Vinyl roof on VB-VC it is a dealer's option or a factory?

So the HD drum braked car stoped better than a HQ drum braked car.
My brothers 173 Kingswood was doing 100mph down a hill on to a flat and then jumped on the brakes full on and missed a turnoff we were going to go up, the brakes were cold before hand as we were on the highway for 20 miles before hand and then got flat out brake fade at about 30mph.

The weight of the HD and the HQ being one factor and the size of the brakes being another and then the material of the pads being another point. Back in the days I would think Bendix was the standard Holden pad and also the replacement most likely would be the same ?
with the EH on you could get sintered shoes, it would be interesting to see the difference in performance, they must of made a huge progress because I am sure on the race track the standard shoe material would be worthless given 2 laps of a track.

One could boast down the pub in 1964 about sintered brake shoes fitted to your car a good idea if you towed a van I would say, or you drove the big 179 powered beast hard you would need them and what of if you had the 197 hotted up.

I was thinking of the days when the EH came out what could they do to the red motor in 1964 as to the heads and any valve size options that were on the cards back in the days, I think YT heads came out in 1969 but what did they do before that and as to porting jobs. it was 8/1970 when the XU-1 came with the bigger valves.

always gotta be pipin in and having a say huh... must be leo pruneau here

yep... as i wrote earlier, my HD X2 has discs :)

You got a real hang up with this guy? Been a long time since I've seen any positive input from you, lately you just want to have a dig at this guy?why? you got a chip on your shoulder?

I asked because this option was listed in the official brochure:

http://www.oldcarbrochur...lden%20Commodore-14.jpg

Thanks for the confirmation.

Dave Bennett started Perfectune in 1962 and was modifying heads. GMH copied his head for the LC XU1 after he declined an order from them, but during LJ Bennett was making them for GMH as he could do volume production by then. He did the L34 heads too for GMH.

I think the L34 valve head diameter are just standard size SBC, not sure on length though.

Being such a small production run (~263), I do believe that Perfectune did the L34 heads for Holden.

Maybe the same for the last run of LJ XU1s.

Dr Terry

Perfectune did a lot of the LJ XU-1 heads and the 500 pairs of L34 heads. From memory GMH had to make 500 sets of parts to homologate L34. That is why there were so many L34 parts around for years, and dealers were selling upgrade kits to SLR5000 owners. HDT were even selling what they called a HO engine option in the 80’s that was basically an L34 bottom end.

GMH didn’t really have the capability to do small volume machining. They almost always outsourced it. Almost everything they put into cars came from outside suppliers, they essentially only cast stuff and pressed sheetmetal, and built cars and components from it. When the first few hundred GTS350 manual engines got water damaged they had Repco rebuild them, they didn’t have the ability to do it, or at least to do it economically. Even the minor machining on the bore tops on those final bigger valve XU1 engines was done outside of GMH I believe.

I think L34 valves were just stock GM bits, like the cam, lifters etc. You could change out that sort of stuff in GroupC in 1974. Just had to keep the block, crank, rods, heads, pistons and intake plus headers to the first join.

Edited by user Tuesday, 1 June 2021 3:38:29 PM(UTC)  | Reason: Not specified

GMH never cast 'heads' for Brock.. ever*

VC SL/E Commodores that became HDT Commodores... had standard XT5 'enhanced performance' blue 308 engines fitted and
HDT mules ripped the heads off when the cars arrived in Nort Melbourne and they were sent to Perfectune in Moorabbin .. for a large
valve/standard bowl CNC jobbie Something Perfectune were very good at.

Even the famous 'B' cast heads were never done for HDT or Brock. They were done as part of the homologation process
for the engine fitted to VKSS model as well as the VKSS GrpA (aka A9L) model. Part identification was one reason for that
famous 'B' scratched in the sand mould by whichever production foundry inspector happened to be there (keeping count)

Even the later and better 'big valve' (but no scratched in 'B' on the casting) unleaded petrol head used on VL - on both standard SL's etc
and the carby VL SS GrpA was a better head than that used on the VK .... which was also a better head used on VC