twan

iTrader: (2)

Hey guys. Wow, been a while since ive posted anything but im happy to see the thrill with the awesome machine continues. I have a bit of a problem that I need some thoughts and suggestions on. I have a 93 TT and its been rebuilt already once before by me of course. Its heavily modded if I may say, but I retain stock twins, injectors, fuel map and boost pressures. Well about a year ago, I had an oil starvation problem while heading home from NY. Now she ran fine all the way. Got her home cause she didn't die or heat up to anything like that. But I realized I had been leaking oil from the filler neck o ring and proceeded to fix it. well, when I started her back up, I heard some really disturbing knocks in the rear of the engine. I wasn't sure what it was but long story short, I found that I spun the rotor bearing on the rear rotor due to oil starvation. Now other than the bearing being destroyed past the cooper layer, and the metal surfaces between the od of the bearing and the rotor being gritty and a bit scuffed, all the other surfaces seem to be just fine. the Housings are smooth and undamaged at all. The e-shaft, although slightly discolored remains smooth and unscarred to the touch. The irons are completely smooth and untouched as well. my questions are as follows and Please review the pics for ref. The bearing is obviously trash but; Should I replace the bearing with an oversized one (My thoughts are that this wouldn't work because an oversized bearing would have a smaller ID vs. a reg one. Not a larger Od but correct me if Im wrong please), should I do both rotor bearings since I have most of the engine apart already, or Should I just replace the rotors due to the scoring and scuffing of the one rotor? The rear stationary gear sustained some damage and I did find the one of the eccentric shaft oil journals was plugged with a build up of bearing cooper. was pretty amazed at that find.

GoodfellaFD3S

iTrader: (213)

Wow! It's funny, I was just speaking with another engine builder the other day about how we've never seen a rotor bearing spin..... it's always the stationary gear bearings that go.

How many miles are on the engine?

I would inspect everything VERY closely, replace all four bearings, replace that e-shaft (and obviously the rear stat gear ), and thoroughly flush your oiling system. I'm talking remove oil coolers and lines etc.

I'm kind of amazed that there isn't more damage.... when a stat gear bearing gives it up, it always trashes most the engine in my experience. Rotors smacking irons can do that

More pics would be great

twan

iTrader: (2)

thanks, I appreciate your response. So you think I should replace the E-shaft too. I mean, I get the replacement of the bearings, but the shaft is fine. well besides the discoloration. when I run my bare finger across it, I feel absolutely nothing and regarding the bearings, you think I should replace them versus the entire rotor. I'm all for that because the cost of two balanced and matched s5 rotors is significant. My dilemma is the fact that the rotor bearings are pressed in. I know, freeze the bearings and heat the rotor than press them in. but you thing the rotor will receive another bearing without issues even with the scuffing?

twan

iTrader: (2)

Oh and the car has about 50 to 60kon it. maybe. been a minute since I looked at it. has sat in my driveway more than I've driven it. its an east coast car so with the seasons, I don't drive it , even when its running, too much. I know the pic looks well, not great but the shaft is absolutely smooth to the touch!!! All my seals; the side, corner, and apex are in perfect working order. Yes, im just as amazed as you but there was only about 1k miles on it since the first rebuild. I was very, very lucky. I honestly think most of the damage was done in my driveway from a cold start.

jantore

Do as GoodfellaFD3S says, replace all bearings and eshaft. And clean everything out. You will have bearing debree all over the oil system. The eshaft is toast. It will need to be put on lathe and cleaned alot to get all the debree from the bearing out.

Id have a look at the rotor also. There might be some damages on the gear. Also i dont like the marks on the rotor where the bearing was. Not sure if you can put in a new bearing there. But you might just hafto try.

JT

mcon

iTrader: (2)

I've bought a rotor which had spun a bearing. Previous owner told me it had a new bearing but not why.

Even with the new bearing the rotor would not fit the eccentric shaft.

I had replaced the bearing in one of my rotors as well and it was perfect.

diabolical1

iTrader: (3)

at the end of the day, no matter how smooth the surface of the shaft feels, contact was made and friction made it unusually hot. replace it.

do you know if the jets got pulled and the passages flushed during the rebuild process?

bpdchief

iTrader: (7)

A used e-shaft from Atkins Rotary runs about a hundred bucks shipped to you. Seriously, I just did this. Replace all the bearings and the shaft. hard to fulsh the entire oil system so we replaced the cooler and lines too.

twan

iTrader: (2)

I wanna thank all of you again for you input. ive been weighing my options. im uploading some more pics for your consideration. mainly of the shaft although ill prob replace as advised. I still am wondering what should be done about the bearing mating surface on the rear rotor. its scratched and scored so will a new bearing seat in there properly and securely? and yes, the first time I rebuilt the engine, I took everything apart including the jets. think I did a mod of them. have to check but if there is a mod for them like the thermal pellet, which I did as well, then I did the jets also.

bpdchief

iTrader: (7)

I'm pretty sure a new bearing will fit easily once the old bearing is pressed out. You definitely need a new e-shaft. That one is toast. As far as the bearings go, you may as well replace all of them. Rotor and stat gears. That copper going through the bearings isn't worth messing with. Sorry for the bad news but it should be done right.

RotaryEvolution

iTrader: (30)

stop trying to be cheap, just replace the shaft. they are cheap enough versus wasting another thousand bucks+.

twan

iTrader: (2)

LOL!! yea, I know. I def don't wanna have to go thru this again!!! Looking at the bright side, heres another opp to upgrade. The rotary Aviation OMP kit with the separate reservoir and, I will be premixing from here on out!!

twan

iTrader: (2)

old bearing on rear rotor came out while engine was running due to oil starvation. That's what caused all this mess. my concern is if a new bearing will sit properly in the rotor like its supposed to. or will I have to get new rotors as well?

Mr rx-7 tt

iTrader: (5)

I use to see this all the time back in the non force inducted days. Replace the bearing with the correct one, replace the e-shaft and throw out, yes don't even attempt to clean your oil cooler(S). Throw out your oil cooler(S) and the lines.

twan

iTrader: (2)

oh yea, another reason to up grade!! WOO HOO!! this time ill do the dual coolers!!! I have the touring edition so there was only one!!

tafkamb2

I gotta say that e-shaft looks a lot better than the one I pulled from my old engine! I wish I knew what the previous owner did to it. Mine looked like a crank that walked if that makes any sense.

FD3S2005

iTrader: (11)

i always wanted to ask, how do you go about flushing out the oil coolers?

RotaryEvolution

iTrader: (30)

remove the thermostats and lines, fill up a tub with a few gallons of gasoline and submerge the whole cooler(s) into the tub and let it soak overnight.

drain it and blow it out both directions with compressed air and then repeat the process one more time with a clean tub of gasoline.

once finished do not push the engine for at most 500 miles and do an oil and filter change at that time then regularly after that.




recommending throwing the coolers away is just stupid and an ignorant thing to say for those who have never actually tried cleaning them, repeated by the people who simply don't know any better. the old school/FB/FC cooler is perhaps an exception since it is long and a complete U-loop cooler which is extremely difficult to clean versus the FD coolers, but also very plentiful.

ArmyOfOne

iTrader: (12)

I used your method on an fc oil cooler and it worked very well but I did it 4 times. The last time I hooked up an old fuel pump and pressurized the fuel going through it, zero residue. It's doable, just time consuming.

twan

iTrader: (2)

well, im probably just gonna replace them. mainly because of the bits and pieces of copper I continue to find throughout the components. I fear a blockage and yet another major breakdown. still considering the flush though.