i am going to stroke my 4.0 but i have not decided to what degree yet. i have refined my results to these two options. the second choice is pretty much the same as the first but you have to bore it out if i am correct. i have a couple of questions. the camshaft that it says to use... when i was researching it, it said not for use with fuel injection. is this true? couldnt i just use the stock cam? Also i know that there are many of you on this forum that have stroked many motors to many different degrees, so i would love your opinion on this and the options below. thanks
4.5L Low-buck simple stroker
~ Jeep 4.2L 3.895" stroke crank
~ Jeep 4.2L 5.875" rods
~ Jeep 4.0L 3.875" standard bore pistons
~ CompCams #68-231-4 206/214 degree camshaft
~ Ported HO 1.91"/1.50" cylinder head
~ Stock 0.051" head gasket
~ 0.081" quench height
~ Ford 24lb/hr injectors with adjustable FPR or MAP adjuster for '87-'95 engines, Ford 24lb/hr injectors with stock 49psi FPR for '96 and later engines
~ 260hp @ 4850rpm, 321lbft @ 3500rpm
4.6L Low-buck stroker
Option 1: Same as above except:
~ Speed Pro H825CP +0.030" bore pistons
~ 9.6:1 CR
~ Mopar Performance 0.043" head gasket
~ 0.082" quench height*
~ 260hp @ 4800rpm, 324lbft @ 3500rpm
Based on the information you posted I would go with option one if I were you. The 3lbft difference wont even be noticable. And you hit peak torque at the same rpm and hp just 50rpm higher then option 2. Option 1 seems to be the best option based on what you posted.
What you have to keep in mind is your block will prolly have to be bored, most do. If you use the stock cam it will prolly ping because your raising compression and dont have the cam matched for it. Also, whos gonna port the head?
ibuildembig. i will assemble it but based on the info that i found and put in the post it is saying that i can use the 4.2 rods and crankshaft and 4.0 stock pistons along with everying else and it will be 4.5 without boring it. does that sound right to you? or am i miss understanding it? also should i use the stock cam or do you have one that you would reccomend? i am trying to do it pretty cheap but im only going to do it once so i am debating getting it bored out and getting bigger pistons. what do you think? and thankyou soo much you have given me great info in almost all of my posts in this forum
Well the reason I said that is most engines with 80K+ on them will have to be bored simply because the cylinder walls are out of round by that point and will have ring groove. The best thing to do is go to your local machine shop and talk to them about what you wanna do and let them make a recommendation. I'm not sure which way we are gonna go yet and wont know until I can get the parts down to the machine shop.