These are the two most used [by the factory] camshafts for volvo turbo redblocks.

The T is what we got in the US of A; whether we wanted it or not.

Most everywhere else got the A; until the greenies caught up there as well.

In this image, we are looking at the rear of the camshafts...to see the ID letter stamp. The T cam is drilled and slotted for use in a motor with a head mounted distributor. The A cam is not machined for head mounted distributor use: it was from a motor with a block mounted distributor.


The Sarah Project B230FT engine was equipped with the T cam. It will be converted to block mounted distributor: ease of serviceability and lower cost caps and rotors. That will also allow for an easy cam upgrade in the future; if so desired.

I wanted to know what the actual specs and dimensions of that cam are. And having an A cam to use as a comparison would show the physical similarities and differences; and hopefully shed some light on how and why they perform differently.

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These two camshafts are both "single pattern" camshafts. The intake lobes and the exhaust lobes are identical in dimensions.

These camshafts are also "symmetric" camshafts. The lobes have identical opening ramps and closing ramps.

Volvo did make some dual pattern camshafts, where the intake lobes were different dimensionally from the exhaust lobes. Examples are: the M, the H, and the VX.
I have not read any information anywhere to indicate that Volvo utilized "asymmetric lobes", meaning where the opening ramp of a lobe was different from the closing ramp side of the lobe. With this valvetrain design, I do not see any need to use asymmetric lobes; nor any advantage to be derived therefrom.