For those wanting to run LS1 coolant tubes under FAST intake (Pics)
03-12-2012, 09:54 AM
#1
For those wanting to run LS1 coolant tubes under FAST intake (Pics) *I apologize that a few pics are a little blurry. Working with a camera that I don’t fully understand yet. This was done using a Fast 90mm intake. From my research, a 78mm and 92mm intake have the same base, so this should work for them also.*
I know most people get the Ls6 coolant tube setup where the front two coolant ports are tied together and you use block-off plugs for the back of the heads. Some also get 2 LS6 tube setups and ignore the block-off plugs and run the front tube both on the front and the back of the head and tie them together with a hose on the outside of the intake. I did not like the 1st choice for sure. The second choice is good, but I didn’t want a rubber hose connected between the two which could add 2 more possible leak spots, and I didn’t want anything more on the outside for clutter purposes. So while researching on tech for my 90mm Fast intake swap, I came across maybe 2 or 3 people that decided to use the LS1 coolant tubes, and “massaged” them to fit under the intake. I never found any pics but I wanted to go this route because even if the tubes have to be flattened to the extreme, some coolant is better than nothing. This way I never had that problem and mine flow perfectly, no kinks, nothing. Couldn’t be happier.
I am not going to get into the debate about heat dissipation between LS1 and Ls6 coolant tubes. My personal preference is that the LS1 tubes are superior to LS6 as others do.
As for tools, these were all that I needed to complete the job, only thing not pictured is a caliper
I wanted to have every bug worked out of my spring mod session before I pulled my car from storage, so I threw together a mock-up motor in the basement and attached all of my stock pull-off parts from over the years. To make this all correct, I measured out everything so that everything was mounted just like my car is which means shimming the heads off the block the correct thickness of the head gaskets, measuring the thickness of the coolant tube gaskets and final shimming those to the same spec, also using an oem valley cover gasket I had extra so that I could have everything at the right height. I did all fitment tests with the intake with no port gaskets. This is so I would be 110% certain that there will be no touching of coolant tubes to the bottom of the intake to avoid cracks. You can see in pics that this intake I spent a lot of time porting and fixing the bottom and inside since the original owner ignored the instructions from Fast and didn’t swap valley cover bolts to the smaller ones. So I had 6 cracks on the inside to fix that were only dents on the outside. Fun surprise. This job was also completed with consideration for the knock sensor harness.
For the coolant tubes, since I went to the hardware store and located every bolt for the Fast intake and valley cover in stainless, I decided the coolant tubes needed stainless also. These are stock size m6 x 1.0 x 30mm
I first bolted the coolant tubes on the block and shimmed them off the heads by .050 which is how thick the oem gaskets are that are required. This gave me an idea of how far the coolant tubes were from the top of the valley cover. This distance is how much I needed to bend the entire tube setup first. First step, get it all to lay flat on the valley cover. I achieved this by adding 4 washers on all 4 corners to bring the tubes up really tall. These washers I used to “over shim” the tubes were .080 each. So a total of .320. Bolted them on this way and proceeded to lightly tap all 4 corners aprox 2” from the mounting points on the tube with a hammer. You have to bend the tubes farther than the distance you saw shimmed at .050. This is because the metal will spring back when you bend it. Need to “overbend” a little.
distance at stock height (.050 shim)
.320 worth of shims for "overbend"
Now unbolt it all and remount the tubes so that they are shimmed at .050 (stock height) and see if you have the tubes all resting on the valley cover. May need to try this a few times to accomplish this. So once everything is resting on the valley cover, time to get to the tube flattening. Many ways you can do this, I opted for my trusty hammer. Taking many many light taps, only moving maybe 1/8” at a time all the way down the line till the end of the valley cover. No need to go nuts with the hammer. Test is out lightly first till you get a feel for how hard you need to hit to make a difference in the tube. Then it’s time to test how well your intake fits. (this may take many times of trial and error.) To let me know what parts of the tube were hitting the bottom of the intake, I applied some heavy oil on the entire top of the coolant tubes. So when I put my intake on top, the oil will transfer from the tube to wherever the tube comes in contact with the intake bottom. These are the spots that need to be tweaked. I had some extra bending on mine since I had to add more material on the bottom for extra strength due to some small cracks.
This is the difference between the flattened part, and what it was originally. Not much required.
During the flattening process, you also need to pay attention the 4 corners of the coolant tubes where they mount to the heads. These sometimes will get slightly tweaked in the flattening process. So I would remove the tubes and also remove the .050 shims. Then I would mount the tubes back in place with no shims. This would show me if the mounting pad needed attention. I made sure that in the end that the pads were perfectly flat all around for perfect mounting. To fix these small bends (if needed) I used a crescent wrench. You barely need any force to make a big difference. Takes a light touch.
One place that I was running into problems is right where the factory joined the 2 pipes in the middle of the setup. The metal that they used to seal all the joints was gobbed up pretty thick. This could be a headache if you don’t fix this. I used a file on both top and bottom of this joint to remove the excess. There is a ton there so once you have it filed down to where it doesn’t contact the intake, there is still plenty of material left for the joint seal.
Now it is time to address the knock sensor harness. You cannot run the harness under, or on top of the flattened lines. The harness wires need to be separated so that they can go around the tubes and be entirely out of the way. All you need to do is remove the electrical tape all the way down to the foam that is used as a barrier. Then pull the wires apart to that point. I mounted the harness this way but it still needed more reach to be correct and not pulled tight. So I removed 1” of foam and tape and split the wires that same distance, then retaped the foam in place. This still allowed plenty of foam on the harness to be safe. Routed the wires and saw that it will work.
don’t route it this way:
Don’t route it this way:
Remove tape and split the wires to the foam:
Remove 1” of foam and re-tape foam to wire and add tape to prevent any possible bolt touching:
I know most people get the Ls6 coolant tube setup where the front two coolant ports are tied together and you use block-off plugs for the back of the heads. Some also get 2 LS6 tube setups and ignore the block-off plugs and run the front tube both on the front and the back of the head and tie them together with a hose on the outside of the intake. I did not like the 1st choice for sure. The second choice is good, but I didn’t want a rubber hose connected between the two which could add 2 more possible leak spots, and I didn’t want anything more on the outside for clutter purposes. So while researching on tech for my 90mm Fast intake swap, I came across maybe 2 or 3 people that decided to use the LS1 coolant tubes, and “massaged” them to fit under the intake. I never found any pics but I wanted to go this route because even if the tubes have to be flattened to the extreme, some coolant is better than nothing. This way I never had that problem and mine flow perfectly, no kinks, nothing. Couldn’t be happier.
I am not going to get into the debate about heat dissipation between LS1 and Ls6 coolant tubes. My personal preference is that the LS1 tubes are superior to LS6 as others do.
As for tools, these were all that I needed to complete the job, only thing not pictured is a caliper
I wanted to have every bug worked out of my spring mod session before I pulled my car from storage, so I threw together a mock-up motor in the basement and attached all of my stock pull-off parts from over the years. To make this all correct, I measured out everything so that everything was mounted just like my car is which means shimming the heads off the block the correct thickness of the head gaskets, measuring the thickness of the coolant tube gaskets and final shimming those to the same spec, also using an oem valley cover gasket I had extra so that I could have everything at the right height. I did all fitment tests with the intake with no port gaskets. This is so I would be 110% certain that there will be no touching of coolant tubes to the bottom of the intake to avoid cracks. You can see in pics that this intake I spent a lot of time porting and fixing the bottom and inside since the original owner ignored the instructions from Fast and didn’t swap valley cover bolts to the smaller ones. So I had 6 cracks on the inside to fix that were only dents on the outside. Fun surprise. This job was also completed with consideration for the knock sensor harness.
For the coolant tubes, since I went to the hardware store and located every bolt for the Fast intake and valley cover in stainless, I decided the coolant tubes needed stainless also. These are stock size m6 x 1.0 x 30mm
I first bolted the coolant tubes on the block and shimmed them off the heads by .050 which is how thick the oem gaskets are that are required. This gave me an idea of how far the coolant tubes were from the top of the valley cover. This distance is how much I needed to bend the entire tube setup first. First step, get it all to lay flat on the valley cover. I achieved this by adding 4 washers on all 4 corners to bring the tubes up really tall. These washers I used to “over shim” the tubes were .080 each. So a total of .320. Bolted them on this way and proceeded to lightly tap all 4 corners aprox 2” from the mounting points on the tube with a hammer. You have to bend the tubes farther than the distance you saw shimmed at .050. This is because the metal will spring back when you bend it. Need to “overbend” a little.
distance at stock height (.050 shim)
.320 worth of shims for "overbend"
Now unbolt it all and remount the tubes so that they are shimmed at .050 (stock height) and see if you have the tubes all resting on the valley cover. May need to try this a few times to accomplish this. So once everything is resting on the valley cover, time to get to the tube flattening. Many ways you can do this, I opted for my trusty hammer. Taking many many light taps, only moving maybe 1/8” at a time all the way down the line till the end of the valley cover. No need to go nuts with the hammer. Test is out lightly first till you get a feel for how hard you need to hit to make a difference in the tube. Then it’s time to test how well your intake fits. (this may take many times of trial and error.) To let me know what parts of the tube were hitting the bottom of the intake, I applied some heavy oil on the entire top of the coolant tubes. So when I put my intake on top, the oil will transfer from the tube to wherever the tube comes in contact with the intake bottom. These are the spots that need to be tweaked. I had some extra bending on mine since I had to add more material on the bottom for extra strength due to some small cracks.
This is the difference between the flattened part, and what it was originally. Not much required.
During the flattening process, you also need to pay attention the 4 corners of the coolant tubes where they mount to the heads. These sometimes will get slightly tweaked in the flattening process. So I would remove the tubes and also remove the .050 shims. Then I would mount the tubes back in place with no shims. This would show me if the mounting pad needed attention. I made sure that in the end that the pads were perfectly flat all around for perfect mounting. To fix these small bends (if needed) I used a crescent wrench. You barely need any force to make a big difference. Takes a light touch.
One place that I was running into problems is right where the factory joined the 2 pipes in the middle of the setup. The metal that they used to seal all the joints was gobbed up pretty thick. This could be a headache if you don’t fix this. I used a file on both top and bottom of this joint to remove the excess. There is a ton there so once you have it filed down to where it doesn’t contact the intake, there is still plenty of material left for the joint seal.
Now it is time to address the knock sensor harness. You cannot run the harness under, or on top of the flattened lines. The harness wires need to be separated so that they can go around the tubes and be entirely out of the way. All you need to do is remove the electrical tape all the way down to the foam that is used as a barrier. Then pull the wires apart to that point. I mounted the harness this way but it still needed more reach to be correct and not pulled tight. So I removed 1” of foam and tape and split the wires that same distance, then retaped the foam in place. This still allowed plenty of foam on the harness to be safe. Routed the wires and saw that it will work.
don’t route it this way:
Don’t route it this way:
Remove tape and split the wires to the foam:
Remove 1” of foam and re-tape foam to wire and add tape to prevent any possible bolt touching:
Last edited by BlackDuk98; 03-12-2012 at 10:02 AM.
03-12-2012, 09:55 AM
#2
With one wire done like the above pic, you have to fix the longest wire. Since there is a gap between the valley cover, head, and intake port bottom, this is a perfect place to run the longer wire. To prevent the wire from moving and possibly getting under a port seal, or get pinched, I made a little tab that goes under a custom made stainless valley cover bolt that will barely raise the bolt head, and fit perfectly in the gap I used to run the wire. I made it out of really thin stainless. Then wrapped the part of wire that the tab is holding to prevent any possibility of the wire getting cut.
Here is the knock sensor harness in its final place:
Here is what they look like finalized:
The difference in thickness between tweaked and untouched:
Be sure that you check with the oil, and recheck the 4 mounting points to be true one more time. Then you can throw them on the car, or scuff them up and paint.
But before you paint, make sure you did a good job. Hook the tubes up to a water source and test that you didn’t crush a tube too much. Works like a champ.
Pretty simple job, just takes some time. In the end, I saved money, kept coolant flowing to all 4 head points, didn’t add any more leak points, didn’t add an extra tube running on the top of my engine bay, did it myself and didn’t just bolt on a quick fix. Hope this helps someone. Very easy project
Here is the knock sensor harness in its final place:
Here is what they look like finalized:
The difference in thickness between tweaked and untouched:
Be sure that you check with the oil, and recheck the 4 mounting points to be true one more time. Then you can throw them on the car, or scuff them up and paint.
But before you paint, make sure you did a good job. Hook the tubes up to a water source and test that you didn’t crush a tube too much. Works like a champ.
Pretty simple job, just takes some time. In the end, I saved money, kept coolant flowing to all 4 head points, didn’t add any more leak points, didn’t add an extra tube running on the top of my engine bay, did it myself and didn’t just bolt on a quick fix. Hope this helps someone. Very easy project
12-13-2012, 09:02 AM
#7
not at all. There isn't much of an air gap between a stock intake and coolant tubes either. On a stock intake they have foam the goes between the tubes and intake bottom. The foam won't even melt. This is a little less space but the tubes are no where near hot enough for any concern. The heads get insanely hot directly where the intake runners mount and even racing on 100+ degree days where you can really burn yourself touching the heads it won't even phase an intake. Their composite is insanely heat resistant like an oem intake. Plus you also bend the tubes so they don't make contact with the intake. You will be fine. A lot of people run coolant this way.
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12-13-2012, 04:57 PM
#9
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Nice work, and I'd like to add for those on a budget: If you have LS1 style lines and would like to delete the under intake section and just run two cross-overs front and rear you can cut the tubing, crimp the cut end down together, sand clean, and solder just like brass bathroom pipe. Won't leak a drop.
