Hi to all,

I know this has been discussed before, and I've already done a lot of back reads of the threads and research in the internet.

But I want to know and want to get answers specific to the details below for more clarity:

Engine: 4g15 carb
Status of Radiator: Old/Newly overhaul/re-patched 2 times because of leak
Radiator Cap: Circuit, Silicone Type (daw) is 0.9
I bought another Cap which is federal mogul 1.1
Thermostat housing: Corroded yung kinakabitan ng hose and I see white powder sa connection nya sa engine.
Coolant: I used 2 liters of premix halvoline long life coolant, pinkish stuff before the overhaul. Now I'm running mineral water not distilled dahil yun lang avail after overhaul. I plan to use coolant 50/50 Peak brand mix w/ distilled but I'm opting to get brand new radiator at dun ko na lang gamitin.
Hoses: Looks old and I don't know the age since I got the car November 2013.
Water Pump: Looks old and I don't know the age.
Water Status: Inside the radiator I see glittery particles na parang metal shavings. It doesn't have oil in it so I know my head gasket's not blown. My mechanic confirms it.
Engine: Parang masyado mainit kahit 1/4 lang temperature. Firewall is hard to touch pag afternoon tirik araw, even the sides of the front strut mounts.
Radiator Fan: Rekta Fan
Thermostat: None
Thermoswitch: disabled or sira na ata kaya hindi na naka-connect
Temp Sending Unit: Replaced / Bnew

I have full service manual of the engine and here's the book says:

Radiator Cap
Main Valve opening pressure = 81.4-108 kPa (11.8 - 15.6 psi, 0.83-.1 kg/cm*)
Vacuum valve opening pressure = -6.86 kPa (-1.00 psi, -0.07 kg/cm*) or less

Now here's what I need clarity:
I read that increasing the pressure increases the boiling point but make sure there's no weak points in the cooling system.

I used 0.9 after the overhaul but I read na 1.1 increases boiling point.

Now based sa specs ng book I'm allowed to use 1.1, but based sa nabasa nyong status ng cooling system do you think I should stick to 0.9?

Thanks in advance.