720inOlyWa Posted December 30, 2014 Author Report Share Posted December 30, 2014 Belt tensioners use an ordinary sealed bearing you can change out. No need to replace the pulleys. So I discovered today! Way cool. It is colder than shit right now, so it might have to wait a day or two to go back in. Thanks! 1 Quote Link to comment
Charlie69 Posted December 30, 2014 Report Share Posted December 30, 2014 Stay warm and enjoy your family and the New Year. 1 Quote Link to comment
720inOlyWa Posted January 6, 2015 Author Report Share Posted January 6, 2015 Well, I took your advice, Charlie, and spent Christmas Eve with the relatives, at least two of whom were very sick and should not have been there. So now look what good it did me: I have been suffering through the worst head cold ever experienced in human history over the last few days. Thanks, rellies. Happy whatever to you, too. I’d like to rip my nose off my face so that II could really get in there and scratch whatever it driving me crazy, once and for all. It’s only a nose. Michael Jackson didn’t need one. So we have finally found out what it takes to keep me away from the trucks for a few days: the brutal bug. (Full disclosure, I did stop by Les Schwaub for a set of safety-siped tires yesterday, but that was the sum total of my activity for the week, so far. I had hoped it might make me feel better. It idid.) You do not want this bug, man. Brutal! 1 Quote Link to comment
Charlie69 Posted January 6, 2015 Report Share Posted January 6, 2015 Man I did not tell you to kiss your relatives! LOL I hope you get better soon. I knew it would not keep you away from your truck completely, Tires! LOL Quote Link to comment
720inOlyWa Posted January 7, 2015 Author Report Share Posted January 7, 2015 Well, you could have told me so- and several did! I forget now just who told me that my ‘junker head gasket rebuild’ would be good for only 4,000 miles or so, then I would be right back where I began. I need to remember, because I am at 3,984 since the key turned again, and that person wins the prize! I can tell she is starting to leak a little, so I have grounded the Fudgecicle, until the head gasket job has been redone correctly. I began to pull it apart today, with an eye towards jerking the engine this weekend, if it is doesn’t rain. So I took a gamble and lost, like everyone said I would. Oh well. I enjoyed the last few months of driving so much that it is really a bit of a relief and a delight to tear it all down and start fresh. I enjoy seeing the fresh engine rebuilds in the Ratsun treads, and I know how good it feels to drive a vehicle where everything is like new again. So I’m excited to get it out of there and down to Johnson’s machine shop. 1 Quote Link to comment
Charlie69 Posted January 8, 2015 Report Share Posted January 8, 2015 You did not lose! You gained experience and knowledge plus 3,984 miles in your Datsun!!! 2 Quote Link to comment
720inOlyWa Posted January 13, 2015 Author Report Share Posted January 13, 2015 The new head showed up today. I was hoping that if I left it on the hood long enough, it might find its own way home. You know, self-install... 3 Quote Link to comment
81SVN20 Posted January 14, 2015 Report Share Posted January 14, 2015 Nice and I see its a kangaroo head.... 2 Quote Link to comment
720inOlyWa Posted January 14, 2015 Author Report Share Posted January 14, 2015 Nice and I see its a kangaroo head.... Why... you’re right! I hadn’t noticed that before. Toss another head on the barbie! Supposedly, harder valve seats, better guides, and a little more aluminum near the seats. We shall see... I do like that it is Aussie made, however. They love their 720s over there almost as much as they did on Guam! 2 Quote Link to comment
Lockleaf Posted January 14, 2015 Report Share Posted January 14, 2015 Curious, how can you guys tell it's the head from Oz based on the pics? 1 Quote Link to comment
wayno Posted January 14, 2015 Report Share Posted January 14, 2015 3rd mark down is a kangaroo. Curious, how can you guys tell it's the head from Oz based on the pics? 1 Quote Link to comment
_chiefjt Posted January 14, 2015 Report Share Posted January 14, 2015 I have a kangaroo also. Didn't know the difference but read there was. 2 Quote Link to comment
720inOlyWa Posted January 14, 2015 Author Report Share Posted January 14, 2015 A roo head! I am psyched! I can’t tell you why, but I am psyched. Those Aussies are decent blokes, hardly a barstid amongst ‘em. They know their trucks and they operate them in a harsh environment- all good signs for my ‘roo head. They know how to race sailboats real good, too. I may need to take a flat file and face up and polish my little ‘roo there. I am psyched! As I type this post, I am whittling down my work list for the day with an eye towards pulling the top off of my 720. Maybe I can get it all buttoned back up by tomorrow afternoon, if I get on a wave. Good news is, this is all territory that has recently seen and experienced my cleaning and lubrication wrath, so it should all come apart fairly easily. This time I don’t have to learn that you have to shoot the lower rear intake manifold nut with a flexible and long extension on the ratchet wrench. Should go nicely. I have had an old school torque wrench, the kind with the pointy bar that sweeps across the little plate with numbers, for many years. It works okay, if you pay attention. I think that it works fine. But ever since I began working on the Rolls Merlin engines at the Hydroplane & Raceboat Museum, I have wanted a clicker type torque wrench. I mean, that’s the real deal, isn’t it? Well, I sprung for one yesterday. Stopped at Sears and walked out with a cylinder hone and a clicker torque wrench with a 14 mm, 1/2 inch drive deep socket. Just imagine, if you can, the sense of contentment I am going to enjoy when I torque on my new ‘roo head tomorrow with my clicker torque wrench. Holy shit, a happy man! 2 Quote Link to comment
wayno Posted January 14, 2015 Report Share Posted January 14, 2015 I like the clicker type myself, it's easier to get them all even. 1 Quote Link to comment
720inOlyWa Posted January 15, 2015 Author Report Share Posted January 15, 2015 Did the engine bay tear down today. Ready to remove the head tomorrow. If I decide to do the rings, which I well might, do I have to pull the engine to do it? And if I have to pull the engine, is it easier to just pull the engine without the trans, with all of the head, etc.. removed, as opposed to pulling it with the tranny too? 1 Quote Link to comment
wayno Posted January 15, 2015 Report Share Posted January 15, 2015 It's a lot easier to do engine internal work with the engine on an engine stand, you have to remove the rod ends, so you have to remove the oil pan, doing all that under a truck is a pain in the ass, and a pain in the neck also, pull the engine if your going to do rings, it should be measured anyway if your re-ringing it, maybe it needs bored. Leave the trans in, drop the idler arm down when un-installing and installing engine, Did the engine bay tear down today. Ready to remove the head tomorrow. If I decide to do the rings, which I well might, do I have to pull the engine to do it? And if I have to pull the engine, is it easier to just pull the engine without the trans, with all of the head, etc.. removed, as opposed to pulling it with the tranny too? 1 Quote Link to comment
84720FourWheel Posted January 15, 2015 Report Share Posted January 15, 2015 If you can get the oil pan off, you could probably do rings with the engine in. But then you'll have to roll under it to unbolt the rods and push them up. I think it'd be easier to do with the engine out. Its easiest to pull the engine with the transmission and separate once they are out. I think the chain hooks are bolted into the head, so it'd be easier to pull with the head. You'll have to remove the hood also. Be sure to mark how the hinges line up. 1 Quote Link to comment
720inOlyWa Posted January 15, 2015 Author Report Share Posted January 15, 2015 It's a lot easier to do engine internal work with the engine on an engine stand, you have to remove the rod ends, so you have to remove the oil pan, doing all that under a truck is a pain in the ass, and a pain in the neck also, pull the engine if your going to do rings, it should be measured anyway if your re-ringing it, maybe it needs bored. Leave the trans in, drop the idler arm down when un-installing and installing engine, That does it- Im pulling it. 2 Quote Link to comment
harlow426@mail.com Posted January 15, 2015 Report Share Posted January 15, 2015 Air cleaner colors....stock. I have two z-24 air cleaners that are "aqua". Both off of stock 2wd 83' 720s. know of another 83 720 w/z24 with aqua air cleaner. Maybe they used up the old stock from the 82' z22's in 83 on the z24s. 1 Quote Link to comment
harlow426@mail.com Posted January 15, 2015 Report Share Posted January 15, 2015 When removing hood....drill an 1/8" hole thru hinge and hinge pocket in hood(both sides). U can then slip in the shank of an 1/8 bit to re-align holes later on. Don't drill all the way thru the hood..... Dab some good oil based paint on bare metal where u drilled.....or some vaseline/crisco if that is all u have. U can use same method when removing doors/trunklids, etc. 2 Quote Link to comment
harlow426@mail.com Posted January 15, 2015 Report Share Posted January 15, 2015 If you are going to re-ring.....avoid over-boring if possible. Only remove .010 if that cleans them up. Bigger pistons move slower due to reciprocating mass...in other words bigger pistons accelerate and decelerate slower. I'd use soft cast rings(on orig pistons) and put a good crosshatch in bores w/flex hone. I think bumping compression via decking block ok.....USE A TORQUE PLATE WHEN BORING/HONING(crank mains, head bolts need to be in place and torqued B4 u machine OR MEASURE). If machine shop doesn't have one....find different machine shop. 2 Quote Link to comment
720inOlyWa Posted January 15, 2015 Author Report Share Posted January 15, 2015 As we are pulling things apart again, we are rebuilding them thoroughly, as needed. I felt some play in the upper idler pulley, so when I removed it, I set it aside for further inspection. Then I scanned the threads here for the one about replacing idler pulley bearings and set about beating it all apart last night. I figured it would be better to replace the bearings with new rather than find one with just as many miles on it in a junk yard. This morning, I found the bearings locally and pressed them into the pulley using my vise. The old bearings had King Tuts grease in them and despite being internal to the pulley, their open faces allowed dirt and grime in. They weren’t toast yet, but they were getting there. Once cleaned, they were loosey goosey and crunchy too! The job of replacing them was fun and satisfying. The new bearings are sealed. I got enough for the upper and lower pulleys. All ready to go. A good rainy day project, I got the lower one off before the squalls hit. It is apart and soaking now. I wish there was a rattle can version of this paint. Rustoleum satin finish ‘Lagoon’ blue aint quite it. I really like this color. I know it’s baked enamel. 1 Quote Link to comment
datzenmike Posted January 16, 2015 Report Share Posted January 16, 2015 If you are going to re-ring.....avoid over-boring if possible. Only remove .010 if that cleans them up. Bigger pistons move slower due to reciprocating mass...in other words bigger pistons accelerate and decelerate slower. I'd use soft cast rings(on orig pistons) and put a good crosshatch in bores w/flex hone. I think bumping compression via decking block ok.....USE A TORQUE PLATE WHEN BORING/HONING(crank mains, head bolts need to be in place and torqued B4 u machine OR MEASURE). If machine shop doesn't have one....find different machine shop. I think you'll find that over size pistons are the same weight as the 'smaller' stock ones. Even if a few grams different they will... 1/ run better compression and power than what they are replacing and... 2/ there is a small displacement increase. 2 Quote Link to comment
datzenmike Posted January 16, 2015 Report Share Posted January 16, 2015 Nice and I see its a kangaroo head.... FS5W71C 1 Quote Link to comment
720inOlyWa Posted January 17, 2015 Author Report Share Posted January 17, 2015 Oh, it’s on, alrightie. Head is off and down to the machinist. Short block soon to follow... Quote Link to comment
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