Discussion and questions related to the course Practical Engine Building
Currently doing a 264' cam setup on a rb26dett out of a r32gtr. Need to know what are the recommended valve clearances to use, the stock clearances i found were someting like .018" intake and .015" exhaust which i found strange because i know exhaust always run a wider clearance. Any assistance will be appreciated. Needed asap
Use the clearances that were given with the camshaft(s), unless you are really experienced and know what you are doing. Different grinders will usually use different clearances, often for different grinds for the same engine.
While it is common for exhaust clearances to be greater, they can be the same or even, as may be your case, wider for the inlet. Using the wrong clearance will either unseat the valve earlier & later than intended, or compromise the clearance ramp causing excessive 'crahing' of the valve train.
Its a pair of hks 264 cams. I was just called to sort them out because they were given to the customer, but i guessing id get the specs online... right now most of them are tight so i was just looking for a general clearance i should use
All the information I have found - which isn't a lot - specifies the OEM clearances which have more for the inlet, as your figures show.
If anyone can add to this?
niceness well i guess id jus go with dat
As valve clearance relates to thermal expansion and valve seat degradation rather than valve lift I would suggest going with OEM but make sure the value you use is verified from a workshop manual not just forum/internet conjecture.
You might find that if they’re all tight it could suggest he valve seats are becoming worn or the base circle diameter of the aftermarket cams is larger than OEM.
Yeh there were lots of workshop manual posted on the forums