RotaryResurrection

iTrader: (8)

We already know that all aftermarket seals are made of different materials that may adversely wear the irons or rotor housings. So aside from those, either you use stock "hollow" 2mm corner seals or you use the 74-75 mazda oem 3mm solid corner seals (depending on which apex seal you're running, of course) if you want to avoid that housing wear.

But you say, the stock seals will not handle the boost and will crack or break.

Well, something will ALWAYS be next in line to break. The question is, do you want to break big parts or little parts?

Well, here is how I look at it: I'd rather break a stock corner seal and lose some compression, find out something is wrong and tear the block down to replace some corner seals but have most major (expensive) components be reusable, than put in some "unbreakable" strong aftermarket seals and have those seals survive fine but trash all my expensive irons and rotor housings.

Seals are cheaper than irons or rotor housings in most cases.

BDC

Yep. I almost forgot we'd used the RA 2mm seals in it still then. Or it could've been that we got them brand-new then. I remember ditching them either later that year ot the next year in '05. Those are from the old, original batch that they came out with in late 2003 I'm pretty sure. Man how time flies. I used a set of those 3mm ones in my engine and they scored the rotor housings up in spots. Was very odd.

Yep.

Yep!

B

chino_rx3

iTrader: (3)

Rotary resurrections thanks for all the good info like always . My rebuild on rx8 has been good from the start thanks for all your information and knowledge I tell everyone with out your info correct info my car wouldn't be as perfect has its been . O counting miles lol sorry to hack and BdC seem some of your work before very nice . If I get a high HP engine in my rx3 I would love for it to last that many years that's what I'm looking for in the future .

arghx

iTrader: (3)

I like the "unbreakable" seals for the extra protection against catastrophic failure. It's fair to say that they wear more, but a lot of factors play into it. It's a tradeoff that I'm willing to make on turbo cars that see a few thousand miles a year and make a lot of power.

These engines were never intended to be used the way we use them. Something's gotta give--catastrophic failure or accelerated but steady wear. On a heavily modified turbo engine, I'd rather it scratch the hell out of the housings over time then pop suddenly from a failed apex seal. Catastrophic failure is disheartening and makes you want to give up on the car; wear items are wear items, and they can be planned for. Since there are very limited options for knock control (spark retard), IMO you need that safety margin on the apex seals, at least if it's a pump gas only build.

People drive these cars so little when they get heavily modified that they can go for years and years on used housings + "unbreakable" seals + conservative tune. This engine lasted almost 7 years! How many times do you hear about people popping an apex seal in less than 7 months?! And half those blown motors are due to something totally stupid like an overboost. You need redundant methods of overboost protection (retarded timing, extra fuel, boost solenoid cut, fuel cut).

N/A engines and near-stock turbo builds are a different story though. "Unbreakable" seals when you have stock boost levels and some exhaust is a lot harder to justify. I totally see where BDC and Kevin Landers/Rotary Resurrection are coming from though. You just have to make a choice that fits your personal situation and risk tolerance.

Acroy

iTrader: (3)

Update -

The owner bought a low-mile stock S5 T2 keg and will freshen it up.

What is the preferred setup these days for a reliable 400whp? Based on recent threads, looks like stock or small streetport, 60-1 turbo, and a good tune at around 12psi. Is this reasonable?

The future for the BDC motor is unknown.... It will serve as garage decoration for the time being.

KNONFS

iTrader: (14)

With that setup, you will need more that 12psi in order to reach 400 rwhp, should be able to achieve it around 18psi.

Acroy

iTrader: (3)

From this thread and others, 12-13psi on a frash motor seems to do the trick. No?

KNONFS

iTrader: (14)

Not in my experience, but I am not an engine builder, nor a tuner. My freshly rebuild engine (stock ports), on a t04 60-1 did mid mid 340 RWHP at 9 psi, with a boost spike to 11psi from 5800rpms all the way to redline.

RotaryEvolution

iTrader: (30)

add in the fact that this was probably built around the time that numerous people were posting similar results from the rotary aviation seals. i believe they have since revised the material to be a little softer and less abrasive.

i have no experience with RA seals, because they won't give me a discount rate to try/use them. i have only installed 1 set and never got to see the results as the owner sold that engine and went with a 20B instead.

i personally use Goopy seals on all turbo modified engines and Atkins seals on N/A and stock turbo motors. have yet to see any problems with this combination. i will use OEM on specific builds but i qualify them as very similar to Atkins but they will shatter more readily under knock and cause much more extensive damage when doing so. Atkins seals tend to chip and not shatter, Atkins seals have a very good longevity record, close to OEM's lifespan as i have many engines i built almost a decade ago still running and many probably close to or over 100k miles now(keeping in mind the hard parts in those engines already had over 100k on them initially so the core engines probably have 200-300k on them now).

i prefer Goopy seals because they offer 'oversize' seals that no one else offers for worn rotors. they are also soft enough to not gall up the housings extensively yet allow for more reliable high horsepower. no one wants to hear the backfire of death which usually results in an almost always cost of a rotor and housing. with parts becoming nonexistent in the near future salvaging what you can will keep you in business much longer, which is also why i started the resurfacing service for all rebuilt engines and for those who want it. continued trashing of parts will not keep these engines surviving, especially with everyone wanting turbo rotaries.