226 replies to this topic

[yel327]

Dual cast 173 engines certainly are the fly in the XU! ointment because they were never intended for a XU-1, the dual cast 202 was the engine intended for the XU-1, Dual cast 173 engines were intended for the 1971 LC GTR 173 ( CF ). These were the cars chosen to compete in the 1973 Manufacturers Championship and Bathurst in the under 3 litre class. At Bathurst in 1973 there were 2 Holden engines entered, a 173 & the 202. Dual cast blocks were designed to last and produce maximum horsepower. In 1973 both the 173 and 202 engines were Holdens top selling engines...........

 

Win on Sunday, sell on Monday.......

 

So let me get this straight. GMH specially cast a secret squirrel 173 block in/around August 1973 for use in the two now 2 year old LC GTR's entered in Bathurst for 1973, #36 entered by MKL, a Hunter Valley based dealer with two relatively obscure drivers that qualified in 31st and DNF'ed......Or the #33 car also by a relatively small dealer that qualified 28th and finished 17th.  Where is the evidence that either of these cars was actually a 2850S (or raced in that specification)? They are both listed as Class C which is under 3.0L which means they could be 2850S or 2600S. By the qualifying lap time you'd think the #33 car might be a 2850S but given they'd have been allowed to run the same rubber as the XU1's either would be pretty quick in qualifying but it was still about 20s a lap slower than the top XU1's. Herb Taylor drove an Escort in 1971-1972 and Don Smith drove a Datsun 1600 so you'd assume the GTR was a used car as well when they raced it. Anyone know Herb Taylor? Wouldn't hurt to ask him. Herb is 81 from what I can see and still around, but Don is deceased. Interestingly they were both born on the same day.

 

[Potta]

 1538820_782931935091930_4459726240891199226_n.jpg   48.76K   15 downloads

 

My guess is the dual cast number meant something to these guys, and that's it.

 

The only way we are going to find out is to talk to someone who actually knows.

 

If the 3 amigos think there is a different product used in the casting, they need to find a few examples and weigh them(will show different materials) or get them analysed to find out if they have a different physical makeup.

 

Until you have taken a scientific approach and presented some actual useful info rather than he said she said type stuff, shut up about it.

 

Now, back to Skap's original question.

 

If you are chasing value, then 3 tags are probably better.

 

However, my GTR has only 2 tags, missing the VIN, which I am trying to track down, and most original parts, but there is enough other evidence left to make me sure it is what it says it is so I don't care.

 

If I were to try and sell it I might care a bit more.

 

In reality, it's faults made it possible for me to own it, so I took the opportunity and ran with it.

 

After reading through this thread I think I may have one of those High Performance engines from Bathurst '72, it has a big HP on the side, that must mean High Performance, I dare all of you to contact cams and prove me otherwise.

[yel327]

1538820_782931935091930_4459726240891199226_n.jpg

 

My guess is the dual cast number meant something to these guys, and that's it.

 

I am 98% sure you are spot on, but until I have concrete evidence (as opposed to very good evidence) it will remain hidden for now. Not to these exact guys, but people just prior to when engines were put in this area.
 

Edited by yel327, 29 March 2016 - 12:24 PM.

[Potta]

Yeah but I don't have a pic of that lol.

[yel327]

And add to that Ian, win with an LC GTR at Bathurst 1973 (as GMH obviously intended doing if these secret squirrel 173's that no-one knew about were cast in Jul-August-ish 1973 so some privateer 2 year old LC GTR's could win their class at Bathurst) and sell what on Monday? Who'd want an LJ GTR with their smelly standard 202? I think the straws have well and truly been grasped and they've all come up short.

 

Almost forgot, where are the homologation papers for these super special 1973 173's in LC GTR's, as GMH HAD to have built 250 of them in order to use these special second date coded 173's at Bathurst in 1973?

Edited by yel327, 29 March 2016 - 05:22 PM.

[crabba67]

Even  LC GTR,s in the 1976.under 3 litre class race at sandown.

Attached Files

•  1976 3 litre class.jpg   232.68K   5 downloads

[crabba67]

Ian,i think you may find that is before the dual cast 173's and 202's were cast................ it's per 1973 

[S pack]

Even  LC GTR,s in the 1976.under 3 litre class race at sandown.

So what does that prove? Someone raced a GTR at Sandown in 1976. Fact.

Did you see if the donk is a 173 with a dual cast date? I'll bet not!

[yel327]

The one's send to nz if it's correct on the vin disc the 138 would be after CB 399 the CD399,s and CD402,s i have the cast dates are 20H3 after the dual cast period which the last cast is 10H3.

Cheers

 

What about L249246? It is originally built with a 138. Its engine would fall smack bang in the middle of the trial that dictated the second cast date.

 

As are L253011-L253040 (with a few non 138's in between). These could have engine numbers inside the 150 list engines, and could be cast back in early August. Sure, unlikely to have the second date code but you simply cannot say with certainty they won't.
 

[yel327]

So what does that prove? Someone raced a GTR at Sandown in 1976. Fact.

Did you see if the donk is a 173 with a dual cast date? I'll bet not!

 

Plus why would you need a special 173 block? If the standard style block was good enough to get an LC XU1 (with a lot more power) around Bathurst at 2:54 and come 3rd less than 1/2 lap behind the winning GT-HO II's, why wouldn't a stock 2850 LC block (or any other 173 for that matter) be Ok for a car with far less power, less revs and race rubber be good enough? Sure the LC GTR that finished 14th in 1973 did a similar qualifying time but that was on race rubber - the engine would have been far less stressed than an LC XU1. Or were they running triples and XU1 cam on the GTR's in GroupC?
 

[S pack]

Brocky won Bathurst in 1972 without a dual cast 202 block and I'll bet he didn't have a dual cast block at the Hardie Ferodo 1000 in 1973 either.

 

The dual cast date blocks were so secret that Alan Grice didn't have one at the Hardie Ferodo 1000 in 1973.

Edited by S pack, 29 March 2016 - 07:07 PM.

[S pack]

Hmmm ............    XU-1s were always the ‘hero’ car for Holden racers, however at the 1972 Bathurst 500 where Peter Brock scored his maiden victory, two GTRs contested Class B. Sadly they couldn’t catch the rotary Mazdas.

On the other hand if those GTR's had dual cast blocks they would have denied PB of his maiden victory.

[xu2308]

Some one needs to track down Eddie Mathews the GMH Metallurgy Guru that did HDT's Metal stuff, he would know about the Dual Cast thing, plus he would know who worked where the Engines were cast and may provide names who did the castings in 1973 etc.

?????????

[xu2308]

Skap your the Man to do it, I have enough searching thingy's on my plate

[S pack]

How many LC XU1's did GM-H have to produce for the baffled diff housing (DSL September 1970) and the strengthened lower control arm (DSL February 1971)?

[N/A-PWR]

is this any help Dave:-

 

http://www.gmh-toran...ild-date/page-2

[S pack]

is this any help Dave:-

 

http://www.gmh-toran...ild-date/page-2

Not really Dave. The info relating to the LC XU1 in that thread is incorrect.