RB26 Valve Guide Clearances

[Sileighty_85]

Alright so finally got around to measure the Valve Guides in the head.


They all varied from .40-.60mm
http://i73.photobucket.com/albums/i235/Neil_85/GTR/VG_zpsobxxtopg.jpg


So the FSM says you half the number the number so it would be .20-.30mm


But the allowed limit is .10mm


So according to the FSM looks like these VG are way the hell outta spec.


http://i73.photobucket.com/albums/i235/Neil_85/GTR/VG2_zpsaxxc6ryj.jpg




0.10mm is really tight. Tighter than what id expect for the exhaust side.


I keep reading online (very few threads on this) that there is normally a lot of play in the exhaust guide due to thermal expansion. (make sense) but I guess with the Valves being sodium filled its suppose to help with heat transfer, Mainly away from the head to be absorbed into the stem and then transferred to the VG/Head.


But the FSM show the IN and EX guides have the same clearance spec, and the intake is way more noticeably tighter and closer to 0.10


SO my question is does anyone know what the clearance is on brand new VG's for the RB26? Is it really less than .10mm Anyone ever replaced and measured?


I plan on replacing the VG anyway with JUN VG but wanna make sure that the .10 clearance is correct.
I know it must be since its the FSM but wanna triple check before I do all this work and find out it was too tight and have the valve seize in the head.




Would like to limit responses to ppl with first hand experience and not what ppl have heard.