4.0L tj ebay turbo kit

willness33

willness33

Here for the memes
Joined
May 3, 2005
Location
Alexis,NC
Ok, hear me out. I've been dead set on a SBC swap into my cj7 until I really started to look at a 4.0L since I'm backing it with a brand new ax15. @Jody Treadway may have mentioned how much better a 4.0 is compared to a 258 in a cj. It would make my swap super simple and easily attainable compared to what i originally wanted to do. I just want to make my cj a dd and be able to do interstate speeds and maybe be a touch spicier. That said, there are chicom ebay turbo kits that have been internet proven to be effective and reliable. Does anyone have any experience with these kits or any type of 4.0 turbo setup. FYI, my cj will just be a street jeep. That's all it is now and basically all it will ever be. Hook a brother up with any knowledge you have to offer. Opinions, tech, banter, all is welcome to help me make up my mind.
 
Last edited:
I love turbos. I hate people who say X turbo works on every Y engine. There is a lot of math that goes into volumetric efficiency and rpm range with compressor maps in choosing the right A/R turbo that most people don't do. I would budget stroke a 4.0 10 out of 10 times before I ever considered a turbo.
 
RHSCTJ said:
I love turbos. I hate people who say X turbo works on every Y engine. There is a lot of math that goes into volumetric efficiency and rpm range with compressor maps in choosing the right A/R turbo that most people don't do. I would budget stroke a 4.0 10 out of 10 times before I ever considered a turbo.
Click to expand...
Stroking it is the other option but I need a lot more specific infor.ation on how to do it than what I already have in my head. I will have the 258 crank. I will have the rods. It's the little tidbits of info to go along with it that I lack. Does any head work need to happen? Will the 4.0 ecu know what to do? Are the crank journals between the 2 the same? Rod journals? It's more questions than answers at this point. I have lots of qiluestions with a turbo setup as well. Will the 4.0 ecu understand the boost? Larger injectors are expected but will it compensate for a decent afr?
 
RHSCTJ said:
I would budget stroke a 4.0 10 out of 10 times before I ever considered a turbo.
Click to expand...

why-not-both.jpg


I have no useful information, I just like to help people make poor decisions šŸ˜‚

Duane
 
You don't have to mess with the computer, just change injectors vs a turbo where you will have to change injectors and find a way to pull timing for boost
 
You can use 258 rods and 4.0 pistons to stay cheap or 4.0 rods and custom pistons for a little more power. The journals are all the same.
 
RHSCTJ said:
You don't have to mess with the computer, just change injectors vs a turbo where you will have to change injectors and find a way to pull timing for boost
Click to expand...
That was my other concern, pulling the timing. Thanks for bringing that up.
 
RHSCTJ said:
You can use 258 rods and 4.0 pistons to stay cheap or 4.0 rods and custom pistons for a little more power. The journals are all the same.
Click to expand...
It's literally just that simple? 258 crank and rods and reassemble with the 4.0 pistons? About what compression ratio does this net? Is 91 or higher octane necessary?
 
willness33 said:
Stroking it is the other option but I need a lot more specific infor.ation on how to do it than what I already have in my head. I will have the 258 crank. I will have the rods. It's the little tidbits of info to go along with it that I lack. Does any head work need to happen? Will the 4.0 ecu know what to do? Are the crank journals between the 2 the same? Rod journals? It's more questions than answers at this point. I have lots of qiluestions with a turbo setup as well. Will the 4.0 ecu understand the boost? Larger injectors are expected but will it compensate for a decent afr?
Click to expand...
Itā€™s truly as simple as it gets. If you have a good running 4.0, swap in 258 rods and pistons, use lock washers to space out the bottom end girdle another 1/8ā€, put it all back together, and you have a smooth, reliable 4.5L. If the cylinders are worn, bore 0.030ā€ over, and you have a 4.6. Mine is 100% stock except for the 258 crank and rods, and 0.030ā€ over pistons (because apparently the stock ones melt when thereā€™s no coolant in the engine? :laughing: ) Stock cam, stock ignition, stock injectors, stock fuel pump, stock head, stock block, stock valve train, etc.
 
I stroked my 4.0 to a 4.7.

Looking back I wish I would have just swapped a ls/4l60 combo. and probably will in the next couple years
 
If you have a 258 you can use the crank with new rods and pistons in a 4.0 block to get a budget stroker. Itā€™ll be about 4.6 with efi and get 90% of the power of turbo on a 4.0 without the turbo headaches.

This forum will be your friend

Jeep Strokers - Homepage

Forum News, General Board Discussion, FAQ's, Stroker Basics, Stroker & Performance Tech, Swapology, AMC Car Specific, Projects, General Tech, Electrical, The Pub, Test
www.jeepstrokers.com
 
Jeff B said:
I stroked my 4.0 to a 4.7.

Looking back I wish I would have just swapped a ls/4l60 combo. and probably will in the next couple years
Click to expand...
You should do it now and sell your stroker to Will ;)

Scratch that sell it to me cheap for my XJ and Iā€™ll give him the 4.0 out of mine :D
 
There's a couple ways to stroke a 4.0. You can use 4.2 crank and rods along with 4.0 pistons for one. But you end up with the potential for detonation due to top of of piston travel in relation to deck height not being ideal. You can either deal with it or deck the block. I've done quite a few this way without issue.
Another way is to use a 4.2 crank and 4.0 rods. Along with them you use stroker specific pistons with a relocated wrist pin hole to make up for the difference in piston vs deck height. The bonus is you are using much newer rods compared to 4.2 rods. The last handful of strokers I've built were done this way.
Just food for thought.
 
Jody Treadway said:
There's a couple ways to stroke a 4.0. You can use 4.2 crank and rods along with 4.0 pistons for one. But you end up with the potential for detonation due to top of of piston travel in relation to deck height not being ideal. You can either deal with it or deck the block. I've done quite a few this way without issue.
Another way is to use a 4.2 crank and 4.0 rods. Along with them you use stroker specific pistons with a relocated wrist pin hole to make up for the difference in piston vs deck height. The bonus is you are using much newer rods compared to 4.2 rods. The last handful of strokers I've built were done this way.
Just food for thought.
Click to expand...
I have a 258 crank and rods and a couple spare 4.0's. I've dreamed of building a stroker but the only engine work I have ever done is head gasket. I also don't have a clean shop!
 
ghost said:
I have a 258 crank and rods and a couple spare 4.0's. I've dreamed of building a stroker but the only engine work I have ever done is head gasket. I also don't have a clean shop!
Click to expand...
They're not rocket science or anything. A good micrometer, plasti-guage, feeler gauges and common hand tools is all you need. Verify tolerances after machining, assemble, double check, fire it up.
 
Jody Treadway said:
There's a couple ways to stroke a 4.0. You can use 4.2 crank and rods along with 4.0 pistons for one. But you end up with the potential for detonation due to top of of piston travel in relation to deck height not being ideal. You can either deal with it or deck the block. I've done quite a few this way without issue.
Another way is to use a 4.2 crank and 4.0 rods. Along with them you use stroker specific pistons with a relocated wrist pin hole to make up for the difference in piston vs deck height. The bonus is you are using much newer rods compared to 4.2 rods. The last handful of strokers I've built were done this way.
Just food for thought.
Click to expand...
Any resources on the pistons assuming I'd use the 258 crank and 4.0 rods? Yes I could Google this but I'm leaning on your experience lol.
 
Back
Top