The Science Behind Coolant Reroutes (FM Live)

[@aygwm]

This man is an incredibly clear communicator. Did you steal him from television?

[@merlyn2121]

Miata Mike?

[@FlyinMiataVideo]

Mike is the Bob Ross of Miatas!

[@fireonmytarget8937]

You and Keith have sold me so many parts of the last week. Thank you for the clear explanations!

[@FlyinMiataVideo]

Glad we could help!

[@OuterLimits_RC]

I did A LOT of research and ended up going with the Supermiata reroute. That said, I will eventually switch to this guy when I go FI. Also, the issue about the temp gauge swinging due to bad ground happens to me from time to time. Again, I will get this FM reroute one day.

[@william8687]

It might be worth to remind people not to run VVT 01-05 headgasket on earlier engine (BP05 and BP4W) because most of the coolant route/holes on the head are blocked off in the Aluminum casting on the earlier engine.

[@scottyknows1566]

Right, but that would be running the wrong head gasket... i assume we don't have to be responsible for people not doing their own research?

[@blandflatland8915]

I watched the first 5 minutes and I will flip my head around tomorrow.

[@maneki9neko]

Jim, at 16:20 you point out that a fully open thermostat is highly restrictive, as compared with the hose that the thermostat feeds. While the hoses between the engine block and the radiator are large, the actual flow past the thermostat is small. Beyond that "pinch point" in the system, because of the large diameter radiator hoses, the resistance to flow to and from the block is small. The resistance to flow through these hoses is so small that there is actually a fair amount of thermo-syphon flow going on in addition to whatever flow the pump provides. Water at room temperature is 62.4 lbs/cu-ft. At 180F the weight is 60.0 lbs/cu-ft. The 2.4 lb/cu-ft difference between hot & cold is significant. There were automotive engines in the 20's and 30's without water pumps that relied on this exclusively. Here is a Ford Manual from 1919. en.wikisource.org/wiki/Ford_Manual/The_Ford_Cooling_System While the water pump provides a lot of circulation within the block, thermosyphon pumping between block and radiator is not trivial. BTW I have been a Flyin' Miata customer for 20 years, and I like and use a lot of your components, especially the chassis bracing and the IL bushings.

[@traviscobb8959]

One of the best vids so far... I would suggest telling people what your next video is going to be on so that they can ask questions ahead of time in this section or by other means that way you can cover more questions. Thanks!

[@FlyinMiataVideo]

We usually announce videos and request questions on both Facebook and Instagram a few days before we film. If you have any video suggestions, we are open to those too!

[@FecesPhantom]

I commented on a video earlier in the week not realizing that these are facebook live recordings, great job on these!

[@lastdrummer55]

Thanks for doing these vids. ‘00 NB Miata owner in the past year and very interested in learning what can be done to make it better.

[@jimmac1953]

Love the shopping cart in the background!

[@OuterLimits_RC]

Love seeing the head gasket comparison. Thank you!

[@richardbutterworth1748]

Hi, I am puzzled why your re route has the sensors in the housing, there are blanking plugs in the back of the head that can be removed and the sensors fitted into the head allowing a less bulky housing to be fitted. In the FWD application the sensors would be installed in the head. I have done this on my 1800cc ITB Eunos and it allows more space at the back of the head against the bulkhead. I am RHD in the Uk. Excellent informative Vid though

[@alexmessina3383]

thanks for a great review and common sense explanation. For stock road use, I doubt the benefit given Im enjoying an NA with 120k, a solid engine and excellent compression in all cylinders: no sign of extra wear in #4 ... good to know options for, say, a tubo upgrade. Keep up the great vids!

[@StealthNinja4577]

It'd be interesting if you could run a hose through the block to deliver coolant to the back... maybe with small holes around cylinder 1 to deliver some cold coolant to the front and gradually larger ones as you approach the back. You could then keep everything stock and lower temps

[@richardflaherty2373]

Thank you for another great video and I don't even have a Miata yet.

[@pauliusguzas8063]

Do all nb2 have different head gasket from na and nb1, I mean 1.8 and 1.6?

[@FlyinMiataVideo]

From the factory, the NA6, NA8, NB1 and NB2 all had different head gaskets.

[@michaelh.9866]

Thanks, Mike!

[@FlyinMiataVideo]

Thanks for watching!

[@FecesPhantom]

why cant the thermostat be deleted? could you run something like megasquirt to trigger fan activation and bypass the thermostats use all together?

[@FlyinMiataVideo]

You'd still need a way to efficiently control your coolant flow and engine temperature, such as an electric water pump. Just triggering your fans will not give you the cooling you need. It may be possible, but we don't recommend it.

[@Bertgarrpin]

In my opinion, if an OEM thermostat doesn't fit the reroute housing, it would be an error. Otherwise, if it's only your design, but allow us to use an OEM one, I'm very interested.

[@shadowraith1]

Very valid point. Particularly 10-20 years from now.

[@GoPaintman]

The internet will exist 10-20 years from now. You'll be able to look up their install manual/product page and find out what t-stat it runs.

[@cadconnectioninc7043]

He has a point. Why not make the housing to fit the stock thermostat. Sure there's probably a clearance issue that's why but would like to know.

[@FlyinMiataVideo]

The housing needed to be able to stay as small as possible and still keep all of our needed accessory ports. Flow was more important to us than diameter. The thermostat we used in our new housing is an off the shelf item available at almost any auto parts store. You shouldn’t have any issues finding replacements.

[@FecesPhantom]

9:10 that is a great design!

[@burkean]

I'd like to see the routing of the reroute to the stock miata radiator (or automatic) with a turbo kit installed. I hear the hoses are awkward.

[@burkean]

The reroute seems so sensible that I thought it would be the first priority in turbo support upgrade. Other videos suggest that a radiator upgrade is the higher priority.

[@edgarvazquez1613]

2006 miata nc leaks antifreeze fluid from the tank safety hose, what problem should I correct?

[@FlyinMiataVideo]

Check the hoses and the tank for cracks. The NC has a pressurized coolant expansion tank, so you could have a small crack that is leaking onto the hose, or a crack where the hose meets the tank.

[@edgarvazquez1613]

@@FlyinMiataVideo Thanks for your help. Could I look for you with any additional tech support that could I need in the future?

[@FlyinMiataVideo]

@@edgarvazquez1613 Feel free to reach out to our support team directly. They're more than happy to help troubleshoot most Miata issues.

[@BurningTrapezoid]

Just out of curiosity: As far as I know I don't have a massive opening in the back of my enginge. So what does this new thermostat housing attatch to? Is there allready a capped off hole or something? I'm thinking it might be the place where the original thermostat housing from the 323 was. Is that correct?

[@FlyinMiataVideo]

That's correct, there's an outlet back there that's used for the heater. It's where the 323 had the thermostat. You replace that with the reroute. It actually is a fairly massive hole when the outlet is removed.

[@shadowraith1]

As always thanks for the info. Please see below.👍🏎👍

[@modshop1828]

Great video. You had mentioned the difference between the '94 era head gasket and the later, but what about the 89-93? Is that head gasket like the 94 and up or is it different as well? Again, great video. Can't wait till I get a reroute for both of my NA's....

[@FlyinMiataVideo]

The 1989-93 cars use the 1.6 engine, which is physically smaller in every dimension and cannot use the same head gasket as the 1.8 cars. There was only one head gasket design available so nobody talks about it much because that's the one you're going to use!

[@modshop1828]

@@FlyinMiataVideo thanks for the clarification.

[@mex1848]

Will this fit RHD cars?

[@FlyinMiataVideo]

We haven't specifically tried it, but, from what we know it should fit without any major issue.

[@kennyheishman9046]

How hard it is to change out the thermostat when it wears out?

[@FlyinMiataVideo]

Basically just take the housing off the back of the head, swap the thermostat and reinstall. Assuming you're using one of our reroutes. There are others that put the thermostat in a separate housing inline on the upper radiator hose.

[@ndemeis]

Just ordered mine. Are you planning on doing an install video?

[@cadconnectioninc7043]

Thanks good info will be purchasing one come spring

[@imstuner]

I have a 2005 Mazdaspeed Miata and I think the MSM has the updated head gasket. Would I still benefit this kit with the newer updated headgasket?

[@merlyn2121]

No comment. I went down the rabbit hole. I'm still in the rabbit hole.

[@onlywenilaugh6589]

That thermostat just got a ton harder to change when it goes bad as it's pretty tight to get back there.

[@FlyinMiataVideo]

That's exactly why Mazda put it on the front of the engine in the first place. But it compromised the cooling of the engine, so this allows you to improve the cooling every day in exchange for worse access to a part every 5-10 years.

[@MrERROKK]

3 to 4hr job... 3hrs 45mins of gasket scraping on the back of the head. The rest is pie.

[@ovalwingnut]

Is that a milled billet piece? Ka'ching! I love the idea but that's to rich for my Miata blood. I know you need to justify the cost of that 6-axis CNC. But ouch.. Thumbs Up however!

[@FlyinMiataVideo]

The machining was the best way to keep the level of accuracy and quality control of the reroute. Cast parts are definitely cheaper, but not as precise as this machined unit.

[@meegel]

0:37 Pun intended