My own personal experience with the BEGi spacer reroute solution has not been wonderful. My reroute spacer started to leak like a sieve after five years of use. Read about it here. And please think very hard about what you’re about to read in my blog post below.
A reroute is an important modification for a Miata engine. I’m not saying it isn’t. Just be careful with the parts you install. Really research all of the reroute options.
Okay… where were we? Back in Coolant Re-route part 1, I had installed all of the cool BEGi coolant reroute stuff on the head and was ready to drop it on the engine and do the actual work of routing the coolant back to the radiator. Easier said than done, right?
The big hose above is the “easy” part. It is… unfortunately becoming less easy with every passing month.
Update – 2/2015
When I wrote this in 2011, Autozone part number XL-1215 was the right hose. They seem to have changed it. That Autozone part will MOST LIKELY NOT WORK ANY MORE. Go out and find a Gates #22436 hose or a Dayco #E72380 hose. These are reported to work as of February, 2015.
Back to our blog post, already in progress.
I have MiataTurbo to thank for this excellent hose. In fact, I decided to do this re-route because of this hose. Check out the thread on MT for more info.
This hose seems to be from some sort of American truck (Cadillac Escalade?) and is juuuuust right. You slice off the front U-turn and it routes nicely from the back of the Miata head all the way up to the radiator. This hose is why I titled my initial post “Easy” Coolant Reroute.
That’s where it sits. There’s juuuust enough room to clear the firewall. And with the gaskets installed on the spacer, there’s a little bit of extra room between the neck and that bung to slide the big GM hose on the Kia water neck.
In case you couldn’t tell, the little speedometer cable holder needs to be flattened.
Spend some quality time tightening this hose clamp. After torquing it down, let it rest for a while. Then go back and add more tightness. A leak back here is a pain in the ass to fix.
Really, it wasn’t hard to bolt the intake manifold in place with this hose installed. There’s still plenty of space around it. Sadly, topside oil filter changes are now a thing of the past for me.
And that is the end of the Easy Coolant Re-route.
For most folks.
For those of us with Flyin’ Miata’s FM2 turbos and a 94-97 throttle body, things just became less easy. Uneasy. Sorta-not-very-easy.
This is a problem. But we can deal with it, right? We can just go around the other side of that intercooler pipe! No big deal!
Nevermind how close the big coolant hose is to the intake hose, the big problem here is how the 94-97 throttle body routes the idle air bypass hose. Sure, I could be fancy and get a coily hose, but that’s… really shitty. Let’s be honest. I can do better than this. WE can do better.
So… another hit on MiataTurbo’s search engine and another trip to the parts store.
Thanks to this fine thread of coolant reroute photos, I found just what I needed. Dayco hose 71519 (Pepboys sells Dayco brand) which seems to be for a 91-94 Oldsmobile 88. And just look at it. Those tight 90 degree bends! It’s a beauty.
A quick snip to cut a small “V” from the end transforms the M into a Z. I also sliced off a tiny bit from the leading arm of the Z to bring the hose as close to the radiator as possible.
Just look at all of that clearance in front of the throttle body!
The metal tube is a stock Miata part that normally lives on the exhaust side of the engine bay. There’s a pipe that goes out one side to the radiator and the other to the water pump. Flyin Miata gives you a molded silicon hose with their FM2 kit that takes the place of the metal tube and two hoses. So I just had the metal tube laying around.
One side has a nice flare. The other side has 3 badly done score marks I cut with my dremel to hopefully keep the big hose in place. Time will tell how good a solution this is, but so far there are no leaks. Knock on virtual wood.
Update – 2/2015
That metal tube thing sucked. No idea WTF I was thinking. I replaced it with a very nice metal hose coupler from Jegs a few months later. Check out The Coolant Reroute Strikes Back for more info.
I wasn’t getting a very nice seal on my radiator neck with a regular screw-drive hose clamp, so I splurged on some nice Constant-torque clamps from intakehoses.com. The 1.5″ ID clamps are the ones you want. They’re nice and strong. No leaks yet.
So. Not quite “easy” but really not that bad. And I’m much happier with the hose routing with this extra Dayco M-hose in the system. Time will tell, but I’m tempted to call this coolant re-route project a success.
One last shot. I updated Sharka’s sticker book (otherwise known as the top radiator panel). Sharka is proud to wear a MiataTurbo sticker. And who can resist this robot decal? Not me.
The Coolant Reroute Part 3 is right around the corner.