z24i to z24 conversion

[Logical1]

I have been following this thread and you are not the only one to say that their z24 is underwhelming. I am very curious as to how the many many z24's and 720's are different. My 85' 4x4 with a weber 32/36 rips ass! I was doing an easy 75 on my way home from work yesterday and could hit 90+ easy if I goosed her. I have the exact same tire size as well. Nothing special done to my engines besides direct wiring them as I showed earlier. I do have 2" exhaust with a resonator and no muffler. 

[powderfinger]

That's more of what I would expect and this same engine was in my 2wd and ran great. This truck does still have an extremely old exhaust on it with a cat. I already dumped a lot of shit out of the muffler (small metal/medium flakes) before I put it back on but I did verify I could see though the cat before putting it back on. I would think if the exhaust was too restrictive for whatever reason it would be running a little rich but it isn't.

 

I plan to replace the entire exhaust because it has several leaks and is pretty rusty. When I do, I'll just get rid of the cat.

[datzenmike]

The Z24 is definitely not a ball of fire. The Z24 makes really good torque at low speeds (I heard 130 @ 2,800) which is what you need for pulling a heavy truck, however though it breaths just fine at below 3k it's running out of breath above 4k. Very good on emissions and mileage but this is because of the head design. It was purpose built for low emissions and good torque for highway speeds. Though the carburetor is larger than the earlier Z22 it seems restrictive and a Weber 32/36 will probably work wonders.

 

 

[bottomwatcher]

Check your compression to get an overall view of your engines health. If it is tired you may be stuck with what you have. When I was running a Z24 in my 4x4 I would fine tune the timing by ear up a slight hill. Basically advance in small stages until it would ping and then back up one stage. Seemed to waken the motor up some. Also when doing this time your 45 to 60 time in 4th gear. Sounds wierd but when you eliminate shifting and spread your time over a longer spread improvements in performance become more obvious.

[Logical1]

I had an 84' 4x4 with an engine that was TIRED, all stock with really bad compression numbers... Strapped a weber on, put 2" exhaust, got rid of the cat, direct wired it and it still got me across 6 states on a trip at over 70+mph

[bottomwatcher]

Yeah I ran a Weber for over 15 years. Wore it out, rebuilt it with the sealed bearings and ran it for another 5. They are good carbs and do add a few hp. I was running 31s and drove the truck from Florida to Oregon anually. With all my windsurfing gear on the roof and the winds in the west 65 was about my max. Montana was always a disappointment with thier lack of speed limits and the fact I simply couldn't go any faster. I cured the low power issues of the Z24 with a KA swap. In a stock truck the Z24 is fine. Start adding larger tires, start losing power.

[Thomas Perkins]

No complaints with my 2.4 engine and Weber and no cat.I had a Jasper engine put in back in 2009,now have 90,000 miles on it.I have been using 235-70-15 on mine for 28 years.Just put new All terrain BF Goodrich with black American Racing rims.I tried 31's back in 2000 cause I bought some tires and rims from a guy that had a Toyota,the tires rubbed real bad and I put 235-70-15 on them rims and not long ago a guy with a 95 Nissan truck bought them from me..When I bought my new tires,I bought 5 of them.My bottom end and top end is good.Can't go too fast here,Johnny law are everywhere.My Transmission is only about 4 years old with a brand new yoke.When I bought my 720 back in 94,it had 235-70-15,so I can't compare it with other tires.Had my front end aligned with new tires.That guy is a pro,. Steering wheel is so straight.It was 65 bucks to do it.See how my new A.C. hose goes down the firewall versus coming over the engine.Abrand new complete custom made heating and air.

Edited April 2, 2022 by Thomas Perkins