Z24i INFO/Performance?

[datzenmike]

Z20 is just an L20B with a different head. They will run at redline all day. The cranks are fully counter weighted and rev smooth. With 4.375 gears and one to one 4th gear you will run out of power to push through the air long before blowing it up. 100 MPH with your gears and a 26" diameter tire is only 5,650 RPMs.

 

Oh, BTW 60 MPG is under 3,400 RPMs.

[Zfighter76]

Z20 is just an L20B with a different head. They will run at redline all day. The cranks are fully counter weighted and rev smooth. With 4.375 gears and one to one 4th gear you will run out of power to push through the air long before blowing it up. 100 MPH with your gears and a 26" diameter tire is only 5,650 RPMs.

 

Oh, BTW 60 MPG is under 3,400 RPMs.

*mph. i just wasnt sure when i was driving. i guess im used to bugs and having the loud carbs behind me so i was alarmed by how loud this thing is with open throats. thanks for the reassuraance though. also i have been cruising at half throttle because my linkage was hitting, which i fixed. now burnouts last longer :) i had to extend the actual part of the linkage that pushed down on the tie rod thing to move the butterflies. the tie rod was hitting on the synchronizer balance adjuster thing. sorry i dont know all the nomenclature when it comes to these carbs. and what would it be like if i put my 280z 4 speed trans in it? would it be beneficial? at all.

[datzenmike]

The lower ratos are likely closer together but 4th gears in all 4 speeds are the same one to one, so they would go the same speed. The 280z tranny would be stronger than what's in there now but you would ned to motthe mount and drveshaft on the truck.. This is an early 620 with Z20 multi carb, right?

[Zfighter76]

yeah, its a '73 620 with a z20 block and a z24 head with dual sidedraft webers. what about the 280z rear diff? will that drop in and help overall speed? the custom mount would be no problem, mine is kinda custom now due the the trans tilt with the l series trans and z motor. everyone said the shifter would tilt towards the passenger side but it actually tilts towards me. ik had to bend the shifter

[datzenmike]

yeah, its a '73 620 with a z20 block and a z24 head with dual sidedraft webers. what about the 280z rear diff? will that drop in and help overall speed?

 

You have a solid truck H-190 with leaf spring rear end while the 280z/zx uses a totally different IRS R-180 diff.

 

 

the custom mount would be no problem, mine is kinda custom now due the the trans tilt with the l series trans and z motor. everyone said the shifter would tilt towards the passenger side but it actually tilts towards me. ik had to bend the shifter

 

The shifter will tilt to the right if you use a later Z series 5 speed on an L motor. An L series is is the most common motor in a Datsun, so many ask if they can install an easy to find Z series truck 5 speed in their dine. Because the L motor is leaning over to the right, the Z tranny must rotate to the right for the bolts to line up. In your case you have gone the other way and installed a Z motor, so the L tranny must rotate to the left for the bolts to line up. In either case a big problem is the rear mount is tilted. More than that it raises the tailstock too unless the mount is removed and properly cut and welded back on.

[Zfighter76]

You have a solid truck H-190 with leaf spring rear end while the 280z/zx uses a totally different IRS R-180 diff.

 

 

 

 

The shifter will tilt to the right if you use a later Z series 5 speed on an L motor. An L series is is the most common motor in a Datsun, so many ask if they can install an easy to find Z series truck 5 speed in their dine. Because the L motor is leaning over to the right, the Z tranny must rotate to the right for the bolts to line up. In your case you have gone the other way and installed a Z motor, so the L tranny must rotate to the left for the bolts to line up. In either case a big problem is the rear mount is tilted. More than that it raises the tailstock too unless the mount is removed and properly cut and welded back on.

yeah i had to work the rear trans mount to get it on there. my friend just thought maybe we could swap the rear gear into the housing of the solid axle. sounds like a stretch but i know rear end swaps on 510s are common, like a 280z gear will fit into a 510 housing. so the gear from the 280z will not fit in my housing correct?

[Zfighter76]

and i guess i got alittle carried away with how fast i thought it was, its no doubt pretty quick but itts about even with a stick shift miata so... and its not like i know because i was racing or anything. lost :( but it was wet and you know how trucks do in the wet.

[Zfighter76]

but still enough power to smoke the tires and all none the less

[datzenmike]

yeah i had to work the rear trans mount to get it on there. my friend just thought maybe we could swap the rear gear into the housing of the solid axle. sounds like a stretch but i know rear end swaps on 510s are common, like a 280z gear will fit into a 510 housing. so the gear from the 280z will not fit in my housing correct?

 

510s use an R160, the 280z/zx use an R-180. See how they are similar? Basically the same case just different diameter crown gears. The truck is an H-190... think apples and oranges.

[Zfighter76]

gotcha, i didnt know what the numbers meant haha. whats a good rear gear possibility? maybe a form of lsd, like ive heard detroit lockers are available for the 620 but what would be a good size gear to get, and at where could one be had?

[datzenmike]

The LSDs start at $500 and are unavailable except used on E-Bay.

 

Your gearing is fine. Anything higher like a 4.11 or 3.90 will cut into the acceleration.

[Zfighter76]

i what about that 280z trans swap? would that raise my overall gearing? i know it cuts into acceleration but if it will take the gear higher so i dont have to cruise in 4th gear so i dont sound like some showoff ricer rolling down the street at high rpms? and ive been told that using a switch to turn off the exhaust coil raises performance on the z series dual plug engines at high rpms. is there any truth to this? i know it quiets it down, but is there even an advantage at a performance standpoint?