I have not found 3mm seals to cause a much greater amount of wear than 2mm seals. With 3mm seals you must run premix. The stock oil metering system does not distribute enough oil to cover the surface of the larger 3mm seal. This is why I believe there is a misconception that the 3mm seals cause more wear.

 

they cause more wear because they cause more wear, lubricating the whole area vs just a smaller middle area cuts back on the wear drastically but the rate is still the same from 2mm to 3mm.

for the RA seals not causing damage, i would have to wonder why dozens and dozens of people say they have experienced excessive wear on their rotor housings. unless they were running the engine with no OMP and no premix then the ONLY possible cause is the seals being non conductive or too heavy or both. i don't doubt many people have had success for years with the seals but you can't rule out that the supplier for those seals has had some bad runs of them, which some builders may not have gotten their hands on and that can happen again.

Atkins has had similar response with people showing abnormal wear, i just don't see smaller shops never running into issues of getting the mix wrong and shipping out faulty seals. OEM isn't exempt from it either but i would have to certainly say that the % of getting some bad OEM seals is far less than from an aftermarket supplier.

 

i only run the ra classics in al my builds and costomer builds i ave tested them and detonated the **** out of them to try to break them and nothing they are amazing. i also run premix for better lubrication due to the theory of them wearing housings down faster so it just helps. put it this way they were originally made for a airplane and what do you think happens to a airplane made out of crap parts lol well DEATH. so you can only expect the absolut best from original parts for airplanes.

 

I decided to go with the super seals. As stated before. If people trust them in airplanes they will be fine for my car.

 

I'm running the 2mm RA super seals in my car and I'm at 5k miles and counting (daily driven).

On a side note, even with my ported motor I'm still running -400s vacuum at idle, which is only slightly lower than when my motor was stock port.

 

Good to hear all the positive feedback on the RA seals, makes me feel better about the few motors we've built with them installed .

 

I put down 420 WHP at 15lbs on my seals no problem and have been running them for about 15-20k miles now. I think the side seal springs are going though, having lots of blow by. If/when I decide to give the engine a refresh, I will post how the seals are holding up. I don't have compression numbers at this time.

 

Any more input? Great thread so far.

I'm considering installing the RA 2mm super seals (along with solid corner seals) in my personal build based on the testimonials I've read here....

 

I just built a motor and reused my 2mm RA super seals which had about 4k on them (and half a dozen detonations) because they spec'd out very well. The motor has built compression very quickly and now with a large street port is pulling about 15 inches of vacuum at an 850rpm idle with only 120 miles on it. It has always started right up and never flooded.

I have:

-- Good condition (no chrome flake) used housings
-- all brand new OEM springs for everything
-- brand new OEM side seals and corner seals hand clearanced to 2 thousandths

 

I don't think that's correct. Look at it from a scientific point of view. The 3mm seal (due to it's extra width) will have more contact with the housing. This will naturally make the contact surface area larger at the point of contact. You spread more weight over a larger surface area, you will decrease the pressure at any given point. So theoretically a 3mm seal should wear less. The early 1st gen GSL-SE 13b engines were all 3mm sealed engines. These engines would easily last 200,000+ thousand miles. The only real problem with the factory 3mm seals is that they only use 1 apex seal spring. With only one spring all the force is exerted towards the seals ends which leaves the seal unsupported in the center. This is where all the excessive wear is coming from. The 3mm needs the center support of the small spring to help distribute equalized force across the entire seal. However know one makes a small 3mm spring nor are they machined for it.

 

My 91 vert now has 33k on the classic 2mm seals. Compression does seem a little bit weaker recently. I don't have starting issues at all. My OMP doesn't work so I premix. But really I don't premix as consistant as I should. My 20b project is nearing completion, so I'll be pulling this engine apart shortly for inspection. I'll be sure to post b4 and after pics as I have saved the pics of the housings from when I previously rebuilt the engine back in 05.

 

I used the RA supers in my T2 and i ran my car hard everyday. Cracked four rear plates from tuning issues and completely destroyed a motor by letting my buddy do a 9k rpm burnout til the motor ate itself. Font bearing let go and everything was trash. I had metal shaving sludge in my coolant hoses.

Took the motor apart and all the seals were good. +1 fo the RA super seals.

But im trying ALS in my fd build.