Original submission by T Apr 18th 2007:
The X2 Option:
HD and HR Holdens were available in the X2 option which had an eXtractor exhaust system and 2 Stromberg carburettors (hence X2) unlike the standard HD Holden that had 1 Stromberg carburettor or HR Holden that had 1 single barrel Stromberg Carburettor or 1 dual barrel Stromberg Carburettor (WW Stromberg). Coolant heated inlet manifolds were standard equipment on all HD and HR models.
Holden HD X2's:
HD X2 cars were powered by a 179 cu. in. engine, had an eXtractor exhaust system and were fitted with 2 Stromberg carburettors.
Holden HR X2 cars were powered by a 186 cu. in. engine, had an eXtractor exhaust system and were fitted with 2 Stromberg carburettors.
X2 and 186S Header Part Numbers:
Submitted by 72GTRXU1 on Mon, 07/05/2007 - 12:56. I have been consulting with Dr Terry and others on the Torana forum and this is what we have come up with. X2 Front 7428493 X2 Rear 7428495 186S 161S 173S LC XU1 Front 7433655 186S 161S 173S LC XU1 Rear 7430583 LJ XU1 Front 7428493 LJ XU1 Rear 7430583 There are 3 front sections: (A) Plain X2 (B) Heat riser drilled and (C)Heat riser Blank. As can be seen, the X2 Front and the LJ XU1 Front have the same Part Number. We assume that the Plain one (A) has been replaced with the Blank heat riser (C). Any of the 3 different front sections will fit any of the motors including the X2. However where the auto choke is to be used - part number 7433655 (heat riser drilled) must be used. The rear X2 will not fit any other vehicle except the X2 unless a custom engine pipe is fabricated. The X2 rear flange points more downward rather than more rearward. I hope this helps 72GTRXU1 aka Bazza
HR X2 Info:
This will repeat some that has already been posted but from my HR workshop manual X2 section it lists these changes to make it an X2 engine package vehicle, as that is what a X2 was.
A HR that had this package fitted
X2 Engine available for all HR models.
The engine is a modified 186 with a max power output of 145 bhp at 4600 rpm and gross torque of 184 lb ft at 2200 rpm. The engine is painted deep rocket red with a transfer saying Holden-186-X2 on the rocker cover.
The engine number starts with 186 and the letter K.
The engine mods are Improved material crankshaft bearings Ie Trimetal high lead base babbitt electroplated on aluminum alloy bonded to steel back. Moraine-400.
Redesigned cam with increased overlap and opening period. The listed cam specs are In opens 43 deg BTC. In closes 83 deg ABC. Ex opens 78 deg BBC. Ex closes 48 deg ATC. Aluminium alloy water heated wider twin carby inlet manifold.
Twin exhaust manifolds.
Twin 161 modified carbys both carbys throttle and chokes are coupled together.
Carbys on a manual trans models have the vacuum spark control holes located above the throttle valve and are stamped X2M on the front exterior of the float chamber.
The carbys on the auto models the vacuum spark control holes are located below the throttle valve.
The carby specs are BXUV-2 modified carbys.
Main venturi size 1.094 ins. Flange size SAE 1 3/4 with 1.31 dia. bore. .055 ins main jets.No. 56 drill power by-pass jet. Idle discharge hole upper No.64 drill.Idle discharge hole upper No. 70 drill. Idle tube No. 70 drill. Idle air bleed No 52 drill.
Twin attachment air cleaner with polyurethane element and intake silencer.
Modified throttle linkage to suit the twin carbys.
Exhaust front pipe starts twin from the manifolds and blends in to a y connection midway between the manifolds and the Muffler into a single 2 inch pipe.
Muffler is a straight thru oval shaped and is 7.75 in X 3.25 in X 14.14 in long.
Tail pipes increased in size to Front 1.875 in and rear tailpipe 1.50 in on models 215A 225A 235A and 1.75 in on all other models.
There was also a straight through resonator fitted The engines used a std dissy and std timing.
There was a modified dash and wiring harness that came with the X2 engine package.
The dash had a oil pressure gauge and a temp gauge and a ammeter and a fuel gauge and a generator tell tale light.
On the body they added 3 X2 badges.
I hope that helps a bit.
Something I have been told but I am not 100% sure on is that X2 HR's should have a D stamped on the ID tag.
This does not prove that it is a X2 just that the car as been optioned. (X2 engine package is a option)
So this D will also be on any other base model car that has been optioned too.
Interested to hear if anyone else has heard of this as well.
The Genuine part Number for the X2 cam was 7428531. End of submission by snowdownunder.
there was a kit put out by dufor for this had every thing in it to do this i have seen them selling at swap meet for $20.00
new old stock has all the hose fittings ,hose pcv valve and instructions , if your in vic maybe check out the warragul swap meet i saw he will be there. you shouldent have to drill any holes should be a screw in plug on manifold you unscrew and screw fitting into. wombat..
X2 Aircleaner Colour:
I did say i didn't know, but i did paint mine the colour of my monaro, which is camaro gold......the code is 567-12186.