raldo

Hi guys...when te rotor apex slot its too big whats hapen?...any compresion loss ..any strange noise from carb?...what affect that issue?....thanks...

fendamonky

iTrader: (6)

When you say "too big" what exactly do you mean? Do you mean that a slot is slightly outside of factory specs, or do you mean trying to make a 2mm seal work in a 3mm slot?

Gilgamesh

Goopy makes slightly oversized 2mm apex seals.

peejay

Oversized apex slots destroy rotor housings with chatter wear. Given that rotor housings are far more expensive than any other part of the engine, in 2017, it makes sense to just buy more rotors until you get some where the apex slots are in spec.

Howard Coleman

iTrader: (6)

"Oversized apex slots destroy rotor housings with chatter wear. "

correct.

just so there is no confusion on this, it is the apex seal to groove clearance being too sloppy that causes chatter.

since you will find almost no used rotors that aren't splayed at each end approx .006 it is lots easier to use Goopy oversize (+.004) apex seals. a Swiss file a bit of work and you can be looking at .002 across the slot.

presto, a tired rotor becomes likeish new.

don't forget to open the corner seal slot.

peejay

I have a hard time finding 3mm seal rotors that are in spec. 2mm seal rotors can usually get me .0025 clearance. I did have a pair that ran with Atkins seals that got dust ingestion that severely wore the apex seals thinner (down to 1.6mm in spots!) and the extended corner piece managed to beat the rotor slot out *in that one section* to .004" gap with a new seal slotted in place.

Goopy seals worry me for rotor housing life... actually pretty much all seals advertised as being "detonation proof" worry me for rotor housing life. It'd be nice if the MFR apex seals were available oversize, the carbon-aluminum seals were very chrome friendly.