so I'm getting temps of a consistent 190-197.. usually a hard 194 at idle. I'd like to see 180-185. I'm considering enlarging the weep holes in the thermostat. I have a motorad 180 and it is cooling reliably, but I'm not stisfied. my brothers d1 runs 175-180. has anyone tried enlarging the weep holes to increase waterflow. I am about to experiment with it, if it gets too cold come winter than I'll replace it with a grey soft spring. any thoughts on enlarging weep holes, or adding a couple. I've seen this technique used in other automotive formats.

 

1. A real Rover 180 stat will work better. Perhaps due to Europe stats being marked for fully open vs many other areas stats are marked for start to open temp.

2. Changing size of holes won't change the formula of the wax pellet inside the stat.

3. If holes get too big you will throw a code for thermostat stuck open. There is a thermal sensor on the outlet side of the radiator, and the engine vs rad output is monitored on many D2.

4. People have knocked out the innards of the stat, which is like running with no stat.

5. The in-line modification (conventional stat in a metal housing in line with hose to top of radiator) gives smoother operation, and you have a wider choice of stats.

 

so if I go with an inline housing, what to I replace the current stat with? just hollow it out and leave it in place, and then just put an inline in place above it?

 

Remove it, replace the entire section with a new piece of hose.

 

No, that plumbing is eliminated. The existing stat body is no longer there.

But we have posted pix of guys driving 65 mph with 182F with the Rover 180 F stat. Headed to the desert in western US. The advantage of the Rover stat was that it got almost the same performance as the in-line mod without the mod.

 

okay cool.. well I'm replacing the upper hose wednesday, I think I'm going to play with the holes a little and if it doesn't work then I'll just order a grey soft spring. who is shipping the grey soft springs for sure, I've read several people say they got a motorad instead of a warm weather rover stat. I've replaced the radiator, new stat, just did a head job and cleaned everything. I know the only two things left are heater cores and a better stat. I really want to get the temps down to 180ish

 

Rovers North is one source. Here is the result you seek. Motorad is less quality control (some don't open until very late) and questionable set point. The whole purpose of a new stat is lower temps. The first owner to post about this stat as I recall bought it from the UK, about $120 with the shipping. So $60 in this country is a good deal. Some of these stats have 4 metering holes, some have two larger holes (less chance to clog up?). The size of the holes would impact the speed of response, but the opening temp is determined by a blob of wax inside the thermostat.

 

X2 rovers north. found mine there and you can be more confident than "ebay maybe"

 

Isn't there also a 160 tstat, that can be purchased? Or is that just in line option?

 

Besides trying a Genuine (*180) from Rovers North, why mess with it man, your temps are ideal. And aren't you comparing a D1 to a D2 ???