fully_bodykited_s4

What is better for a 13b turbo engine (Turbo II) 2mm or 3mm. And why what are the advantages and dis advantages for both?
Any info please

bureau13

The real reason rebuilders sometimes use 3mm seals is so you don't have to buy new rotors...with used rotors, the channel in which the apex seal sits can become worn, so they enlarge it a bit more and put in 3mm seals. Technically speaking, they're probably marginally stronger, but in the face of detonation, insignificant. I've heard the 2mm seals with new rotors would be the best choice in terms of compression, etc but Pettit used 3mm seals and the old rotors on my engine (3rd gen) and it works great.

Actually...you said TII...did 2nd gen motors come with 2mm or 3mm seals? If they came with 3mm seals, then I can't see any reason to change, and I can think of a number of reaons why you couldn't change...would 2mm seals even fit in that case? I'm not sure what they would do about worn apex seal channels in that case though...do they usually have to use new rotors with 2nd gen rebuilds (if in fact they used 3mm seals stock).

jds

MAZMAN

TII motors have 2mm seals standard

Scott 89t2

2mm seals will take just as much boost and will seal better (more power) but 3mm seals will take a ping or 2 before blowing up to help if you screw the tuning up.

fcturbo2

Obviously 3mm is better. But i've heard over the years that alot of machine shops cannot cut the groove perfectly therefore resulting in poor sealing of the new 3mm apex seals. The only rotary engine i know that has factory machined 3mm grooves are the 84-85 gsl-se.