81 replies to this topic

[FLY_AGAIN_XU-1]

Please read page 79 (SLIPPED DISCS) of the latest Australian Muscle Car magazine (Issue 38). If you wish to further enhance your knowledge about the mighty 1973 Bathurst XU-1. (The Truth).

In 1973 the rules were changed to Group C Production Touring Cars. Eligibility was bumped up to 500 cars. The 50% rule still applied, meaning that a minimum of 250 cars had to be sold for homologation purposes. (Not 150)







According to the Holden vin disc (Microfishe) Holden built a total of 789 1973 LJ XU-1 Toranas.

500 being for Eligibility (These cars are plated 1/73, 2/73, 3/73, 4/73 & 5/73)
289 being for Homologation Purposes (These cars are plated 6/73, 7/73, 8/73 & 9/73) Holden offically ceased production of the XU-1 Torana in September of 1973.



Then of course theres Mike Bells Production Broadcast Sheet.

8D11PCL249710 JP389265 COMP 16-08-1973 SOLD 08-1973 DEALER 166

Mikes car is plated 08-73 & had factory fitted extractors, fine spline axles and the cutouts in the fan blade. However Mikes car never made the 150 list.

The last batch of 150/151 will all ways remain the 1973 Ultimate Finale in my eyes.

Cheers, B.

[meanmachine72]

[WhiteA9XS]

cheers and beers

[nzxu1]

So after all this , why did holden bother to release a list with just 150 / 151 numbers on it in the first place ?

[robj]

I don't see why Holden would need to produce 500 73 Xu1s for homologation for group c, i would have thought that it was the LJ that was homologated, not the specific year it was produced. This sort of holds weight as the CAMS homologation for the LJ has the amendments added to it. There is no distinction as to if its a 72 or 73 LJ xu1.

The recognition form in the Fiv xu1 book on page 180 would have been for series production. Would there have been another one for the change to group c production rules?

Yes, it is strange that Holden only produced a list with 150 on it. Its clear from the vin listing that the engine numbers in the list appear in only the last 150 cars built. We need some Holden employee from back then to explain!!

[FLY_AGAIN_XU-1]

I don't see why Holden would need to produce 500 73 Xu1s for homologation for group c, i would have thought that it was the LJ that was homologated, not the specific year it was produced. This sort of holds weight as the CAMS homologation for the LJ has the amendments added to it. There is no distinction as to if its a 72 or 73 LJ xu1.

The recognition form in the Fiv xu1 book on page 180 would have been for series production. Would there have been another one for the change to group c production rules?

Yes, it is strange that Holden only produced a list with 150 on it. Its clear from the vin listing that the engine numbers in the list appear in only the last 150 cars built. We need some Holden employee from back then to explain!!

In 1973 you could race a 1972 car with its old recognition form (Eligibility), however in 1973 to race a 1973 built car you would need a recognition form (Eligibility) of which 500 cars needed to be built. So basically to race a 1973 built car in 1973 required 500 cars to have been built. Eligibility allows the cars to race provided a certain number have been built (500). If the race teams wanted new parts, these new parts needed to be homologated and a further 500 cars built. For CAMS to accept the homologation 50% (250) of the required minimum of the 500 cars all ready needed to have been sold (Not 150). Eligibility and homologations are 2 different things, however both require the same amount of cars to be built.

The list of 150 High Performance Engines is just that. A list of 150 High Performance Engines. Im assuming these 150 engines were the ones that recieved the added port work and much lumpier XJ camshaft ?

[torry nut]

maybe holden did the sneaky and counted some pre 73 bathurst cars in their 250 ??

just a thought

[Bazza]

Hi

Re the camshaft. Didn't vin150cars say already that his car came fitted with the standard XH/HX cam?

Bazza

[Bazza]

Hi

Here's the quote from vin150cars

"my 73 bathurst car[ex n.s.w police car]came with from new
xh cam 429'' lift i still have it if you measure the height
of lobe you should get about 286'' then halve that figure
and add to 286'' you will get 429'' valve lift.
the cam as xh or hx stamped on it."


So it sounds like the cam was optional.

Bazza

[nzxu1]

When it all comes down to it , Holden must have released the list of the 150 cars to suit some particular requirement of the time , otherwise why would they have bothered to take the time and trouble do so in the first place ?. To me it seems that some people who perhaps may own a car that was built just outside the 150 build list are trying to throw doubt on the validity of the 150 list to perhaps try and up value their own cars . Nothing will ever change the fact that the list does indeed exist for all to see in BLACK and WHITE .
ps : l own an august 73 orchid pink metallic XU1 built one week before the start of the 150 run , anyone care to pay me 73 bathurst 150 list price and it's yours !

[Bazza]

Hi

Spare a thought for the owners of the 14 cars built between the lowest and highest engine numbers on the "150 list" whose engine number doesn't appear. Does anyone think that there was nothing special about the engines in their cars?

Bazza

[FLY_AGAIN_XU-1]

When it all comes down to it, Holden needed to produce a minimum of 750 LJ XU-1,s in 1973 before ceasing production. They ended up building 789. Thats BLACK and WHITE and based on FACT rather than FICTION.....................

Why a list of a 150 High Performance Engines ? Dave Bennett hand ported around 150 heads in 1973 for Holden. 830hp may be able to shed some further information on this...................

[WhiteA9XS]

dave said he did 200 of the heads , perhaps 50 were spares

why did chysler only produce 149 E49 chargers which was enough to allow homologation and put the E49 onto the track ?

[FLY_AGAIN_XU-1]

why did chysler only produce 149 E49 chargers which was enough to allow homologation and put the E49 onto the track ?

The E49 was a homologated special being built around June/July 1972. In 1972 the amount required was 200. A homologation required 50% (100 cars) needing to have been sold before CAMS would accept the homologation. As long as Crysler had built and sold a minimum of 100 cars (50%) and then ceased production it was allowed to race. By ceasing production and building 50% of the cars required was one way of defeating the CAMS rules.
Holden followed suit in 1973 (XU-1), 1974 (L34) and in 1977 (A9X).............. From 1973 the rules were changed (Group C) 500 cars were required or a minimum of 250 cars (50%).

[FLY_AGAIN_XU-1]

Black & White..............