3.8L Aluminum Block to Lighten Jeep
Thread Starter
JK Newbie
Joined: Oct 2008
Posts: 48
Likes: 1
From: Ottawa, Ont
3.8L Aluminum Block to Lighten Jeep
Hi there,
Looking to see if someone with engine building experience/knowledge of the Chrysler engines can confirm the possibility of using a 3.5L aluminum block instead of the 3.8L iron block when rebuilding a 3.8L.
The purpose of this would be to drop some weight from the front end when doing a future rebuild. This would allow someone to use a heavier front bumper, without worrying about stiffer springs, coil spacers, change in steering/drive characteristics etc.
3.8 liter is derived from the older 3.3L. Similarly I it seems the 3.5L is derived from the 3.3L as well. It may have a similar block, but different internals in the head. I found this change made to the 3.8L block for the Jeep JK from: Rebuilding Chrysler's 'Revived' Engine Family - Engine Builder Magazine
“The 3.8L was usually updated when the 3.3L was revised because they’re both part of the same family, so the 3.8L got the newheads in ’01 and the 4666031AB block casting with the extra bolt holes for the RWD Wrangler in ’07.”
So can a 3.5L aluminum block be used with little modification?
Looking to see if someone with engine building experience/knowledge of the Chrysler engines can confirm the possibility of using a 3.5L aluminum block instead of the 3.8L iron block when rebuilding a 3.8L.
The purpose of this would be to drop some weight from the front end when doing a future rebuild. This would allow someone to use a heavier front bumper, without worrying about stiffer springs, coil spacers, change in steering/drive characteristics etc.
3.8 liter is derived from the older 3.3L. Similarly I it seems the 3.5L is derived from the 3.3L as well. It may have a similar block, but different internals in the head. I found this change made to the 3.8L block for the Jeep JK from: Rebuilding Chrysler's 'Revived' Engine Family - Engine Builder Magazine
“The 3.8L was usually updated when the 3.3L was revised because they’re both part of the same family, so the 3.8L got the newheads in ’01 and the 4666031AB block casting with the extra bolt holes for the RWD Wrangler in ’07.”
So can a 3.5L aluminum block be used with little modification?
JK Enthusiast
Joined: Jun 2012
Posts: 382
Likes: 0
From: None
swapping to an aluminum block so you don't have to swap in heavier springs lol! Seems like a lot of work for minimal gains, if even possible. Just use heavier springs and save yourself the hassle. Plus, if youre going that route I would hope/assume youre going aluminum everything...sliders bumpers skids etc etc....which if you can afford all that maybe just get the 3.6 or do a complete swap. i think youre in the land of diminishing returns with this one.