John dillinger Posted September 17, 2015 Report Share Posted September 17, 2015 So I took my radiator to a repair shop yesterday and picked it up today got it in the truck and filled up started the truck and it started blowing smoke out the exhaust then died... I got out checked under the hood to make sure evening was still hooked up and found a puddle of water under the truck but no leak tried to start the truck again and it didn't turn over. I checked the oil and found that some of the water went into the oil so I took the plugs out and found they were full. I'm hoping it's a head gasket but have a bad feeling is worse. Anybody have ideas? Quote Link to comment
Doctor510 Posted September 17, 2015 Report Share Posted September 17, 2015 Head Gasket fix it Quote Link to comment
datzenmike Posted September 18, 2015 Report Share Posted September 18, 2015 What happened that you needed to or felt the need to take the rad to a repair shop?????? This info has more bearing on this than you thought and should have been included. 1 Quote Link to comment
MicroMachinery Posted September 18, 2015 Report Share Posted September 18, 2015 ^^^What he said. Let me guess; it overheated, so the radiator was assumed to be in need of repair. Quote Link to comment
John dillinger Posted September 18, 2015 Author Report Share Posted September 18, 2015 It was leaking when I bought the truck the truck sat for a few years before I bought it the guy hit a deer and then a curb it pushed the radiator into the fan and made it leak I filled it when I bought the truck drove it on a trailer towed it home backed it into a parking spot and went out yesterday pulled the radiator took it to a shop got it today put it back in and then this happened Quote Link to comment
John dillinger Posted September 18, 2015 Author Report Share Posted September 18, 2015 I'm going to start digging into it this weekend and hopefully it's just a gasket but knowing the guy I got it from he probly drove it for a while and cracked the head or worse Quote Link to comment
distributorguy Posted September 18, 2015 Report Share Posted September 18, 2015 Or was it leaking from the excess pressure caused by a blown head gasket? Napa sells a "block tester" that detects carbon monoxide in the coolant. Its great for diagnosing a blown head gasket. A simple compression test will almost always tell you definitively which two cylinders are leaking. Very low pressure in one, maybe half pressure in the other, with the other two cylinders holding full pressure. Worst case scenario, the valves got bent in the bad cylinder and will no longer seal due to hydraulic pressure. Very worst case, the cylinder wall could be split in that cylinder. Quote Link to comment
John dillinger Posted September 18, 2015 Author Report Share Posted September 18, 2015 It was definitely leaking because the radiator was pushed into the fan... I have straightened the top support that goes across the front as much as I can now the fan doesn't hit the radiator Quote Link to comment
datzenmike Posted September 18, 2015 Report Share Posted September 18, 2015 Or was it leaking from the excess pressure caused by a blown head gasket? Napa sells a "block tester" that detects carbon monoxide in the coolant. Its great for diagnosing a blown head gasket. A simple compression test will almost always tell you definitively which two cylinders are leaking. Very low pressure in one, maybe half pressure in the other, with the other two cylinders holding full pressure. Worst case scenario, the valves got bent in the bad cylinder and will no longer seal due to hydraulic pressure. Very worst case, the cylinder wall could be split in that cylinder. The rad cap limits the pressure to about 13 PSI. If the rad was driven into the fan this is more likely the cause of a blown gasket. Again as the OP said, the PO probably drove it and it over heated. Gasket may be blown from the head warping from the heat. Gasket doesn't always blow between cylinders but is probably the most common. My last one blew out above the dip stick. It would take a lot of water to hydro lock a cylinder and can't flow in fast enough in a running engine. Hydro locking usually happens when the engine has been sitting and enough water enters the cylinder to prevent the engine from being cranked over by the starter. As both valves are closed at the time it's pretty much impossible to bend one. Extreme over heating can expand the rings, closing the end gap and breaking them and the lands on the piston and this could score the walls but not split them. For now assume the gasket is blown and possibly the head warped. Before removing the head do you know to block the timing chain from falling out? If not ask and find out what to do. Failure to secure the tensioner will add about 6 hours of work to a simple head gasket replacement. I would spare you that. 1 Quote Link to comment
John dillinger Posted September 18, 2015 Author Report Share Posted September 18, 2015 I did not know anything about the timing chain stuff... but if it winds up being warped head or cracked head are there other heads I can use (please be specific on year model info if there are any)... I'd really like to modify the engine for more power while I have it apart any suggestions on what to do there would be greatly appreciated Quote Link to comment
datzenmike Posted September 18, 2015 Report Share Posted September 18, 2015 It's imperative that you find out what to do to prevent the tensioner from falling out. Once it falls out the only way to fix this is to remove the timing cover. That's pretty much the whole front of the engine... and it's preventable! read... http://community.ratsun.net/topic/41595-timing-chain-wedge/ If warped just have a shop 'fly cut' it to flatten it. There's not much you can do to your W58 head to improve it. Biggest bang for the buck would be a mild cam increase. But this comes with it's own disadvantages. 2 Quote Link to comment
flatcat19 Posted September 18, 2015 Report Share Posted September 18, 2015 You didn't answer his questions Mike. Any head from any 4 series L will fit. Do you know that you have the L20B motor in your truck? If you can find a closed chamber head its worth a slight bump in power. For any noticeable increases you are looking at a cam, carbs, and/porting. Just get it running first. And block your chain. 2 Quote Link to comment
red13 Posted September 18, 2015 Report Share Posted September 18, 2015 If you overheated the head and getting oil in the water, but not water in the oil. More then likely an internal crack in the head Quote Link to comment
John dillinger Posted September 18, 2015 Author Report Share Posted September 18, 2015 Yes I knew that my truck has the l20 engine. And any L series head will fit even if it's not a 20 Quote Link to comment
datzenmike Posted September 18, 2015 Report Share Posted September 18, 2015 The only head that comes close to the W58 is the U67 but the holes for the intake cooling would need to be drilled out to be compatible and then you have a head with no clear cut advantage over it. Ports are smaller on an A-87 and a closed chamber A87's higher compression would hardly make up for the smaller ports. A 219 or 912 head? ..... yes... but this only bumps the compression to 8.9, about 1/2 point. At an optimistic 5-6 hp per point of compression that just a few hp for all that expense and effort. As a part of a package including carbs, and cam and a less restrictive exhaust it would help a lot. They would be a couple of hundred to find one and an equal amount to have rebuilt, then carbs and intake, then a cam..... Quote Link to comment
banzai510(hainz) Posted September 18, 2015 Report Share Posted September 18, 2015 THis is just me. Cheapest MORE POWER is a weber 38/38 and its more or less a bolt on. I would pull the water pump off also and see if the cover looks like termites went thru it. Cavitation will ruin a front cover and when water gets warm pump thru the fron cover in to the oil. If water in cylinders then head gasket is more likely but still need to ck the fron as its been sitting a long time.Anti freez needs to be changed Just starighten the head you have. As you live in ND its going to be hard getting parts unless a guy has a stack of datsun in his yard Quote Link to comment
banzai510(hainz) Posted September 18, 2015 Report Share Posted September 18, 2015 olddatsuns.com the tech section read that first. Quote Link to comment
datzenmike Posted September 18, 2015 Report Share Posted September 18, 2015 Can't bend a valve from hydro locking. Quote Link to comment
John dillinger Posted September 18, 2015 Author Report Share Posted September 18, 2015 Will a carb off of a 1980 510 z20 engine work on a 1979 620? Quote Link to comment
red13 Posted September 18, 2015 Report Share Posted September 18, 2015 no different engine. Nationalcarburetors is having a sale carbs for $143 lifetime warranty Quote Link to comment
datzenmike Posted September 18, 2015 Report Share Posted September 18, 2015 Will a carb off of a 1980 510 z20 engine work on a 1979 620? No but you might make it work. The Z20 carb throttle lever would pull toward the valve cover on an L series engine. Probably the lever could just be unbolted and flipped upside down??? or use the one off an L series carb. The lever is the part that the throttle cable clips into and rotates counter clockwise as viewed from the rear of the carb. Check the mount bolt pattern... probably the same. The fuel on the Z20 comes up from underneath on the driver's side. Air filter is held on with a threaded post from the center of the carb... just use the Z20 air filter housing. Quote Link to comment
John dillinger Posted September 19, 2015 Author Report Share Posted September 19, 2015 So far I think I got screwed on this truck radiator was busted fixed that, found out its got an issue with the water going to the oil going to see what the cause of this is tomorrow hopefully. lower left control arm supposedly is bent come to find out that the frame is bent... anybody know if I can use a old toyota helix frame cause my neighbor has one I can get for $50 if it doesn't involve a lot of custom parts and pieces I would do a body swap Quote Link to comment
datzenmike Posted September 19, 2015 Report Share Posted September 19, 2015 Water in oil is most often a blown head gasket. Water or steam in the cylinder gets pushed down past the rings and into the crankcase oil. No mystery here. Pictures of LCA and it's 'bentness' anybody know if I can use a old toyota helix frame cause my neighbor has one I can get for $50 if it doesn't involve a lot of custom parts and pieces I would do a body swap Please.... you can''t be serious. Quote Link to comment
John dillinger Posted September 19, 2015 Author Report Share Posted September 19, 2015 I'll get pictures tomorrow when I get the truck moved into the drive way Quote Link to comment
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