Koyo Half Size Radiator for 99-00 Civic Si/94-97 Del Sol VTEC

Koyo Half Size Radiator - 99-00 Civic Si / 94-97 Del Sol VTEC (B16A)

Your stock plastic and aluminum radiator on your B16A Civic Si or Del Sol VTEC is fine until it's not. The plastic end tanks get brittle after twenty years of heat cycles and they crack. Then you're overheating on the side of the road. Koyo makes this half-size all-aluminum radiator as a direct replacement for the stock radiator. It's designed specifically for the B16A motor in the 1999-2000 Civic Si and 1994-1997 Del Sol VTEC. All-aluminum construction means no plastic end tanks that are going to crack. The core's hand-assembled and TIG welded from aircraft-grade aluminum. It bolts into your stock mounting points and works with your stock radiator hoses, fan shroud, and A/C condenser. No modifications, no custom work. You're swapping radiators and you're done.

Here's Why the Stock Radiator Fails

The stock radiator on your B16A Civic Si or Del Sol VTEC has plastic end tanks and an aluminum core. That's fine when the car's new but after fifteen to twenty-plus years, the plastic gets brittle from constant heat cycles. The end tanks crack, usually at the seams or around the inlet/outlet necks. When that happens, you're losing coolant fast and you're overheating. We've seen plenty of EK Si and Del Sol radiators fail this way. The Koyo all-aluminum radiator doesn't have plastic end tanks. The whole thing's aluminum so there's no plastic to crack. The end tanks are TIG welded to the core and the core's brazed using the Nocolok process. That's a furnace brazing method that creates strong, leak-proof joints between the tubes and fins. You're not dealing with a radiator that's going to crack and leave you stranded.

All-Aluminum Construction with TIG Welding

Koyo builds this radiator from aircraft-grade aluminum. The core's hand-assembled and then furnace-brazed using the Nocolok process. After brazing, the end tanks are TIG welded to the core by hand. TIG welding's way stronger than the crimped connections you see on cheap radiators. The welds don't leak and they don't crack under thermal stress. The radiator's also triple pressure-tested before it ships so you know it's not going to leak when you install it. Koyo manufactures these radiators in their own factories in Japan. They're not outsourcing production to the lowest bidder. They control every step of the process so the quality stays consistent.

Direct Fit with Stock Components

This radiator bolts directly into your stock mounting points. You're using your stock radiator hoses, your stock fan shroud, and your stock A/C condenser if you've got A/C. No trimming, no custom brackets, no fabrication. The radiator comes with a billet aluminum filler neck and a 1/8" NPT female fitting for an aftermarket temp sensor if you're running a standalone gauge. If you're not using the temp sensor fitting, there's a threaded plug that seals it off. The core dimensions are 13-3/4" x 13-3/8" x 2-1/16". The top and bottom headers are 2-3/8" x 14-1/2". Those dimensions match the stock radiator so fitment's tight.

Radiator Cap Compatibility

You need a proper radiator cap for this radiator. Don't reuse your old stock cap. The billet aluminum filler neck works with Koyo, Hybrid Racing, or Speed Factory radiator caps. Any of those brands will seal properly. If you're ordering a new cap, any of those three work fine. Just don't use a cheap auto parts store cap or your old factory cap. They might not seal right with the billet filler neck and you'll have coolant seepage or pressure loss.

What You Get

• Koyo half-size all-aluminum radiator for B16A motors
• Aircraft-grade aluminum construction
• Hand-assembled core with Nocolok furnace brazing
• TIG welded end tanks
• Triple pressure tested for leak-free operation
• Billet aluminum filler neck
• 1/8" NPT female fitting for aftermarket temp sensor (plug included)
• Direct fit with stock mounting points, hoses, fan shroud, and A/C condenser
• Core dimensions: 13-3/4" x 13-3/8" x 2-1/16"
• Top/bottom header: 2-3/8" x 14-1/2"
• Made in Japan by Koyo

Fits Your Car

• 1999-2000 Honda Civic Si (B16A2 motor)
• 1994-1997 Honda Del Sol VTEC (B16A3 motor)

Note: This radiator is designed for B16A motors only. It will NOT fit D series, B18 series, or K series motors. Radiator cap is sold separately. Use a Koyo, Hybrid Racing Type F, or Speed Factory Type A radiator cap.. When you're installing the radiator, make sure all your radiator hoses are in good condition. If your hoses are old and cracking, replace them at the same time so you're not pulling the radiator back out in six months to fix a leaking hose. Burp the cooling system properly after you fill it with coolant. Run the engine with the radiator cap off until the thermostat opens and you're not seeing air bubbles. Top off the coolant and reinstall the cap. Check for leaks at the hose connections after the first heat cycle.