Old school Holden six
Hi everyone. This is the engine from my 73 Holden LJ Torana GTR XU1. (replica) running a Go-Street 400.
These were a six cylinder muscle car built in the early 70s here in OZ. They won the Hardie Ferrodo endurance race at Bathurst in 1972 and would have won again in 73 had it not been for an unfortunate pit stop miscalculation that caused them to run out of fuel.
From that point on they earned a reputation as a bit of a "Giant Killer" because most of the cars they were competing against were V8's. But the Torana was a very small and light little car with a comparatively big and powerful engine and was able to hold its own against the more powerful competition.
This engine is a 206 cid with an Aluminium Yella Terra high comp head, Flat top pistons, 10.53:1 C/R. 1.6:1 roller rockers, chrome molly pushrods, Balanced internal, ARP bolts throughout, Lightened flywheel, Pro-Comp HEI distributor, Crow flat tappet Cam with 224 in/ex duration @ .050 and .490 lift. It makes a healthy 200hp and is very free revving.
I know 200hp doesn't sound like much, but the car is only 2300lbs and has very short gearing.
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I was doing a little reading on the Holden inline 6. Grey, Red, Blue and Black....
I would assume these run along the same design of the US GM inline 6. Ours had a little more displacement. 230, 250, 292, etc.
My curiosity is based on the lack of a 12 port head in the US. Is your aluminum head a 12 port? I'm interested in a cast iron or aluminum 12 port if it will fit a 230.
Here is a teaser. Our Siamese port heads have horrible flow and the intakes have horrible fuel distribution. We have already identified how we could build a hybrid multi port Fitech for an inline 6. This would be a great improvement over stock, but would be outstanding with a good flowing 12 port head.
Yeah they are very similar in design to the GM motor, they even look very similar. The head I'm running is a 12 port. There is a lot of miss formation about the heads for these engines and which one is better for performance.
I'll just say that it's not by chance that the 12 port is the only one still being manufactured by the aftermarket industry. The 12 port head came on the blue / black engines 1978 through to about 1984. (in 1985 we got the Nissan RB30 engine in our Holden's because the old design of the Holden six could no longer meet pollution laws)
We never got the GM six over here but I've seen guys who have got their hands on them and have bolted them into old Holden's as an almost straight bolt in fit.
Check out the attached link, it'll tell you everything you ever wanted to know about these engines and how to hot them up.
http://www.bur.st/~oljohnno/page2.html
http://store.yellaterra.com.au/categories/cylinder-heads/holden/holden-straight-6.html?sort=priceasc
The lack of a 12 port head in the US might just be more because you guys went to V6's sooner than we did rather than continue development on the old designed L6. whereas we persevered with the old inline sixes for a while.
Actually now that I think about it, Australia has a long tradition of really Hot Snot inline sixes in production cars.
If your interested look up the following:
Valiant Charger E38 / E49
Holden Torana GTR and GTR XU1
and more recently the Ford Barra 4 liter inline six. (this thing is capable of 1000hp on a stock bottom end. Its like the LS of the six cylinder world)
You might have noticed I'm a bit of a fan of the six 🙂
Thanks for the info. Look forward to hearing more about your 6.