some trails and we hope to plan a few RV trips this year, although our son is getting married in June which may slow our RV’ing a bit the first part of the year.

Body separated from the frame.


Chrysler powertrain removed and chassis prepped to accept the new GM powertrain.


6.2 liter L94 engine and 6L80E transmission in place.


GM OEM wiring harness installed.


Engine swap completed. I was even able to install the OEM engine cover, with a little tweaking and machining of the mounting studs. Engine looks like it belongs there.


Exhaust system built and ready to install for the final time.


Ready to back out of the shop.


Pictures from our weekend drive and just over 500 trouble free miles.




The only indication (other than the music coming out of the exhaust) that there’s something else looming under the hood. Other than the small badge it is a complete sleeper.




Thanks for looking.

[Burgy]

Fantastic job!, planning on the Hemi swap into our JK soon as the warranty expires

[zmotorsports]

Originally Posted by Burgy

Fantastic job!, planning on the Hemi swap into our JK soon as the warranty expires

Cool.

[rpasetto]

Wow! Awesome upgrade.

[zmotorsports]

Originally Posted by rpasetto

Wow! Awesome upgrade.

Thank you.

To be honest, the 6.2 liter engine is much more than even my heavy JKUR needs but it definitely upped the fun factor.

This thing drives so nice and smooth it is like driving a Denali with a Jeep body strapped on it. Everything functions perfectly and the road manners are just AWESOME. It idles so smooth at 550 RPM you can hardly notice that it is even running. It floats down the interstate at 70 MPH @ 2k RPM and can barely hear the exhaust with the radio off. Leaving a stop you just let your foot off of the brake and barely touch the accelerator and it just moves and anything more than a quarter throttle and it goes from Dr. Jekyll to Mr. Hyde instantly.


With well over 400 HP on tap I don't suspect much throttle will be needed for most of the driving scenarios. Actually, I haven't found a reason yet to give it full throttle. I've done half throttle once just to see what it's like and it was plant you in the seat and trying to wipe the grin off of my face.

[RPrince]

I really like your engine swap!

I have a question regarding the exhaust system you are using.

I am in the process of putting the same drivetrain (l94/6l80) that you used into a 1950 Willys. I have dual exhaust Magnaflow mufflers) currently connected, but it's way too loud. May have to revise to single exhaust set up. What muffler did you use?

Thanks, Randy

[vito.a]

Great work Mike. Looks like it came this way.
The hot rodding world is slowly discovering the LS engine is the new small block V8 of choice. Lighter and more powerful than the old Chevy 350.
Did you buy an adapter kit for the motor mounts?

[kketterling]

Gotta love those LS motors.

[10Boomer]

Originally Posted by zmotorsports

I know this isn’t “exactly” RV related, but it kind of is because our Jeep is connected to our coach much of the time.

I’ve been away from the forum for a while as I’ve pretty much built two Jeeps over the past seven months and haven’t done much RV’ing or playing. Both of which I hope to be able to change soon.

We basically built my son’s new Jeep WJ starting in July of 2018 and we finished it up and had it on the road by the first part of December.

I then tore into our Jeep to perform an upgrade that I have been planning in my head for over four years, although life got in the way of actually doing it due to our move, building a new shop and putting a yard in.

Last May~ish I started collecting the pieces and parts a little at a time and by September timeframe I pretty much had everything I needed for my little upgrade. I was hell bent on having my Jeep ready for the 2019 RV’ing and Jeeping season and I think I’m ready.

My upgrade consisted of pulling the body off of the frame, removing the anemic Chrysler 3.8 liter engine and 42RLE transmission and replacing them with a 6.2 liter aluminum GM LS engine with 6L80 transmission.

I also took a couple of weeks in December to regear my Jeep from the 5.38 gears that I had ran for the previous 90k miles/7-years with 35” tires to new 4.56 gears to handle the new powertrain as well as my new 37” tires. I also added hydraulic assist steering. All if that was completed prior to my engine swap which has now been done for about two weeks. I have about 500 trouble free miles on her now and ready to tackle some trails and we hope to plan a few RV trips this year, although our son is getting married in June which may slow our RV’ing a bit the first part of the year.

Body separated from the frame.
Attachment 233327

Chrysler powertrain removed and chassis prepped to accept the new GM powertrain.
Attachment 233328

6.2 liter L94 engine and 6L80E transmission in place.
Attachment 233329

GM OEM wiring harness installed.
Attachment 233330

Engine swap completed. I was even able to install the OEM engine cover, with a little tweaking and machining of the mounting studs. Engine looks like it belongs there.
Attachment 233331

Exhaust system built and ready to install for the final time.
Attachment 233332

Ready to back out of the shop.
Attachment 233333

Pictures from our weekend drive and just over 500 trouble free miles.
Attachment 233334

Attachment 233335

The only indication (other than the music coming out of the exhaust) that there’s something else looming under the hood. Other than the small badge it is a complete sleeper.
Attachment 233336

Attachment 233337

Thanks for looking.

Very nice Mike! Hopefully getting to my 66 El Camino later this year, still working on house and RV garage. Not as nice as yours, but it will work for us. Keep the beast out of the weather.

[zmotorsports]

Originally Posted by RPrince

I really like your engine swap!

I have a question regarding the exhaust system you are using.

I am in the process of putting the same drivetrain (l94/6l80) that you used into a 1950 Willys. I have dual exhaust Magnaflow mufflers) currently connected, but it's way too loud. May have to revise to single exhaust set up. What muffler did you use?

Thanks, Randy

Thanks. Good luck on your engine swap. You will love it when done.

As for the exhaust, I prefer a common chamber muffler on these LS's. They have an odd firing order compared to the old traditional small block Chevy's of past. With dual mufflers they sound weird unless you put in an H-pipe or crossover to help with the scavenging and cancellation of pulses.

I am running a stainless steel Magnaflow knock-off that is dual 2-1/4" inlets and a single 3" outlet. I love the sound of mine, deep and throaty at idle yet barks when you get on it. Going down the interstate @ 70 MPH and 2k RPM it is undetectable and definitely no droning. I am also running dual hi-flow catalytic converters which will take some of the rumble out as well.

[zmotorsports]

Originally Posted by vito.a

Great work Mike. Looks like it came this way.
The hot rodding world is slowly discovering the LS engine is the new small block V8 of choice. Lighter and more powerful than the old Chevy 350.
Did you buy an adapter kit for the motor mounts?

Thanks Vito. They sure are the way to go. Horsepower numbers that were achievable only through a lot of aftermarket support and work from 15+ years ago are available in stock configuration and stock tune nowadays. Unfortunately I think the LS's days are numbered with the introduction of the LT. I would have loved to have put an LT (L86) in my JKUR but it would have been quite a bit more money as well as a bit more technology in the engine and I wanted to keep mine as simple as possible yet reliable.

Having the VVT definitely is nice for moving a heavy Jeep though.

As for kit, I didn't buy a kit per se, I used some components from Robbie @ Motech like his billet accessory drive so I could retain my JK accessories and his bolt in motor mounts but all other parts I sourced from either my local GM dealer or my local NAPA. I was going to fabricate my own motor mounts because fabricating is not something that is foreign to me but after talking to him about his brackets he talked me into his bolt in engine mounts and I can attest they are very nice. I also used his MoCAN bridge and integration harness to get the Chrysler BCM to talk to the GM ECM/TCM. Basically to make that handshake between the two CANbus networks. My intentions with this build all along were to keep it as OE looking, running and reliable as possible so I tried to use over the counter available parts as much as possible. That is why I used an OEM GM engine wiring harness and chassis harness as well. I needed to keep it all USEPA compliant.

I've built many custom one-off vehicles over the past 3 plus decades and all have performed as designed but most had very bespoke components that I had either machined or fabricated and as much as my wife and I travel I wanted this build to use over the counter available parts in case I ever needed anything while out of town.

Thanks for checking it out Vito.

[zmotorsports]

Originally Posted by kketterling

Gotta love those LS motors.

Yes indeed. They definitely put down some very respectable numbers, and with the VVT it is amazing just how much of that torque is available right off idle.