datzenmike Posted June 19 Report Share Posted June 19 Just above the starter ring teeth is a ledge. Measure up to the bottom of the head. Here's the L16. Notice the distance is wayyyy less. So here is the back side. What is it??? Quote Link to comment
Socalman Posted June 19 Author Report Share Posted June 19 1 hour ago, datzenmike said: Just above the starter ring teeth is a ledge. Measure up to the bottom of the head. Here's the L16. Notice the distance is wayyyy less. So here is the back side. What is it??? Wait! Is it a Z block with a L head? 1 Quote Link to comment
datzenmike Posted June 20 Report Share Posted June 20 Yup. Good running '84 720 Z24 which when I pulled it was marked on the flex plate '88 D21. So it was originally a Z24i switched to carburetor and swapped into a 720 that was in a wreck so I knew it was moving at the time. I had it briefly in my 620 and it ran smooth and quietly. When I got rid of the truck I pulled and saved it. Later I had a spare U67 head so I reworked it to unshroud the valves to fit the 89mm bore better. The L head is about 10cc smaller combustion chamber so compression would be 9.5 so a little material removed won't hurt anything. Quote Link to comment
Socalman Posted June 20 Author Report Share Posted June 20 16 minutes ago, datzenmike said: Yup. Good running '84 720 Z24 which when I pulled it was marked on the flex plate '88 D21. So it was originally a Z24i switched to carburetor and swapped into a 720 that was in a wreck so I knew it was moving at the time. I had it briefly in my 620 and it ran smooth and quietly. When I got rid of the truck I pulled and saved it. Later I had a spare U67 head so I reworked it to unshroud the valves to fit the 89mm bore better. The L head is about 10cc smaller combustion chamber so compression would be 9.5 so a little material removed won't hurt anything. Nice! Quote Link to comment
datzenmike Posted June 21 Report Share Posted June 21 Engine strokes of 2.65" or 67mm (or less) are safe at 9,000 continuous RPMs. The L16 is 73.7mm and safe at 8,250 RPMs. On stock rods/bolts you can buzz a little higher at your peril while rowing through the gears, but for sustained running keep below 8,400. The Z24 with a monster 96mm stroke quickly maxes out at just under 6,500 RPMs Quote Link to comment
mrbigtanker Posted June 22 Report Share Posted June 22 IS that my old windshield wiper motor ? And please tell me those wires are getting like massively cleaned up. Im shaking in my seat right now. 1 Quote Link to comment
Socalman Posted June 22 Author Report Share Posted June 22 9 hours ago, mrbigtanker said: IS that my old windshield wiper motor ? And please tell me those wires are getting like massively cleaned up. Im shaking in my seat right now. Yes it is. Wiring is pretty much stock, anything beyond following the manual or advice on here is past my abilities. Lol 1 Quote Link to comment
Socalman Posted June 22 Author Report Share Posted June 22 (edited) Can’t see much anymore anyway… Edited June 23 by Socalman 3 Quote Link to comment
Socalman Posted June 22 Author Report Share Posted June 22 Good news and bad, the headers for a ka24e truck fit but I lost my emergency brakes. 😢 4 Quote Link to comment
Socalman Posted June 23 Author Report Share Posted June 23 17 minutes ago, datzenmike said: Here I have a spare... lol. I also didn’t know my shifter location would be moved back with the 5 speed. I hope it’s enough room without hitting bench seat and will need to make a need tunnel cover. Tomorrow I’ll take out seat and measure for a new driveshaft. Quote Link to comment
datzenmike Posted June 23 Report Share Posted June 23 My 710 has the same length 4 speed as the 510/521 and the 71B 5 speed shifter comes out the same hole. Though the two transmissions are 5.5" different in length the shorter 4 speed shifter extends to the very back of the transmission and the 71B is slightly forward so the difference in shifter positions is much less than the 5.5" difference in length. Quote Link to comment
Socalman Posted June 23 Author Report Share Posted June 23 I can’t even see the shifter on mine yet. Quote Link to comment
datzenmike Posted June 23 Report Share Posted June 23 Oh wait! Is this a 71C from a 240sx?? That would be way longer than the 4 speed. Quote Link to comment
Socalman Posted June 28 Author Report Share Posted June 28 On 6/22/2024 at 7:13 PM, datzenmike said: Oh wait! Is this a 71C from a 240sx?? That would be way longer than the 4 speed. Mike, how much play if any should there be between fork and slave cylinder rod adjustment nut? Quote Link to comment
datzenmike Posted June 28 Report Share Posted June 28 You're using the 521 clutch arm with hole in the end??? with the adjustable push rod????? Why not the 71B clutch arm???? If using the adjustable arm just 2 mm of play, about 0.080" eighty thou. You want clearance.... just not too much clearance. Quote Link to comment
Socalman Posted June 29 Author Report Share Posted June 29 39 minutes ago, datzenmike said: You're using the 521 clutch arm with hole in the end??? with the adjustable push rod????? Why not the 71B clutch arm???? If using the adjustable arm just 2 mm of play, about 0.080" eighty thou. You want clearance.... just not too much clearance. The clutch arm for the 521 and the one that came with the 71B were identical. I’m using the 521 adjustable rod. Quote Link to comment
Socalman Posted June 29 Author Report Share Posted June 29 Only difference was the size of the bearing and holder Quote Link to comment
Socalman Posted June 30 Author Report Share Posted June 30 On 6/28/2024 at 4:36 PM, datzenmike said: You're using the 521 clutch arm with hole in the end??? with the adjustable push rod????? Why not the 71B clutch arm???? If using the adjustable arm just 2 mm of play, about 0.080" eighty thou. You want clearance.... just not too much clearance. So I received the new mount bracket and bought a new 620 mount, seems the mount holes are off and the rubber section off centered, where did I go wrong? I can redrill one hole and get the rubber close to center, but is this the correct way to add the 71B to a 521. I also tried to cut a section off the 521 mount but that didn’t work out as the rubber part was too wide and hit frame rail…. Quote Link to comment
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