Camshaft - valve hits piston

[hbrand]

To prevent the exhaust valve from hitting the piston, I had to set the valve overlapp to 35mm instead of 67mm. Cam is 911R. number 901 105 103
What consequences does this have to the performance of my 2.8 high performance engine?
Dyno test right now shows 180 HP on rear wheels.


thanks, harold

[ChrisBennet]

Do you mean you used 3.5mm for the setting distance instead of 6.7mm? That change would retard the cam timing and move the torque peak up the power band wouldn't it?
-Chris

[camgrinder]

Should kill the midrange torque and move the powerband up.
3mm is enough to kill the power all over the band.
I would be curious what a compression test says...