Joel’s SL-C Build Thread

Joel K

Supporter
(Going to use a 1 Liter for the expansion tank and a 2 Liter for both the recovery and intercooler tanks. I ordered black anodized, but they also come in natural aluminum and red anodized.)
Joel, I would use the 2 liter for expansion and the 1 liter for recovery. I have a 2,7 liter expansion tank (with approx 1liter in it cold) and a less than 1 liter for recovery, works great.
Water expands little more than 8% from 10˚C to 120˚C. I can’t remember exactly but I think my system is 13-15 liter total so the expansion will be slightly more than 1 liter.
Only time I have any coolant in the recovery tank is after complete drain and refill.
Thanks Johan, I definitely agree having a larger expansion tank is ideal. I don’t have the room for a 2L expansion tank up high unless I custom make or modify one. Originally as per Ken’s advice I went with the larger Moroso tank and it can be made to fit, but sort of cramped in that area so bought a smaller tank.

I guess my question is, assuming when the coolant overflows into the recovery tank and is drawn back in to the expansion tank does it really matter which tank is first? If 100% of the coolant overflow is not returned then I can see a problem.
 

Kyle

Supporter
It shouldn’t matter, I don’t even have a recovery tank. As long as you fill to the proper level the coolant will expand and contract within the confined volume, assuming it isn’t overfilled. Although I’m sure if you were tracking the car they’d want some sort of spill recovery.
 

Ken Roberts

Supporter
Personally I wouldn’t want the expansion tank at max capacity (completely full) as the air bleeds at the top of the tank would be submerged in coolant instead of being in a air pocket. Their function would be compromised in my opinion.

If Joel’s tank was at least 1.5 liters then there might be room at the top for a air pocket.
 
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Joel K

Supporter
Personally I wouldn’t want the expansion tank at max capacity (completely full) as the air bleeds at the top of the tank would be submerged in coolant instead of being in a air pocket. Their function would be compromised in my opinion.

If Joel’s tank was at least 1.5 liters then there might be room at the top for a air pocket.
Thanks Ken, more things to think about! I think Kyle is using a 2L tank based on a pic in his build thread.
 

Johan

Supporter
Personally I wouldn’t want the expansion tank at max capacity (completely full) as the air bleeds at the top of the tank would be submerged in coolant instead of being in a air pocket. Their function would be compromised in my opinion.

If Joel’s tank was at least 1.5 liters then there might be room at the top for a air pocket.
Yeap, think of the expansion tank as a shock absorber. If filled to the correct level it shouldn’t spill over to a recovery tank.
 

Rich Kruger

Supporter
As far as I know the expansion tank should be full with no air when cold because this is actually part of the primary/ radiator system. Think of it as being the top tank of the radiator. Air is a proponent of corrosion. The overflow tank therefor eliminates air from entering the cooling system and it should have a little coolant in it when cold.
 

Ken Roberts

Supporter
That may be true for a typical front engine car with the top of the radiator being at or near the highest point. Not ideal for a car with the engine in the rear and a radiator canted at the front and far from being the highest point.

Lots of OEM systems have a air gap at the top of their expansion tanks. They are usually found on cars where the radiator is canted and the expansion tanks have the pressure caps. The following picture shows such an example. It is the one include with the purchase of the car. You can see the “cold“ fill range in the middle of the tank and the air bleed at the top.

image.jpg
 
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Joel K

Supporter
Interesting different viewpoints. I thought about what happens when the expansion tank is on the smaller side and fills up and sends fluid to the recovery tank. To Rich’s point, over time and repeated cycles the expansion tank will stay full when cold with some fluid in the recovery tank which keeps the line primed to assure fluid is drawn back when needed.

Ken, to your point ideally you want the radiator bleed line and steam line to be above the water line so they have less resistance and allow the air/steam to move through those lines. I don’t disagree that is ideal.

I am not a fluid expert so not sure. Was wondering in the case of using a smaller expansion tank that is filled up, because the expansion tank is connected to the pump inlet, would that create an effect to help draw water through the steam and bleed lines? If this is the case, maybe a smaller expansion tank is ok.
 

Rich Kruger

Supporter
Ken come to think of it the Kenworth I drive on occasion does use a tank similar to what came with the SLC. Maybe I'm just jaded because I was a Chevrolet service manager when Dexcool was causing a lot ( A LOT :mad:) of cooling system corrosion problems for cars and trucks with iron engine blocks. The sludge seemed to be never ending is some cars and trucks. I do use it for my LS3 because it works well with aluminum. That being said I just wanted to eliminate the possibility of a problem. Joel I do have a radiator vent line as well as 4 cylinder head steam vent lines into the pressurized coolant tank. My car seems to circulate well and I've never had a overheating issue. Any gases appear to simply get forced out of the rad cap under pressure. My overflow fluctuates 1-2 inches cold to hot.
 

Joel K

Supporter
Ken come to think of it the Kenworth I drive on occasion does use a tank similar to what came with the SLC. Maybe I'm just jaded because I was a Chevrolet service manager when Dexcool was causing a lot ( A LOT :mad:) of cooling system corrosion problems for cars and trucks with iron engine blocks. The sludge seemed to be never ending is some cars and trucks. I do use it for my LS3 because it works well with aluminum. That being said I just wanted to eliminate the possibility of a problem. Joel I do have a radiator vent line as well as 4 cylinder head steam vent lines into the pressurized coolant tank. My car seems to circulate well and I've never had a overheating issue. Any gases appear to simply get forced out of the rad cap under pressure. My overflow fluctuates 1-2 inches cold to hot.
Rich, thanks for the info and that is encouraging. Doesn’t appear your system expands all that much when it reaches operating temperature.
 

Joel K

Supporter
Started fabricating the brackets for the rear compartment. First up is the recovery tank mount bracket.

Took a page out of Dusty’s build thread and purchased some ballast clamps to mount the overflow tank on the passenger side. These are really nice and allows you to securely mount components without drilling holes in the frame. They come with 1/2”-13 threaded holes for mounting things.

Pic of the brackets purchased from Southwest speed…
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Drilled a couple holes and chamfered them at 82 degrees…
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Here are the clamps from behind…
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Since the 1/2” flathead screw heads are pretty deep I used 3/8” thick aluminum plate, so wanted to pocket it out to lighten it up. Drilled border holes for the areas to pocket out…
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All pocketed out plus drilled and tapped M6 holes to mount the tank…
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Bracket mounted on the frame…
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Installed the tank. Have a decent amount of adjustment. Can move it along the diagonal frame rail as well as use the slotted holes on the tank…
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Next up is the intercooler tank mount.
 
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Joel K

Supporter
This post covers the install of the front engine mount to the chassis.

Here is a video on the process…

First step was to make sure the rear engine mount bolts were tight and double checked that the front engine mount was square and in the correct position. Going to use 7/16” grade 8 bolts to attach the engine to the front engine mount and wanted to make sure the mount was aligned and those bolts just dropped right in to their holes.

Because the engine was moved back 1.5” there is only about 3” of space between the outside frame rail and the front engine mount. I was planning on using my Harbor Freight right angle drill attachment and simply drill out the frame rails with the engine mount in place, but there is just not enough room for a right angled drill head with a chuck…
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So did a little searching and found the following combination of tools to do the job:

1)Dewalt MAXFIT Right Angle Magnetic Drill Attachment
2)Milescraft Metal Stubby Bit Set with 1/4 in. Hex Shaft (5-Piece)
3)Grand Rapids Industrial Products Titanium Coated Steel Step Drill Bit Set (3-Piece)
4)Removable drill bushing McmasterCarr part #8509A11

Pic of the Dewalt Right Angle attachment and drills below. Super compact and perfect for the job…
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Because it is not possible to get a 3/8” drill into the rear outside holes decided to make a tool using a drill guide to make 1/8” pilot holes which would then be enlarged to 3/8” with a step drill…
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Pressed the drill guide into a piece of 1/8” flat stock. Used a 3/8” piece of flat stock to hold the tool over the engine bracket so it lays flat against the frame…
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The tool gets clamped on the frame and gets inserted into each hole on the engine mount. This assures that the drill guide is centered in the mount hole and is perpendicular to the frame rail. By doing it this way the pilot hole will be perfectly centered in each of the engine mount holes.

Pic of the drill and guide placed into one of the engine mount holes…
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Well that was super easy and accurate. Pilot holes came out nice and centered…
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After all the pilot holes were drilled I raised the engine and slid the engine mount out of the way. Then used a step drill to drill out the holes in the rails to 3/8”. I like the step drills since the holes are nice and round and do not walk.

Test fit the 3/8” bolts, they aligned well though the frame but were a little tight. To help the bolts slide through easier drilled out the holes with a regular 3/8” bit through the frame which helped aligned the holes…
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Next step, getting the bolts through both the clamp and frame took a little persuasion. Ran a 3/8” drill through the clamp and frame on a couple of the holes that were not perfectly aligned. Pic of the bolts through the mount and frame. So far so good…
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Installed the bottom C-brackets, they aligned perfectly without much fuss. Applied anti seize to the bolt shafts, washers and portions of the bracket that contact the aluminum frame. Secured the front engine mount with 3.5” long grade 8 3/8” bolts, washers, and lock nuts. All tightened up. Pic from the bottom…
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Pic from the top…
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All in all this process worked out well and am very happy it all lined up with zero play. In retrospect, it probably would have been easier to only do the pilot hole approach on the rear two outside holes. Then with the bottom c-brackets in place, just drill out the other holes with a right hand drill chuck and short 3/8” drill bit.

Checked this off my list and time to move on…
 
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Hi Joel, your coolant overflow tank is very low, I thought that you needed to mount them high up to keep air out of the system?
 

Joel K

Supporter
Hi Joel, your coolant overflow tank is very low, I thought that you needed to mount them high up to keep air out of the system?
Hi Mason,

That tank is a recovery tank. I’ll place an Expansion tank up high on the firewall and connect the cap to the bottom of the recovery tank. Having it down low should not be a problem. In theory, when the coolant expands, coolant is pushed to the recovery tank from the expansion tank. As it cools it is pulled/siphoned back into the expansion tank. I am hedging by using those ballast clamps just in case it needs to be moved or re-designed.

Here is a pic of a similar setup, but not an SLC…
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Joel K

Supporter
Time to attach the rear bulkhead panel. Not sure if kits delivered as rollers are delivered with the panel already mounted, but my kit was crated and this panel needed to be attached.

I mocked the panel up in a prior post to get a sense on how it will need to be modified in order to clear the throttle body relocation elbow. I noticed one side of the panel touched the side of the body and the other side had a good 1/2” gap so before I mounted the actual panel wanted to double check the fitment. Because the body at this point is centered, the rear bulkhead panel should also be centered to the body.

Here is a pic of the panel and you can see it touching the driver side body…
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Turns out the panel is not symmetrical and one side is longer than the other.
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Decided the shorter side needs to be on the driver’s side. When I mounted the mocked up panel I had it reversed…
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And the longer side on the passenger side…
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Now that the panel is centered to the body, next step is to mark and drill out the bottom holes. Used clamps to secure the panel and 1/4 wood spacer to raise the panel so it clears the roll bar mounting base. Used a center punch to mark the lower holes…
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Once the bottom holes were drilled. Mounted the panel back on the roll bar and scribed out the top holes. Could not use a center punch because the roll bar was in the way. So scribed the holes out, then used the down bar brackets and a center punch to located the top holes…
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You can see the holes are skewed to the left which moves the panel about a 1/4” to the right which centers it in the body…
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Here is a pic showing the body to panel gap on the passenger side…
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On the driver side…
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Once the intake reversing elbow is welded up and installed I’ll modify the panel to clear it and then it’s ready for heat shield and sound deadener.
 
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Joel K

Supporter
This post covers the fabrication and placement of the intercooler tank and pump bracket. Decided to make a bracket similar in size and shape to the dry sump tank bracket and place it behind the fuel tank on the driver’s side.

The approach is to create an intercooler tank and pump assembly with the pump mounted directly under the intercooler tank. This feeds the pump with the maximum head pressure and should work well. It’s also nice and compact saving enough space for a rear mounted battery. Pic of the assembly to be mounted…
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Used a 1/4” x 24” x 8” aluminum sheet and marked up the panel with blue dye…
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All cut and trimmed up…
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Made a pair of 1” spacers to mount the pump and also secured the tank to the bracket with M6 screws…
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Another view showing the spacers and the amount of room on the bottom of the pump for the connector to the harness. Ready to be mounted on the chassis…
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The intercooler reservoir and pump assembly gets installed against the rear frame on the drivers side. Very similarly to how the dry sump tank is installed on the passenger side. This will leave plenty of room for a full size battery in the remaining available space. Pic of the bracket installed…
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The tank and pump now installed…
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Pic from the side…
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All the cooling tank brackets have been finished and mounted. The rear compartment is coming together…
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Trying to make every item look neat and serviceable. After I finish the cooling tubes and engine intake system then the transaxle gets installed.
 
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Ken Roberts

Supporter
Joel keep in mind that the fill cap needs to be at the highest point for proper bleeding of air.

My finger is pointing to where the height of the fill port should be. Perhaps others could chime in as well.

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Joel K

Supporter
Joel keep in mind that the fill cap needs to be at the highest point for proper bleeding of air.
Thanks Ken. Totally agree. Planning to use a fill port up top like a stock Z06. A company called LSX concepts makes a couple different models. Here is the one I’m thinking of using. It clips right to the outlet of the LT4 intercooler manifold…

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Ken Roberts

Supporter
Joel you might have a challenge trying to install that type of fill port due to the location of the intake tube right next to it. Here is the fill port with a built in pressure cap I’m planning on using. It’s from a 2015 CTS-V. It also can be installed into one of the hoses feeding the manifold. #25884797 for the fill port and #15076936 for the 5psi cap.

image.jpg
 
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Joel K

Supporter
Joel you might have a challenge trying to install that type of fill port due to the location of the intake tube right next to it. Here is the fill port with a built in pressure cap I’m planning on using. It’s from a 2015 CTS-V. It also can be installed into one of the hoses feeding the manifold. #25884797 for the fill port and #15076936 for the 5psi cap.

View attachment 121353
That is a nice unit. It also turns out the chassis down-bar which connects the K-brace to the role bar runs right over the supercharger manifold outlet further complicating adding a fill port. Always something! Once I get the intake finalized I’ll focus on the fill port and hose route for the intercooler. Always appreciate your help Ken.
 
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