Cylinder Head Temperatures, Calling on the Brain Trust and they Win! |
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Cylinder Head Temperatures, Calling on the Brain Trust and they Win! |
Mblizzard |
Aug 30 2016, 12:49 PM
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#1
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
OK so I have reviewed the information by Jake regarding cylinder head temperatures http://www.914world.com/specs/JakeRabyHeadTemps.php.
A bit of background. Engine 2056 based on 74 2.0 engine # GA 014782, stock cam, stock FI, fuel pressure at 31 psi, recently added big valve heads, external oil cooler, valves adjusted correctly with engine install, 150+ compression on all cylinders, stock Trans, Evo Muffler, all stock cooling items in place (flaps and tins), running 123 electronic distributor set to the curve for the 0 231 174 011 dizzy which is correct for the 74. Timing seems to be correct using the marks as indicated in the photo below. Likely at about 25 BTDC. At cruise I see temps in the 350-375F range with it being pushed to the higher end and above. On hill climbs it will go quickly to the 400F range and run at that for the duration of the climb. Most I have seen is about 405F. Letting off the throttle quickly brings the temp back down so I have to think the cooling system is working. I would expect a 2056 to run some warmer but not to be consistently in the upper end of the range I am not sure what is causing this. I have seen lower temps on cruise by richening up the mixture. But overall based on the guidance it seems to be running too hot. I have suspicion my AF meter is reading too rich so that might be part of it showing an acceptable AF range but could be going lean under load. Changing out the sensor and will recheck. So given all of that what do I check or where do I start changing things to bring the temps down? Taking a few degrees out of the timing helped but not significantly. Anyone? (IMG:style_emoticons/default/headbang.gif) |
era vulgaris |
Aug 30 2016, 03:10 PM
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#2
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J is for Genius Group: Members Posts: 982 Joined: 10-November 13 From: Raleigh, NC Member No.: 16,629 Region Association: South East States |
On the interstate it is going to be higher due to the increased wind resistance, and even higher still if you've got the top off (even more wind resistance). I'm around 335-345 on the interstate in 5th gear on a flat grade. Taking the top off will increase that by 5-10 degrees on the interstate, about 5 degrees in 4th gear speeds, and negligible if any difference at all in lower gears.
What AFR gauge are you running? If it's working at all, then you probably don't need to replace the sensor. It probably just needs to be re-calibrated. With mine (Innovate MTX-L) you unscrew the sensor from the bung in the exhaust and leave it in open air, turn the ignition to 'on' for like 30 seconds IIRC and it recalibrates itself. If you have the manual for it it'll tell you what to do. |
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