Sinking Creek 4WD Association

working on that wj prob gonna do it after big dogs this fall... got to find enough time i can pull my trany down and not wheel for a month or two.

Keeping the 3 speed with the future Dana transfer case?

Sure am. Run that shit till it blows and it ain't ever gonna blow!!!!!!!

Cause there are basically no electronics in it haha.

Yea idk how it's still together I've run it dry and overfull overheated and beat shit out of it and it just keeps going

redneckrapunzel wrote:Yea idk how it's still together I've run it dry and overfull overheated and beat shit out of it and it just keeps going

Hah beats me. What's next on the TJ? Other than the D300.

well all the stuff is coming to fix the corner this week, so gonna do all that. Then I need to do something about keeping the nose down so im trying to decide if I wanna go the suckdown winch route or just a short central limiting strap. Hood louvers will be purchased next paycheck and put on. gotta cut all the old brackets off the frame in the rear still as well. Then just tinker with stuff, gotta figure out what I wanna do about a motor before next fall.. thinking a stroked low compression 4.6 with a nice big super charger would be cool... Ive decided I want to stay with the ol 4.0 they are so cheap to fix and I would have trouble finding a v8 setup that would not be to long with how short my rear driveshaft already is.

what Im thinking is like a 7.2-3:1 compression ratio and push like 12-15 lbs of boost and it would be a freaking rocketship and be cool. or other option is to build it with like a 8.2-3:1 compression ratio and put a turbo pushing about 8-9 lbs of boost. Still got to do all the math and whatnot but I think im going to go with a supercharger for simplicity. trying to run a clean exhaust safely under the motor and have enough space to fit a turbo and all that stuff would be challenging. I think just taking my ac compressor off and putting a supercharger there running 1 hose and being done would be much better.

redneckrapunzel wrote:stroked low compression 4.6

Stroked how? A 4.7 kit?

Have you put your link geometry in the calcs? Have you thought about adjusting mounting points to fix all of your undesirable handling before you talk about putting a blown motor in

get a crank out of a 258 (4.2) motor and put it in with dished out .030" over pistons on stock 4.0 rods you end up with a 4.6 what we did to gus's motor.

nah not to worried about that... it actually is a lot better since fixing all my steering shit work and the axles I put in last fall. the extreme body roll is gone for the post part and not much funkiness while driving on the highway either.


plus blown motors are way cooler than geometry

redneckrapunzel wrote:get a crank out of a 258 (4.2) motor and put it in with dished out .030" over pistons on stock 4.0 rods you end up with a 4.6 what we did to gus's motor.

So, just a normal 4.6? I read that as a 4.6 that is stroked, not a 4.0 that is stroked.

Yea

Supercharger, cause turbo lag is for people who don't have a supercharger!

couldn't have said it better myself WJ. nah I still kinda want to do a turbo cause I could keep it a decent compression ratio and push like 7-8psi of boost but the big thing that steered me away was all the extra work of a turbo. between making an exhaust manifold, mounting a turbo, the cooling lines and all that stuff, plus I don't think I would be able to keep it all clear of any hazards and might damage it quickly. Supercharger just gotta mount and bore out my throttle body and run new tubing much easier. I wasn't really worried about turbo lag cause as long as I didn't drop my compression to much on the motor I should be able to retain the same ability to just idle up obstacles like I do now then when I wanna get reckless hit the loud pedal and let that baby spool on up. With a SCharger ill just kill my compression and push a lot of boost and definitely be able to idle up obstacles and hopefully do some wheelies or crazy shit like that

What type of supercharger? Does the MAF adjust fueling adequately? How do all those details work? I think you should do this soon.

So I would have to get a reprogrammed computer or a re-programmer of some sort. From what ive seen jeep computers a bitch to try work with and a tune is nearly impossible so you have to flash it and rewrite the program. I am not sure about the stock sensors for the MAF haven't gotten that far in my research but I would run bigger injectors, I believe stock are like 19lb/hr and I would just get a set of injectors from a ls1 I believe which fit right in and are 23lb/hr. Nice thing about a reprogrammed computer is it will be programmed with the larger injectors instead of just putting 23s in and have the computer think it is still running 19s. All that being said as of next year I can register my jeep as historic and just get a third party system if I needed to. don't really wanna put historics on it yet though.

Things I have figured out;
if I use a 258 crank, 4.0 rods, 4.0 pistons with like 40-50cc of dish I will have a 4.6 and my compression ratio will sit about were I want I believe with 40cc dish it will be like 7.9-8.1 and with 50cc it would drop to about 7.1. (all rough estimates at this point. other options I might look into is using shorter roads with flat top pistons might get me around the right comp ratio. I will most likely put a longer duration cam with not much more lift in it. maybe roller rockers can get a set for like 600-700 so ill see how carried away I get. reason to get roller rockers is there isn't much aftermarket head support for the 4.0 and they are one of the only upgraded rockers you can get ( 2 companies make them and that's it). Theoretically stock rockers will flex a little bit which takes away some open valve duration so by using upgraded stiffer rockers you eliminate that. Some truth some bs.


Need to figure out the best bet for a supercharger both size and type. Trying to understand all the numbers and what not to see what size supercharger I need first. also do I need an intercooler or not? When I put all this on I probably need to upgrade my cooling system and install a oil cooler cause I already have a slight cooling issue in the summer. going to talk to some of our friends who are part time engine builders next week about it. Sorta wanna see whats actually possible for what price before i decided to do anything. Some people are gonna say if your gonna go historic why not put a SBC in it.. thought about but nah everyone does that.. not everyone has a ballin blown 4.6. If anyone has ever done any supercharger sizing and really has a good understanding of it or knows a good book or article please feel free to help.