Drifter93

You shouldn’t have to worry about putting 3mm apex seals in as long as you have a good tuner, tuning your car for you. All the 3mm seals are good for is withstanding a little bit more detonation then the 2mm seals would. So all in all tuning has a lot to do with it and also keeping up with regular maintenance such as making sure you keep your plugs clean, having a good fuel filter, good fuel injectors and stuff like that.



Good Luck.

BDC

Me and a buddy (Tony) ran 25psi of boost on a Ser 5 13BT with the 2mm 3-piece apex seals. Ran just fine. The issue is tuning, both fuel _AND_ ignition. Most people don't stress that enough but ignition timing control is probably even more-so important (and detrimental) to the life of the engine under load.



B

bigbignacha

has anyone tried these guys

http://www.rotaryaviation.com/2_mm_apex_seals.htm



this is what they claim

These seals offer 700% more bending strength and are 85% harder than the current after market competitors (Atkins and Hurley).

j9fd3s

it doesnt matter, detonation is almost 100 times stonger than normal combustion, it will break anything you put in there

kahren

amen

Kathy Atkins

We are using 3mm in all of our turbo engines, they can take a little more abuse. We charge 300.00 for the machining of the rotors, and we use a CNC Mill that is dedicated to just the milling of the rotors, so it is very accurate.

RETed

Waste of time...



Milling of apex seal grooves are suspect.

The apex seal grooves need to be proper clearance.

The apex seal grooves need to be at the perfect angle.

Stock apex seal grooves are hardened - are the milled 3mm grooves hardened?



Serious detonation will break 3mm seals almost the same as 2mm seals.



There are tons of big power 2mm apex seal engines out there.



What's the secret?

As everyone else has said, proper fuel and ignition timing (and intercooling) will minimize chances of detonation.





-Ted

Kathy Atkins

Waste of time... Not allways...

Milling of apex seal grooves are suspect.



In some cases Yes, but it is an acceptable builders practice to use 3mm in turbo applications. In some cases the groove maybe out of spec's, if the client is planning to use hi boost and not properly allow the apex seals to seat, or known to to tweek it a little more it can add some benifits



The apex seal grooves need to be proper clearance.



Very True. We list the acceptable clearance on all of our 2mm apex seals as they have the most wear and are susceptable to "mushrooming" at the tips due to the 3 piece style stock apex seal.



The apex seal grooves need to be at the perfect angle.

This is the very reason that we have a dedicated CNC mill for just 3mm processes



Stock apex seal grooves are hardened - are the milled 3mm grooves hardened?

not allways, but most if not all 3rd gens are. Before that I don't recall any that were, any time you change the surface of a hardened surface you will most likely change the degree of hardness. But you should consider the reasons for the hardness, was it because of the 3 piece design that the engineers made the design change? Did it prove effective? they are both questionable.





There are tons of big power 2mm apex seal engines out there.

Very True, we have some of the fastest and most abusive racers out there using our seals. Do they expect long life? Do they plan to change the seals every event? most do change the apex seals every event as 1 hp difference can make the win.



My 2 cents is that there is not an absolute rule to the use of 3mm or not. if the grooves are too beat up, then yes it's the least expensive way to go. If you plan to use new rotors then 2 mm are the way to go. But there is alot of room for the in between, driving styles, fuel styles, turbo or no turbo all add into the equation. Check with your builder to see what they advise, you are spending good money with them and they want you to have the longest life with that rebuild since it shows (in some cases) the quality given to the job and project

Sorry if this was a little long, but I thought several things should be addressed in more details, and I am not trying to offend anyones position.

Kathy Atkins

Maybe we can get some of the professional engine builders to give their yeas and neas and why since they would have the most experience. I think this is a great discussion, and bringing out good reasons for and opoosed is a way for all of us to learn.

BDC

I'm not sold on 3mm although I've used them in the past and will use them again this next go-around on my personal engine. I think what it boils down to is weighing the advantages (stronger seal, more insurance for deadly engine knock) vs the disadvantages (apex seal chatter? less longevity of engine life?).



B