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Oh so long since the last update… I assume you’re driving the wheels off it by now?
I thought copper tubing was extremely prone to stress fractures when subject to vibration, doesn’t it go brittle when repeatedly flexed?
Yep, seems to be fixed now, thanks to all concerned!
Andrew
I’m still getting this error right now…
Yep, definitely worth the money for an SFI-approved bellhousing if you’re gonna be doing things like that… cheap insurance!
Should “move” to SA for the build. No BS weight vs capacity crap here
Until you guys adopt the National Code Of Practice (NCOP) that is, then you’re screwed!
AFAIK, only SA and NSW are still holding out on using the NCOP, all the other states have already changed over, but then NSW sucks so bad that I sometimes think we’d be better off with the NCOP anyway?
You certainly need at least one port in each head “vented” because the coolant outlet (to the radiator) on all LS engines is down in the block, well below the level of the cylinder heads. If you blocked-off all the steam ports you’d have a massive pocket of air/steam trapped in each head.
And as you say, there are pros & cons to venting all four ports.
Some say, depending on driveline angles etc., that air can still be trapped in the back of the heads if only the front ports are vented, GM originally vented all four ports in the early motors then started blocking off the rear ports later, I’d guess to save production costs?
Also, these ports do flow a small amount of coolant all the time, they’re not just bleeding air, so depending on the plumbing these ports can bypass the radiator (if say connected to a header tank) so you don’t want very much flow through these lines. They are usually just a small 3/16″ line (-3AN) or 1/4″ (-4AN) at most.
Another thing to consider is the circuit of the coolant as it flows through a motor, cooled coolant goes into the water pump from the radiator, is pumped into the front of the block, goes past all the cylinder walls to the rear, then up into the cylinder heads, forward past all the combustion chambers/valve seats/exhaust runners, and finally back out the front to the radiator.
As has been physically tested on an LS motor (on the Holley forums), if you install a temp sensor in the front and rear of the cylinder head, the rear will run around 63°C while the front is at 85°C, as most of the heat is actually generated in the combustion chambers.
The upshot is, bleeding-off cool water from the back of the heads will also reduce the effectiveness of the cooling system, only a small amount I’ll grant you, but when you’re chasing every last horsey…
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This reply was modified 7 years, 4 months ago by
Andrew.
It connects all four steam ports in the cylinder heads (which prevents air being trapped in the cooling system).
But good luck convincing Mr Plod of that on the side of the road when he sees “Nitrous Outlet” printed on the manifold!
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This reply was modified 7 years, 4 months ago by
Very much agree with @gtrboyy, reinforcing the upper arm mounts is an absolute must if you plan on launching the thing hard.
Think of it this way, the lower arms are basically responsible for driving the car forward, but whenever you see a car lift the front wheels off the deck, remember that it’s the top arms doing all that lifting!
The upper mounts must be strong enough to carry the full weight of the car from the rear axle forward, times whatever the leverage of the fulcrum effect is (so adding 1 kg to the very front of the car is worth like 10 times as much force on the upper mounts).
Andrew
~ One on each drum I assume.
If you have both rear drums fed from a single master cylinder port then you only need one RLPV in that line (somewhere before the T-piece on the diff).
If you have split circuits for each individual wheel then yes, you will need one in each line to the rear drums.
And I’m happy to hear it, but what IS the way around it? I really want to know. Everybody keeps telling me there is a way around it, but whenever I’ve asked an engineer I get the same story, refer to the table.
BTW, vehicle manufacturers don’t have to comply with a COP for “modified vehicles” as their vehicles aren’t modified, but they are subject to destructive testing which wouldn’t be too popular with most resto guys!
Thanks for that, the weight is taken from the factory figures for the heaviest sedan variant for that model, I asked about weighing my own car but was told no because it’s too easy to add weight and up the capacity.
Even at 1600kgs (x3) that still only allows you a maximum of 4.8L supercharged, so I still can’t work out how he’s able to approve a 6.2L supercharged V8?
I don’t mean to be argumentative (apologies if it sounds that way), I would just love to find a way to get around those limits myself, but I’ve been told that the table pictured above is gospel and I’m not allowed a cubic centimetre over.
I know about the ICV loophole, where you do not have to comply with the NCOP for Light Vehicle Mods, but then you do have to comply with all the current ADRs. Not such a big deal for a later model car but I’m dealing with ’70s and ’80s models so a lot of extra work.
G’day all, just joined up especially to ask about this build as we were discussing a similar concept over on the JC forum.
If this car is to be registered in Victoria, which is now under the NCOP, how are you getting around the maximum capacity limits specified in “NCOP3 Section LA Engines”:
Maximum weight for a VS Commodore would be 1477kg (I think) so the maximum engine capacities that can be approved would be:
Normally Aspirated: 1477 x 5 = 7385cc (450.7ci)
Forced Induction: 1477 x 3 = 4431cc (270.4ci)As the supercharged LSA engine is 6162cc (376ci) capacity, which is way over the NCOP limit of 4431cc, how are you getting around the limits?
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This reply was modified 7 years, 4 months ago by
