Bender
NAXJA Forum User
- Location
- Cambridge, Ontario
So far about 600 miles on it so I'm still in the "break-in" period. I setup happens to be quite similar to Dino's "DR. DYNO" on this forum, minus a few items.
1989 4.0L block bored .030" over.
1989 Head milled 0.010" and reconditioned.
1987 "short snout" 258 Crank and rods
1989 fuel injection system with knock sensor and EGR system.
24# Accel fuel injectors...fuel pressure the stock 39 psi "effective".
Comp Cams 68-231-4
Mopar Performance valve springs, retainers, and keepers
Sealed Power 677CP pistons...the ones with graphite coated skirts
Fel-Pro standard gaskets
Estimated compression about 9.6:1
Estimated Displacement a tad under 4.6L
Initially I ran it for a few miles with the stock 19# injectors and found some pinging at any throttle over about 1/8. The 24# units seem to have done the trick as I have no pre-ignition although I am still running high octane gas for the break in. I'll soon start lowering my octane to see how low I can go. I'd love to run 87 but I'm hoping for 89.
The low end power is wonderful and the engine seems to be developing a nice feel as it breaks in. The shop I had do the work set the tolerances up fairly tight so the engine has been "loosening" up quite a bit as it breaks in.
The idle is very smooth...same as stock.
I do hear a little more valve train noise compared to stock which I partly attribute to the higher cam lifts and valve spring rates. I'm keeping an eye on this just in case.
I'm noticing a huge difference at highway speeds where I can pull hard up a hill in 5th gear where I previously would have to downshift. The driveability is quite nice as it is not jerky off the start but has good power from about 800 rpm and up. I don't really need to go over 1800 rpm driving around in the city and I accelerate the same if not more than the average motorist.
I haven't let this thing hang loose yet...waiting for about 1000 miles before I go WOT.
The entire cost into this project including the donor 4.0L..all 258 parts, injectors, machine work, etc...$1695 USD. Really there isn't much cost over a regular rebuild...just a little more for the cam, springs, and you need new injectors.
I'm a happy camper so far.
1989 4.0L block bored .030" over.
1989 Head milled 0.010" and reconditioned.
1987 "short snout" 258 Crank and rods
1989 fuel injection system with knock sensor and EGR system.
24# Accel fuel injectors...fuel pressure the stock 39 psi "effective".
Comp Cams 68-231-4
Mopar Performance valve springs, retainers, and keepers
Sealed Power 677CP pistons...the ones with graphite coated skirts
Fel-Pro standard gaskets
Estimated compression about 9.6:1
Estimated Displacement a tad under 4.6L
Initially I ran it for a few miles with the stock 19# injectors and found some pinging at any throttle over about 1/8. The 24# units seem to have done the trick as I have no pre-ignition although I am still running high octane gas for the break in. I'll soon start lowering my octane to see how low I can go. I'd love to run 87 but I'm hoping for 89.
The low end power is wonderful and the engine seems to be developing a nice feel as it breaks in. The shop I had do the work set the tolerances up fairly tight so the engine has been "loosening" up quite a bit as it breaks in.
The idle is very smooth...same as stock.
I do hear a little more valve train noise compared to stock which I partly attribute to the higher cam lifts and valve spring rates. I'm keeping an eye on this just in case.
I'm noticing a huge difference at highway speeds where I can pull hard up a hill in 5th gear where I previously would have to downshift. The driveability is quite nice as it is not jerky off the start but has good power from about 800 rpm and up. I don't really need to go over 1800 rpm driving around in the city and I accelerate the same if not more than the average motorist.
I haven't let this thing hang loose yet...waiting for about 1000 miles before I go WOT.
The entire cost into this project including the donor 4.0L..all 258 parts, injectors, machine work, etc...$1695 USD. Really there isn't much cost over a regular rebuild...just a little more for the cam, springs, and you need new injectors.
I'm a happy camper so far.