Why & How to Cool Down Your Twin Cam Engine
#21
04-12-2017, 08:30 PM
Seasoned HDF Member
I agree with you martin10. Also, it is my opinion these mods are more detrimental than beneficial. It's been a while since I've mentioned this, but Charles Lindbergh had a similar argument while serving in the pacific during WWII regarding leaning out the engines of P40 Warhawks and P38 Lightnings to increase range. Everyone told him this would destroy the engines due to overheating. He proved them wrong.
Modern FI engines running under electronic management can very safely run leaner, increasing fuel economy and reducing wear. It is not uncommon for engines to achieve 300,000 or more miles before overhaul instead of the typical 80,000 I grew up with running carbureted engines with NO emissions controls. Reason, AFR being constantly maintained by computer control at about 14:1, just on the rich side of stociometric value for gasoline, results in max power, virtually complete burning (minimum pollution) and, in my opinion, almost no washdown of the cylinder walls by fuel.
Screwing around with this seems to me to result in increased cylinder wear over the lifetime of the engine, not decreased wear.
Modern FI engines running under electronic management can very safely run leaner, increasing fuel economy and reducing wear. It is not uncommon for engines to achieve 300,000 or more miles before overhaul instead of the typical 80,000 I grew up with running carbureted engines with NO emissions controls. Reason, AFR being constantly maintained by computer control at about 14:1, just on the rich side of stociometric value for gasoline, results in max power, virtually complete burning (minimum pollution) and, in my opinion, almost no washdown of the cylinder walls by fuel.
Screwing around with this seems to me to result in increased cylinder wear over the lifetime of the engine, not decreased wear.
I didn't know that 14 to 1 results in max power... My own experience has shown it to be about 13.2 +- 0.2 which is where fuel burns fastest. As you move lean or rich from there the rate of combustion slows.. From what I've seen slower combustion generates more heat.. It's a burn time / cylinder area thing.
I do know that if I lean the AFRs close to stoic at cruise, oil / engine temps seem to go up. It becomes a balance between leanness and motor heat. Enough heat a detonation can follow.
#23
04-13-2017, 06:05 PM
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#24
04-13-2017, 07:52 PM
Seasoned HDF Member
It's fine.. I thing the issue is what you want to go for, max power or max efficiency.. For efficiency, 14 is fine. I would say even a little rich.. I would lean it out till you see temps rise then back off.
#25
04-13-2017, 11:41 PM
Seasoned HDF Member
I agree with you martin10. Also, it is my opinion these mods are more detrimental than beneficial. It's been a while since I've mentioned this, but Charles Lindbergh had a similar argument while serving in the pacific during WWII regarding leaning out the engines of P40 Warhawks and P38 Lightnings to increase range. Everyone told him this would destroy the engines due to overheating. He proved them wrong.
Modern FI engines running under electronic management can very safely run leaner, increasing fuel economy and reducing wear. It is not uncommon for engines to achieve 300,000 or more miles before overhaul instead of the typical 80,000 I grew up with running carbureted engines with NO emissions controls. Reason, AFR being constantly maintained by computer control at about 14:1, just on the rich side of stociometric value for gasoline, results in max power, virtually complete burning (minimum pollution) and, in my opinion, almost no washdown of the cylinder walls by fuel.
Screwing around with this seems to me to result in increased cylinder wear over the lifetime of the engine, not decreased wear.
Modern FI engines running under electronic management can very safely run leaner, increasing fuel economy and reducing wear. It is not uncommon for engines to achieve 300,000 or more miles before overhaul instead of the typical 80,000 I grew up with running carbureted engines with NO emissions controls. Reason, AFR being constantly maintained by computer control at about 14:1, just on the rich side of stociometric value for gasoline, results in max power, virtually complete burning (minimum pollution) and, in my opinion, almost no washdown of the cylinder walls by fuel.
Screwing around with this seems to me to result in increased cylinder wear over the lifetime of the engine, not decreased wear.
BTW, You really don't need to worry about wash down till you get below about 12 to 1. I do know that if you run them at 10 you'll see wear pretty fast...
#26
04-24-2017, 11:33 PM
Road Warrior
I actually used some of DK Custom’s “inexpensive” tips (removed all wind deflectors - had three different sets installed and the left side thigh protector) and I must say, rode the RGU for three hours on Sunday and the bike felt so much cooler.
I wonder how their "Dual-Cool Oil Cooler for 2009-Up” is routed and installed as an auxiliary oil cooler with MoCos oil cooler.
I wonder how their "Dual-Cool Oil Cooler for 2009-Up” is routed and installed as an auxiliary oil cooler with MoCos oil cooler.
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