Coolant Bypass Kit Soon!

[oldtimer02]

Hey, all you "track dogs" out there!
I have been busy working on a bypass coolant kit for the NBs (will need to be tried on the NA 1.8s for fit)
The Kits are complete with all hardware, no sourcing on your part!
I am initially making up six kits. Four have been spoken for.

Any interested?

[Michael T]

Nice, how much do you want for it?

[oldtimer02]

The kits use all the best parts & hardware. SS clamps & support clamps, silicone rear elbow. $175

[Tom @ Fast Forward]

That is really a good looking kit. Nice and clean.

$175 is a neat price as well.

You might want to post pictures of some of the machined parts. They are works of art as well.

[tann3r]

I am guessing you have the thermostat relocated to the rear of the head. Does it retain the heater core loop?

I'd like to see some pictures of the parts, but I am interested.

[Steve in VC]

I am interested too. More pictures please.

[oldtimer02]

Here are some more pictures.
Yes the heater fitting and coolant temp sensor are retained.

[bogey]

I have an NA and would be willing to test it. The clearance behind the engine will be tight, but probably the same as an NB. My concern would be the high route of the return pipe and possible interferance with the coils and CAS.

From looking at the pictures, it appears the return line is via the existing heater fitting and a new fitting is added pre-thermostat. Is the hose diameter sufficient for the flow?

I like the solution, It appears simple and cost effective, especially with a coldside.

[bogey]

How do you join the return pipe to the outlet? The heater hose is about 5/8" id and the pipe looks to be about 1 1/4" id. I assume there is another hose that is not pictured.

[BlownMX5]

Is there interference with the EGR pipe?

[oldtimer02]

Answers:
1) The existing thermostat cover / outlet is moved to the back of the engine.

2) The coils will have to be moved, or an outlet from a 1.6 (not included)

3)The EGR, if you keep it, will need to be modified. either moved away from the outlet for a 1/4" spacing or lengthened. I am looking at an option of modifying the EGR tube with a "flex" and about 1" longer. This will be on an exchange basis. Presently sourcing the Flex tubing. Looking for SS braided tubing if anyone has a good source!

[oldtimer02]

these pics should answer some of the questions asked.

[bogey]

Ok, I thought you were keeping the heater outlet and using that as the return.

Where would one move the coils?

[oldtimer02]

probably have to fab a bracket, or go to COPS. I haven't tried it on an NA, only NB so I am not sure on an NA.

[Steve in VC]

Ouch! I'm in CA, moving the EGR and coil packs may create questions I'd rather not have asked.

[bogey]

What if you used the existing hose fitting on the back of the block and just added the thermostat sandwich under it? Then attach the heater hose to the adapter, and use the existing heater outlet as the return to the radiator.

This way both connections would be facing out to the driver side. My concern would me if the flow through the smaller heater host fitting would be sufficient to the radiator.

[bogey]

Another option to consider it rotate the return fitting 180 degrees so the outlet is pointed down towards drivers side. Then get an how to connect to the return pipe. The return pipe bend would need to be pointed down instead of across the back of the engine.

[oldtimer02]

The outlet from an NA 1.6, looking at the rear of the engine, would put the outlet at the 9 - 9:30 o'clock position. I believe this would allow for the coil packs.

As far as the EGR tubeI think maybee a little rebending might work, since with our Coldside Kits the EGR valve placement can be moved with a longer SS tube to the intake manifold.

[bogey]

The 1.6 outlet is an option, but the 1.8 outlet would point at about 7 o'clock position if rotated 180 degrees.

Can the EGR pipe be eliminated? Is it really necessary? Can the sensor be fooled so it does not throw a CEL? It would be very easy to cap it on the manifold.

[oldtimer02]

some have capped it at the manifold & didn't get a CEL others disconnected from the manifold no cel. others got a CEL.
I have mine capped at the manifold so I'll let you know.
if not the Scangage II hides the light. LOL

[FormerDatsun510Man]

To fool the EGR system all you need to do is hook everything as normal except:

1) remove the EGR crossover pipe and put a cap on the fitting on the header
2) put a small pipe and filter on the intake manifold side that the EGR pipe used to connect to.
3) leave the EGR valve and electronics in place

An easy, but non-reversable way of combining #1 and #2 is to cut your EGR crossover pipe in half and pound the side that goes to the header flat at the end so it is sealed off, then on the other side bolt it up as normal with the 2 x 10mm nuts put a little filter (I used a breather filter) on it.

Using this method, you have effectively eliminated the exhaust gases from going back over to the intake manifold and yet the stock ECU will be "fooled" into allowing fresh (rather than dirty exhaust) air into the intake manifold as needed. Doesn't cause any fuel trim or mixture problems that I have seen.

Bill

[Tom @ Fast Forward]

If you disconnect it and get a CEL, you are probably under 1500 feet altitude. If you cap it off and don't get a CEL, you are probably above 1500 feet. Mazda only tests below (roughly) 1500 feet altitude.


some have capped it at the manifold & didn't get a CEL others disconnected from the manifold no cel. others got a CEL.
I have mine capped at the manifold so I'll let you know.
if not the Scangage II hides the light. LOL

[bogey]

So if I am willing to cap the EGR, I could use the 1.8 thermostat cover and a U-shaped hose, or a 1.6 cover and an L-shaped hose.

All I would need then is the return pipe cut and bent to point down instead of accross the back of the engine.

Sounds like the making of an upgraded kit!

[BlownMX5]

To fool the EGR system all you need to do is hook everything as normal except:
(EGR fooling technique snipped)
Bill

Wow Bill, thanks for this! I have a permanent CEL due to my missing EGR pipe so I just cover it with my Zeitronix display :redface:. It will be nice to have a functioning CEL again.

Pat.

[bogey]

Are the fittings for the thermostat and water neck a standard size? I have not see any sizes listed on these types of components, as though they are all standard dimensions.

[oldtimer02]

Thanks Tom & Bill! I guess my light will shine as I live in Fl at sea level.

The waternecks for different cars are different sizes.

[Tom @ Fast Forward]

Well, if there is room for the EGR valve but not the crossover pipe, you can always just remove the crossover pipe and leave the valve. Just put a little piece of screen on the EGR assembly where the crossover used to connect. The system doesn't know/care whether it is exhaust or fresh air. Still works the same and no light. Lot cooler too. :)

[oldtimer02]

Here is a picture of what is included

[MS2KSE]

To fool the EGR system all you need to do is hook everything as normal except:

1) remove the EGR crossover pipe and put a cap on the fitting on the header
2) put a small pipe and filter on the intake manifold side that the EGR pipe used to connect to.
3) leave the EGR valve and electronics in place

An easy, but non-reversable way of combining #1 and #2 is to cut your EGR crossover pipe in half and pound the side that goes to the header flat at the end so it is sealed off, then on the other side bolt it up as normal with the 2 x 10mm nuts put a little filter (I used a breather filter) on it.

Using this method, you have effectively eliminated the exhaust gases from going back over to the intake manifold and yet the stock ECU will be "fooled" into allowing fresh (rather than dirty exhaust) air into the intake manifold as needed. Doesn't cause any fuel trim or mixture problems that I have seen.

Bill

OK, Does the 1500' + - sea level hold true doing what Bill said above ? and is there any advantage to doing it to a stock Miata ??

[FormerDatsun510Man]

My instructions will work at any altitude that I can imagine... or at least as well as any stock Miata could handle it. Basically the EGR is hooked up completely like stock except that the tube that would feed exhaust gas to the intake manifold is replaced with a fresh air breather filter. The stock ECU doesn't know the difference. A side benefit is the intake manifold will be kept free of exhaust fumes and buildup of crud :). A bad effect I suppose would be the emissions would go up. Actually, I would be interested in back to back runs on the dyno checking emissions with and without the EGR functioning what the difference would be. I would think it would be pretty small.

Bill