Will the LS6 coolant tube conversion hurt cooling system performance?
01-04-2007, 07:08 PM
#21
Hmm, wonder if it has anything to do with those back cylinders being tucked against the firewall? Just a thought in the dark.
Originally Posted by cablebandit
i remember somebody running a race setup with the intake reversed and #7 was still a problem......
01-04-2007, 07:12 PM
#22
Let's look at it a little more analytically: How many degrees hotter does #7 and #8 run than cylinders at the front of the engine? (I think about 1350 degrees F starts to melt the cylinder but I am not sure.) What is the difference in coolant temperature from the front of the engine to the rear of the engine?
I can see an air pocket causing some issues but I don't know about the direction of the coolant. But then again I just don't know.
I can see an air pocket causing some issues but I don't know about the direction of the coolant. But then again I just don't know.
Originally Posted by cam
If there was some extra heat specific to one single cylinder and the extra cooling brought said cylinder back on par with the others then i would say yes. I read that whole #7 thread and the air crashing into the back of the intake sounds like the smoking gun BUT connecting those pipes to the cooling system cannot in anyway hurt. I dont know how much it would help either but I'm going to post up and see if any of those guys who lost number 7 had the plugs vs plumbed coolant tubes.
01-04-2007, 10:23 PM
#23
i remember somebody running a race setup with the intake reversed and #7 was still a problem......
I know some of the LSx conversion Porsche and lambo guys mount the intake in reverse.
01-05-2007, 01:30 PM
#24
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We ran the tubes in the Motorola cup cars because if we put the back plug types in the #7 cylinder would have problems. It seemed to me with the testing we did that air pockets formed in the back of the head from the coolant boiling causing the engine to detonate on the back cylinders. Normally #7 would eat the piston or break the rod and #8 would show signs of trouble. These are just guesses on my part based on what the parts looked like broken!
One thing I did in the late 90's was put thermocouples on the 4 corners of the heads with the water still flowing. Then we put 10 02 sensors in, one in each port and one in the collector of each bank. I then parked the engine at 6500rpm/full load for 15 minutes at a time with the intake on normal and reversed to record coolant temp and afr. Nothing showed up that clued us in on why the 7 cylinder was fragile. The engine was a stock stroke forged piston Motorola cup legal LS.
Around 2000 or 2001 Unocal started sponsorship of the Nascar stuff and the Motorola cup could no longer use 94 Sunoco as the fuel on Union tracks, this forced them into 100 octane and the number 7 problems went away so we stopped looking for why....
Kurt
One thing I did in the late 90's was put thermocouples on the 4 corners of the heads with the water still flowing. Then we put 10 02 sensors in, one in each port and one in the collector of each bank. I then parked the engine at 6500rpm/full load for 15 minutes at a time with the intake on normal and reversed to record coolant temp and afr. Nothing showed up that clued us in on why the 7 cylinder was fragile. The engine was a stock stroke forged piston Motorola cup legal LS.
Around 2000 or 2001 Unocal started sponsorship of the Nascar stuff and the Motorola cup could no longer use 94 Sunoco as the fuel on Union tracks, this forced them into 100 octane and the number 7 problems went away so we stopped looking for why....
Kurt
01-05-2007, 03:11 PM
#25
We ran the tubes in the Motorola cup cars because if we put the back plug types in the #7 cylinder would have problems. It seemed to me with the testing we did that air pockets formed in the back of the head from the coolant boiling causing the engine to detonate on the back cylinders. Normally #7 would eat the piston or break the rod and #8 would show signs of trouble. These are just guesses on my part based on what the parts looked like broken!
One thing I did in the late 90's was put thermocouples on the 4 corners of the heads with the water still flowing. Then we put 10 02 sensors in, one in each port and one in the collector of each bank. I then parked the engine at 6500rpm/full load for 15 minutes at a time with the intake on normal and reversed to record coolant temp and afr. Nothing showed up that clued us in on why the 7 cylinder was fragile. The engine was a stock stroke forged piston Motorola cup legal LS.
Around 2000 or 2001 Unocal started sponsorship of the Nascar stuff and the Motorola cup could no longer use 94 Sunoco as the fuel on Union tracks, this forced them into 100 octane and the number 7 problems went away so we stopped looking for why....
Kurt
One thing I did in the late 90's was put thermocouples on the 4 corners of the heads with the water still flowing. Then we put 10 02 sensors in, one in each port and one in the collector of each bank. I then parked the engine at 6500rpm/full load for 15 minutes at a time with the intake on normal and reversed to record coolant temp and afr. Nothing showed up that clued us in on why the 7 cylinder was fragile. The engine was a stock stroke forged piston Motorola cup legal LS.
Around 2000 or 2001 Unocal started sponsorship of the Nascar stuff and the Motorola cup could no longer use 94 Sunoco as the fuel on Union tracks, this forced them into 100 octane and the number 7 problems went away so we stopped looking for why....
Kurt
01-05-2007, 10:49 PM
#26
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With the LS1 tubes and a LS6 intake we had no problems in 98-99 and 2000, then around 2001 when the LS6 intake was released we tried the plugs in the back. Prior to that we ran with LS1 tubes (4 corners vented).
We still vent all 4 corners on high power stuff.
Kurt
We still vent all 4 corners on high power stuff.
Kurt
01-06-2007, 12:16 AM
#27
Wow, that's some good information. The Motorola cup cars are naturally aspirtated, right? How hard it is to boil your coolant... how quickly can you do it? I wonder if it has anything to do with the #7 and #8 being tucked back against the firewall?
Originally Posted by 427
We ran the tubes in the Motorola cup cars because if we put the back plug types in the #7 cylinder would have problems. It seemed to me with the testing we did that air pockets formed in the back of the head from the coolant boiling causing the engine to detonate on the back cylinders. Normally #7 would eat the piston or break the rod and #8 would show signs of trouble. These are just guesses on my part based on what the parts looked like broken!
One thing I did in the late 90's was put thermocouples on the 4 corners of the heads with the water still flowing. Then we put 10 02 sensors in, one in each port and one in the collector of each bank. I then parked the engine at 6500rpm/full load for 15 minutes at a time with the intake on normal and reversed to record coolant temp and afr. Nothing showed up that clued us in on why the 7 cylinder was fragile. The engine was a stock stroke forged piston Motorola cup legal LS.
One thing I did in the late 90's was put thermocouples on the 4 corners of the heads with the water still flowing. Then we put 10 02 sensors in, one in each port and one in the collector of each bank. I then parked the engine at 6500rpm/full load for 15 minutes at a time with the intake on normal and reversed to record coolant temp and afr. Nothing showed up that clued us in on why the 7 cylinder was fragile. The engine was a stock stroke forged piston Motorola cup legal LS.
01-06-2007, 05:14 PM
#28
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im putting on an ls6 intake, i asked my installer/sponsor and he said they just use ls6 coolant lines, but after seeing this, im worried. Im doing a heads/cam setup. Should i tell him to modify the coolant lines?
01-06-2007, 05:41 PM
#29
im putting on an ls6 intake, i asked my installer/sponsor and he said they just use ls6 coolant lines, but after seeing this, im worried. Im doing a heads/cam setup. Should i tell him to modify the coolant lines?
We still vent all 4 corners on high power stuff.
01-06-2007, 11:25 PM
#31
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Motorola cup was NA 346. The coolant will not boil easy and it may never happen on a street car. A normal Motorola cup race was between 3-6 hours long. The normal coolant temp is around 230F during the race with higher temps seen with rubber and debris in the rad at the end of the race. With Evans coolant we have seen teams run over 250F for more than a hour without damage to the engine. I don't think the firewall can change the coolant temp, it is dictated by the radiator/waterpump system.
Kurt
Kurt
Originally Posted by FastKat
Wow, that's some good information. The Motorola cup cars are naturally aspirtated, right? How hard it is to boil your coolant... how quickly can you do it? I wonder if it has anything to do with the #7 and #8 being tucked back against the firewall?
