When i toured nissans facilities in 79 I had access to the works dept.
As i was leaving with a heap of gear, including a new FIA head,
I noticed a guy porting a head in a sealed glass room.
Asked my guide if i could enter, your pass ok he said.
Porting heads was my forte , so was super interested to see what was being done.
He was porting an FIA head ( the early one like in the pic.).
Heaps coming out of the exhaust ports.
I watched for while as he finished roughing out, and I had seen what i wanted, I asked why is he porting
a new FIA head.
The guide asked the mech & the answer was . : The factory always must have advantage over privateer.
So guess what I did?
BTW both early & late FIA heads ( had a few) Measured intake ports were the same.
main difference was early had 45mm inlet valves 35 exhaust & late ( smaller
) 44mm, but larger exhaust 36mm.
I found the torque under the cam with the ported erly head was very good.
When on transport stages or driving in traffic, i would shift 1 3 5, skipping 2 & 3.
When you have a 2.3 first & 1:1 fifth the massive ports & 48 webers come into their own.
Competitive stages would never see you under 6K in any gear.
My max effort & best L series race heads were done on new 200B LPG heads.
40mm intakes for customers heads & 41.5 for my own.
The bigger ports were a bit iffy & if I stuffed up , it was my own fault.
My favourite was the FIA head,and still is, they just needed porting.
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"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT