z24i in a 720 project swap thread

[sick620]

should I save this D21 or part it out and use the motor and tranny in my 720? I got them both for parts originally. stole the head, flywheel, and timing cover off the bad l20b in the 720... Was planning on using the powertrain from the d21 in the 720 but I feel bad because it started right up and runs pretty good... D21 only has 123k miles, its in fairly good shape for sitting in a field for a while, but someone cut the roof off in california, then when it came to idaho it was glued back on with like caulk or something... Would you use this d21, weld the roof back on better and drive it... or use it for parts? I don't want to have two junky trucks sitting around so I need to make a plan... I plan on keeping the 720 for sure, but if I don't use the motor and tranny out of the d21 I will have to rebuild a motor and source a l20b head, timing cover, and a flywheel... 

 

my options as I see them...

1. Sell the D21 as a running truck for 1k or so and use that money for some of the 720 engine rebuild and finding the parts I need..

 

2. take out the d21 drivetrain and scrap it or part it out, maybe make a bed trailer out of it....use the drivetrain in 720

 

3. clean up the d21 keep it as a beater dump run truck

 

4. weld the roof on better and make it kinda nice? 

 

 

Edited July 14, 2022 by sick620

[datzenmike]

 Looks like maybe that's a Z24i engine?

[sick620]

41 minutes ago, datzenmike said:

 Looks like maybe that's a Z24i engine?

Correct z24i with the 4 speed 1988 truck

 

if I use the power train out of d21 I plan on ditching efi and I have some of the parts to convert it to normal z24

 

720 is a 1980 l20b 5 speed

 

want to see what you guys think about the d21 with its wierd cut off roof … worth saving or part it out?

Edited July 1, 2022 by sick620

[datzenmike]

Easiest to keep the D21 and fix the roof. Put a removable vinyl cover on it. Like a button down toneau.

[Crashtd420]

Or cut the roof back off for a summertime cruiser.... 

Add a jeep style roll cage and soft top...  

[bilzbobaggins]

Running driving hardbodys fetch a quarter around here in meh shape.  Shame they cut the cab up.

[sick620]

I think i've decided to part it out and scrap the remains... got the title today and it came with 3 bill of sales, one from original owner to someone, then that someone to someone else etc.. I don't want to deal with making that legit. so its a parts truck if anyone needs anything cheap engine and tranny are being used for 720

Edited July 2, 2022 by sick620

[datzenmike]

Had H-190 differential 3.889 or 3.70 ratio. Check the engine plate inner passenger side fender below the hood hinge.

 

What year 720? should put this in your profile.

[sick620]

1 hour ago, datzenmike said:

Had H-190 differential 3.889 or 3.70 ratio. Check the engine plate inner passenger side fender below the hood hinge.

 

What year 720? should put this in your profile.

1980 720

Edited July 2, 2022 by sick620

[datzenmike]

'80... then grab the front brakes, hub, spindle, rotors and calipers from the D21 also.

[sick620]

okay so along with motor tranny and driveline I should also grab rear end or no? 

okay I'll deff get the front hub stuff and brakes I assume that will let me run drop spindles too so thats nice good idea... 

[Crashtd420]

2 hours ago, sick620 said:

okay so along with motor tranny and driveline I should also grab rear end or no? 

okay I'll deff get the front hub stuff and brakes I assume that will let me run drop spindles too so thats nice good idea... 

I'd check the rear end.... 

I know early 4 cylinder d21 could possibly have a lsd rear end....

 

[datzenmike]

They did but it was only optional on the KA powered ones... '88-'93. 

 

Just saying that it would fit your 720. You could also sell it.

[Stoffregen Motorsports]

Donor. Lots of good parts there. Nuts and bolts, hose clamps, brakes, etc. I wonder if the D21 fuel tank is close enough to fit into the 720.

[datzenmike]

It will have the high pressure submerged electric pump in it.

[sick620]

I wonder how difficult it is to save all the throttle body injection bits and retrofit. 

 

edit

found this how to, and I think I might try to do this I mean why not I have everything.. 

http://nissannut.com/projects/z24i_fuel_injection/

This would be perfect for the 720 to just make it a reliable driver etc.. 

Edited July 3, 2022 by sick620

[sick620]

will the d21 bellhousing go onto the original Lseries 5 speed in the truck?

[datzenmike]

Yes.

 

You will need to remove the 56mm countershaft bearing from the 5 speed. Easy enough with a gear puller. Then source a new 62mm D21 counter shaft bearing and hammer it onto the 5 speed. You will need to use the D21 cover plate which is sized to fit the 62mm bearing.

 

The top shift rod hole for 1st/2nd in the D21 front case is 2mm larger than needed but I don't think this will affect anything.

 

That should do it and allow the Z series 71C front case to fit the 71B transmission body. I don't see any problems.

 

[sick620]

Ok well I think i've decided to change the 720 over to TBI using all the bits from the d21. I'll install the z24I full setup in the 720... Probably use the 5speed in the 720 and do the bellhousing swap. Ill save spindles brakes etc from the hardbody and maybe the rear-end... try to sell the hood, bed, and other body panels, or possibly make a bed trailer before scrapping the remains...

 

mike can you move this thread to 720 or project datto? I'll document what I do to get this swap working in the 720.. 

Edited July 3, 2022 by sick620

[sick620]

Ok now that I have my plan (thanks for your input) do you think it's wise to replace head gasket along with other gaskets while I have it out, maybe valve stem seals etc... Or just retorque head and run it until it has issues one day and do a full rebuild then? engine has 123k on it 

 

I'll probably start working on pulling engine and carefully labeling the wire harness this week sometime

[datzenmike]

Don't fix what isn't broken. Head gaskets don't leak oil. Valve cover and oil pan gaskets can and do. If you want to renew them while the engine is out, fine. 

 

The Z24 engine should have the head bolts loosened and re torqued separately once a year, yes.

 

You can easily replace the valve stem seals with the head on. Those are cheap and easy to do. If it's not smoking then why bother? Drive it and see first.

[Stoffregen Motorsports]

22 hours ago, datzenmike said:

It will have the high pressure submerged electric pump in it.

Does the Z24i require high fuel pressure? Or is it a low pressure EFI system?

[sick620]

It’s 45psi by what I’ve read…

[datzenmike]

36.3 when engine running +- as pre FSM but the pump has to be capable of at least this and probably more. The FPR (fuel pressure regulator) sets the injector pressure and returns any extra to the tank.

[bottomwatcher]

You guys are talking about swapping in a motor that makes about 15 hp more and parts that are 34 years old. Doing this is upgrading his power train by less than 10 years. Find a hardbody with a ka or frontier. These are cheap and in your neck of the woods not rusty shit. It doesn't take much of an accident these days for them to be totaled. Every decade parts are infinitely cheaper and easier to find just because of the shear number of hard bodies produced over the 720s and the frontiers over the hard bodies. My 82s drivetrain is long gone and good riddance chasing down obsolete parts,  you got both trucks now so I guess it is nothing but time so have at it if that's what floats your boat   For the time involved a few dollars more for a more modern engine/drivetrain would lead to much more satisfaction at the end.