Height dimension of HK-HZ stubs.

mr imp · Post by **mr imp** » Thu Sep 03, 2009 10:03 am

These figures are from the Boyces 4 in 1 tune up book 1968 to 1979, this book also has the front wheel alignment figures in it as well.

All HK models to all HX models have a King Pin Inclination (KPI) of 7 deg 30 min plus or minus 10 minutes.

Torana’s all models from LC to LX the KPI ranges from 7 deg 30 min plus or minus 30 min to 8 deg 40 min plus or minus 1 deg 30 min.

I could not find the book with the HR figures in it, but would suspect they would be the same as the HK.

If anyone would like the exact figures for a particular make or model within this year range, please PM me.

I will have a hunt around for the other books that have the earlier models in it.

The other thing I have in my mind is the HR had the calipers to the front of the stub axle and the LJ Torana had the same calipers but they were at the rear of the stub axle, this was because of the steering arms.

The HK had the same calipers as the HR but the disk was larger in diameter and thickness, the first of the calipers had a spacer fitted between the two halves, then the later models had it built onto one half of the calipers.

The LH Toranas have the caliper forward of the stub axle and have a different steering arm, they also have a different type of caliper to the earlier ones, it was a PBR single piston side pull caliper, the early ones had a twin piston caliper.

From the DBA catalog, disc sizes, dia followed by thickness

HR 253 9.7
HK – HT 270 12.7
HT V8 270 15.9
HQ – HZ 276 25.4 vented disc
LC – LJ 256 12.7
LJ XU1 256 15.9
LH, LX, UC 256 16 built in hub
A9X 276 25.4 vented disc

As you can see there are a lot of small differences between the models.

LT5 · Post by **LT5** » Thu Sep 03, 2009 11:44 pm

G'day Mr Imp,

That is really interresting, it is hard to find any printed specs on this stuff.

Whilst I cannot measure KPI with my setup, I can certainly measure difference in KPI down to the 0.1 degree (or 6 minutes).

I have measured a fair few sets of these HJ and HX stubs (at least the 3 I have here and 1 other set) and they were all within 0.1 degree of each other.

The figures stated for the Toranas are a little confusing though.
The LH L34 and LX A9X Toranas used the identical part number stubs as the HJ one tonner (I have checked the Holden parts manual) but swapped to opposite sides which would agree with the first figure stated of 7 degrees 30 minutes plus or minus 30 minutes.

I have measured 6 sets of Torana stubs (LC, LJ, LX and several sets of UC stubs) and they all measure between 1.6 to 1.8 degrees more than the HX ones.
This means they are 9.1 to 9.3 degrees KPI. The tolerance would be plus or minus 30 degrees as per the HX stubs, not the 1 degree 30 minutes stated, I reckon that is a typo.

I would be very interrested if you can find the spec on the HR ones as I have heard all sorts of wildly varying stats on the HR type.

This pic below shows my new top control arm pivots I was talking about with the offset so you can flip them over to run the different KPI stubs.

They are pretty much made identical to the originals but with the hump in the middle removed and the threads are longer so I can drill and split pin them. They are also made from 4340 chromoly.

Matt

mr imp · Post by **mr imp** » Fri Sep 04, 2009 11:11 am

I hope Mr Boyce doesn’t mind me posting these.
The top one is an explanation of KPI or Ball Joint Inclination.
The second one is the different Torana KPI.

These images are from the DBA catalog and show the different measurements for Holden and Torana disc.
Note the drawing to the top right side and what they mean

If you would like a better copy PM me with your email address and I will forward them on.

Dave if these present a problem please remove them, but it is good information.