what thread size for water injection brass plug?

[keebler65]

on the si/itr JR manifolds, there is that little brass plug for water injection. does anyone know what kind of thread/what size thread is used on this plug? i cant seem to find any fittings at my hardware store or home depot that will thread in there. the threads on the plug are too fine for anything in stores. i found some online sites that might have finer threads, but the problem is i cant hold it up to the plug to guage the size. i'm not experienced in reading thread sizes, so can anyone lend a hand?

thanks!

[grand600intercooled]

1/8" NPT

[keebler65]

thanks for the fast reply. are you sure its standard? because the head is 12mm metric. also, 1/8" NPT sounds pretty common - shouldnt i have been able to find it in stores?

[grand600intercooled]

I am positive and yes you can get it at a hardware store

[keebler65]

well i went to the hardware store again and found an 1/8" NPT fitting and the threads are 2-3 times more course than the plug that i'm trying to match. however, i found a fitting that will screw into the manifold where the pressure sensor usually sits, so i'm deciding to go that route intsead, since i dont use the pressure sensor anyways.

[CivicR]

No i think that port is the same as your studs on your wheels beleive it or not...something like 10x1.25...I unfortunately do not remember the exact size right now sorry!!...maybe you can cross reference a wheel stud to get the right size...good luck!

[Jonny Black]

actually wheel studs are 12X1.50

kinda funny craig I was looking for the same thing awhile back, I found out that I actually have the water injection sprayer in there and didn't even know it. what luck huh?


Jon

[JRCivic]

The thread size/pitch for the water injection port is 8mm x .75 pitch. This is VERY hard to find through your local channels... I have tried THREE large nut/bolt/fastener supply warehouses in my area and cannot get anything on the shelf. Ordering is a must.
Call JR and spend the $$$ for a new plug bolt if it is necessary... if you are trying to add a hard point to get boost signal from, use the pressure switch port instead. It is threaded as John stated (Grand600) at 1/8" NPT. These fittings can be found almost anywhere.

[96IntegraRS]

The pressure switch port is a great place to connect your boost gauge to, as it is easy to find that size fitting at the Home Depot, and you get a real manifold reading without having to T vacuum fittings (provided you have the MAP mod or Hondata or something) which are prone to be problems.

Chuck

[CivicR]

Jim you sure it is that size?? I do remember something about them changing the size of it on the later JRSC units??...I know I added a boost guage to my friends car on that port and it was the same size a the wheel studs?? Maybe it is different on the later units?