ShutterMeShort 32 Posted October 6, 2014 Report Share Posted October 6, 2014 Hello all! I'm Robert and I am new to Ratsun. I recently aquired my grandfathers 1983.5 720 standard cab. The truck has been in the family since mile 0 and I've been eying it for a while now! I'm so excited to tear into this awesome little truck and bring some life back to her! It has the Z24 engine with a nasty wrist-pin knock. I'm wanting to upgrade/update the engine to the KA24 out of a 240 or a Frontier but am still a little unsure. I may just rebuild the engine and call it good. Anywhoo, I have my first post here --> http://shuttermeshort.blogspot.com/2014/08/grand-pas-truck-day-1.html with even more info and photos. I hope you all like it and i'm hoping to learn a lot from this community! (already have!) Robb 2 Quote Link to post
WI 720 59 Posted October 6, 2014 Report Share Posted October 6, 2014 Thanks for posting. It'll be interesting to see what you do with it. I have an 82'that I've been working on. Quote Link to post
ShutterMeShort 32 Posted October 6, 2014 Author Report Share Posted October 6, 2014 Thank you! I've got my work cut out for me for sure! This will be a somewhat slow build but ill make sure to keep the blog and this thread updated! 1 Quote Link to post
datzenmike 39,280 Posted October 7, 2014 Report Share Posted October 7, 2014 Use the truck KA, it's lighter and the oil pan fits. The 240 engines are front sump and the crank girdle prevents a truck oil pan from fitting. Any engine sounds could be a misdiagnosis. How many miles are on the 'old girl'? Maybe check set the valve lash (0.013") Quote Link to post
ShutterMeShort 32 Posted October 7, 2014 Author Report Share Posted October 7, 2014 Its a loud knock that is at crank speed (as opposed to valve train speed) and is only present and varies under load. I pulled the valve cover and spun things and it looked okay - didn't measure lash. Quote Link to post
ShutterMeShort 32 Posted February 2, 2016 Author Report Share Posted February 2, 2016 So the truck is up and running! I'm still hashing out some small details and tightening up loose ends but she purrrrs! I ended up rebuilding the Z24 instead of swapping. It turned out to be a bad crank journal. Here's my day 2 & 3 post. http://shuttermeshort.blogspot.com/2016/01/grandpas-truck-day-2-and-3-engine.html Enjoy! Feedback is always welcome! Quote Link to post
ShutterMeShort 32 Posted February 5, 2016 Author Report Share Posted February 5, 2016 Latest update is up! http://shuttermeshort.blogspot.com/2016/02/grandpas-truck-day-4-and-5-engine-prep.html Quote Link to post
ShutterMeShort 32 Posted December 31, 2020 Author Report Share Posted December 31, 2020 (edited) Okay, this has taken forever to get around to but a lot has been happening! I got the engine together and running well. It lasted about 2k miles and appears that the rings didn't set right. I had carb issues when I first started it and think the cylinder walls got fuel washed. Engine will be coming back out soon.... 😞 Moved in order to help my mom since my dad just passed and started my own shop back in my hometown of Bishop, CA. In the meantime I have gotten around to some of the suspension and interior. Suspension: 3" napa blocks with a 2 degree shim, U-bolts from sdtrucksprings.com (thanks Crash), and Beltech drop spindles, and Procomp wheels. New KYB shocks all the way around and new brake lines as well. As a note, the Beltech 5456 sway bar does NOT fit the 720 even though it is listed under the vehicle selection. 😞 Hardbody only. Went with the Napa sway bar bushings instead (didn't really NEED a thick sway bar). Interior: Rust repair on passenger floorboard and Herculiner (3 coats). Tires and Wheels: 15x8 ProComp 69's wheels 205/50 R15 Nitto NeoGens I still have a very cracked dash that I'm trying to figure out what to do with. Seat upholstery (or MAYBE buckets) is next. Also, any suggestions or inspiration on redoing door cards? Edited April 9 by ShutterMeShort 3 Quote Link to post
ShutterMeShort 32 Posted January 27 Author Report Share Posted January 27 (edited) Work continues... My Weber flooded the engine so bad that it washed the cylinder walls of oil. Waiting to see if a hone can take care of it or if it needs to be bored out and new pistons. I'm still convinced that carbs are the devil... Engine is back out and at the machine shop. Seat is at the upholstery shop. I'll post interior photos once I get the seat back. Going black vinyl and fabric to match the floor. Here's a few others. Pretty happy with the suspension and wheel/tire set-up so far! Sorry if you've seen a couple of these in another thread Edited January 27 by ShutterMeShort 2 Quote Link to post
Lockleaf 5,007 Posted January 27 Report Share Posted January 27 This has no bearing on your engine, but fyi, your center console gauge bezel is in upside down. Its supposed to provide shade to the gauges so you can see them. Quote Link to post
ShutterMeShort 32 Posted January 27 Author Report Share Posted January 27 50 minutes ago, Lockleaf said: This has no bearing on your engine, but fyi, your center console gauge bezel is in upside down. Its supposed to provide shade to the gauges so you can see them. I realized that about a month ago. Truck came with it that way and I was a bit confused! lol Thanks! Quote Link to post
Lockleaf 5,007 Posted January 27 Report Share Posted January 27 If its any consolation on the engine, the very first Z24 I rebuilt, I put the main bearings in upside down and completely blocked off all oil flow to the rotating assembly. Brand new pistons, rings, bearings, etc. The only oiling was the engine assembly lube I used and splash oiling. It ran for about 30 minutes before locking up completely. Destroyed 2 of the pistons completely. I was in too deep to totally give up though. So I pulled a crank and 2 rods/pistons out of an engine in the junkyard, honed the galled aluminum off the cylinder walls, and reassembled that hunk of junk with new bearings and seals again. Never was a very good engine though and eventually it just got swapped out to one I pulled from a parts truck I bought. Though that engine is still in it, it hasn't ever been very good either.... 😄 Quote Link to post
ShutterMeShort 32 Posted January 28 Author Report Share Posted January 28 (edited) 7 hours ago, Lockleaf said: If its any consolation on the engine, the very first Z24 I rebuilt, I put the main bearings in upside down and completely blocked off all oil flow to the rotating assembly. Brand new pistons, rings, bearings, etc. The only oiling was the engine assembly lube I used and splash oiling. It ran for about 30 minutes before locking up completely. Destroyed 2 of the pistons completely. I was in too deep to totally give up though. So I pulled a crank and 2 rods/pistons out of an engine in the junkyard, honed the galled aluminum off the cylinder walls, and reassembled that hunk of junk with new bearings and seals again. Never was a very good engine though and eventually it just got swapped out to one I pulled from a parts truck I bought. Though that engine is still in it, it hasn't ever been very good either.... 😄 OUCH. Yeah, thats a mistake you only make once! lol! The kicker on this one for me is that I'm only rebuilding it to pass CA emissions then I'm looking for something else to put in it. The regulations here are pretty hard when you swap motors to something else. It can be done but its a PITA... I'll be keeping my eye out for a KA24 out of a newer truck - no more carbs!! Edited January 28 by ShutterMeShort Quote Link to post
datzenmike 39,280 Posted January 28 Report Share Posted January 28 Don't you have to re-smog every year or two? Quote Link to post
ShutterMeShort 32 Posted January 30 Author Report Share Posted January 30 (edited) On 1/27/2021 at 8:00 PM, datzenmike said: Don't you have to re-smog every year or two? Negative. I live in a change of ownership area only. Only when a vehicle enters the state or registration changes ownership or area. I'm not planning on selling so I'm good to go. If I do sell it will have to be out of state or I revert everything back... Or sell it as non-op trailer baby. I'm currently finishing up everything I need for me and my shop to be Smog check and repair certified. Got about another month to go. Edited January 30 by ShutterMeShort Quote Link to post
carterb 3,812 Posted January 30 Report Share Posted January 30 Awesome build! I hope you are able to get back on the road soon and enjoy your (re)creation. Quote Link to post
ShutterMeShort 32 Posted January 30 Author Report Share Posted January 30 (edited) 25 minutes ago, carterb said: Awesome build! I hope you are able to get back on the road soon and enjoy your (re)creation. Thanks bud! It's been a long time coming. (almost 7 years) Just got the seat back yesterday and set it in. Pretty happy with it! Man I wish I had the skills and patience to do upholstery - it's definitely an art form! I think I'll stick to engine and suspension. lol Edited January 30 by ShutterMeShort 3 Quote Link to post
iceman510 69 Posted February 3 Report Share Posted February 3 If you want to get away from carbs, there are Hardbody trucks that have the Z24i with fuel injection, up through '88 I think. Maybe even the last of the 720's are FI (can't recall right now). Quote Link to post
Lockleaf 5,007 Posted February 3 Report Share Posted February 3 Yeah the 86 720s are also FI. I think possibly even some late 85. Although honestly if I were going to do the swap, I would consider using the late 80s GM s10 throttle body FI. Parts are WAY more common and available than the z24 FI stuff. Quote Link to post
datzenmike 39,280 Posted February 4 Report Share Posted February 4 April '85 and up were Z24i. So were the '86.5 through '88 D21 Hardbody and Pathfinder Z24i but there were lots of parts that would not interchange. Quote Link to post
ShutterMeShort 32 Posted February 5 Author Report Share Posted February 5 No reason to stick with the Z24 or Z24i CA emissions makes it the easiest to keep the Z24, not the Z24i - stupid, I know... So i'm going to pass emissions with the factory Z24 and then source a KA24. Much better parts and aftermarket support. More power and more reliability as well. Just a waiting game for the right KA to come around Quote Link to post
ShutterMeShort 32 Posted April 9 Author Report Share Posted April 9 Just added the wheel and tire set-up. Been meaning to do this! 15x8 ProComp 69 wheels 205/50 R15 Nitto NeoGens Quote Link to post
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