RS Aizawa ITB 1.6 - valve stem seals - improvements while in the head ?

[— kung fu jesus —]

I don't know if 1.8 VT components are lighter. I do know the 1.6 stuff has more specific orientations and placement. I also don't know if the FM stuff is ST, but it wouldn't surprise me.

Cams get tricky because I don't know the current specs on the regrinds and there is a fine line between drive-ability and performance if you start getting aggressive.

On the bottom, look into King racing main bearings or similar. I would be considering uprated con rod and main cap hardware (ARP) for "cheap" insurance.

I don't like a 3mm spacing on a 1.6, it's too fragile at that point for as high as you want to spin it. I wouldn't expect it to last long.

You should get solid numbers, like leakdown and compression before you start doing any of these repairs and upgrades. It's really useful data and helps you see where you have come from.

FWIW, my rebuilt 1.6 was built to survive track and street in pretty warm climates. After the rebuild and break in, I saw 210 PSI across the cylinders. Stock is about 190-195. The head was a mild port with gasket matching. I used a new OEM 1.8 BP oil pump shimmed because I had the long nose crank.

If you are going high RPMs, you are going to want to consider a blueprinted oil pump from Boundary. Those OEM pump gears aren't fond of those speeds for long.