What size oil and water fittings thread into a Garrett T25?
What size and grade head to exhaust mani studs do I need?
Should I drill out the mani and turbo flange to fit 10mm studs, or will 8 be enough?

More coming, I'm sure...

 

The coolant line fittings are 7/16 x 20 (-4) to 14.0 x 1.5mm.

Oil Line fitting is a -4 to 7/16 x 24 Inverted Flare.

I believe the exhaust head studs are 10 mm x 1.25.

Go with 10 mm studs! 8 is not enough if you run any track/autocross events. Even then..... If anyone has our manifold w/ 8 mm studs, will we drill them out to 10mm free of charge.
Stephanie

 

Thank you

 

The studs break under the increased heat/load of track duty I assume? I suppose I could take off the mani while I'm home for winter break, hopefully I'll get some money for xmas to pay for shipping.

 

Sam, you'll probably also need to drill out the turbo flange too. If you don't have a drill press, I think it would be a lot more economical to just pay a machine shop than to ship it all.

The 8mm studs I have here really look undersized to me.

 

My dad has a year old drill press, I guess I could just buy a 10mm tap and some studs.

 

What is the diameter of the hose in inches for the coolant lines? or is it 7/16 if im not using an AN fitting?

Kinda suck at these measurements.

 

keep in mind when buying clamps that they are labeled by ID size. Your piping will be labeled by OD size... BUT you have couplers inbetweeen. Figure on an additional .25-.375" on the diameter. So, if you have 2" pipe buy 2.25" clamps. 3" buy 3.25" clamps.... etc.

 

Ben, don't listen to anything you get in this thread. That turbo has got some really insane fittings. Did I leave anything in that CHRA as far as fittings go?

The drain "flange" is a metric thread. The oil feed is NOT 7/16-24 inverted, but if there's a fitting in the feed already it's the converter I bought to convert it to 7/16-24. The water lines are kind of normal, but you're still going to have to size them at a pneumatic supply store.

 

Besides the -4 side fittings, those are fittings we have used in all Garrett turbos for the last 4 years; including GT2560, GT2554, GT2860, GT2871, and GT3071 turbos. We do not convert them to anything or re-drill any holes. The -4 is what we use for oil/coolant lines.
Stephanie

 

You can either go up to 1/2", or slightly down to 3/8". I would recommend that you get a 7/16 fitting that has a standard size hose barb on the other end.
Stephanie

 

There were two fittings, IIRC one of the water lines and the oil feed. I have no idea what sizes either of them are. The water fitting was too long and bumped the exhaust manifold, so I took it off. The oil drain flange looks like it would thread into my mitsu's oil drain, but does not. And it doesn't have the "ears" to bolt the fitting to.

Steph, this turbo is a Garrett TB2522 Part # 465749-5001. I couldn't find any info on Garrett's site about this turbo, and I found no way of contacting Garrett directly.

 

Good luck. Finding the right fittings for my variant of the small 16g was one of the biggest headaches of my build.

Go to a Fastenal store and use their bolts to find the right threads for the fittings, and then either source the appropriate fittings somewhere online or have them machined if you get in a jam.

 

Thanks. There's a Fastenal not too far from me.

 

OK. The feed is a 7/16-24, as long as you leave that fitting in. The drain fitting is a metric thread. The two water fittings should be pretty standard.

 

Sorry if this was mentioned already but the holes on the garrett T2 flange are 9mm ID. If you use a 10mm stud you also have to drill holes in the turbo larger.

kinda obvious info but I figured I'd share. I used 10mm studs on paul's new manifold.

I'm using 5/16 studs (close to 8mm) on my new TT manifold cause i have studs and nuts lying around. It's easier to get a smaller wrench on the 5/16" studs.

 

I'd use the largest and easiest to find studs. Ironically metric fastners are more difficult to come by in Canada. I used 3/8 on my greddy.

 

Sorry to bump this but im starting to search for the lines that I need and I need to know one thing. Are the above hose measurements internal diameter or external diameter?

I have piece of the cars hose sitting on my desk and its 1/2" external and 3/8" internal. Which is it?

 

internal diamater

 

A good way to remember whether something is spec'd in ID or OD is what the important dimension is. For pipes or hoses, you will be transporting a liquid or whatever through the pipe/hose, so the critical dimension is the ID because that is important to flow. Now for a strutural tube, the OD is the more important dimension and that is why it is spec'd. The exception that comes to mind is exhaust piping. Exhaust gases are flowing through, so I would think that the ID measurement would be best, but I guess that a fairly standard wall thickness is used, so OD measurements seem to be given exclusively.