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</head><body><p>Bit off topic, but OMG, The Grapevine!<br></p><p><br></p><p>My dad hauled lumber from Potter Valley, CA to L.A.. When I was in 5th grade he took me along. Going up the long, tedious grade, trucks were overheating and pulling over. Sassy 5th grader I yelled something smart*** and my dad just shook his head and said, "I wouldn't do that. It could just as easily be us."<br></p><p><br></p><p>Then it was. <br></p><p><br></p><p>Dad got some stranger truck driver going the other way to give me a ride home so I could catch my Little League game. <br></p><p><br></p><p>Who would do that today!!<br></p><p><br></p><p>Terry Smith, whose (yes, obligatory TR content) TR3A is, for once, running solid. Well, except the wires to the OD switch under the tranny tunnel came loose today.) <br></p><blockquote><p>On June 21, 2017 at 6:05 PM Randall <TR3driver@ca.rr.com> wrote:</p><blockquote><p>In other words, it goes like a "bat out of hell".</p></blockquote><p>So did my Dad's TR3A (first one I had to maintain, over 40 years ago). It<br>would run right up to red line in 4th gear with no problem at all. But it<br>still had a severe overheating problem. I believe (in retrospect) that the<br>primary root cause with it was either worn fuel jets, or some ill-considered<br>carb mods by a previous owner.</p><blockquote><p>From what I've heard from<br>others, the cap should not come loose at 210 degrees, thus depressurizing<br>the system,</p></blockquote><p>Yeah, I said that too. Cap should not come loose by itself, even with the<br>system actively boiling.</p><blockquote><p>So maybe that's the area of questions. With everything being equal,<br>engine timed and tuned, do you think in extreme heat and driving pretty<br>hard uphill, that 210 degrees is acceptable temperature?</p></blockquote><p>Well, maybe. Depends on things like how accurate your temp gauge is, and<br>what kind of thermostat you are running. With no thermostat at all and an<br>accurate gauge, I would say that definitely indicates a problem. I can go<br>up Grapevine hill with my foot on the floor (as long as no cops around) in<br>100F heat, and the electric fan won't even come on.</p><blockquote><p>When getting to<br>that temperature range, or higher, would you expect the radiator cap to<br>get loose, or blow off via the overflow hose?</p></blockquote><p>Cap should _never_ come loose on its own. It might play a tune for you, but<br>it should stay in place.</p><p>Depending on circumstances, you might lose coolant through the overflow; but<br>in general not at 210F unless the system was overfilled or you are at high<br>altitude (like 5000 feet or more). IIRC, 33% glycol, and a 4 psi cap,<br>should boil around 215F at 7500 ft.</p><p>-- Randall</p><p>** triumphs@autox.team.net **</p><p>Donate: <a href="http://www.team.net/donate.html">http://www.team.net/donate.html</a><br>Archive: <a href="http://www.team.net/archive">http://www.team.net/archive</a><br>Forums: <a href="http://www.team.net/forums">http://www.team.net/forums</a><br>Unsubscribe/Manage: <a href="http://autox.team.net/mailman/options/triumphs/terryrs@comcast.net">http://autox.team.net/mailman/options/triumphs/terryrs@comcast.net</a><br></p></blockquote></body></html>