Yes…generally true…the originals are cast iron…and I suspect from special,cast iron called SG or nodular cast iron which is better than grey cast iron because the graphite is in a “nodular” form rather than a flake form and this gives the SG cast iron better properties…but not as good as “steel” …but there is no such specification as “billet” steel…a billet is a lump of a particular shape produced at the steel makers …what is important is what is in the steel “soup” . This is a specialised branch of Engineering in itself but Engineers need to know enough to choose the right stuff and use the right heat treatment if necessary. As a general rule the higher strength steel the better the fatigue life…and this is normally what will kill a bearing cap…enormous number of stress cycles in an engine. So highly likely that the steel caps are made from a high tensile steel and would be superior even if cast in the same shape as the originals…but there are some well accepted Engineering principles that should also be applied to a new design to reap an even greater benefit than just that available from the change in material…and the extractor hole wouldn’t get past my red pen!!!
I don’t like the extraction hole, either…
Never mind, I misunderstood what you wrote.
ITB’s finally arrived, they are tapered… 48mm on the airfilter side and 42mm on the cylinder head side.
for interest here , WAY back 1964 ,i was into Drag racing, and built a GM diesel blower for SUPERCHARGING, 1/2" more stroke 350 Chevy , custom center counter balanced 4340 Steel billet crankshaft (moldex),$$$$$.
i worked at the GE (General Electric), Aviation division! mid 60s Vietnam era.
and one of the machinist guys was interested in what i was doing, came buy my shop, and said 2 bolt main caps were noted to be a weak link, he measured this and that, and took the three center caps with him!
couple weeks later came buy and had THREE 3 , 4 bolts caps, 2 long studs of 1/2" chrome moly!
and two angled into the main saddles of the cooling jacket!
MADE FROM BERLYIUM, now adays banned from most racing venues! even F1 racing.
impossible to crack or deform , doesnot change phyisical shape from temperature changes !
he did not charge me anything, Free? just the fun of something over the top unusual!
of course had to align bore the block.
he was bored with making expensive machines designed for killing people! LOL.
that engine engine dynod over 1000hp in late 1964, dyno gave up and stopped data info!
i wish i had pic of custom forged custom pistons, almost half piston top for a tight squish, matched to wedge chamber!
it had 1 st yr of New CRANE cams Billet alum. needle rocker arms, and the most unusual roller cam setup from HERBERT cams Calif. the lifter bodies had some type coating on them(light yrs ahead of where we are today).
lot of other mods i have forgotten !
lately i wonder where that engine is today, OMG hope not a scrape yard!
ron
speaking of pistons , pic made by Cosworth for TWR , XJS racing program!
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for you guys trying to catch up with yesterday, hope this Video comes thru?? its about fuel injection ITBs.
nope no go! how can i load this vid, without going thru a bunch of BS?
ron
K ,pic of my small diameter converter , 10" dia., 700R4 overdrive, 40% lighter rotating weight, than the T400 12" dia.!
throttle response is encredibley quicker!
ron
Somewhat similar to the pistons in a P6 Rover: I’ll see if I can find one to snap a happy of.
WIGS i s that Rover engine the one related to the GM BUICK engine?
ron
No: that’s the 3500 (215) BOP engine, of which I have 3.
The Heren chambered pistons are in the 2000/220O 4-bangers.