thisismatt Posted December 4, 2023 Report Share Posted December 4, 2023 5 minutes ago, Stoffregen Motorsports said: L series valve adjusters are known to come loose, and I try to get the jam nuts as tight as humanly possible. I use a pair of Snap-On wrenches for the job. If the jam nut is so close to the pedestal that it needs a thin wrench, your rocker arm geometry is probably off. Or your 💩 exhaust valve seats are all sunk 2 Quote Link to comment
Stoffregen Motorsports Posted December 4, 2023 Report Share Posted December 4, 2023 Good point. Quote Link to comment
thisismatt Posted December 4, 2023 Report Share Posted December 4, 2023 Just now, Stoffregen Motorsports said: Good point. Speaking from experience. I'm out of adjustment on mine 😆 1 Quote Link to comment
andyZ00m Posted December 4, 2023 Author Report Share Posted December 4, 2023 45 minutes ago, thisismatt said: Speaking from experience. I'm out of adjustment on mine 😆 Here’s what mine look like. 1 Quote Link to comment
Stoffregen Motorsports Posted December 4, 2023 Report Share Posted December 4, 2023 That's pretty low on the pedestal. I bet your valve seats are shot. Or your valves are worn thin. Or it has a hot cam in it and someone didn't properly set the rocker arm geometry. Quote Link to comment
datzenmike Posted December 4, 2023 Report Share Posted December 4, 2023 This is the lock nut. The top one is how much I ground it down, about 1/2 size. Now the ball pivot can be turned down into the head more. Good idea to grind a few threads off the bottom of the pivot so it doesn't bottom out. Probably way more than I needed but show what can be done to get a few tens of thousands of miles out of a head with sinking valves. 1 Quote Link to comment
andyZ00m Posted December 5, 2023 Author Report Share Posted December 5, 2023 (edited) I still have plenty of room, was just trying to fit wrenches around the springs and such. This motor is in good shape and it’s totally still adjustable. I have no problem admitting that I didn’t realize at first that there are three nuts on there…. I’m a dingus but I figured it out. Edited December 5, 2023 by andyZ00m 1 Quote Link to comment
andyZ00m Posted December 6, 2023 Author Report Share Posted December 6, 2023 Can never keep a girl from new shoes… 2 Quote Link to comment
thisismatt Posted December 6, 2023 Report Share Posted December 6, 2023 Ah, I see you've got an extra pocket ripper on the bed 😅 1 2 Quote Link to comment
andyZ00m Posted December 6, 2023 Author Report Share Posted December 6, 2023 5 minutes ago, thisismatt said: Ah, I see you've got an extra pocket ripper on the bed 😅 Ha! I haven’t ruined any pants yet! Quote Link to comment
datzenmike Posted December 6, 2023 Report Share Posted December 6, 2023 Depends on how low it is. Quote Link to comment
banzai510(hainz) Posted December 6, 2023 Report Share Posted December 6, 2023 love the white walls 1 Quote Link to comment
Stoffregen Motorsports Posted December 7, 2023 Report Share Posted December 7, 2023 Looks great! 1 Quote Link to comment
andyZ00m Posted December 8, 2023 Author Report Share Posted December 8, 2023 Been driving the truck a lot all week and it’s so fun!! After I realized these motors want a higher RPM I’m finding My groove. It’s definitely not without power. Im Noticing that it seems a lot happier and has much better/more smooth power band when the choke is out just a little bit even after warm. What does this mean? Seems like it wants a richer mix. With the choke fully disengaged it lags a bit in second gear whereas is its engaged just a bit then second gear is POWER 1 Quote Link to comment
Crashtd420 Posted December 8, 2023 Report Share Posted December 8, 2023 6 minutes ago, andyZ00m said: Been driving the truck a lot all week and it’s so fun!! After I realized these motors want a higher RPM I’m finding My groove. It’s definitely not without power. Im Noticing that it seems a lot happier and has much better/more smooth power band when the choke is out just a little bit even after warm. What does this mean? Seems like it wants a richer mix. With the choke fully disengaged it lags a bit in second gear whereas is its engaged just a bit then second gear is POWER Generally yes It sounds like it wants a richer mix... did you rebuild the carburetor yet? Could be as simple as that or possibly something up with the secondary too.... A lot of people, including myself, have added a wide band 02 sensor and gauge... This helps pin point rich and lean conditions alot easier.... Quote Link to comment
andyZ00m Posted December 9, 2023 Author Report Share Posted December 9, 2023 23 minutes ago, Crashtd420 said: Generally yes It sounds like it wants a richer mix... did you rebuild the carburetor yet? Could be as simple as that or possibly something up with the secondary too.... A lot of people, including myself, have added a wide band 02 sensor and gauge... This helps pin point rich and lean conditions alot easier.... Have not rebuilt the carburetor! Maybe this is a good time to do that. I was thinking about getting a Weber 32/36 anyway, maybe I just go that route. Will work with a L20 if I ever go that route as well... Quote Link to comment
datzenmike Posted December 9, 2023 Report Share Posted December 9, 2023 57 minutes ago, andyZ00m said: Been driving the truck a lot all week and it’s so fun!! After I realized these motors want a higher RPM I’m finding My groove. It’s definitely not without power. Im Noticing that it seems a lot happier and has much better/more smooth power band when the choke is out just a little bit even after warm. I assume this is at full throttle? If so then you are well into the secondary and it may be the secondary jet is slightly blocked so it is not getting all the fuel it needs... but there is an even better cause. On the under side of the carburetor, the bottom casting with the two throttle plates is secured to the main body with 4 philips head screws. The one to the front and the one at the rear are long and the same length so they are easily mixed up and can be put in the wrong location. Which would be fine but the very front one is hollow. The bottom end is open to the intake vacuum and sends this vacuum signal to the power valve which opens under heavy load and makes the mixture richer for more power. My 710 L20B was this way. Someone had presumably rebuilt it and mixed them. It ran fine but it ran way better when the secondary opened. You could feel it on the ass dyno. Like a Quadrajet kicking in... well not quite. 1 Quote Link to comment
andyZ00m Posted December 9, 2023 Author Report Share Posted December 9, 2023 2 hours ago, datzenmike said: I assume this is at full throttle? If so then you are well into the secondary and it may be the secondary jet is slightly blocked so it is not getting all the fuel it needs... but there is an even better cause. On the under side of the carburetor, the bottom casting with the two throttle plates is secured to the main body with 4 philips head screws. The one to the front and the one at the rear are long and the same length so they are easily mixed up and can be put in the wrong location. Which would be fine but the very front one is hollow. The bottom end is open to the intake vacuum and sends this vacuum signal to the power valve which opens under heavy load and makes the mixture richer for more power. My 710 L20B was this way. Someone had presumably rebuilt it and mixed them. It ran fine but it ran way better when the secondary opened. You could feel it on the ass dyno. Like a Quadrajet kicking in... well not quite. Crazy! Totally possible. This truck was clearly worked on by the owner (some funky hoses and dangerous in line fuel filters etc). Not out of the question that they could have rebuilt the carb and switched those screws. Quote Link to comment
andyZ00m Posted December 9, 2023 Author Report Share Posted December 9, 2023 (edited) Just for.... reference... this is the kit I would want right? https://www.piercemanifolds.com/product_p/k657.htm?CartID=1 Need this thing too if I want to use the original air filter (which I do) https://www.californiadatsun.com/carburetor-parts/weber-32-36-dgev-adapter.html Edited December 9, 2023 by andyZ00m Quote Link to comment
datzenmike Posted December 9, 2023 Report Share Posted December 9, 2023 K657 will work but K660 I think is an electric choke which makes things much easier. I know the '71 was manual but '72 on were electric. Just a thought. Quote Link to comment
andyZ00m Posted December 16, 2023 Author Report Share Posted December 16, 2023 Was on vacation with the fam this week but back at the truck tomorrow. Got the K657 kit to replace the hitachi. Gunna keep it of course and probably rebuild it but at a nice pace so I can learn it. Gunna flush radiator and replace the heater hose that I believe is leaking. The bottom of the hose is not really wet so I’m hoping it’s not the heater core itself that is leaking. It’s a super small amount of fluid but it’s pretty consistently overnight after I drive it as the engine cools. 🤷♂️ Then I’m gunna do shocks and bushings. Also found another good Hitachi 60A regulated alternator from a buddy gunna try. Will be putting it in with the new carb. 1 Quote Link to comment
mainer311 Posted December 17, 2023 Report Share Posted December 17, 2023 On my L16, there was a coolant leak from the back of the head gasket that was running down the back of the block and making it look like the hoses were wet. Sometimes leaks travel. Don’t rule anything out. Quote Link to comment
datzenmike Posted December 17, 2023 Report Share Posted December 17, 2023 I had a gasket coolant leak blow out between 3 and 4 spark plug. Never over heated, W58 head, replaced and it was fine. Quote Link to comment
andyZ00m Posted December 17, 2023 Author Report Share Posted December 17, 2023 Do I use the throttle lever from the hitachi? Or use the swiss cheese thingy with the supplied bolt? Seems like the swiss cheese is easier. She cleaned up nice! Here is the coolant leak below the heater inlet. The hose isnt wet though so I dont think its traveling from the engine down the hose. 1 Quote Link to comment
datzenmike Posted December 17, 2023 Report Share Posted December 17, 2023 Preferably use the Hitachi. Quote Link to comment
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