GTR Header

[ek ute]

Hi I have discovered I have a set of GTR headers. Is it worth getting them powder coated for my 179, or just go for new set?

[Blacky]

You could probably flog them off to a restorer and buy yourself a new set plus a full system and a set of carbs and .........

[Errol62]

149 179 179X2 186X2 186S GTR XU-1 exhaust header flange plates

Sonic Injection are about to stock these for anyone interested. Best ring them as website still shows out of stock.

Been casually trying to get my hands on a pair of these for some time, so I’ll be on the phone first thing Monday. User on the Torana site offered me a pair for $150 a while ago. These are $40.


FB ute fixer upper, EK van on rotisserie

[mph]

Hi I have discovered I have a set of GTR headers. Is it worth getting them powder coated for my 179, or just go for new set?

New set as in someone makes twin cast headers new for a red?

[Harv]

149 179 179X2 186X2 186S GTR XU-1 exhaust header flange plates

Sonic Injection are about to stock these for anyone interested. Best ring them as website still shows out of stock.

Been casually trying to get my hands on a pair of these for some time, so I’ll be on the phone first thing Monday. User on the Torana site offered me a pair for $150 a while ago. These are $40.

G'day Clay,

Did you end up fitting a set of the Sonic plates?

I bought a set of headers for the HR Prem. They have the tube running through for the auto choke, so not GTR. Not sure if the X2 headers had the auto-choke tube, or only the 186S ones. Managed to get them sent to me last week (with thanks, Andrew). The studs were all shagged, so drilled them out and retapped. Got a set of the short 3/8 studs from Redline Performance, as the 2" Champion ones from Supercheap look 'orrible with 1" of stud hanging out (they are also UNC, and I retapped to UNF).

I thought I would get smart, and buy the header flange plates from Sonic. They arrived this morning, but it has dawned on me that they are a different setup. The original header flange plates were thin sheet steel. The exhaust pipe was pushed through the plate, then bell-mounted (flared). The bell-mouth seated the exhaust o-ring. The headers also suit the o-ring, and have a dished end (not a flat flange).

The Sonic plates are pretty thick (8mm), and look to be designed to have the exhaust pipe welded to them rather than being bell-mouthed. They are a flat flange (not dished), so may not seat the o-ring real well.

Curious to see if anyone has fitted the Sonic flanges, whether they welded or bell-mounthed the exhaust pipe, and how the o-ring went.

Cheers,
Harv

[ardiesse]

Harv,

The auto choke tube in the red motor headers is for a WW Stromberg - so 186S and GTR. X2 headers don't have the choke tube.

And forgive me for pointing out something obvious, but I thought the exhaust studs were 3/8" UNC (not UNF).

Rob

[Errol62]

Hi Harv,
Only test fitted at this stage but they work same as original. Better in that they won’t bend. You could file a wee chamfer. You can try a grey engine pipe with standard gasket for 132, 138, 149, 179.
The original 149, 179 flanges are identical to original but the grey has different stud spacing, although the pipe size is the same @ 1 3/4”.

Prolly out of stock Clint but ring or google sonic injection. Doing more if demand demonstrated. $40 a set.


FB ute fixer upper, EK van on rotisserie

[Harv]

Thanks Rob.

Any way of telling the difference between 186S and GTR (is there a difference)?

No idea what thread the original studs were in the header, though the outside threads were UNC. I pulled a stud out of the spare-parts department, and it was UNC/UNF. Stupid me then went and tapped out to UNF. My mental picture said I had a full set of studs... but of course there were only 2. So went and bought a set of 4 from Redline.

Cheers,
Harv

[Errol62]

Harv, the GTR rear flange is more inclined to vertical than Holden. Front is same part except HD which has no boss for the tube.


FB ute fixer upper, EK van on rotisserie

[ardiesse]

Harv,

The exhaust flanges were tapped UNC. It sounds like the UNC/UNF stud you found was from a red motor cylinder head.

Rob

[Harv]

Harv, the GTR rear flange is more inclined to vertical than Holden. Front is same part except HD which has no boss for the tube.

Not sure if these help identify or not:

Headers 1.jpg (105.66 KiB) Viewed 721 times

Headers 2.jpg (106.04 KiB) Viewed 721 times

Headers 3.jpg (109.04 KiB) Viewed 721 times

Headers 4.jpg (102.79 KiB) Viewed 721 times

Cheers,
Harv

[Fex]

Harv

Quick google search “x2 exhaust headers” revealed this if it helps.. scroll down a bit from the top.. There is a heap of explanatory text in that forum as well

Cheers, Andrew

5870831A-DA05-484E-BE21-B5E80E3E05E9.jpeg (159.73 KiB) Viewed 699 times

F2CD4C8E-4FEE-4DD7-9F07-B546171A7D2E.jpeg (151.64 KiB) Viewed 699 times

[Fex]

Sorry Harv, I just reread your question. That might not be as helpful as I thought..
Cheers, Andrew

[Harv]

Many thanks - that is useful. Summarising the info from that site:

There are three versions of the front header:
1. no casting for the auto choke pipe,
2. casting for the auto choke pipe but not drilled, and
3. casting for the auto choke and drilled to accommodate riser pipe.
All three versions of the front section will 'fit' either the X2 or the LC GTR, XU-1s or 186s. The plain (no casting) was originally fitted to the X2 but the drilled auto choke version is needed for the LC GTR and 186s. Typically LC GTRs, LC XU-1s and LJ XU-1s are fitted with front version type 3.

There are two versions of the rear header:
1. the flange points more downward,
2. the flange is longer and points more rearward.
Version one was used on the HD 179 X2, which had two separate engine pipes all the way to the front muffler (all of the others had a Y-pipe which will not fit up to the HD headers). The HR X2, GTRs, XU1s and 186S used version 2.

I've got front header version 1, and rear header version 2. Suits everything except a HD 179 X2, and suits a WW Strommie.

I'll call them HR X2 headers, but if any of the Torana boys ask, they are LJ XU-1 headers

Cheers,
Harv

[ardiesse]

. . . and now I am confused. My HD X2 had a Y engine pipe like the HRs, and when it became unrepairable, I fitted an HR X2/186S Y-pipe. Maybe the change to the Y-pipe happened late in HD production.

Rob