Hey guys... After my screw up with the new rings on my car, I don't want to go through this crap again. I want the rings to seat in right. Now a lot of people say that allowing a car to idle too long is bad for breaking in new rings. The problem is that often times it takes 20 minutes of idling to get the cooling system to "burp" on the z32. I was thinking: What if I jacked the car up in the back, and filled the block and heads from the outside heater hose outlet, seal that up, then jack up the front and finish filling it? Would that, in effect, force the air out of the cooling passages in the heads, and allow me to just start the car, and drive off without having to idle for 20 minutes?
Not a simple answer - yes it can be done but its not proper engineering practice Yes, but it has a limited effect and still requires minutes to warm up properly regardless.It would be much more effective if you also heated the oil and passages up as well, but again still requires minutes to warm up. It is viable but is it worth while? Only the owner can determine this as we all have different expectations and requirements. Personally myself, it is not viable because the best way to treat the engine when its new, is to avoid turning the motor on and off, but rather only turning the motor off after long periods in order to change the oil - that is a sound mechanical engineering practice in providing maximum life of an engine, including during running in. Remember filling from the rear would only remove air pockets properly once the car water pump is turning anyway. If you recall the bleed air hole on the thermostat sits slightly lower than the lip to reduce water cavitation which means it only works when water is pressured to run through it and is not as effective at removing cavitation if the water is allowed to just flow through it under gravity (don't forget the thermostat is closed until the water warms it up - so with no pressure the air bubbles will collect at the lip instead of being forced to flow through the hole which is lower as the air will rise quicker than being forced through the bleed hole - it must be pressurised to avoid any sudden air cavitation/ rising and flow properly through the hole) Yes the thermostat will open after the bimetal element has heated up but this will still take some minutes still as the passages will cool the water down. Technically however the water is heating the engine from the passages inward, instead of from the cylinders outwards to the coolant/ passages. This means there is a different heating pattern of the metal and different expansion rates at different areas during different stages of the running and gives more variable to the block tolerances in standard operating procedure. In a period of running in, it is actually prudent to try to avoid/ reduce this and keep the expansion pattern to a minimum no matter how small this expansion is given as running it in means it is actually still cutting the metal at this stage at the rings/ bearing and seats. Meanwhile at the same time, having the cap off means pressure in the vessel (water passages) has been lost as the water has been expanding whilst filling(whilst technically at the same time requiring more heat and delaying the process of the block reaching normal temp) and conversely when the motor is stopped it will cool down uneven at the top as the water contracts and leave air passages at the top of the water jacket and allow the top of the block or plenum to heat up and once again unevely changing the variable shape of the block heating pattern due to different temperatures at different times. Of course you would have to fill it up again once its cooled. So - In Summation The engine is designed by engineers to to be filled at the front for a reason, whilst it can be be done to run more energy / cost efficient, it is not tolerance viable under engineering practice nor time viable in practice and work. It is no different to saying - I change my oil at 10,000klms instead of 5,000klms because I save the environment and save more money, but it is not good engineering practice to do it. The differences may only be small, but cumulatively they add up and significantly/ noticeably change the life of the motor. Remember running in / cutting in is best when 1. Its done for long periods with little stops in between 2. Kept at a constant efficent temperature for all individual items such as water/ oil /fuel / metal / chemicals/electricity etc) 3. Its kept at low - medium revolution speeds 4. Throttled gently up and down rather than constant in revolutions 4. Doesnt use more than 2/3 total power or 2/3 total revolutions until run in 5. Has regularly scheduled oil and filter changes 6. It runs mechanically sound in operation (timing /valves etc are according to specifications) So filling it up at the front like is part of an engineering design, standard operating procedure and reccommended if you ask an average mechanic (without a better reason and plan than the one you supplied) Hope that helps answer your question JC
If you use a decent sized funnel with a length of hose and a barb fitting screwed in to the bleed screw hole in the rad you can get a good head of coolant. Then you can loosen the heater hoses and allow air to escape there if you want to do things that way. You could go around all the high points of the system and crack the hoses loose to bleed the air without starting - but once you fire it up you'll have to do them all again.
Get the car up onto ramps or elevate the front high as you can go. This really helps the process. I just drive my car with the nose pointed up the hill on my driveway. Its enough. Ignition on so heater works, heater temp on full which opens heater tap. You want the tap open to help burp air when filling but the fan OFF to accelerate coolant heating later on when you put a fire in its guts. Fill the system reasonably SLOWLY. It allows time for trapped air to make its way along, up and out as you fill. Dont fill it to right to the brim. It will burp out anyway when things heat up so leave the level down from the top. Leave radiator cap OFF. Start the engine, switch on lights to but NOT heater fan. This loads the motor quite a bit via the alternator and speeds up warmup dramatically. Run it at elevated rpm. <>2000rpm. Just chock the throttle linkage open a bit. Check coolant level and top up as necessary but leave the level down a bit as you go. VG's heat up quite quickly at elevated rpm so the thermostat will be open within a couple of minutes. Youll feel the sudden rush of heat at the top of the radiator as the thermostat opens. Top up the coolant as the level drops (which it will) but again not all the way up. When the thermostat is well open, still with elevated RPM, the coolant flow around the engine is quite high and any remaining trapped air will purge out pretty quickly. Its a good time to see if the fan clutch is working correctly as the heat released into the radiator will engage the viscous clutch quite quickly once things heat right up. If it boils before the fan clutch engages, your viscous fan clutch is well rooted!!!!! Fill the coolant right up and fit the cap and your good to go. The whole procedure should take about 5 minutes. Go close to doubling that if you let it chug away at idle and let the heater fan run which cools everything by quite a bit. Remember tho, the system is still unpressurised and if you put the car under extreme conditions you can easily boil the coolant locally within the engine and aerate the system. Chances are pretty remote but worth remembering. If you let it cool off, after recouperating, the system will pressurise normally and wont boil below about 125Deg.C. Check this recovery tank level for a few cold starts. Any remaining air eventually collects in the radiator top tank and each cold start will purge out of the radiator to the recovery reservoir as the coolant heats and expands. This method has been working perfectly for me on every cooling system I have worked on in excess of 40 years including my own Zed when i replaced the radiator last summer. E
Instead of re-inventing the wheel - do it the professional way Instead of re-inventing the wheel, there are better alternatives to consider (and I don't mean doing it the russian military way by lighting a fire under your sump). The professional way is as per how the fire brigades do it in order to ensure trouble free starting and quick operating temperature achievement. This method runs a actual heating element into the radiator or water pump outlet pipe and personell plug the electrical lead in on return at the station to power it, so in fact the engine never cools down (they also plug in the charger externally onto poles which has inbuilt leads that run to the battery so it is a quick connection not requiring the bonnet/hood to be opened at all). This method avoids any bleeding requirements and heats the block up evenly and thoroughly through conduction via the water in the passages. It is the simplest fastest and easiest trouble free way possible to heat the block up hence why emergency services do it this way. Hope this is more helpful Cheers Jamie
my kid drives a 3000gt... it has a bleeder on the back side of the thermostat housing and it is so easy to get it burped with where it is located. I always jack it up in the front, and I know that helps, but it still takes 15 to 20 minutes to get it to burp when the motor has been completely drained.
You could also use a radiator pressure tester with the bleed valve to get a bit more out of it before you fire it up. You won't get all the air out but you will get more out than doing it without pressure. I refilled the rad on my black zed last night so I could pressure test the coolant hose bypass removing the throttle bodies hoses. As tass said the coolant naturally drops 3 or 4 times as you're filling it as it burps out air. Once the level had stabilised I put the pressure tester on, pumped it up to 15psi, waited 10mins, no drop of pressure, all good , removed the pressure tester and the coolant level had dropped again, and this was without releasing the bleeder.
I tip mine on ramps or similar and remove the temp sensor to bleed air out. When coolant bubbles out the temp sensor I refit and continue. Removing the sensor does not save burping the system just makes it a little easier
I always fill on ramps and fill the block before putting the thermostat on. Then after the radiator is full, pull the bleed screw out the left top of the radiator. Then stick a 2 litre Coke bottle of water in the neck with some Teflon tape around it so it sits there and let the system drink out of it. You can see the bubbles escaping into the bottle, put the bleed screw back in once the thermostat is open. The bottle will suck down and squash as the system gets close to full. When the bubbles stop the system is chockers. Back the car off the ramps and go thrash its ass off to run it in.
If theres a bleed valve behind the thermostat then theres a good chance that the thermostat in a Mitzi might not have a jiggler valve in the thermostat. Not all cars have them. The Zed does or at least should. E
Smart man.... it doesn't have one. I was helping him put it back together recently and was surprised when I went to install the thermostat and couldn't find the jiggly bit to center at the top.
So long as the front is elevated like most said run the engine keep topping up till its full. The system will take care of the rest. Never had issues.
