This is just my second thread, and I am a little anxious not to be considered cheeky (for not replying to an existing relevant thread ).
The subject is coolant routes in an 1.8L NB '99 engine (BP4W).
A lot of miata owners seem to hate all those little coolant hoses that travel from the back of the car to the thermostat housing, after visiting the oil filter plate and the throttle body housing, for being so difficult to access.
I, personally, have one more reason to hate them. They are almost impossible to inspect! And I payed for that with a blown engine a few years ago, when the hose that leaves the engine and travels to the oil filter plate, decided to fail and leave me running at top end speed for 30 minutes ignorant of what was going on down there...
Anyway now this is all past.
The first thing I did before installing the new engine was (guess what!): get rid of all that coolant route altogether.
I sealed the coolant output at the bottom/right/back of the engine and the corresponding coolant input on the thermostat housing, instead of just bypassing the oil filter and the TB, by connecting the two (now sealed) spots.
Here comes the question. Did I act wright or wrong?
I have no issues at idle speed, I have no other indication that something is wrong, but my main concern is:
Does the back half of the block (cylinders 3-4) get even worse cooled than before or no?
I am well aware of the miata's inherent cooling issue. My mod was not intending to heal this fault. It was a way to get rid of a 'weak' point of failure that cost me a lot in the past.
Here is a diagram of my setup to make things clear.
Coolant bypass setup
Do you think I should revert everything or just stop worrying?
Thanks and sorry for the long post...