Fun project
Parts Specialist
Rennlist Member
Rennlist Member
Joined: Aug 2008
Posts: 16,326
Likes: 30
I just had an interesting talk with one of our engineers about this subject. Some background is he was in racing for years, (AC Cobra's) and built a couple race engines. He understand thermal issues quite well and we talked about this.
I guess what I came away with it, why are you removing it? If you live in a warm area (i.e. Texas) this actually might make sense, where as the cold areas would not benefit as much. That said, there are some flow issues (as earlier discussed) where the RPM is driving the water pump so fast that the inlet pipe restriction will not supply enough water, thus resulting in cavitation on the pump (pumping air) which we all agree is bad. The solution is dependant on your specific needs. In the hotter (120 F summer weather) areas, opening up the flow (street use) should get more cooling to the radiators where the cooling is limited by the outside temp (something about delta T) In a race environment where cavitation is more likely the reason for the change, an increased diameter pulley to slow the pump down may very well be worth more in the end. (and agreement that less restricted flow would increase cooling as long as there was sufficient radiator and there was enough drop in temp while passing thru them)
Either way, this is a good bit of info and I am glad we have been talking about it. I don't think I will make any changes, but I like knowing these things matter... and some of the reasons why they do. Since my bursts of rpm are few and far between, reducing the pulley speed is not in my future plans, but having air pumped will be on my mind since some of what we think happens to these engines might be caused from "hot spots" near the cylinder sleeves.
Food for thought
I guess what I came away with it, why are you removing it? If you live in a warm area (i.e. Texas) this actually might make sense, where as the cold areas would not benefit as much. That said, there are some flow issues (as earlier discussed) where the RPM is driving the water pump so fast that the inlet pipe restriction will not supply enough water, thus resulting in cavitation on the pump (pumping air) which we all agree is bad. The solution is dependant on your specific needs. In the hotter (120 F summer weather) areas, opening up the flow (street use) should get more cooling to the radiators where the cooling is limited by the outside temp (something about delta T) In a race environment where cavitation is more likely the reason for the change, an increased diameter pulley to slow the pump down may very well be worth more in the end. (and agreement that less restricted flow would increase cooling as long as there was sufficient radiator and there was enough drop in temp while passing thru them)
Either way, this is a good bit of info and I am glad we have been talking about it. I don't think I will make any changes, but I like knowing these things matter... and some of the reasons why they do. Since my bursts of rpm are few and far between, reducing the pulley speed is not in my future plans, but having air pumped will be on my mind since some of what we think happens to these engines might be caused from "hot spots" near the cylinder sleeves.
Food for thought
Drifting
Joined: May 2002
Posts: 2,770
Likes: 118
From: Germantown, Maryland
My upcoming weekends are filled w/ the tech inspection this Saturday, HPDC the next, DE after that, free weekend (to do some yardwork and make amends w/ the family), then Hershey. Whew, where did April go??
Three Wheelin'
Joined: Jul 2008
Posts: 1,288
Likes: 13
From: Jacksonville, FL
You guys make an awful lot of extra work for me. Since the first post on this thread, this whole cleaning the radiators thing has been on low heat in the back of my mind. So today I went out and got down and dirty with a prod and a shop vac and cleaned out the area in front of the radiators. There were a few leaves and some "dirt" but it wasn't seriously blocking the radiators. Still it is much cleaner now.
Now I come back to read this thread, and you tell me I only got the condensors and that the real issue is hidden between the first "layer" of coolers and the second "unseen" layers.
Damn you guys, anyway! Now I have remove the bumper. Grumble grumble grumble.
Now I come back to read this thread, and you tell me I only got the condensors and that the real issue is hidden between the first "layer" of coolers and the second "unseen" layers.
Damn you guys, anyway! Now I have remove the bumper. Grumble grumble grumble.
Last edited by Thundertub; Mar 29, 2009 at 11:16 PM.
Nordschleife Master
Joined: Oct 2006
Posts: 7,446
Likes: 69
You guys make an awful lot of extra work for me. Since the first post on this thread, this whole cleaning the radioators thing has been on low heat in the back of my mind. So today I went out and got down and dirty with a prod and a shop vac and cleaned out the area in front of the radiators. There were a few leaves and some "dirt" but it wasn't seriously blocking the radiators. Still it is much cleaner now.
Now I come back to read this thread, and you tell me I only got the condensors and that the real issue is hidden between the first "layer" of coolers and the second "unseen" layers.
Damn you guys, anyway! Now I have remove the bumper. Grumble grumble grumble.
Now I come back to read this thread, and you tell me I only got the condensors and that the real issue is hidden between the first "layer" of coolers and the second "unseen" layers.
Damn you guys, anyway! Now I have remove the bumper. Grumble grumble grumble.
