Jeep 4.7

jeepin916

Active member
does anyon ehave any experience with the stroked engine? im starting mine and just looking for some tips on what not to do...

also does anyone have any good articles about this build up?
 

I just did a search on google and there is more info than you can read in a setting. give her a try. tug
 
if you have any specific questions, i've read about every online article there is on that topic... ask away, and i will answer
 
yea i read them all and this is what i have come up with...
i will need:
4.0 engine
4.2 crank and rods
aftermarket cam and pistons
but what i dont understand and cant figure out is what harmonic damper i will need to use,,,,,,
since its a 4.2 crank wont i have to use a 4.2 harmonic damper?
and if i do why would i have to cut off 1cm off the crank snout?
does that mean i need the 4.0 damper?
or does that mean that the design of the old block and the new block is too big and makes a gap?

thats about the only thing i cant figure out rite now...
 

Also i was just thinkin about it and realized another thing....
since the crank harmonic damper and flywheel is a blanced unit i will have to use all those with the 4.7..... now with the 4.2 flywheel i am gunna have to use the 4.2 starter also or can i use the original 4.0 starter?
 
4.0 engine
correct

4.2 crank and rods
correct

aftermarket cam and pistons
stock pistons will give you a 4.5, .030 will give you a 4.6, .060 will give you a 4.7

since its a 4.2 crank wont i have to use a 4.2 harmonic damper?
and if i do why would i have to cut off 1cm off the crank snout?
does that mean i need the 4.0 damper?
you will need to machine the snout off the 4.2 crank so the end looks exactly like the 4.0 crank, this will allow you to use the 4.0 damper

since the crank harmonic damper and flywheel is a blanced unit i will have to use all those with the 4.7..... now with the 4.2 flywheel i am gunna have to use the 4.2 starter also or can i use the original 4.0 starter?
you will use the 4.0 flywheel, it is required for the crank position sensor, it will bolt right up to the 4.2 crank.. and you will want that complete rotating mass (4.0 balancer and flywheel, and 4.2 crank) to be balanced professionally... if you have the money and means, it may be a good idea to get a ring of metal machined to add mass to the flywheel, this is called an inertia ring... this adds momentum to the flywheel and will greatly increase your torque

you will want to use injectors from a high output, it may be a good idea to upgrade those as well

any more questions, or anything i didnt answer?.. keep asking
 
ok so the only thing i am going to use from the 4.2 is the crank and rods everything else will either be original to the 4.0 or new and improved.... cool i think i got it now...
 
ok now for the 4.7 build, i will need to bore the block out .060, would that make the cylinder walls too thin? or is that still safe? i know on the SBC .060 is pushing it and may cause the engine to over heat and sometimes crack the cylinder walls. is .060 too much for the 4.0 block?
 
if your walls are fine, i would personally suggest simply rehoning them and sticking with stock diameter pistons... if the walls need some work, i would then say go with .030 pistons... there really is no need for a 4.7... plus, if you ever score the walls again, you have room to go further
 

true good point ill probably just stick with the .030 build. im trying to think of some way to make more power out of it but other than a larger profile cam i dont know what to do.. i guess tho, ill be fine with the reg build up and all that aftermarket stuff...
hey snitty do u know if i can use a jet chip with that stroker build up?
 
you can use a jet chip, it is not suggested though... you will not want to use platinum plugs... the compression ratio will be high... though, if you want to run only premium fuel, you can raise the compression to gain more power
 
BL

nah i plan on keeping ht ecompression ratio around 9:1 maybe 9.5:1 but i will use premium neway thats all i use now.

why is the chip not recommended?
i was also planning on supercharging it sometime in the future.also
 

I'm currently starting this project myself on my 2000, the only problem that I have had is the injectors. In 96 jeep changed to a higher psi injector and I am having a hard time finding any info on the newer engines. I have also checked out many different kits that are available for doing this. I so far think it is better to buy a new crank and connecting rods that are already set up for doing this. I have found a couple kits that drop down to $600 for the crank, connecting rods, bearings, rings and pistons. Just add the cam and lifters with some new injectors and your off and running. for about $900 in parts. I guesss I believe that if your going to rebuild it that you might as well start with new parts.... Any ideas about the injectors?
 
24-26 lb-hr injectors are recommended... if you plan on keeping the compression ratio down, you will certainly have to go with the right pistons... with such a long stroke, it will be tough to keep the ratio down. if you keep it down, a chip will be ok, but you don't want the spark too crazy otherwise
 

you can use them.... but basically an injector is an injector, whether its from a jeep, a mustang, a truck, whatever... they are all just port injectors, some do have differences, but many are interchangeble... and a 32 lb-hr is not needed... there is only so much that it will flow with a given fuel pressure anyway.. any flowrate higher than that is just either doing nothing, or wasting gas
 
hmm good point snitty, but i read that you have to install an adjustable fuel pressure regulator to use those injectors for optimum performance
 
Oil Pressuge Gauge - 95 YJ w/ beastly 2.5 - I4

na... only if you go with very high flow injectors.... if not... it is simply thinking that it is a stock setup, and will adjust injector performance based on O2 sensor readings
 
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