7120 head swap
#1
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Model: Grand Cherokee(WJ)
Engine: 4.0
7120 head swap
So recently .....my karma dialed the wrong number my radiator blew out warped the hell out of my 0331 head so I went and salvaged a 7120 head had it port and polished valve job done gasket matched idler pulley hole milled had .030 milled from the deck for higher compression of 19.1 instead of 18.1 waiting for apn header to come in and o2 bungs ...not sure if I can wire down to use just 1 down stream o2 or if I need both will find out soon 62mm bored tb 24lb injectors ,and a set of harland sharp roller rockers in the future should be pushing 30 hp and 50 ftlbs of torque over factory with a much better head...
#3
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Looks cool. How many miles on your motor? The reason I ask is if the motor is starting to get tired adding the extra compression may decrease its life.
At one time I looked at adding a turbo (electric or mechanical) and with the miles I have I decided not to take the risk.
At one time I looked at adding a turbo (electric or mechanical) and with the miles I have I decided not to take the risk.
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Model: Grand Cherokee(WJ)
Engine: 4.0
It's in had to cut a corner of the header flange as it was touching the block ****ed up an o2 thread had to weld it in(hopefully still works) can't put Cali cats back on....hopefully no code when I finish the exhaust
#7
How did you handle the O2 sensors? I'm doing the same swap on my '00 XJ and installed what looks to be the same header. Did you weld in a couple of bungs into the y-pipe on each bank? From what I've gathered, it's just the two upstream O2 sensors that are needed most for AFR – the downstreams can be sim'd out.
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