Bypass Thermostat

[GasSavers_Scott]

The Bypass Thermostat will allow your car to warm up in 45 seconds to 2 minutes. How it works? It connects the upper and lower radiator hoses. The inblock thermostat is removed and the bypass thermostat sits inline on the upper radiaor hose with a "T" connecting the lower radiator hose. When you start the car, water flows around the block via the water pump, The engine heats up completely before the thermostat moves water through the radiator. When the thermostat begins to open it mixes radiator water and prevents shock cooling.

With a conventional thermostat, hot water sits behind the thermostat and builds up in the head, slowly the thermostat opens and has to heat the entire cooling system before all the water heats up. This leads to long warm ups and a cold engine wastes fuel. Not to mention, in winter you have to wait for the entire radiator to warm up before you get heat in the car.

This is a Fiat part, they used to be $16 at the local Italian parts store, the company has since subcontracted out the part and it is available at Autozone, part # 25692, $50.00 or online at International Auto Parts #3446 at $39.95. If they can't find it, tell them you want a bypass themostat for a 1980 Fiat 124 Spyder 2 litre DOHC w. fuel injection.

Now this little device has been on many European cars since the late 60's. My Volvo and Ford 2.8 V6 had them internally in the block, it was great, quick warm ups save gas. Also the only American manufacture I know of to feature a bypass style thermostat was the mid 90's Corvettes. They had a double reverse flow thermostat system, water was pumped in over the heads first, then went down to the cylinders. Water circulated around the engine first, then was plumbed out to the radiator. From what I read, the Corvettes heated right up with very little warm up time.

Like I have said before, why haven't all the manufacturers gone to the bypass system? Cost, 1 million cars with a 10 dollar thermostat saves more money than 1 million cars with a 40 dollar thermostat.

Now having been a convertable small car enthusiast for years, I have owned a Fiat 124 Spyder, as well as other little sports cars. What they say about Italian cars is false, they are just as relaible as all the others cars out there.

The bypass thermostat is genious, the little device can be fitted to any 4 cylinder with a maximum of 2 litres. It is a little cylinder that looks like a "T" or a jarge jack, three radiator sized outlets come off it and inside is a thermostat. You have a choice between 180 or 192 degrees. The only mods would be to take the stock upper and lower hoses and cut 2 inches out of them. You can insert the bypass themostat in the upper radiator hose, you will have to make a "T" in the bottom hose. I used a copper T I got from Home Depot, there is a T available through Italian parts dealers that is iron. Now the bypass hose is the same diameter as the radiator hose, what I did was go to Autozone, they let me browse through their hoses till I found one that was straight enough to connect the 2 ends, I forgot the part number.

Put the whole thing together and enjoy quicker warm ups, heat, and save gas.

I don't know if bypass thermostats were made for larger engines V6's or V8's The overflow bottle has been incorperated as a part of the pressurized system on newer cars, so you'll have to map out your cooling system before you do the conversion.

I will definetly put one on my next car.