NA & NB LSX Cooling System



Out of stock

Due to supply issues and lack of communication & transparency we are seeking new suppliers for our cooling systems. 

We are proud to announce the release of our new radiator. Teaming up with Fluidyne a leader in racing and high performance cooling systems. Together we've designed an extremely efficient and low profile cooling system specifically for LS conversions.

The T-3x core is a new FLUIDYNE design which was developed to provide the maximum amount of heat rejection in applications with less than 400 sq. inches of core surface available and where core depth was critical to assure spacing would accommodate a good electric fan and shroud.

The T-3x core is a triple-row core, constructed with our high performance 5mm air fin in lieu of the traditional 7-8mm air fin and 5/8” flat tube.The 5mm air fin allows us to pack additional rows of water tube in each core… essentially providing the cooling performance of a 20% larger core area.

This new core [called the Slimline core] with our new Slimline 5/8 tube, measures only 2 inches in overall depth. Saving up to 2" of clearance over standard conversion radiators.

Additionally, the Slimline core is capable of handling significantly higher internal water pressure than traditional radiators with 1" or 1.25”"  water tubes. The Slimline core is rated at 40 PSI burst pressure so installation of a high pressure radiator cap [28-32 PSI] is recommended which will increase the boiling point of the radiator water from 212 degrees to 230 degrees.
We have added 1" additional height to the core to increase surface area, coolant volume, and maximize use-able area within the factory shroud. Installed a anode to protect the cooling system from electrolysis. Correct size inlet and outlet to match the LS water pump and steam vent port on passengers side. One large 16" Spal curved blade 2350CFM fan with individual shroud and adjustable mount. Fan can be set on center or to either side of the radiator. This allows for proper airflow at speed. One large fans has the same CFM and efficiency as dual fan units with less amperage draw.

Laminar Flow:
Fluid travels thru any pressure vessel in a column meaning it leaves a area of stalled water on either side of the column’ of flow. The bigger the inside diameter of the flat water tube, the larger the amount of stalled water alongside the column of flow. This stalled water forms an insulation barrier which inhibits the heat transfer from the water to the inside of the water tube so reducing the amount of boundary layer is always a good idea.
By reducing the size of the water tubes and increasing the number of tube rows, the T-3x Slimline core has essentially reduced the overall impact of the boundary layer associated with the Laminar Flow and in doing so, increased the heat rejection properties of the radiator.

Note: The radiator is designed to work with NB style mounts. The radiator will mount in NA cars with use of NB mounts or custom mounting. This is done because of tank expansion. Side tank aluminum radiator expand upwards of .200" when hot. Utilizing side mounts like the NA can cause additional pressure against the end tanks and cores. NB mounts can be source from salvage yards or dealers. We do have plans to produce a mount solution in the future.


The upper radiator hose is Gates parts number - 23409(should be spliced in the center to shorten)

Lower radiator hose is Gates part number - 22553

Additional information

Weight 40 lbs
Dimensions 8 × 32 × 28 in

Customer Reviews

Based on 5 reviews
Patrick H.
Leaked after 600 miles

As the title states, started leaking after 600 miles. Contacted V8r and they directed me to fluidyne. Fluidyne stated to send it back and if it was fixable they would fix it free of charge. I sent it to them, emailed to notify it was sent and provided them tracking number. Multiple phone calls to them and kept saying "they will look for it" after 3 months of zero help from them I had to go to summit and buy a radiator from them. Everything else from the v8r kit is amazing and v8r customer service is top notch, but now I am out the money on this radiator and cannot even get it back. Just google Fluidyne radiator leaking and you can see the stories.

Radiator leaking from endtank. Less than a 1000 miles/1 year.

Bought the radiator new in March of 2021 and the situation I have just experienced is that my radiator, a beautiful piece with beautiful welds I must say no fuss at all in its presentation, started leaking from the passenger side end tank.

Now, being no fool in this area of motor swapping, I have years of experience using these style radiators in everything from Custom CJ-7 builds, various kit cars, and dozens of turbo Miatas, I was aware that going into this build that aluminum radiators are particular when it comes to installation, the mounts must be flexible for thermal expansion, and so I utilized NB lower mounts and NB upper mounts and I paid special attention that the radiator had no obstruction from either X,Y, or Z axis.

To the folks at V8 Roadsters, everything has been smooth sailing with my first (definitely not my last) LS-swap Miata. Does Fluidyne have some warranty on this unit? I know that their radiators I believe are warranted for a year.

Help me here guys. All in all, been very happy with V8 Roadsters products thus far, just perplexed with this radiator though…

john foote
Solid radiator bad shipping

I have ordered this radiator for my lT1 swap. It showed up with a broken port on the radiator and a few bent fins. For the price of this thing I expected more and I am waiting for the replacement fitting that broke from shipping as I can not find one local and I would like to get moving. I have loved everything from v8 untill this purchase.

John Patterson
Well Made Solution

The radiator appears to be very stout, with a heavy duty core and thicker aluminum used for the end tanks than I've seen on others. All the welds are uniform. The cooling fan is quiet and moves a lot of air. With the LS3 engine idling after warm-up in 75 degree weather the fan runs 45 seconds on and two minutes off.


Recently got this radiator looks to be a really solid setup can't wait to mount it to the vehicle.