Here’s the actual specs on the 355vlad01 wrote: ↑Tue Jan 02, 2024 7:24 pm Yeah I've done this tuning with a decently large cam on a 355, the COME manifold was a step backward in every way compared to the banana, even though logic said it should have performed better, at least at the top end. But it gained nothing there and lost everywhere else significantly.
Iirc, it was about 235@ 50 on the duration, somewhere mid to high 500 lift and 10 ish odd comp. It made the same power as Gareth's ecotec with arguably a lot more mods, but on a smaller 228@ cam and 540 lift cam and at lower rpm too. But interestingly the eco ran banana manifold and good heads, alloy ones with extensive re-work done here locally (as cast they were pretty bad, lots of mistakes). Both made around the 210 rwKw, the v8 was at I think 5600 rpm the eco was at 5000 rpm. Torque was higher on the eco iirc hence the same sort of power but at a lower rpm. The comp was crazy high though on e85 but not anywhere enough to account for the difference in nearly 2L and making it at a lower rpm and a smaller cam.
Also it's worth pointing out that the holden 8 has a notably larger cam per specific output than most engines used in our cars, which tells me that the heads are most likely the issue. It's also odd that the intake lobe is larger than the exhaust which tells me there could have been some band aiding done to try to improve some deficiencies.
It’s not actually a 355 as it’s running std bore still, only thing that’s been done to it is slightly more comp which is 9:2 and a baby cam, no where near the specs as quoted. It is basically a std motor, that’s why the come manifold never did anything. I have been collecting parts to make it go better and auto the manifold so stay tuned.. pic of cam card for reference
. That and heat soak. I did get the blower manifold on my one tonner ceramic coated. It was supposed to have come back with the industrial heat insulation coated on the underside (it’s a mission brown colour) to reduce the oil splash heat transfer, but they ended up just giving it the “appearance” coating which I suspect is just that, and less about heat. Water injection could work too but the water would displace some air flow and its more weight than the gain I guess too. And bonnet vents too, but I’ve never seen any that would suit a Commodore other than the Lotus Carlton ones. I do remember seeing some Mercedes Actrol truck vents cut into a bonnet and they looked ok, but wouldn’t do it on my car. So not many viable options to keep them cool.