Okay first off yes, I am a tight wad. But more than that I am a person who likes to look at all perspectives, and reasonings of things, in order to get a better understanding. So with that now stated, has anyone ever re-used apex seals? Under a magnifying glass mine look fine, just some scuffing on the sides that enter the rotor slots, the edges which seal to the housing are smooth as a baby's butt, and are chrome and shiny, with no damage what so ever to either 2 pieces. After cleaning them with mineral spirits they look almost new to the naked eye. Do apex seals get weak after being used? I imagine they would since they are subject to all the revolutions caused by the rotor. What chances if any can be attributed to using them. I highly doubt I would since all the troubles of rebuilding, but none the less would be pleased if someone could answer my questions.

THanks in advance,
Loren

 

did you measure the height? new is something like 8.5mm and they will get down to the 5mm range before you need to replace em.

i have reused without trouble, but in an na race car the apex seals arent the reason the motor is torn apart.....

 

The reason mine was torn apart was because two off the side seals got stuck by carbon, and the reason for making low compression, probably the pitted housing didn't help either.

 

Why? You have the motor apart why put used parts back in? I always use new seals/gaskets etc. from front to back. Don't be a skin flint, especially with this car... it'll bite you.
BTW: Apex seals get brittle after use.

 

Can you? sure. I've done it before. It depends on the circumstance. For instance, if you tear apart recently rebuilt or very low mileage engine for a port job or other issue not related to seal damage. You can complete the other work, reinstall all the hard seals in the original orientation, and not have any breakin or change in compression. The only way I'll do this is if

a) the engine's compression was accurately measured beforehand at 110psi or better.

or

b) the engine's mileage was documented at 25k or less

or

c) the apex seals can be spec'd to .305" or greater (a new seal is usually .330")

And I will only do this when reinstalling the apex seals in their original positions...the front 3 seals in the same rotorhousing they came out of, and the rear 3 seals in their housing...even if housings are reversed or something. The housing has certain wear patterns, and the seals are worn to match these patterns naturally. Every housing is different, and changing the relationship of the seals to the housings makes you lose a lot of compression and makes for a long breakin...both of which negate the purpose of reusing the seals (new seals would have been better, since you have to break them in regardless).

In honesty, on a car so sensitive as the FD, why would you try? Seals can be had for less than $200 these days...that's less than the 8 tanks of gas you'll need to break them in properly.

 

Thanks again, Kevin that is just the information I was looking for. I was just curious, about how they affect compression. ANd obviously they do as you have mentioned.

 

Yeah, the apex seals are hands down one of the big wear points in the engine. I've seen TurboII seals that were fully 1/3rd smaller than a brand-new seal. It is a good question to ask!

Other seals, like side seals, wear VERY little.

Dale

 

I find that being too cheap costs me more in the long run. I would not be too happy if I paid for a rebuild to find out the builder reused apex seal....regardless. So I'd rather not take that chance.

 

umm ok, im prolly gonna get heckeled or scold for this but uh...when u take out an engine to work on it (for the FD) u take it out by hand or do u need like a cherry picker or sumthin? cuz i hear about workin on this engine a lot

 

You are a serious badass if you take it out without a picker..

Sure it's only ~300lbs or so, but it's not exactly easy to get the right angle on it to pull it.

I carry the shortblocks around all the time.. But that's different.

 

I know people who have stripped the engine totally down to the shortblock and pulled it from the car by hand, so to speak. One used a 2x4 and a chain, the other used a chain and the driveshaft from the car .

It's a WAY better idea to use an engine hoist. Even if you don't want to buy one, pretty much any decent tool rental place will rent you one for a reasonable fee. The chance of something going wrong and the engine falling on the car or yourself is just too high.

Or, you can do it redneck-style - a comealong and a big tree .

Dale

 

sounds like a really nice workout..how do u all know what to do when u hear sumthing wrong with the car..it seems like u always know where the prollum is, why, and how to fix it..are you all mechanics? because if i had a prollum im kinda like "oh uh" *opens hood* (scratches head) "looks ok to me" (blown engine)

 

Unless you're rich and have 1) the money to pay shops for repairs and maintanance constantly, and 2) time and other vehicles to drive during downtime, you pretty much need to learn the ins and out of the car and it's systems, and do your own repairs and maintenance, if you own an FD, or an rx-7 in general.

 

Kevin,

I was once told by someone who should know that "apex seals get brittle with age" meaning for example that seals with 80,000 miles would have a higher chance of breaking than would a set with 0 miles. Based on your experience does this sound plausible?

 

It depends on boost/tuning etc. They start getting brittle around 50,000/60,000 miles. On normally boosted engines (stock) it's not much of an issue but on a higher boosted car it can be an issue, a big one.