Charlie69 Posted February 8, 2020 Report Share Posted February 8, 2020 Mike Klotz did a write up or a video on rebuilding the stock 521 heater valve. Contact him to find out where it is. Very informative. Quote Link to comment
datzenmike Posted February 8, 2020 Report Share Posted February 8, 2020 The stock one is a much larger diameter, both the metal tube from the block vent and the rubber one to the PCV. I had an old 318 that was always plugging itself. I think the thermostat was stuck open. 1 Quote Link to comment
Charlie69 Posted February 8, 2020 Report Share Posted February 8, 2020 I have the other heater box and miscellaneous parts if you need something in the future. 1 Quote Link to comment
Crashtd420 Posted February 8, 2020 Author Report Share Posted February 8, 2020 37 minutes ago, Charlie69 said: Mike Klotz did a write up or a video on rebuilding the stock 521 heater valve. Contact him to find out where it is. Very informative. I have seen a few different write ups about fixing it.... I'm not to worried.... I know to be careful this time.... But I'll definitely look up Mike's video or write up.... 1 Quote Link to comment
Crashtd420 Posted February 8, 2020 Author Report Share Posted February 8, 2020 36 minutes ago, datzenmike said: The stock one is a much larger diameter, both the metal tube from the block vent and the rubber one to the PCV. I had an old 318 that was always plugging itself. I think the thermostat was stuck open. Sounds like another good reason just to run the line across the top.... easier to check and replace if needed.... 1 Quote Link to comment
wayno Posted February 8, 2020 Report Share Posted February 8, 2020 I would route it down till I knew there was an issue. I would also have connected the PCV to the Tee if possible, but things don't always work out. 1 Quote Link to comment
Crashtd420 Posted February 8, 2020 Author Report Share Posted February 8, 2020 37 minutes ago, Charlie69 said: I have the other heater box and miscellaneous parts if you need something in the future. Should be good for now... you already gave me move than I expected.... Even just having the spare box outside of the vehicle is helpfull.. If I have any ideas I can try it with the spare parts instead of having to tear apart the truck .... Thanks Charlie.. 1 Quote Link to comment
Crashtd420 Posted February 8, 2020 Author Report Share Posted February 8, 2020 30 minutes ago, wayno said: I would route it down till I knew there was an issue. I would also have connected the PCV to the Tee if possible, but things don't always work out. I'm playing with all possibilities.... I like that it looks cleaner but it's real tight... right now the only place I can put the pcv is just off the block vent as it reduces to the 5/8 line.... but that makes getting from under the intake to the pcv a pain..... 1 Quote Link to comment
wayno Posted February 8, 2020 Report Share Posted February 8, 2020 I wonder why they don't make a plate that goes between the manifold and carb that has a balance tube/PCV connection, how hard would that be to make? 1 Quote Link to comment
mainer311 Posted February 8, 2020 Report Share Posted February 8, 2020 (edited) Not very hard. I think there are some aftermarket ones for DGV’s, but the same sort of principle would be possible for a DCOE. Edited February 8, 2020 by mainer311 2 Quote Link to comment
Charlie69 Posted February 9, 2020 Report Share Posted February 9, 2020 9 hours ago, Crashtd420 said: Should be good for now... you already gave me move than I expected.... Even just having the spare box outside of the vehicle is helpfull.. If I have any ideas I can try it with the spare parts instead of having to tear apart the truck .... Thanks Charlie.. You are welcome and Thank you. Quote Link to comment
Crashtd420 Posted February 9, 2020 Author Report Share Posted February 9, 2020 Well this was almost too easy..... Removed the tiny screw that stops the valve from turning, a few taps from the inside with a long rod and out it came... Cleaned it up and put a new oring on, so far so good.. right now the heater core is full to see if it will leak... going to try to figure out a was to preassure test it next... Not such good luck with the fan.... Tried to remove the connection on the back and broke them off.... I did manage to get the nut off without breaking the cage... and I got my old one off the motor without breaking it more so hopefully I can remove the good one without breaking it.... 1 Quote Link to comment
Crashtd420 Posted February 9, 2020 Author Report Share Posted February 9, 2020 Is there a specific oring I should be using before I put this back in the truck? I have just a box of orings.... I used the best fitting one but I question if it will last or degrade because of the coolant... 1 Quote Link to comment
Stoffregen Motorsports Posted February 9, 2020 Report Share Posted February 9, 2020 An o-ring from one of those "assortments" may not be the best quality you can get, but in this case, it will probably work fine. It's in a sort of compressed state and it's not exposed to sunlight or oil. 1 Quote Link to comment
Stoffregen Motorsports Posted February 9, 2020 Report Share Posted February 9, 2020 21 hours ago, Crashtd420 said: Would a rubber lines make a difference... or covering the metal line? I didnt want to run a rubber line down because of the exhaust, I though with the metal line I could keep it closer to the intake..... I could also turn the tee to point towards the head and just connect a rubber line up top.... I might try the line up top to see how it looks.... underneath is proving to be a challenge to get over to the the block vent without making things look wierd.... 22 hours ago, datzenmike said: Check that regularly. You'll get lots of condensation that the hot exhaust will evaporate leaving deposits that will clog the metal pipe. 21 hours ago, Crashtd420 said: Would a rubber lines make a difference... or covering the metal line? I didnt want to run a rubber line down because of the exhaust, I though with the metal line I could keep it closer to the intake..... I could also turn the tee to point towards the head and just connect a rubber line up top.... I might try the line up top to see how it looks.... underneath is proving to be a challenge to get over to the the block vent without making things look wierd.... You guys are overthinking this. On start-up, the junk that's in the tube will get sucked into the intake before it has time to coke up. 1 1 Quote Link to comment
mainer311 Posted February 9, 2020 Report Share Posted February 9, 2020 (edited) A good o-ring material would be EPDM or Fluorosilicone, but I imagine standard Buna or Silicone would both work fine. Type in propylene glycol in the chemical search: https://www.marcorubber.com/o-ring-chemical-compatibility-chart.htm Edited February 9, 2020 by mainer311 1 1 Quote Link to comment
wayno Posted February 9, 2020 Report Share Posted February 9, 2020 Bummer, I have never tried to remove the wires from the motor, I just remove them from the heater box on the outside and slide the wiring thru the hole, how are you going to fix that? In all the time I have owned Datsuns I have never turned the heater box knob to the off position, I just shut the fan off, if it gets hot in the cab I open the door window, if it gets really hot I open the rear slider window, that creates a fierce gale force wind in the cab, enough to raise dust/dirt into the air to get in my eyes sometimes. 1 Quote Link to comment
Crashtd420 Posted February 9, 2020 Author Report Share Posted February 9, 2020 (edited) 1 hour ago, wayno said: Bummer, I have never tried to remove the wires from the motor, I just remove them from the heater box on the outside and slide the wiring thru the hole, how are you going to fix that? In all the time I have owned Datsuns I have never turned the heater box knob to the off position, I just shut the fan off, if it gets hot in the cab I open the door window, if it gets really hot I open the rear slider window, that creates a fierce gale force wind in the cab, enough to raise dust/dirt into the air to get in my eyes sometimes. Are you talking the fan motor? I am hoping to remove the bird cage from the one I messed up and move it over to my good motor .... if I feel like I'm going to break it I'll probably grind back some of the plastic on the motor to expose just enough of the terminal and solder on some wires..... As far as the heater core it was stuck in the off position, so I had to mess with it to restore flow.... I'm still trying to see what's out there for orings.... I am not real confident with using the current oring.. I think the original was square...... I've been trying to find some write ups but haven't found anything good on the oring..... One said it leaked, and one said use 2 thinner ones , but I think the way the square style seals it better for the job.... Edited February 9, 2020 by Crashtd420 1 Quote Link to comment
Crashtd420 Posted February 9, 2020 Author Report Share Posted February 9, 2020 I have the valve out right now measuring it... and I'm leaning towards trying a dash 111 square o ring... this is from the mcmaster's catalog.... I actually just checked and this is the same size I chose from my o ring kit.... so I might be on the right track here.... The groove on the valve body measured .460 and about .125(1/4) wide... the valve body itself is .625(5/8)... I'll share the extras if they work... looks like I might have to order either 10 or 25 depending on the supplier.... 1 Quote Link to comment
mainer311 Posted February 10, 2020 Report Share Posted February 10, 2020 (edited) I would go with either round or the “X” shaped seal. You’re at 80% compression, which is spot on. Make sure to grease it up really well, it else it will dry out and make the lever stick. A -111 has a little bit of stretch (generally around 2-5% is okay), so you’ll end up with a little less compression. You could also try a -112, but it might overfill the gland. Edited February 10, 2020 by mainer311 1 Quote Link to comment
Crashtd420 Posted February 10, 2020 Author Report Share Posted February 10, 2020 (edited) 24 minutes ago, mainer311 said: I would go with either round or the “X” shaped seal. You’re at 80% compression, which is spot on. Make sure to grease it up really well, it else it will dry out and make the lever stick. A -111 has a little bit of stretch (generally around 2-5% is okay), so you’ll end up with a little less compression. You could also try a -112, but it might overfill the gland. They do have an x seal in the 111 size.... These are the sizes.... Just realized the is no indicator to what the numbers are... For reference on the 111 .424 is the id/ .630 is the od the 112 would be loose, and the 110 tight.... I do think the 111 size is the right one..... The x seals do seam even a little better then the square, and much better than a standard o ring.... Edited February 10, 2020 by Crashtd420 1 Quote Link to comment
mainer311 Posted February 10, 2020 Report Share Posted February 10, 2020 (edited) I deal with o-ring designs almost daily. The 112 would be loose around the shaft, but tight in the bore, therefore it would most likely squeeze down. The problem is it could bunch up, or not have enough room, and up shearing during insertion. I think you’re right with the 111. It seems like a good fit. X-shaped seals are cool because you get decent compliance, and when the lobes squish down, it’s almost like having 2 o-rings. Round o-rings are the easiest to install when it comes to piston-style seals though. If you end up with an X seal, just be careful during installation. Edited February 10, 2020 by mainer311 2 Quote Link to comment
Crashtd420 Posted February 10, 2020 Author Report Share Posted February 10, 2020 8 minutes ago, mainer311 said: I deal with o-ring designs almost daily. The 112 would be loose around the shaft, but tight in the bore, therefore it would most likely squeeze down. The problem is it could bunch up, or not have enough room, and up shearing during insertion. I think you’re right with the 111. It seems like a good fit. X-shaped seals are cool because you get decent compliance, and when the lobes squish down, it’s almost like having 2 o-rings. Round o-rings are the easiest to install when it comes to piston-style seals though. If you end up with an X seal, just be careful during installation. I guess my biggest concern is turning the valve in general once installed.... That's what I thought the difference between a standard oring and the square would be.... what I removed from the valve seemed to be a square profile.. Would the x profile still be better in that sense? 1 Quote Link to comment
thisismatt Posted February 10, 2020 Report Share Posted February 10, 2020 They can get square looking when old and hard. 2 Quote Link to comment
mainer311 Posted February 10, 2020 Report Share Posted February 10, 2020 (edited) Yes, it looks square because of compression set. It was almost definitely round originally. The biggest factor is lubrication I think. Pack the gland with grease before assembling. An X-shaped seal might actually retain grease between the lobes better, but a round ring will work just fine. We use a silicone-based “o-lube” that is extremely tacky. It doesn’t dry or wash out, and actually allows the o-ring to swell once installed. Edited February 10, 2020 by mainer311 1 Quote Link to comment
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