I can feel something in the line from the radiator to the overflow bottle about an inch from the radiatorI think it's some kind of restrictor...as I said, I've been running this way for over 5 years without problems.

 

Post pics if you can hehe

 

OK...I stand corrected. Mine isnt EXACTLY like yours, though similar.

And my cap DOES have a spring in it, and I only have one cap.

 

From all the *hundreds* of FC's I've seen, I think I'm the most qualified to speak on what is and is not stock. HEre is how it goes.

early 86's used a sprung cap on the thermo neck, with the overflow line feeding out of there. The radiator was flat top with no cap or opening. The overflow jug was by the leading coil.

Later 86's and early 87's used the same setup as above, except the overflow jug was moved up front by the hood latch.

Late 87's and 88's used an unsprung cap on the thermo neck with no overflow nipple. The radiator had a hole in it, and another plastic housing bolted on top. A sprung cap was used here, and the overflow nipple and hose go here.

89-91's all used the same setup, with the radiator with the long neck and fill cap by the battery, using a sprung cap and an overflow nipple there. The thermo neck on the engine was closed off. They also deleted the bleed screw from the radiator in 89.

 

"Late 87's and 88's used an unsprung cap on the thermo neck with no overflow nipple. The radiator had a hole in it, and another plastic housing bolted on top. A sprung cap was used here, and the overflow nipple and hose go here."


this is the configuration i was referring to by looking at his filler neck and radiator, there has to be a pressure cap on the overflow hose somewhere. i have never seen or heard of a pressure limiting device that you could simply put into the overflow hose to keep the cooling system pressure constant and also allow the tank to relieve back into the engine.

 

Very strange - the next time I'm at my rotary guys shop I'll se if he has a T-stat housing with an overflow hose and connect this stuff the right way. I find it really strange that I've been able to run this way without problems for like 7 years!

 

If you can't find the correct housing, I'm reasonably sure that the short plastic neck that holds the pressure cap to the rad (for the cars that have the pressure cap on the rad) is the same size bolt pattern as the neck on your car's t'stat housing. If they are, you should be able to just bolt one of those onto your existing housing and connect the overflow tube there. Probably easier to find a junk rad than the housing you need.

 

Thanks, I'm sure my guys have the parts around - they've got a ton of that stuff hehe I wonder who/when that restrictor was put inline from the rad to the overflow. It works, but it's just obviously not right.