respectfully disagree,
the block heater is not an option on some model engines (HDT,1HZ).
i agree about the head but the location for the temp reading was at the very highest back corner of the head and only after 25 min of heating.
also, the ease of install of the lower rad hose heater makes it very appealing.
you need airflow to pass through the rad to do much in the way of cooling the tempts and i found the front of the block heated up much faster than the rad did showing the coolant was heating the block first similar to the block heater.
i am satisfied with the lower rad hose heater.
what would be interesting is doing the same test with a block heater to compare the findings.
location of testing:
upper hose was rad side of the thermostate housing
lower hose was just above the heater
upper rad was the furthest corner away from the upper inlet for the hose (coldest corner upper part of the rad)
block front was under the head front upper corner
head rear was the furthest corner away from the heat source just below the tappet cover back corner.
hummm, this just brought up another question...maybe the head coolant passeges design is the problem with the 2LT heads, if htey are not warming up properly in the back corners then mayb ethey are not REMOVING heat properly either hence the crackign of the heads due to over heating...
hummm, thanks Mark...you got me thinking.
cheers
