Replacing Radiator... a few questions. - MX-5 Miata Forum

Quote:

Originally Posted by PSM Still, I have some basic questions: (1) What temperature thermostat should I go with? Should I stay with stock (195*, I believe) or should I consider a step lower to 185*? It's noted in the Garage section that the OEM thermostat is something called a double or two-valve thermostat. They are a bit pricey but do they in effect act as both a lower and normal range thermostat?

Stick with the 195, and the OE is best for a stock car, IMO

Quote:

(2) I was told by a NAPA parts guy that a miata should be using red anti-freeze (I forget the name of the stuff). Something to do with lubricating the water pump and helping to keep crud from building up in the system. Is this true?

I use any old brand, no problems. The "Red Stuff" antifreeze must have a higher profit margin.

Quote:

(3) Once everything is buttoned up again, is it really as simple as fill, bring up to temp and then top off? I don't want to get any air in trapped in the system.

Yep. Fill the overflow tank, fill the radiator and screw on the cap. When it gets to temp it will "burp" itself and draw from the overflow tank.

Quote:

(4) From what I've read, it seems that the bolts involved are either 10mm or 12mm. Does anyone happen to know what length they are and what the threads are? In case I need to replace one or two, I'd like to have some on hand.

The two nuts on top that hold the brackets are 14mm. The bottom of the radiator has two large pins with rubber bushings, and they just sit in two holes in the bottom radiator bracket. The driver side fan has two 10mm bolts at the top,and the bottom fits in two holes like the radiator. The passenger side fan has two 10mm bolts at the top, and two more 10mm bolts at the bottom. The bottom ones can be a PITA because the a/c lines are right there in the way, and the inner bottom bolt also holds a support bracket for the a/c lines. You can reach them from up top, but it's easier to see if you pull the belly pan and go from underneath.

I don't know offhand what exact size these bolts are, but half the bolts on a Miata are 10mm and about an inch to an inch and a half long. Take one of them out, go to Lowe's, and match them up in the specialty hardware aisle.

Quote:

By the way, I own a basically stock '00 NB, she's my daily driver and I'm going to be putting in a 37mm Koyo radiator.

I also replaced my OE rad with the 37mm Koyo. Fits right in, stock fans fit perfectly.

If you have a/c, you'll have to modify the top a/c condenser brackets so they don't hit the thicker radiator. I flattened the two angled pieces, which leans the top of the condenser out towards the front of the car a bit, gives the needed extra room. Just make sure the bolt heads on those top brackets don't contact the new radiator when you install it.

__________________
Wisdom comes with Age; Sometimes, Age comes Alone.... 2000 Brilliant Black, Rotrex and much more