The goopy oversized seals sound great for my next rebuild. I'm curious on how people have achieved the proper machining at the base of the seal. Was it by just using the file on both sides of the apex seal and blending it in with the tip clearance?

I'm a little concerned about the final finish also. I have not seen any information on good tips to use these seals. Any help would be great, thanks!

 

they come with a feeler gauge and you literally sit there with the rotor on the coffee table and file away at the rotor slots trying to square them up as best as possible till you get a comfortable fit with the gauge

it takes a lot of time and is hard on your hands and wrists and the end finish will be determined by your patience

if you are concerned about it moving around then you can form a jig to hold the rotor like a snooker table triangle

 

i am a big fan of Goopy apex seals as well as the oversized option. back in the dark ages if the apex seal to groove clearance was sloppy we generally switched to 3 mm seals.

typically, a groove that is sloppy is around .004+.

a 3 mm seal is about 10 times the fix widthwise. what is needed for a fix is an additional 4 thou thickness, not 4 hundredths of an inch, w all that additional mass hammering against the rotor housings...

kind of like using a 6 pound hammer to swat a fly that is perched on an expensive table. (your $864 retail rotor housing).

in addition, there are significant challenges as far as machining the 3 mm groove. not only does it need to be the correct width to the thousandth but it has to maintain the exact centerline as the original groove. i see lots of hack jobs. if you go the 3 mm route be extra careful as to picking someone to work on your $709 retail rotors.

bumpstart is correct that it does take time to custom file the groove. typically you are looking to do a thou or so and you also have to do the corner seal. primary tip is clean your file(s) often.

the plus is that you can end up w really nice tight clearance... around .0015 to .002. it is valuable to have a fixture for the rotor and corner seal so you can pressure the file.

there are two file options, fine and medium. i think you need both.

i congratulate Goopy for coming up w the solution to worn apex seal grooves and run them in my personal motor. i also use Goopy seals standard or oversize in all my current builds. i really like the corner design and the fact that they tend to bend not break.

break = $$$$$

howard

 

Thanks for the info guys. I'm a bit of a rotary rebuild engine newb.
I'm wondering if I should be filing all the way to the bottom. Would the springs have any issues if they had a slightly oversized width? How deep does an apex seal fit under full compression?

 

Look at it this way,if it bounces up into the groove for whatever reason, you wouldn't want it to get stuck in there.