I reused my side seals too....lol its a budget operation here man. I spent 7-800 on the fc rebuild and 700 on my fd rebuild. I've put almost 4000kms on the fd since October we got a lot of decent weather up until a month ago .
Those 10k kms on the fc is mostly driving it hard I just run castrol Gtx 20w50.

 

I have to ask. Did you measure the clearance at all or did you just use the fact that its usable and used it?

thewird

 

i did a case study on hydrodynamic bearing modes of failure. you are right that on the surface there is no signs of wear and the bearing will measure to be in spec.

the part we cant see is that there is subsurface fatigue and therefore subsurface microcrack formation. these cracks can only be inspected with very expensive tools such as eddy current array probes.

so i agree with you that it is essential to replace bearings as a preventative measure since they are relatively cheap to replace!!!

 

I checked the sideseal to cornerseal gap. And heighth .apex seal to rotor clearance. Checked the bearings and eccentric shaft and set the end play. You guys act like I'm the first person to do this . My cars run perfect. Yeah I blew my fc engine a few years ago from my stupidity but I had the rebuild kit waiting at home anyways. Piston engines don't have stationary gears taking the majority of the load and only spin the piston rod 1 time for every three rotations of the crank .the rotor bearings are more of a bushing than anything . If I was spending all kinds of money on a rebuild I probably wood replace all the bearings and everything. But reusing a perfectly good rotor bearing is fine. re you guys saying my fc would make more power if I had changed the rotor bearings when I rebuilt it a few years ago? If I get a few more years before I tear it down again I'd be more than happy. A lot of it has to do with the break in

 

No no man, you do whatever you want when you build your own engine. Glue apex seals back together and re-use them too if you feel the need.

You spun a bearing in a motor while going through a corner at high speed and your blaming it on oil starvation. My immeadiate thought was that old bearings were used in a rebuild.
I had the same thing happen to me on the dyno, e-shaft welded itself to the front stat gear during a pull. There's no g-forces on a dyno making the oil slosh. I'm blaming it on the fact that I used a whith-in spec bearing that showed no signs of copper.

No, new bearings in a engine will not make more power, but it will make that engine more reliable in the long run.

It bothers me that these so called "professional" engine builders are selling "rebuilt" engines to customers with used bearings going back into them and spreading rumors on the internet that a used bearing is much better to re-use than a new one.

 

Lol I would never buy an engine from them. When people pay for a quality rebuild that's what they expect .I agree there's not a person out there that wouldn't be pissed if they didn't get new bearings
It's extra insurance like the accusump some people might think its silly till something goes wrong and they wish they had it

 

I'm all for learning from mistakes, but how many engines did you build before deciding this was a good idea? Accepting money for rebuilds would then make you a professional builder no?

 

Stock set-up is good for what you are doing Ken, use a large catch can, open vented, have the can drain back into the engine and use 1 liter more then normal...if your going to road race look into a dry sump.

Steering rack is ready to go when you want.....

 

I wondered when you were going to put your $0.02 in here, which btw, since the penny is discountinued rounds your $0.02 down to $0.00 which then makes your opinion null and void.

In all seriousness, I would say I had about 30-40 engine builds under my belt before some bearing problems started to show up, now granted, there were only 4 engines that came back to me. Fairly small percentage, but 4 engines nonetheless. It shouldnt have happened. I made things right with the customers, they are probably still pissed at me regardless.

I took the appropriate steps to measure the bearing clearances on all my engines and yet some still failed. Shouldnt have been my fault the old crappy bearing failed.
But my fault for using that old crappy bearing which spec'ed out fine.

I'm trying to do everyone a favor here and teach all the internet mechanics, like yourself Nismo, what not to do when building an engine for yourself.


Buy hey, what do I know....I'm just a professional Rotary engine rebuilder.....

 

Some good ol' fashioned engineering to back up a debate topic... I like it.

 

I think that I can contribute something from a real life racing experience. A couple of engines ago, early 2001, I was using a well worn stock 6 port in my car, with RB headers. The engine had over 170,000 kms and worked okay, but was on its last legs. I was using Redline 20-50 Race oil in it and stock pressure relief valves. I was starting to get concerned with things as I was noticing sustained drops in oil pressure (down to the 20-30 lb range) going through Turns 8, 1 and 3 at Mosport. It was just after we had added a rear wing and new front splitter. I was also fortunate at that time as I had just got a new Data Logging setup installed in the car and could see that I was pulling a sustained 1.15 to 1.2 g's in those corners. I was also filling up my oil catch tank with over a litre of oil with every hour of race time.

I was getting concerned so I added a 3 quart Accusump to the car to cover for those pressure drops. It worked well as it maintained a 45 - 50 lb level in those corners, but I noted that it took almost the whole next straight for the car to develop more than 60 psi again as the Accusump had to be refilled. Needless to say that after that motor went south (no compression at all) and a couple of other ones for various reasons (bad oil rings, spit out an apex seal), but the oil pressure situation was exactly the same for all 3.

I finally had Joe build me a new motor using newish parts and put it in to the car. At the same time I was tired of having to drain out a litre of oil every hour from my catch tank so i worked on developing a better breather system. In my case I added a K&N valve cover breather to the top of my oil filler cap. Instantly the amount of oil getting pumped into my catch tank went down tremendously and the oil pressure were more stable. So as my Pig was very heavy and the pressures looked good, I took the Accusump out of the car and crossed my fingers. It was okay and I the pressures remained okay. I did get some drop (about 10 lbs) in Turn 3, but as I was generating almost 120 psi the drop was okay. There was no oil pump out anymore and the return to max pressure was almost instant.

So long story short, the Accusump did what it was supposed to do at a cost of a delay in return to max pressure. Improving the sump breathing improved oil spit out a ton and also allowed me to maintain decent pressures without the Accusump. Car still generates over 1.1 g's sustained. I gave my buddy in Vancouver my Accusump for his wetsump Cobra R and he is still using it. My newish motor has been seriously abused for almost 6 years now and still makes great pressure and good compression.

Just an FYI.

Eric

 

23Racer, if you install a drainback from the catch tank to the oil pan, you never have to empty out your catch tank and you keep the oil in the pan. I have mine in the front cover. This also gives your system another vent line which improves the whole system. I've been running my car like this for years. Jim adopted this setup a while back as well after I told him about it.

thewird

 

I understand Marco, but my catch tank also catches overflow and fumes from the gearbox so it is just a catch tank.

Since improving the venting, after a 3 hour race I end up with less than a cup in the catch tank including gearlube.

Eric

 

I read something about recirculating it back into the pan being bad due to the moisture and contaminants that the catch can is designed to catch along with the oil. Is this only applicable to piston engines where it's tied into the PCV system? So our rotary catch cans are only catching oil blowback or whatever from increased pressure during a high-force turn, or what?

CorkSport Mazda Performance – Blog » Product Release! CorkSport Oil Catch Can Development and Release Notes

Look at what they pull from the can.


Edit: I'll do some searching for the answer to the rotary catch can so that we don't clutter this thread, but I still want to know the relation between a rotary and piston catch can system with the contaminants you see in the Corksport article.

 

This was my concern as well and why I never considered a recycling catch can. All the catch cans I have had on my cars always had crap in them after a while from condensation and other contaminents, even when they were only engine oil units.

What I did was install a baffle in the filler neck to deflect some of the oil like the one developed by Mazdacomp, then use both of the filler neck vents to the catch can and a drilled top of the filler cap that I push in a standard K&N crankcase vent to the atmosphere. Works awesome and I get only spoon fulls into the catch can now.

My Cougar has a proper baffled pan with trap doors and windage tray. It also has 4 large vents to vent the block and crank case. I never get a drop in that car's catch can. It also has a 3 quart electric driven Accusump.

Eric

 

It wasn't meant to be a shot (but heres my $.05)but hey take it as you will, I would think in a race engine this would be done anyways, the Mazda FSM even states if they are within spec it's ok to reuse. Everyone wants to save money, and builders are no different.

I'm just a Millwright that works on Nuclear reactors, when I rebuild my crap, at work and home, I overhaul it, don't just change parts. I have never had an issue with an engine I built.

 

With a track used car, what isn't oil will just evaporate since that's how it got to the catch can to begin with. The oil that gets into the can is from the oil slushing around that gets caught in the air and pushed out. That's why its important to run huge lines (whether there is a drainback or not) to minimize the amount of oil that gets pushed out. Of course you need to have a filter on the catch can for it to make sense.

thewird