I saw alot of info on boost and apex seal selection. Anybody running any hard core doses of the laughing gas? Whats a good choice for apex seals on a full bridge 12a with say a 150 shot of the juice? How do the carbons hold up? The atkins? Ito..help!!!



Jay https://www.nopistons.com/forums/pub...R#>/unsure.png

ask judge ito...... he would know, he posted a 620hp no boost rotary

Thats phuckin sick.. how much squeeze? https://www.nopistons.com/forums/pub...1047683894.gif

I have used Atkins Rotary apex seals for nitrous oxide engines with great results. The trick is to make sure you give the apex seal enough room to expand and grow as the Atkins seals will expand and grow under a serious engine load. If you don't give the apex seal room to grow they will get jammed inside the rotor groove. Make sure you pre-mix all the time.



Do not run your nitrous oxide in the lean side. Atkins apex seals don't like lean conditions to much. They will curl up like a banana if you run your n2o on the lean side.

Ignition timing is very important to apex seals reliability. Don't forget to Bevel your exhaust ports. Atkins apex seals could handle the 150hp your thinking of using on your 12A with no problem if you tune right and build the engine right your going to have alot of fun. good luck.

Judge



Thanks!!!! It is nice to know I am not as insane as some think!



It is interesting that you make the comment I quoted here. My last engine lost compression due to this very problem despite having 2 "BRAND NEW" perfect spec rotors. (The rotor slots were measured and spec'd out to the minimum end of OEM recommendations). Unfortunately, for me, Atkins did not provide the information that their new fabrication seals had a larger coefficient of expansion and required additional clearances. I am glad to hear that you have good luck with their seals (for your sake and those who fly Atkins motors) but, in my case, their customer relations were unacceptable.



Note to all: Take the Judge's word for it and believe that you need to be very careful in providing sufficient slot thicknesses. I wish I knew this about a year ago.

Atkins did not provide me with any information as far as metal expansion. I had to learn with trial and error. Since I'm a quick learner, it only took me one engine failure in my race engine to figure it out. Once you take into consideration that this apex seals expand a bit more then OEM apex seals and adjust apex seal to engine clearances, Atkins apex seals work great for N/A and nitrous applications.



For turbo application I saw early failures due to higher exhaust gas temperature that a turbo engine creates,Atkins apex seals do not like high EGTs. But for N/A and n20 engines they work great once the engine is built to work around the expansion problem.

https://www.nopistons.com/forums/pub...#>/biggrin.png thanks for the info ito.....question though, how much additonal clearancing are we talking about? Also which way? Sides of the apex, an length?



Thanks again