stroke it?..NOW?

[jeepthrills]

Hey all. I have a CJ with a well worn 258 ( good oil pressure..just worn oil rings..no noise..just lots of smoke). Very recently a 96 XJ rollover with a very strong 4.0 ( compressions all around 155 @ DA 5500ft) came into my posession. I was just planning on dropping the 4.0L in...but now I am thinking...Since I will have the 4.0L out and on a stand to replace the oil pan /rear main / timing cover seals.....why not just go ahead and drop the 258 crank in while leaving the pistons in their bores, add the Hesco CPS and spacer.viola...poor mans stroker...right?

what am I missing?
I thought I read where stock pistons could be reused...or is that with the 4.2 rods?

Thanks,
NOOB

[amcinstaller]

thats with short (258) rods. while you could quickly throw together a 4.5 at this point, youd still need bearings, pistons, rings, and a few other misc parts but it would be relatively quick, depending on parts availability and machine shop speed.but hey, like you said, why not just do it now?

[jeepthrills]

so...stock 4.0 pistons will work with 4.2 rods?

rings and bearings are easily available, and I do have a ball hone...was going to try to avoid the machine shop to minimize down time. There is only 1 good one in town...and he is backed up about a month.

[amcinstaller]

yes, stocker 4.0 pistons will work with 258 rods. and if all the block needs is a quick hone, then youre off pretty quick and runnin again also may need a map adjuster and a wideband to make sure your running right, and not leaning out

[jeepthrills]

Was planning on running with OBD II from the 96 XJ. So that should take care of it..Right?

[ibanezjeepguy]

without proper adjustment you're going to be on the tipping point of running lean. let me know what kind of deck height you end up with when you throw your setup together.
and which block cast are you going with?

[jeepthrills]

Very recently a 96 XJ rollover with a very strong 4.0 ( compressions all around 155 @ DA 5500ft) came into my posession.

[montelibre]

I was running my 4.6 stroker OBD II (1997 XJ) without any problem using the stock injectors for a long time and later with a ford 24 lb/h injectors.
I think that your OBD II engine computer will be able to adjust air fuel ratio all time fine (at WOT the O2 sensor will be ignored and the air fuel ratio will be more rich).

[ibanezjeepguy]

I believe at WOT is when the injectors are going to start having delivery problems at higher RPMs. light throttle cruising below 2,000 RPM shouldn't necessarily mean the immediate need for higher flowing injectors then again, flow rate is calculated based upon maximum anticipated HP which is directly related to engine displacement.
using popular fuel injection calculators online spec out an injector around 23.5 lb/per hr for a 6 cylinder pushing 225 peak HP at the flywheel

[SilverXJ]

On one engine I ran stock injectors, but bumped WOT fuel up on the APEXI. It worked... but... I had teh battery out for a while. Put it back in, didn't think about the Apexi and drove it up to PA. I was planning on swapping heads as I was having a ticking from too much valve to guide clearance. About 30 minutes from where I was going is a big hill. I was in the throttle constantly on that hil, not paying attention to the wide band. So I get to my destination and oddly enough the ticking from the head stopped. Pulled the head and all the exhaust valves were tulip shaped. While the battery was disconnected the Apexi lost its program and I was just running off the stock PCM with no correction.

So, if you like your engine don't use stock injectors.

[ibanezjeepguy]

that story deserves a thumbs up