streetxj
NAXJA Forum User
- Location
- Pembroke Pines, FL
I haven't been on 
for a while. Been very busy lately.
Currently the jeep has an ebay intake system(chrome intakes), 180 degree thermostat, old internally rotted 40 series delta flow flowmaster and new ngk spark plugs.
Oil: A while back my dad installed a fram oil filter and poored in Advanced Auto Parts brand standard engine oil. Compared to the mobil synthetic oil, I notice a bit more valvetrain noise, especially the rockers. Also, I've heard bad things about Fram oil filters, such that they are built with cheap parts and can actually reduce the psi of the oil system. In my 93' 5.0 mustang I went from mobil 1 to Royal Purple and I noticed that it had a tad more low end oomph and the engine was actually running quieter and smoother. I'm thinking about buying Royal Purple for my 4.0 jeep, along with Puralator Pure One oil filter. Would this be a good idea, or would you recommend a different engine oil for a jeep 4.0 engine?
Intake: I currently have a pretty old ebay intake system. The filter is still good. Should I keep it or should I buy a stock intake and install a K&N panel filter?
Exhaust: My jeep is the california emissions model, meaning that it has the main catalytic converter and the two other cats near the headers. I won't say what I did to the main big cat. :shhh: I'm going to replace the old rotted flowmaster with a new flowmaster, same model(40 series delta flow) instead of the louder original 40 series or super 40 series, because I don't want to attract bad attention and my mom still drives it occasionally when she needs to go somewhere. Should I run a 2.25 pipe from header to muffler and 2.5 inch after muffler or vice versa? Or 2.5 inch all the way for the stockish 4.0? I don't want to really hurt low end torque.
Cooling: I have a 180 thermostat, but it can only keep the temps down for a certain amount of time. With 90 degree temps in stop and go traffic, it stays slightly above 210 and slightly below when cruising, especially with head-wind. It takes much longer to reach that temp since I took off the factory insulation heat shield that was on the intake manifold. This removal even fixed the hot re-start piston #3 and #4 misfire
. This heat shield was actually holding a lot of heat, especially where the headers split and where the 0331 head would crack. Personally, I believe some early model 0331 heads would crack not only because of the thinner casting, but also because of the hot spot created by the factory fiberglass-aluminum heat shield mat. The bottom of the engine bay has a black plastic mat, which I believe is also blocking hot air from escaping the bottom of the engine compartment. Should I remove that? My dad's old lifted 98 4.0 cherokee always stayed below 210 with just the 180 degree thermostat and it didn't have this mat.
Future mods: bored stock throttle body and superchips flashpaq.
Further down the future: Replacement "TUPY" 0331 head or Alabama cylinder head with a thinner mopar performance head gasket to raise the compression ratio a bit. :repair:
I'll appreciate any advice and I'm thankful to be back in.
for a while. Been very busy lately. Currently the jeep has an ebay intake system(chrome intakes), 180 degree thermostat, old internally rotted 40 series delta flow flowmaster and new ngk spark plugs.
Oil: A while back my dad installed a fram oil filter and poored in Advanced Auto Parts brand standard engine oil. Compared to the mobil synthetic oil, I notice a bit more valvetrain noise, especially the rockers. Also, I've heard bad things about Fram oil filters, such that they are built with cheap parts and can actually reduce the psi of the oil system. In my 93' 5.0 mustang I went from mobil 1 to Royal Purple and I noticed that it had a tad more low end oomph and the engine was actually running quieter and smoother. I'm thinking about buying Royal Purple for my 4.0 jeep, along with Puralator Pure One oil filter. Would this be a good idea, or would you recommend a different engine oil for a jeep 4.0 engine?
Intake: I currently have a pretty old ebay intake system. The filter is still good. Should I keep it or should I buy a stock intake and install a K&N panel filter?
Exhaust: My jeep is the california emissions model, meaning that it has the main catalytic converter and the two other cats near the headers. I won't say what I did to the main big cat. :shhh: I'm going to replace the old rotted flowmaster with a new flowmaster, same model(40 series delta flow) instead of the louder original 40 series or super 40 series, because I don't want to attract bad attention and my mom still drives it occasionally when she needs to go somewhere. Should I run a 2.25 pipe from header to muffler and 2.5 inch after muffler or vice versa? Or 2.5 inch all the way for the stockish 4.0? I don't want to really hurt low end torque.
Cooling: I have a 180 thermostat, but it can only keep the temps down for a certain amount of time. With 90 degree temps in stop and go traffic, it stays slightly above 210 and slightly below when cruising, especially with head-wind. It takes much longer to reach that temp since I took off the factory insulation heat shield that was on the intake manifold. This removal even fixed the hot re-start piston #3 and #4 misfire
. This heat shield was actually holding a lot of heat, especially where the headers split and where the 0331 head would crack. Personally, I believe some early model 0331 heads would crack not only because of the thinner casting, but also because of the hot spot created by the factory fiberglass-aluminum heat shield mat. The bottom of the engine bay has a black plastic mat, which I believe is also blocking hot air from escaping the bottom of the engine compartment. Should I remove that? My dad's old lifted 98 4.0 cherokee always stayed below 210 with just the 180 degree thermostat and it didn't have this mat. Future mods: bored stock throttle body and superchips flashpaq.
Further down the future: Replacement "TUPY" 0331 head or Alabama cylinder head with a thinner mopar performance head gasket to raise the compression ratio a bit. :repair:
I'll appreciate any advice and I'm thankful to be back in
. 
