Maintenance questions
#16
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Location: Littleton, CO
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Year: '96
Model: Cherokee (XJ)
Engine: 4.0 HO
The Jeep engine is port injected and the combustion chamber features a swirl inducing ridge on the plug side. This ridge will atomize fuel even if you blast it in with a fire hose. Multi-hole injectors were introduced to atomize fuel in OHC engines where inducing swirl is impossible. They are also required for 4 valve chambers where the injector is positioned directly in the center of the chamber. AFR being the same, Injector flow rate being the same, there will be zero difference in performance between a Jeep engine with OE injectors v the Chinese 4 or 12 hole injectors.
Now we are going to have people start asking "can I shave off the ridge so my 4-hole injectors work better? I'm trying to hit 18 seconds in the 1/4 mile so I need all the help I can get...."
Seriously though.... what if. Atomized fuel directly into the chamber (ridge removed) vs. atomized fuel thats been re-collected on an obstruction and is then just allowed to flow into the chamber as physics allows it. OBVIOUSLY concentrated and no longer atomized.
Im not talking about a 10hp improvement, but I'm sure acceleration could see an improvement across the board. Maybe even a MPG increase if its effective enough... 1-2 MPG, not miraculously achieving 25 MPG.
This is just hypothetical since I wont be grinding on my motor............. Hahaha...
BTW it took 2 complete sets of china crap injectors for me to get 6 good ones. At least they didnt argue with me and just sent 6 more injectors no questions asked.
Last edited by RockyMtn96XJ; 12-02-2022 at 02:32 PM.
#17
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
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vroomvroom (12-06-2022)
#18
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Year: 1989
Model: Comanche (MJ)
Engine: 4.0
The refurbished 4-hole Bosch I installed were a huge improvement, only because the old ones were weeping gas out of the rusty bodies. Maybe a slightly better idle over the 30-year old originals, but otherwise no real change in mileage or power.
#19
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Year: 2000
Model: Cherokee (XJ)
But that too was about it.
Somebody once said a long time ago and I kinda agree with it that it is not the 4 hole injectors that are causing any improvement you see.
It is just the fact that you have fresh clean injectors in there that don't have 200K on them.
LOL.
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cruiser54 (12-03-2022)
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