Getting warm when towing up hills
So at highway speeds here in Colorado while towing my trailer (with my D90, 4.6l) I start to get warm going up the hills such as parts of Boulder Canyon and I70 (going through mountains, steep hills, sustained for miles, 55-65 mph typical). I watch close and sometimes it approaches 220F, which is my personal limit. Couple questions and ideas.
First, what temp for you engine builders is your absolute max? Mine is 230, at which point I pull over.
Next would be how to keep it cooler. Let me tell you where I am at---it is a 4.6l (slightly overbored with oversized pistons), dual electric fans, 4-core radiator (just redone 6 months ago), mainly H20 and Water Wetter in great shape, 10 BTDC, stock coil, Mallory Unilite distributor, custom chip (Pendy).
Truck runs great. Strong, solid. But strong hills at highway speeds (particularly if it is hot out) is when it can get hot and I get worried (rightly so....)---my trailer weighs about 1200 lbs.
I am pretty good mechanically, built the truck from scratch, motor from a block. So in the depths of my research, I have found that the 3.5l, 3.9l engines really like an overall advance limit of 36 BTDC where as the 4.6l likes 28-30 BTDC...
The Mallory distributor (4768901) has a mechanical advance of 24 degrees (plus vacuum advance if you are using it, which wouldn't come into play at full throttle) which means that with my base timing of 10-12 BTDC, I am getting around 36 BTDC timing when it wants 28. Would this be enough to cause the extra heat?
I don't think this is a head gasket/leak down/liner etc issue---I have been over this engine and tested it thoroughly.
It just may be that I am trying to go too fast hauling too much, but I think it should still keep it...
Let me know what you think---