I have some apex seals worn past the suggested reuse limit.
3 are about 6.95 in height.
3 are about 6.75 in height.

If these were to be used, how many miles could I get out of them?

It's a budget build so please don't just tell me to buy new ones, thanks.

 

Isnt the limit 7,5 MM? There is absolutely no reason to bother taking an engine out, tearing it down, and rebuilding and not replacing the weakest part of a rotary engine. Get the Atkins seals for $200!

 

Wear limit is 7mm. and I've pulled apex seals that are around 5mm before.
I was wondering if anyone knows approx. how many miles you get per mm of wear or like I said before, how many miles you think I could get out of the seals I have.

It's nice to know you can read locopr1.

 

Dude i hear yah on the BUDGET issue. But wouldnt it suck to get it all together and it dosnt run or last only 200 miles. Go donate plasma or soemthing and get the seals. But if i where to guess i would say under 5,000 miles depending on how you drove it. But again is it worth trashing some houseings to find out????

 

its nice to know your a dumbass waysrx7

 

Okay, I'm building this from some donated 12a's and the only thing i'm planing on buying is a gaskit kit (including oil seals).
It is so I can get some experience porting as well.
I don't really care how long it lasts as my investment is only the gaskit kit.
I don't have a tonne of experience but I would think 5k miles is a little low. I would guess closer to 10-15k or more miles.
Any other guesses.

 

i hear yah on this...trust me i do. But youre gonna have time porting and money in the gasket kit whats another 200-300 bucks for the seals. Then you got a totaly wicked motor

 

I don't feel like putting new apex seals in rotor housings that have a little chrome flaking, I'm talking about 2-3mm wide and a couple inches long on both housings.

I'm saving money for my 13b turbo incase you want to know why I'm being cheap.

 

I have to interject here. Forgive me if I am some what harsh on this.

You asked for information that no one can provide. When the member guessed at 5k then you state that it sounds low. Then you state that you guess that 10k or 15k would be closer?

It's all a guess period.
When you have metal components that are below the wear limit the wear from that point on is accelerated. Things like the condition of the housings and the oiling system also come into play. How the car is driven is another factor.

You won't know how long it is going to last until it fails.

I can relate with you being on a budget and all and wanting to experiment with porting but you are still going to spend money on gaskets.

Why don't you check with Kevin at rotary resurrection or Robert at Rotary shack and see if they have some used seals for cheap.

 

I can understand wanting to do a temporary 'budget' rebuild. To increase your chances of building an engine with fair or better compression #s, I would purchase/install new apex, 3rd gen coner and side seal springs. You can reuse the side seal and 3rd gen corner seal springs in the TII rebuild.

I hope you marked each apex seal as you removed them. Returning them to thier original position will do the most to keep your compression #s up.

 

Don't use any apex seal below 7mm in height.

 

Dont ask questions if the only answer you accept are the ones you want to hear. There is someone on Ebay that sells all the hard parts used (including apex seals) for 44 bucks. Just make sure they are within spec. I hear you on the cost but once you put all that time into it you have to figure that as a cost as well.

 

are they 3 piece?- OUT OF THE QUESTION!
if ya wanna be that cheap screw the gasket kit and buy rtv silicone in bulk. happy building.

 

3mm was never 3 piece, unless it's broken.

 

I didn't ask for opinions if I should replace my apex seals, sorry if I sound like a jerk but READ what my question is. I know I should replace them, that's why I didn't ask if they need to be replaced.

rx7doctor, I agree with everything you said, and I definately don't want to get on your bad side. I was hopeing a fellow forum member had also done a 'cheap' rebuild with seals that were 'close' to spec and could tell me how their motor lasted. It would be a guess on miles but it would be an educated guess.

Trochoid, Thank you for giving me info that will help my chioce in reusing these seals. I am going to use the 3rd gen corner springs.
Could you please explane the the difference between the side seal springs. I assume they're better, is it because they are a stronger spring?

True, very true.


Sorry if I have offended anyone, I was in a bad mood yesterday and felt like people were ignoring my question. If nobody knows then that's okay. I asked because I coudn't find anything to answer my question while searching. When I do get this motor finished (probably not for a few months as it just snowed today) I will be able to share with everyone here not to do this because my motor died 50miles down the road OR you can do it to have your motor last ???? miles.

 

locopr1 I just realized my reply to you wasn't the best, sorry.

 

I'll take a look in my parts stash. I should have 3 apex seals from a 12A (used). I would be happy to send them to you. Not sure on the wear on them, but if I find them, I'll measure them and see if you want them. I know that I do have 6 GSL-SE apex seals, but that wouldn't help you. I'll see what I can find.

 

Kent, how tall are your 13B apex seals? And what would you sell them for? I need to build a clunker for a friend that only needs to last a year (but not break apex seals) so he can pull it and learn to do a proper rebuild. Basically if he can start with a running engine, it would be a great learning tool so all he has to do is replace the parts that are no longer in spec, vs trying to build an engine from parts I have lying around (which is what I'm doing right now - the hard part lol).

I just picked up a shaft and rear counterweight for it yesterday.

 

Seal springs weaken over time/heat cycling, thus reducing compression. Afaik, there is little if any difference between the side seal springs and are interchangeable since thier length doesn't change between the 12A/13B rotors. Even if an engine is torn down to simply freshen it up, replacing all of the seal springs is always a good idea to help maintain maximun sealing.

Keeping track of where each hard seal came from, apex and side, and reinstalling them to thier original slot eliminates the need for the hard seals to wear in as in typical of a full rebuild.

If your housings were still good, I would not recommend reusing old seals.

Not sure if you're asking the question correctly about the side seal springs. The 3rd gen corner seal springs were redesigned. The older ones are a wire spring, the newer ones are designed more like a split lock washer. They last longer and hold up better to heat cycling.

 

Jeff,

I'll dig them out and measure. They should have good life left. I can't remember the miles on them, but wasn't a lot. I cracked the motor open to replace oil control rings and such and got a good price on some OEM apex seals, so I thought that I would replace them while I had the chance. As for price, I'd give them to you if you want them. They aren't doing me any good. I'd rather see them put to use than to just be sitting around in the garage.

Kent

 

waysrx7 : when you are ready for the parts let me know and I will give you the best deal possable....

Dan

 

learning something new everyday.

 

Kent, I'd love to get those seals from you. I'll send you a PM.

 

Here are some pics of one of them. Are they still good in your mind trochoid?

 

Interesting that your from Edmonton, where abouts?

I personally wouldn't re-use those components but like others have mentioned I can understand you wanting a budget build. Those housings looks pretty rough and I would never run them in an engine that I was putting together.