jeeperxj2000

Hi all,

My 2000 xj had a cracked head and low oil pressure, long story boring I've replaced 3/4 of the motor (head, main and rod bearings, oil pump, lifters, arms, rockers) still couldn't fix the low oil pressure problem. The last possible cause could be the cam bearings so now that I'm stuck pulling the motor why not upgrade the stock 4.0?

Since I'm a garage do-it-yourselfer I decided a swap to an LS1 or 5.2mag would be out of my range of abilities with the transmission and electronic adaptations needed. Decided the easiest improvement would be keeping the current 4.0 and get a stroker kit, machining the current block etc.

Any other options I should consider? I don't want to spend more than $2,000-$3,000

Thanks!

jebmccall

if you have one all that work already just get 4.2 crank and rods with an aftermarket cam. 4.2 crank and rods in a 4.0 give you a 4.5

jeeperxj2000

So I wouldnt need new pistons or machining right? Everything in engine would be new besides the pistons and rings. If I'm already that deep with the motor pulled would it be worth it to just do it?

CrawlerXJ

Not going to be a sheep and post "do-it". When I had my YJ (3yrs ago). I bought everything to do it. Had crank shipped from NY, had it machined was all ready to go. Then starting reading to get it ready. The more I read, the more I heard people with issues. Have you ever noticed, everything (or most) that turbo, super charge, stroke, end up selling shortly after? My theory is, they run into issues, and sell it to have someone else handle the issues. So, I sold off everything and did nothing but a rebuild.

Just another side of the coin/opinion.

jeeperxj2000

I appreciate your input. What else can I possibly do to beef up my motor? If I'm doing a new engine I'd like to have more power.

Aljay

I too will be needing to rebuild but I'm thinking stock but with a touch more fuel . I want stock reliability with a twist .

jeeperxj2000

Interesting. You talking new injectors or adjusting the FI?

SeriousOffroad

Bigger or multi-hole injectors will only deliver as much fuel as the PCM allows. The PCM controls the Injector Dwell Time (the amount of time the injector is energized) based on the signal received from the O2 sensors.

Injector upgrades should be performed to provide better atomization.

Adding the wrong injector (based on rated pressure) without understanding how the fuel pressure from the pump affects the performance of the injector is foolish.

I've been down this road before with my old motor, that's why I added 2 cylinders.

94XjSport94

THIS. Best thing i've read in a while... Also, bought some KC lights from you today... Thanks!

SeriousOffroad

Oh No Sir! Thank You for being a Serious Customer!!

[/hijack]

94XjSport94

Haha anytime! Well more specifically, next payday... lol

EVILXJ

i built my stroker over the summer and had alot of troubles getting it dialed in, did a ton more research, got a little better then more research and finally all the bugs are worked out, and i couldnt be happier with with i have

people get discouraged and sell because it isnt just a simple rebuild plug and play, there are alot of variables, i had to try several types of plugs with several gaps from .040 all the way up to .060, 3 different sizes of injectors, different FPS and a map sensor adjuster


just do alot of research and do what your budget allows u to do right

Aljay

Bigger injectors more fuel pump , bored throttle body .
I've Played around with injected cars a lot (5.0 mustangs , turbo eclipse/talon)so as some folks have had issues I have not . You can get away with bumping fuel pressure but if the injector is run to long at a higher fuel pressure it will cause it to over heat and you will run into hurt parts like some folks above obviously got greedy . I've had huge injectors in several cars and my present diesel it's all in tuning .

jebmccall

my buddy ran the 4.2 crank and rods in his 4.0 with a stock cam and liked it. the only thing he didnt like was having to run premium gas.

Aljay

The static compression is alittle high on that set up several ways to fix that simple cam swap would work wonders with that set up . Strokers need different cam timing events to really work right .