strokin it

[fluidmotion]

im getting ready to do a 4.7 stroker. ive been reading up on http://www.jeep4.0performance.4mg.com/stroker.html and talking to a few people who have done it before but i just want to get a good idea for parts before i start buying and i have a few questions on things i should do.
first question; what do i do with the 4.2 crank because its too long, do i use a spacer/adapter or do i have it ground down?

also how big should i make the valves?

steveXJ88 (from jeepin.com) helped me a lot and im going with a crane cam (http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=6&Engine_Make=AMERICAN%20MOTORS&Year=1992&Engine_Size=243-258%20C.I.&partNumber=751111&partType=camshaft) that one to be exact.

next question would be what size fuel injectors do i go with?

finally im planning on using the 4.7 parts list on the website i listed above, so is there any other parts i should look at getting?


my jeep is a '92 XJ, auto trans, 35 xterrains, 4.56 gears, 30/44, locked 44

 

[old_man]

Personally I would go with the spacer, rather than shortening the snout. You want to keep as many threads as possible.

 

[5-90]

Anybody have dims on that spacer? I've got access to a machine shop at school, and maybe I could crank out a batch or two...

5-90

 

[fluidmotion]

yeah griding it down didnt seem like a great option to me but i didnt know for sure. im suprized dyno hasnt chimed in yet

 

[MJ_Chubs]

The good doctor lives in a time zone approximately 10 hours ahead of OR time. He's probably still sleeping...

 

[old_man]

I made mine out of .250" stock. I can't remember the other dims. It just has to have the middle hole large enough for the snout of the crank to fit through and the outside large enough to hold the harmonic balancer.

 

[5-90]

That's most of it - I just replaced my HD this week-end. How thick does it need to be?

5-90

 

[old_man]

I made mine out of .250" stock.

 

[5-90]

Just checking - I didn't know if you'd had to thin down the stock at all...

So, same ID/OD as the damper snout, and 1/4" thick? I guess this goes between the tailend of the damper and the ledge at the base of the crank nose, then. I'm sure I'll need to duplicate that keyway as well, right? I'm pretty sure we've got a set of broaches there.

5-90

 

[Dr. Dyno]

The good doctor lives in a time zone approximately 10 hours ahead of OR time. He's probably still sleeping...

You got that right. My time zone is GMT+4hours so I'm nine hours ahead of the East coast and 12 hours ahead of Pacific time.
As far as the crank snout goes, I put a 10mm thick spacer in front of the crank pulley to keep it properly aligned with the others. Having the spacer made is easy. Just get hold to an old crank pulley, take it to a lathe, ask the machinist to cut a 10mm slice off the keyed rear portion, and voila, you have your spacer.
Injectors? I'm using Ford 24lb'ers, stock 39psi regulator, and MAP adjuster set at 5.15v with the A/F ratios absolutely spot on.
You might wanna read my 4.6 stroker build up and see what parts I used and how it all went together. It'll help you draw up your parts list and avoid any potential "gotchas" that could crop up along the way.
_______________________________
Dino's "Mean Green Machine"
1992 XJ Laredo 4-dr - 191k miles - 16k miles on 4.6L HO Stroker
AX15, NP231, D35c, D30

265hp@4900/325lbft@3500, 1/4 mile = [email protected], 0-60 = 5.5secs
Websites - Jeep 4.0 Performance, 4.6L Stroker Build-Up, Dino's Jeep Tricks

Forever in the s__t. It's only the depth that varies!

 

[fluidmotion]

thanks dyno, ill be sure to check it out. i dont want to go with the map sensor so i think im just going to run a FPR, what size injector should i run?

 

[Dr. Dyno]

thanks dyno, ill be sure to check it out. i dont want to go with the map sensor so i think im just going to run a FPR, what size injector should i run?

The same ones that I'm using i.e. Ford 24lb'ers.
An adjustable FPR will cost you $180 from Hesco whereas a MAP adjuster will cost you $9 in Radio Shack parts so don't dismiss the MAP adjuster idea just yet.

 

[fluidmotion]

The same ones that I'm using i.e. Ford 24lb'ers.
An adjustable FPR will cost you $180 from Hesco whereas a MAP adjuster will cost you $9 in Radio Shack parts so don't dismiss the MAP adjuster idea just yet.

well i saw a write up, maybe yours?, on doing it and it look way more confusing then anything. im pretty good with electronics and stuff but maybe i just didnt look close enough at it.

 

[junkjeep]

turbo city makes the map adjuster. If I remember right it's $100. just in case you don't feel comfortable making your own.

 

[Dr. Dyno]

well i saw a write up, maybe yours?, on doing it and it look way more confusing then anything. im pretty good with electronics and stuff but maybe i just didnt look close enough at it.

It's a lot easier than you might think and it's definitely better than paying $94 for Turbo City's. I'm not exactly an expert with electronics but I took the time to read it up properly and made sure I had the correct parts. Here's my write-up:

http://www.angelfire.com/my/fan/MAP_adjuster.html

 

[fluidmotion]

i read your write up and the other 2 that you linked in your write up. they all basically said the same thing. GoJeep did one on his page too which i found very helpful as well because he explained how to connect everything which was where i confused on the whole thing. now im just confused as to what to put the whole thing in and what volt to set it at

 

[Dr. Dyno]

Just buy a small empty black plastic box from any electronics store and set your MAP adjuster inside it. Set it at 5.0v initially, determine whether the engine needs to be enriched or enleaned, and go from there. I don't think you'll need to deviate very much from 5.0v.

 

[fluidmotion]

well what will be the best way to determine if im too rich or lean. i dont have the A/F guage and i dont have access to the exhaust reader. what else could i do?

 

[Dr. Dyno]

well what will be the best way to determine if im too rich or lean. i dont have the A/F guage and i dont have access to the exhaust reader. what else could i do?

You'll have to do either one or the other because reading the plugs alone won't be enough. I went for the Autometer A/F ratio gauge. It's cheap, easy to install, and you can wire it up to your existing O2 sensor signal wire. I have mine mounted in a cup that's screwed to the driver's side A-pillar.

 

[JJacobs]

Narrow band O2 sensors are not accurate for performance tuning. You might get away with it on a stroker, but for accuracy a wide band setup is needed. Kinda $$$ though.