[flatspin911]

I am building a 3.2 short stroke (using JE 10.5:1 98mm pistons) on a 3L case and want to use a Webcam 171e cam. The purspose is a track only car. I will be using Weber 46's.

The timing spec from Webcam for the 171e cam is 6.2 to 6.5mm at overlap.

I've installed the cam and checked Piston to Valve clearance.
The exaust valve to piston clearance range from
1.0mm to 1.5mm Cyl 1-3
With timing set to 6.5mm
I am using racing valve springs but I am still concerned this is very close.

I can advance the cam to 7mm and get 1.5 to 2mm of clearance
and advancing the cam to 7.5mm gets me 2+mm of clearance on exhaust.
At this point the intakes are between 1.5 and 2mm.

So my question is about tradeoffs.
I can make this cam work but at 1mm advance over max recommended.
My other option is to stay with the cam spec of advance and then shim up the cyclinders. But I would give up CR and not sure I want to do that.

What am I giving up with this amount of advance?