apexFD

Perfect sounds good. But for the record, is it truely more cost effective to rebuild an engien before it is blown( i am assumign so)? and can these core be stored for periods of time? Thanks

RotaryResurrection

iTrader: (8)

If the rebuilder intends to reuse most of the major internals, yes it would be cheaper to catch it before it goes. IF the builder intends to simply start from a mazda reman and send your old one back to satisfy the core, I dont see why it would matter, since you incur no extra part replacement costs.

Most of the time what I see is when cores sit for a long time (in or out of the car) the seals stick, specifically side seals. Especially on water seal motors...just a couple of months without weekly startup can yeild all the internals rusted beyond use.

Blake

You never want to store a failed engine whole but a fresh rebuild will store quite well for long periods. There is no coolant or carbon in them to cause problems and all surfaces should be lubricated. You do need to rotate them over periodically to keep the apex seal springs from going flat and keep out moisture, rodents and debris. Seals, hard or soft, will not "dry out".

Whenever I store an engine, used or new, I like to shoot some WD-40 in the ports periodically when rotating it over, press on every apex seal as it comes across the exhaust port and cover all the openings with stainless covers, plastic plugs or even just tape...anything to prevent dust or worse from getting in.

As for rebuilding engines, yes, a running core is typically ideal, but even those can have expensive problems...theoretically, any or every part could just be out of spec and require replacement. Oil leakers or water leakers can be good candidates if torn down shortly after failure. Blown up cores usually mean a rotor housing and rotor are write-offs, but if you are replacing the rotor housings anyway, the added expense is only the cost of a used replacement rotor. Really, what you want is a *low miles* motor, almost regardless of whether it is running or not...just as long as it was not overheated severely or was a water leaker that was left to sit and rust. Rebuilding a previously rebuilt motor can be a gamble too. Often times you will find a whole lot of worn out parts that probably should not have been reused in the first place, let alone so much farther down the road. If the plates have already been lapped, you might not be able to lap them again if needed, or you may find it was not done well to begin with. Lots of variables. This is part of the attraction of rebuilding a fresh Mazda Reman. Mazda seems to spare no expense in replacing parts with brand new stuff but they can't seem to manage to assemble one without making mistakes, so it's best considered a nicely packaged collection of parts you are purchasing as a core for rebuilding.

It will probably cost less to rebuild your low-miles, running core than to buy a Mazda Reman and have us go through it, but the difference in cost will be fairly small and the convenience of it will easily make it worth while for most people. However, also keep in mind that Mazda Remans are in short supply and it can sometimes take months to get one. Availability changes but right now it's tight. We constantly have them on-order, just in anticipation of customer needs.

If you blow an apex seal, keep in mind that (1) you *must* identify and correct the problem that caused it and (2) apex seal pieces and other debris are often thrown back up the intake tract, where it will then get sucked in by the replacement motor unless you thoroughly clean every nook and cranny of every part of the intake tract with a fine-tooth-comb. But the best cure is prevention. If you freshen up a running engine, you typically save a lot of time and effort on the installation end.

GoodfellaFD3S

iTrader: (213)

Blake, you've seen evidence of apex seal debris being spit up into the intake manifolds? I've seen many cases of FOD on turbines, but never manifolds.

Blake

Yes, we have. Usually in the really high boost motors that genade violently. We find steel apex seal fragments in motors with ceramic seals and ceramic seal fragments in motors rebuilt with metallic apex seals. One time we found the equivalent of 7 apex seals in a motor. Sometimes we see an apex seal end-piece impact (perfect imprint on rotor), but all the apex seal end-pieces are intact. Mostly, it is subtle stuff and you would have to know what to look for. Other times it is obvious. A motor we tore open last week just had a bunch of little tiny pock marks all over the insides, which could have been anything but we believe to be FOD from not cleaning out the intake tract.

[EDIT: I mistakenly said "corner seal", when I meant "apex seal end piece". Corrected above.]

ScuttleRX

Hi Blake,

Firstly, great thread, has made for some very informative reading.

I was wondering if you could elaborate a little more about the oil modifications you've mentioned a couple of times, i'll be having a rebuild in the coming months so would be interested in having these mods done, thats if there not a trade secret type thing

Oh, one other thing, and considering im having the engine rebuilt it might be a bit pointless but ill ask it anyway. My engines been sat for a year now without being used, and was a runner with no probs beforehand, I never planned on being off the road for so long so never prepped the engine for storage/sitting (I assume it would have been best to drain all the fluids, etc), is this likely to have caused any problems?

Ah, one more, promise its the last, do you happen to know how much that cermet A coating is, the JHB website seems to be down at the moment. My plan is cermet coated housings rather than new and some NRS ceramic seals. I think you said nearly cost of new housing so roughly $700-$800?

Cheers

Andy

FM #13

Blake, what do you think is going on with a Darryl Drummond sealed 13B in my Formula Mazda that suddenly started detonating last weekend with 17 hours (1600 miles) on it? I assume it's detonating; it makes a machine gun sound in all gears from 4K to 6800 (rev limit). I barely heard a hint in a practice session, then it started coming on strong at 5500 rpm in the 25 minute qualifying session and then was starting as low as 4K in the race. I know I should have parked it, but.........well, denial is a powerful thing. But, I was surprised that it kept pulling; lap times remained about the same thru the race as they were in practice and qualifying.

As for external conditions: I managed to avoid hot weather this year (water never got over 200 F and oil was about the same). I use Chevron or 76 pump gas (91) with these additives: The first 8 hours I added 1) Redline 2 stroke at 1/2 oz per gal and 2) 110 or 112 race gas at at ratio of 1.5 gal race gas and 3.5 gal pump gas per session. The last 9-10 hours I used Blendzall 485 Gold Label at 1 oz per gal. So, is this a case of a single blown seal or broken spring or what else failed so quickly?

Thanks for all the information.

Ted
Shoe String Racing

Blake

The oil system modifications we do are somewhat of a secret, but basically it consists of porting the oil pump cavities and drilling out several of the oil passages in both the front and rear plates. The Stage III oil mods include a loop line to balance the pressure between the front and rear main bearings, in addition to a few other tricks. Usually, there is some change in oil pressure regulator setting, but the ideal pressure varies with the application. Sorry I can't go into details but Rob likes to keep secrets. I have been pushing him to manufacture the jigs, sell the bits, write a manual and perhaps even do a DVD, but he has resisted me so far. I was told one of our former customers tore apart his motor and documented some of the mods and posted it on one of the forums, but I cannot possibly believe they really saw everything we did...many of the changes are subtle, yet are vitally important to the end result.

ScuttleRX

Thanks Blake, I did think it would be a bit secret squirrel

It will be a few months before im rebuilding so keep on at him for that manual!

Thanks for your reply

Andy

Blake

Well, first of all I would recommend talking to Darryl. He is the engine builder (a damn good one, at that) and far more familiar with FM applications. That said, I would start off by taking a close look at the trailing coils and plug wires to see if you are getting a crossfire. Trailing crossfire is not at all uncommon when the spark finds an easier path to ground, often doing so through the wiring harness and thus tricking the other coil into fire simultaneously. This sets off the incoming chamber of the other rotor. We see this frequently on 3rd gen RX-7 and the results are disasterous. On an NA, the effects would be more mild but still serious. We are now at the point where we automatically replace trailing coils on any 3rd gen when replacing the engine. Anyway, it's worth a look. You might also want to test the injectors, to make sure they aren't sticking. Can you borrow another ECU to swap in, just to see if there is a problem there? Have you done a compression check or at least looked through the exhaust ports to see if everything is intact?

DreamWoRX

Alright, I am loving this... I wish I had the time for this but between working at a Mercedes-Benz dealership (that's right I'm bragging, ASE master and advanced engine diag and master certified by Mercedes) and dealing with those headaches and having a girlfriend(who is wonderful ), and everything else(dog, housework, etc.), I've put everything on hold. Anyway I've been out of the rotary scene for a while now, and I am reading up on things and learning. I have a couple questions...I have a 91 I am rebuilding, aventually, which will be a just keep it together rebuild while I work on my Honda(I know, I can hardly believe it myself).

#1- Can I run s4 rotors with the s5 fuel injection? (I heard it would not run, but I am thinking why not?(all my better judgement is telling me it can but Murphy's law is always there.)
#2- Just mainly for my own knowing... Will renesis rotors work in a s5 motor?
#3- How can you, if it is even possible, tell the s4 and s5 counterwieghts apart?(in case #1 happens).
#4-Can the 3piece apex seals be resued? I don't like the design or even the idea, but as a cost effective build, can it be done(with success)?
#5- How much are corner seal springs? And for an na motor do you recommend the fd corner seal springs?
#6- Any recommendations on how to try to remove side seals that are stuck, or is the rotor now officially a paperweight?
#7- If a rotor has been damaged by a seal that acted as a tornado in a trailer park, can it be used if the protruding edges and metal is filed down very carefully?
#8- How do you remove the rotor gear? Long thin punch?I want to attempt a project that isn't even motor related, but more interior design related.


I will probably have others but for now thats it. I gave the rotaries up for better gas mileage and then liked the Honda, but a lady on the cell phone, more than a year ago ran into me and screwed up the front, I have been driving it since messed up and I think its time to fix it myself.

Stephen

DarkKnightFC

What do you think the compatibility of these coatings and Alky injection might amount to? I doubt the Alky is corrosive to ceramic but its a possibility.

Chris

sniperstevedave

I wish there was a rotary specialist with your abilities in my area. Sigh, oh well. I was wondering if you had any information about auxilary bridgeports, i.e. bridgeporting the 5th and 6th ports on a n/a S5. Similarly, have you ever come across something like a semi-peripheral port? I was thinking about peripheral ports that are actuated at sufficiently high rpms, much like the aux ports. It would be great to be able to keep the low end performance while gaining big high end.

This thread is excellent. Thanks!

Blake

(1) Idle & Part throttle mapping is off the most.
(2) Will work; no proven improvement.
(3) Weight is S5=1820g and S4=1840g or so for rear (a/t). Front S5 = 1186g; S4 = 1264g.
(4) If not too worn.
(5) $3.10 for the FD springs. I don't even know the cost of the earlier ones, since they are NEVER used for any reason whatsoever.
(6) WD-40 & slight heating & patience
(7) If all the seals move freely, clearance is correct and balance correct, perhaps. But, why not get a used rotor? Why put a questionable part in?
(8) If damage doesn't matter, weld metal across gear and press out.

Blake

If Cermet, no problem.

DarkKnightFC

What about this Polydyne? coating that Turblown offers?

Chris

sublime42o

I had my car up on jacks with the exhaust manifold off for a couple months while I was working on a turbo project, now I have a stuck apex seal. The car ran perfectly fine before I put it up on jacks for the project. The motor was rebuilt about 6000 miles ago by Kevin Landers. There is one apex seal stuck on the front rotor, and all of the rest on the front and rear rotors feel/look great, nice and springy. My question is, would it be possible for me to just remove the front rotor and replace the one apex seal (assuming the rest really are fine) without having to take the entire engine apart? And if so, which components MUST i replace when doing this? I have no experience doing this, and I will be working with my father who has experience building engines, but he has no experience with rotaries. We plan on using the FSM and a rebuild DVD.

thanks!

Tom

Blake

Not aware of any issues there, but check with the manufacturer. As always, application of the product is just as important as what the product is.

FM #13

Hi Blake, I have talked to Darryl Drummond and detailed more of my investigation of what I thought is detonation in this thread

Before I try Darryl's suggested decarbonizing treatment, I may as well throw on a new set of coils and elimiate cross fire first?

Also, if it's not detonation or cross fire, and it is carbon deposits, is it pre-igniting? Any other observations or opinions you'd care to offer would be much appreciated.

Thanks.

Ted

Blake

Actually, you should just try decarbonizing first. Quick & easy to do and you should see results one way or the other. I wouldn't have suspected carbon deposits because of the conditions (continuous high-RPM/load), but (1) Darryl knows these RENESIS FM race motors better than anyone and would be familiar with the usual problems, (2) there could be an issue with your pre-mix brands and (3) it is your engine builder suggesting it. Seriously, I don't want to be the guy telling you Darryl Drummond is wrong or even to suggest it. They guy knows his stuff and it's not my place to question him. As for replacing the coils, I would say just try one thing at a time and start with the easiest one first. Next to not solving a problem, fixing it without knowing what you did is the most unsatisfactory feeling on earth. We have been seeing a lot of problems with trailing coils on 3rd gens, but I can't tell you if FM race cars suffer from that problem too. I just threw that out there for consideration. Good luck!

FM #13

Hi Blake, thanks for the perspective.

Agreed. But since I was going to run a couple laps on track to get the motor up to temp before I try the treatment, changing the coils first would be the easiest thing to do at home. Who knows, maybe it is the coils and I'll be done?

Just to be clear, I have the mid -80s (2nd gen right?) 13B in a standard FM. The Renesis is really only in the Pro FM.

I'm not at all clear on what carbon buildups do. I hear the word stuck seal and I would assume that means the seal is stuck open, but I'm seeing 1/2 to 1 mm movement on all 6 seals, so they're not "stuck" per se. I'll be calling Darryl tomorrow, but your take is always welcome.

Thanks again.

Ted

Blake

Ahh, yes. For some reason, I call the older cars "Star Mazdas" and the new ones "Formula Mazdas", so when I see "FM" I just presume it's the new ones. Sorry.

Carbon build-up is more notorious for sticking apex seals but it can also build up in the combustion chamber bathtub and increase compression, causing a problem. Carbon deposits can also form peaks that glow hot and can cause pre-ignition. Rob mentioned to me that with the side draft carbs, you guys sometimes run a super-rich idle jet to take care of an off-idle flat spot and that can cause a lot of carbon build up, if you are not careful. A normal NA will run about a 60 idle jet, bridgeports are around 65, and peripheral ports more like 70, but FM guys sometimes run an 80! He also pointed out that there have been fuel pump problems in those cars that causes a progressively worsening lean condition up top, so you might want to look into that too. Rob didn't think the trailing coils would be the problem on an NA, so I wouldn't recommend changing them out on the off-chance that they are the problem, though you could inspect them for carbon tracks.

apexFD

If your engine has a small street port... Do you have to use all avaiable power, or can you tune your engine to run just above stock power? I guess as long as the air/fuel ratio isnt too rich or too lean, you will be fine? Also can you breifly explain air fuel ratios, like why exactly a lean mixture is bad, and how to get the correct air/fuel ratio. thanks, i hope my questions arnt too vauge.

Hellkat

lean makes you detonate too early working against your eccentric shaft. the combustion has nowhere to go other then throught your seals :/

RonInWaState

Hey Blake

Thanks for the rotor housing and the rotor we got from you guys when we stopped by last week they are on the shop bench.Josh’s FDR2 is on the truck from Florida.
What is your opinion on premixing feul with the 3rd gen and on my Rx8?

Thanks for all of the info

Ron