I've done this a few months ago but didn't have time to post pics until now.

Background:
The stock injector base has a coolant port for the intake air bypass valve to regulate air being applied to the injectors based on coolant temp. This mod basically isolates the hot coolant away from the injector base to keep the intake temp cooler without affecting the air bypass valve function.

Parts required:
1. Intake adapter plate - The intake adapter plate is made by Hasport and originally designed to run different intake manifolds when performing K24 engine swaps.

2. K20 intake gasket - To be used with the adapter. I used the heatshield type

3. Silicone sealer - To provide better seal around the coolant port on both sides of the adapter plate.

4. Teflon tape - To provide thread seal on intake bypass valve and fitting.

5. Fitting

6. Hex head bolt - To replace one of the original mounting bolt for better clearance.

7. Cover plate and epoxy - To seal off EGR port opening.

Tools needed:
1. Basic sockets, wrenches, metal file
2. Dremel is very helpful but optional

Install steps:
Well, since the remove and reinstall steps of the injector base is the same as installing a Hondata gasket, I will only outline the steps of doing this specific mod.

Intake adapter plate and K20 gasket


1. The first step is to bolt the K20 gasket on the stock injector base. Then trace the outline of the area to be cut.







2. Cut off the old coolant port. Leave a little room outside the traced line for final finishing.




3. Smooth out the cut area to the traced line.


4. This is how it should look when done.




5. Seal off the EGR port with cover plate and epoxy. I used JB Weld. Note: don't worry about the hole. The EGR function was not implemented on the TSX.


6. The next step is to drill a hole in the K20 gasket so the intake air bypass function is restored. Just bolt the oem and K20 gaskets together and trace the large hole.




7. Drill the marked hole and test fit on the plate


8. Test fit the injector base on the adapter and make sure the coolant passage block does not touch the injector base.




9. Swap the fittings on the adapter with new fitting and air bypass valve. The fitting that came with the adapter is too small and won't seal properly.




10. Ready to install. Install the oem metal gasket first. Use some silicone sealant around the water passage on the gasket (both sides).


11. Then the adapter plate and modified K20 gasket.




12. Then reinstall the injector base and check for proper clearance. Note the upper right oem flange bolt is too close to the air valve. It's hard to use a socket to tighten the bolt.


13. Therefore, I've had to replace it with a hex bolt and problem solved.


14. I also replaced the oem intake gasket with a heatshield type to further reduce heat transfer.


15. Everything is pretty much downhill from here. Just reinstall the intake manifold and refill the coolant.

16. Start engine and check for leaks. Note the blue silicone around the adapter block.


17. Done. The surface temp of the injector base is now much cooler, even when the engine is heat soaked. The temp is approx. 40 degrees F cooler when measured with an infrared temperature meter. Enjoy.

 

amazing work

 

duplicate and sell to forum members please

 

This one?

http://jdmultimate.com/hasport/haspo.../i-150418.aspx

 

Never ceases to amaze!

 

Awesome work jtso but i think this might be a bit difficult for many =P.

hey when removing the manifoil did you have to drain any liquids?
im guessing coolant?

 

lol, how did you even come up with this mod?

as always, real ingenuity and quality work.

 

Yes, you need to drain the coolant.

 

Thanks, I've been looking for a way to bypass that coolant passage for a while but didn't find an easy way until now. Hondata also posted some info awhile back using a similar adapter plate but that particular plate doesn't restore the air valve function.

The potential advantage of this mod is you can basically use any intake manifold (I guess SC as well) or ITB that's made for the k20 to fit the TSX cylinder head.

 

yeah...what the heck?! haha

Amazing, but kinda crazy in my opinion. I don't think the majority of the people here have the tools or balls to chop part of their intake manifold off. haha

But amazing writeup as always, Thank youu

 

Do you feel any difference?

 

work of art!
good thing your still here with the tsx

 

I'm new here & relatively new to the TSX but not new to modding cars. Excellent info and thread by JTso.

I have a 2006 6MT TSX, slowly modding. I bought a used 2006 intake manifold & injector base to study & possibly extrude honing.


The injector base (lower intake manifold) is very complex & I have a few questions.

1. JTso mentions that the EGR passage on the TSX intake manifold is not used at all. But the hole is there in the TSX head.
Does the hole in the head not go anywhere?

2. The air valve that screws into the water passage...
What exactly is it's purpose? It must be a thermovalve, opening/closing depending on coolant temperature.
One end goes to the intake tube. The other end goes to a port on top of the intake. This port goes to a hole in
the head. Does anyone know where this hole in the head goes to?

When the thermovalve is open (hot coolant temp) it would open & allow flow from the hole in the head to intake tube. I can't think of what this might be for...


Thanks for any info... Joe

 

^^
1. The hole in the head doesn't go anywhere.
2. You are correct. It's a thermo valve for emissions control that regulates air from the intake tube to the head during warm up via a small hole on top of each intake runner (reference the intake gasket). Once the temp is up to spec, the valve shuts off.

 

Thanks for the reply JTso.


I finally found the the thermo valve mentioned in the Emissions section of the TSX service manual.
The call it a "intake air bypass control thermal valve" & they describe the purpose of this system as "sending air to the injectors.

As you mentioned the thermal is open when cold, closed when hot. The air flow is the opposite of what I thought.
When the engine is cold, air flows from the intake air tube to the hole in the head. As you mentioned there must be passages in the head going to all those small holes above each intake runner to the base of each injector.

I still have no idea why Honda did all this... Perhaps heating a small amount of intake air during cold engine operation?

Anyway I was hoping to get rid of some of the clutter but it doesn't look like one can get rid of the valve and tubing.


The Hasport injector plate plus the intake thermal spacer moves the injectors from the intake port but no issues there I take it?

On the other forum, a small vendor is talking of making an 8-10mm insulator gasket between the head & intake base.
This would be great for heat isolation but I was concerned about relocating the injectors that much.

Thanks..

 

So, isolating the intake manifold from the coolant passage is clearly the right thing to do.

My question is, can it be done without the US$140 HASport adapter plate?

If the idle air valve is eliminated, it looks easy.
Tap the coolant port in the head. Thread in an elbow (street pipe elbow). Add another elbow to connect the hose. Done.


It doesn't look like eliminating the idle air valve is a good idea though, especially for cold climates.

I wonder if the HASport coolant adapter can be used without the adapter plate?
Tap the coolant port in the head. Tap the hole in coolant adapter. Screw in a short pipe into the head & then screw in HASport coolant adapter into it.
The screw holes in the HASport would have to welded shut or the adapter ordered with out the holes.

Another option would be to try to use the coolant adapter that is cut off the intake.

Any other ideas?

 

The coolant port is not just for the thermo valve. It's also part of the coolant bypass for the thermostat housing for proper coolant circulation when the thermostat is closed. This allows coolant flow to the head and to the heater core.

You don't really need to use the Hasport adapter if you can tap the hole in the head and fit it with a fitting. You then would use a 3-way fitting to join the coolant hose, thermo valve and a short hose to the head.

 

Agreed, any "coolant" adapter would have to maintain all 3 ports to be functionally equivalent as original.


Fabricating a 3-way coolant "block" wouldn't be easy but it would work. The idle air valve is likely some weird metric thread.

Perhaps connecting the HASport coolant "block" to the head using a hose would be easier, although more connections to leak.

Modifying the coolant adapter that is cutoff the original intake would be more work than I initially thought.
The oblong/oval hole would have to be welded up & then re-drilled & tapped.
And then the coolant passage is exposed when cutting it off which would also require welding that up.


It doesn't look like anything simple is apparent...

 

A 3-way coolant block is not that hard to make and the thermo valve is normal pipe thread. All you need is a block of aluminum of the correct size/thickness. Drill the first hole from the top, then all the way through. Then drill the second hole from the side, intersecting the first hole. Tap all 3 holes for the thermo valve and fittings.

 

Thread Revival…… what type of fittings were used with this operation? what size? thanks in advanced

 

Odd that I don't remember this thread as I'm always on the lookout for further evidence that this forum has a fairly large percentage of guys with way too much time on their hands. Won't find a much example than this mod.

 

This is a complex modification that requires excellent technical skills and experience.
Plus it's a permanent mod with no going back unless you purchase another intake manifold base.

I did a fair amount of research on this. Getting heat out of the intake tract is always worthwhile but the complexity of this mod plus the purchase of the US$140+ HA Sport adapter plate doesn't really make it worth it.

If you live in a warm climate, I would delete the IABP valve.
Then I would tap the coolant port in the head and use a 90degree 1/2" NPT street elbow and 1/2" hose fitting.

Much easier is to just use an insulating intake manifold gasket.
This also reduces some heat transfer to the intake manifold without all the complexity and cost.

 

9. Swap the fittings on the adapter with new fitting and air bypass valve. The fitting that came with the adapter is too small and won't seal properly.




I just needed the size of these fitting and where to get them. i see what you wrote 1/2 in NPT

i already have the hasport plate, actually got a good deal on it, and i live in South FLA. I'm gonna go ahead and port/polish my RBB for now as i don't have money to buy Flash pro + ECU + Tune + adaptor cable ($50). so while i save up i can get the most out of my tsx by cooling the IM. and air going into the engine, and eventually sell my setup to someone doing what I'm doing now.

Also k20.org people sell RRC and RBC manis already cut for a k20. although I'm pretty sure if i am to buy an RRC or RBC mani the injector base isn't even used anymore as the are 1 piece. i could be wrong as I've never owned one of those bad boys.