Many of you doubted my hunch that "creep" temperatures of 390F can be reached on the air cooled Intek 24 head,and cause the common valve guide movement and associated valve train failure. I have use four K thermocouple probes on the Intek during this hot season with ambient of 75F to 93F (today). I have not reached that temperture. Here are the sensor locations and temps I have reached:
Sparkplug sensor ring: 312F during 80F ambient 3 bagger mowing on a slight incline.
Oil sump probe: Beedee oil temp gauge said 300F, K probe in sump said 272F. Ambient 80F, 3 bag mowing on slope.
Valve cover bolt nearest exhaust valve guide 272F today when oil temp gauge said 320F ( probably 300F but not taken), ambient 93F. Hard mowing , 3 bagger on slope.
Notes: The sparkplug sensor started leaking (the plug read lighter than the other cylinder) so I took itoff and do not know how hot it would have been today 93F)
I tried a clamp sensor around the cast "cylinder" housing the exhaust valve guide, but could not get good heat transfer. This would have been ideal. Rats
Like other testing when things are changed I do not know how hot the Intek was when it failed and now it has the oil cooler Apparently the sump oil without the
oil cooler fan on is 20-30F hotter than the valve cover bolt. Oil pressure today at 93F , 300F oil sump temp is 30 psi with Chevron 5W-30. The mystery continues.
Sparkplug sensor ring: 312F during 80F ambient 3 bagger mowing on a slight incline.
Oil sump probe: Beedee oil temp gauge said 300F, K probe in sump said 272F. Ambient 80F, 3 bag mowing on slope.
Valve cover bolt nearest exhaust valve guide 272F today when oil temp gauge said 320F ( probably 300F but not taken), ambient 93F. Hard mowing , 3 bagger on slope.
Notes: The sparkplug sensor started leaking (the plug read lighter than the other cylinder) so I took itoff and do not know how hot it would have been today 93F)
I tried a clamp sensor around the cast "cylinder" housing the exhaust valve guide, but could not get good heat transfer. This would have been ideal. Rats
Like other testing when things are changed I do not know how hot the Intek was when it failed and now it has the oil cooler Apparently the sump oil without the
oil cooler fan on is 20-30F hotter than the valve cover bolt. Oil pressure today at 93F , 300F oil sump temp is 30 psi with Chevron 5W-30. The mystery continues.