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chrisgt posted:Do they use a thermostat still? Or just regulate the temperature by controlling the speed of the pump? I bet they still have a thermostat, just so they can circulate coolant through the engine without going through the radiator.
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Apr 10, 2012 15:33
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This, you still want the water moving (to avoid hotspots), but not through the radiator until the engine's up to temp.
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Apr 10, 2012 15:48
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IOwnCalculus posted:I bet they still have a thermostat, just so they can circulate coolant through the engine without going through the radiator. The whole point was not to have a piece of phase-change wax to control the temperature. They might have an electric valve actuation system of some kind, though.
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Apr 10, 2012 16:54
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Sure, and that'd make sense...but I wouldn't want to warm up an engine with absolutely zero coolant movement other than convection alone.
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Apr 10, 2012 18:17
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IOwnCalculus posted:Sure, and that'd make sense...but I wouldn't want to warm up an engine with absolutely zero coolant movement other than convection alone. I've done that before. It doesn't end well. Also, the BMWs I've worked on with an electric water pump also have an electronically actuated thermostat. It's retardedly expensive and has a coolant temp sensor built into it. Both are controlled by the ECU.
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Apr 10, 2012 18:49
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 "Boss, the customer base is complaining that our cooling systems are too failure prone and expensive to fix" "Really? I mean, I know there's a fair bit of plastic in there, and yeah, the impeller might not have been the best thing to make from that, but I didn't think we were making anything much different from everyone else. Ask Fritz to sort it."Some time and one Oktoberfest later:  "I've managed to not only remove the plastic impeller, I've removed the engine-driven waterpump entirely! And that stupid mechanical thermostat thing we've been using since Karl Benz decided he couldn't be hosed with walking everywhere." "Top man! Fit it to everything!"Every single person who keeps a car longer than the warranty: 
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Apr 10, 2012 23:50
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Pretty undramatic from the inside but pretty spectacular: http://www.youtube.com/watch?feature=player_embedded&v=ST6FQV2GBIk
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Apr 13, 2012 12:05
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Motronic posted:I've done that before. It doesn't end well. But do you have to dumb a half dozen of them into a pot of boiling water to see which ones actually work?
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Apr 13, 2012 17:07
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Motronic posted:Also, the BMWs I've worked on with an electric water pump also have an electronically actuated thermostat. It's retardedly expensive and has a coolant temp sensor built into it. Both are controlled by the ECU.
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Apr 13, 2012 18:54
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Can you explain your thinking on that? We just covered why you'd still want a thermostat even with a variable-speed electric water pump.
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Apr 13, 2012 19:00
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2ndclasscitizen posted:Pretty undramatic from the inside but pretty spectacular: http://www.youtube.com/watch?feature=player_embedded&v=ST6FQV2GBIk Wowzer! I figured I'd have to look for the shadow of something under the bac...oh the tire's come off.
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Apr 13, 2012 19:02
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*nevermind*
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Apr 13, 2012 19:08
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I thought thermostats used a bimetal spring. Shows how much attention I've paid to them.
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Apr 14, 2012 05:24
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General_Failure posted:I thought thermostats used a bimetal spring. Shows how much attention I've paid to them. Well, household HVAC thermostats do, so there's that.
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Apr 14, 2012 05:33
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General_Failure posted:I thought thermostats used a bimetal spring. Shows how much attention I've paid to them. Thermostats are actually pretty interesting tech for something so simple and common. As far as bimetal springs on engines, the only thing I can think of are on old carburetor automatic chokes.
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Apr 14, 2012 05:48
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Yep, and they're loving pieces of poo poo too if you ask me. I don't think a bimetallic spring is capable of generating the force necessary to keep a thermostat either closed or open against the flow from a water pump.
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Apr 14, 2012 07:22
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 Don't run over mattresses.
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Apr 14, 2012 20:08
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Motronic posted:
Now that's an unusual repeat to have in here.. 
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Apr 14, 2012 20:12
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Regarding all the BMW thermostat chat; yes, they have one. Not only is it a thermostat, it also has a sensor (to see if it's open or not) and, I poo poo you not, an electrical heater element so it can be forced open faster (why that is, I have no clue.) I guess it's all done to squeeze the last few MPGs out of the engine to get better ratings. One could ask the question if a simpler, more robust construction wasn't worth a few tenths of an MPG over the life of the car, but car makers don't sell used cars, they sell new ones.
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Apr 14, 2012 20:38
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You're making a value judgement on what you think is robust, if a multinational engineering firm (BMW) decided that it was beneficial for emissions and any other reasons not disclosed, I'd tend to trust what they say. Not to say that the plastic waterpump impeller was a bad idea, just poor materials engineering from when it was bleeding edge technology.
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Apr 14, 2012 22:32
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Yeah, trust big business, they have everyone's best interests at heart.
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Apr 15, 2012 01:57
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DJ Commie posted:You're making a value judgement on what you think is robust, if a multinational engineering firm (BMW) decided that it was beneficial for emissions and any other reasons not disclosed, I'd tend to trust what they say. Reasons: passes emissions. Cheaper than redesigning the engine. Despite being absurdly complex, it at least lasts the warranty period often enough that a risk assessment said it would be worth the warranty repairs on the failed units.
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Apr 15, 2012 02:06
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Bruton Smith's crazy 4-Wide drag strip is 25 minutes from my house and they're running one of the two National Events of the year there (the only one that they actually run 4-wide, the other one is only 2 lanes) Anyway, two years ago at the first 4-wide in 2010, Funny Car driver Matt Hagan blew one up big time. (He's in the second lane from the left, but this video shows it plenty of times. http://youtu.be/9oj1O8ip-VQ Matt went on to become 2011 World Champ, and was actually the first nitro funny car driver to go in to the threes last fall at Zmax with a 3.995. Yesterday at the 4-Wide Matt was qualifying in the same lane as the 2010 explosion and did nearly the same thing. http://youtu.be/9jVN5sJhb4Y The violence of these things is a crazy. Everyone needs to experience a nitro pass in their life. Here is a picture of his carbon fiber body on the side of the track later in the day  We were there in the Alcohol Funny Car class. Made one pass on Friday, dropped a valve in number 2 over boosted and burned a hole in the block and the head. Got the car back together, but sat out the first round and just got the car ready for another race this weekend. We're sort of a low budget team, and it means more to just qualify for us than it does to go out and try to break something else. This is our car in Body Tech on Thursday  Here are a few Iphone pics of the damage we did, I can't seem to get good pictures covered in oil. Copper head gasket and valve, Fire wanted out  Valve, it was upside down in the #2 cylinder. Not much damage, we think it broke right when he shutoff. Put another sleeve and piston in #2  Melted block on #8, if you you look close you can see where it was trying to weld the firewall. New sleeve is already in, we fixed the block with JBWeld.  Valve mark on the cylinder head on #2, its pretty mangled in the valve guide too  Melted part of the head on #8, it will be pricey to get these welded back up, but they're fixable.  Our times on the one pass were: .959 60ft 2.564 330ft 3.89 @ 185.38 1\8th mile 5.032 1000 ft 6.011 @ 225.75 mph 1\4 Mile It was probably a 5.8 if it hadn't burned up. The top tier teams are running 5.50s and a few 5.40s with a screw blower instead of the older roots blowers like we run.
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Apr 15, 2012 02:11
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the_worm_ posted:we fixed the block with JBWeld. I love racing. 
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Apr 15, 2012 02:24
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In all seriousness do you know of any way to get ahold of a blown out headgasket like that for some wall art? Do any teams sell parts? I've seen a couple NHRA castoff odds and ends on ebay and the like but nothing nice and easy to hang like that head gasket.
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Apr 15, 2012 03:11
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the_worm_ posted:The violence of these things is a crazy. Everyone needs to experience a nitro pass in their life.
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Apr 15, 2012 03:25
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Dr 14 INCH DICK Md posted:In all seriousness do you know of any way to get ahold of a blown out headgasket like that for some wall art? Do any teams sell parts? I've seen a couple NHRA castoff odds and ends on ebay and the like but nothing nice and easy to hang like that head gasket. Unless you specifically want one from a funny car it's pretty easy, wait till you blow one (alright maybe easier in some vehicles than others...) and then hang it on the wall. I had the rear head gasket out of my M54A2 on the wall in my cube at Intel, it was a pretty good conversation starter.
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Apr 15, 2012 03:32
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Godholio posted:Yeah, trust big business, they have everyone's best interests at heart. Yeah, like broken aluminum or plastic timing sets 
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Apr 15, 2012 05:42
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kastein posted:Unless you specifically want one from a funny car it's pretty easy, wait till you blow one (alright maybe easier in some vehicles than others...) and then hang it on the wall. I had the rear head gasket out of my M54A2 on the wall in my cube at Intel, it was a pretty good conversation starter. I do want one from a funny car, I've been making a collection of the head gaskets pulled out at work and so far have Subaru and Jeep covered 
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Apr 15, 2012 06:01
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kastein posted:Unless you specifically want one from a funny car it's pretty easy, wait till you blow one (alright maybe easier in some vehicles than others...) and then hang it on the wall. I had the rear head gasket out of my M54A2 on the wall in my cube at Intel, it was a pretty good conversation starter. Easy way to blow one. Add water.
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Apr 15, 2012 06:29
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My friend blew up his Evo X. His timing chain stretched at around 30k miles, resulting in this.  
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Apr 15, 2012 15:43
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B-b-but chains are better than belts because they last forever and don't stretch!
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Apr 15, 2012 16:33
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Splizwarf posted:B-b-but chains are better than belts because they last forever and don't stretch!  Indeed.
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Apr 15, 2012 16:48
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Splizwarf posted:B-b-but chains are better than belts because they last forever and don't stretch! Let me introduce you to a concept known as the "non interference motor"
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Apr 15, 2012 17:32
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Splizwarf posted:B-b-but chains are better than belts because they last forever and don't stretch! kastein posted:Let me introduce you to a concept known as the "non interference motor" 
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Apr 15, 2012 18:00
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Does it bother anyone else that transverse V6's never have symmetrical valve covers?
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Apr 15, 2012 18:30
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Rev. Dr. Moses P. Lester posted:I recently crossed this one off my bucket list, and I gotta say, you're goddamn right. Seriously, if you are a fan of fast, loud, unnecessary cars, you need to get a cheap Thursday/Friday ticket to an NHRA event and watch the Top Fuel/Funny Car field. Nothing else even comes close to that experience. If you are a SF Bay goon, go watch them at Sonoma at night - holy 
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Apr 15, 2012 18:50
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revmoo posted:Does it bother anyone else that transverse V6's never have symmetrical valve covers? The 3800 does, with the exception of the oil filler cap being on the front (but is still centered).
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Apr 15, 2012 19:09
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revmoo posted:Does it bother anyone else that transverse V6's never have symmetrical valve covers? If by this you mean "does anyone hate transverse V6's because changing the rear bank spark plugs is a bitch and a half," then yes.
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Apr 15, 2012 19:27
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lazer_chicken posted:If by this you mean "does anyone hate transverse V6's because changing the rear bank spark plugs is a bitch and a half," then yes. I looked up the procedure for changing the plugs on the girlfriend's 1MZ and stopped reading at removing the intake manifold. gently caress that, it only has 120k on it.
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Apr 15, 2012 21:59
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