1992 RX-7 FD. A tale of two Rexes and several engines...
Discussion
Nik da Greek said:
WaferThinHam said:
Dunstable's a hellish place, maybe it blew up in disgust? :P
lol. The only thing you can say about Dunny is it's a hell of a sight nicer than Luton 
Aww man Nik, im really feeling bad for you after all that, that was major blow up number three after you built this red one right?
Im starting to wonder what im missing out on with these cars though, if they are awesome enough to make a person suffer through this much blowing up and rebuilding..
Im starting to wonder what im missing out on with these cars though, if they are awesome enough to make a person suffer through this much blowing up and rebuilding..
I have to say I really feel for you on this - the sheer heartache/anger/despair and effing cost!
I also have say I do like the way you write - I keep coming back to this just because I could read your output all night.
Could the bridgeporting have had something to do with it blowing? tolerances or something? Just a thought.
I also have say I do like the way you write - I keep coming back to this just because I could read your output all night.
Could the bridgeporting have had something to do with it blowing? tolerances or something? Just a thought.
I've just spent an hour and a half of my ten hour night shift reading this and what a machine you have and you've been through a bloody lot so far.
It seems like a wonderful engine and great technology in principle but the wankels always seem compromised and plagued by horror stories.
Would you say the engine design was compromised or is it just one of those things like Porsche and the IMS?
It seems like a wonderful engine and great technology in principle but the wankels always seem compromised and plagued by horror stories.
Would you say the engine design was compromised or is it just one of those things like Porsche and the IMS?
I've just spent an hour and a half of my ten hour night shift reading this and what a machine you have and you've been through a bloody lot so far.
It seems like a wonderful engine and great technology in principle but the wankels always seem compromised and plagued by horror stories.
Would you say the engine design was compromised or is it just one of those things like Porsche and the IMS?
It seems like a wonderful engine and great technology in principle but the wankels always seem compromised and plagued by horror stories.
Would you say the engine design was compromised or is it just one of those things like Porsche and the IMS?
To be fair, not all rotaries are like mine. And I was asking it to almost double the factory power output after all. However, we did eventually get to the bottom of the issue that was causing the engines to blow, and it was neither easy nor something you'd really have expected. All will be revealed...
Meanwhile...
It sorta goes without saying that this was another one of those low points. It was the piece de resistance when the guy who came to trailer the car up to Super 7 managed to crack the bumper winching it into his wagon with a badly-placed tow strap. It also goes without saying that the conversation was rather fraught when I finally got there. The way I saw it, there was clearly some underlying problem which was causing the car to keep breaking and it ought to have been sorted the first time, not allowed to continue blowing motors at random. The way J saw it was that he couldn't just keep throwing engines at me in the hope one held together. We settled our differences and came out the other side better for it, I think.
This time, the engine didn't even cost me the price of parts
However, I'm getting slightly ahead, lets have a look in the old one before we move onto the errrr.... fourth 
shall we?
Errrm, yep. It was FUBAR.
The front rotor had blown again, which is slightly unusual. Generally the rear fails first, presumably due to the increased heat management problems back there. So at least it was consistent... Considering this time I'd driven it about five miles after it blew as opposed to the fifty the previous time, it was in a much worse state, it had let go big style
The rotor was scrap. It had dropped at least part of all three tips this time. To be fair, I've got quite a collection of these now, including one on the hearth in the front room. My wife's marvelous, she's very understanding
Pretty, innit!
Don't think I'm excessively weird, I'm just a true rotard lol. I deserve pity, not contempt ahaha. *ahem* Right, back to the autopsy. The three disappearing tips had obviously totally destroyed the rotor housing as well, it was ruined comprehensively. More depressingly, the turbine wheel of the turbo was now scrap as well (yep, that one I'd only had a year, barely boosted, and had paid about a grand on refurbishing, that one). A new wheel wouldn't have been a disaster, but in addition to that...
It had broken the turbine casing as well. This is a bit of a dodgy one, I can't prove anything one way or the other, so I won't go throwing blame around, but it appears the weld where the flange (ooooh, flange!
) had been fixed was no good. It's hard to see in these pics - ignore the black stuff, that's where petrol sloshed through the broken seals and washed the carbon out through the fracture. Makes it easier to see the break, I guess
but of course, the casing's cast iron, which is hard to weld at the best of times. As I understand it, it needs to be heated before welding to allow full penetration. Now the fault was clear, it was easy to see on close examination where the welded flange was simply stuck onto the surface without any real penetration. The local tame fabricator, a man of immense skills with a TiG torch, sucked his teeth and shook his head. He said it was more likely to shatter into a million pieces than stick back together if you tried a repair.
I've heard suggestions that the ceramic coating might have contributed to the demise of the metalwork by keeping too much of the heat in, forcing the metal to expand and contract too quickly. I don't know, I'm in no way qualified to hold an informed opinion on that. However, given the rate of failure, the dodgy colour of the coating, and the brief timescale since refurbishment, would I go back to the firm who did the work? Nope. Would I recommend anyone else did?
Nope
Oh, and the HKS manifold had cracked as well, in the web where the runners joined the turbo up-pipe.
So, to recap and precis... 50% of the engine was scrap; the turbo was scrap; the manifold was scrap. Oh, and I'd managed somehow to do the impossible...
Yep, I'd managed to break a titanium exhaust
God alone knows how, but one of the strengthening webs was missing and this crack in the weld for the mid-box was where the brace had been. I can only assume it took a clout from a speedhump or something, and the brace took the brunt of it, but cracked the weld in the process. Because the exhaust was designed as a system, a normal FD mid-pipe wouldn't fit with just the titanium back box because the lengths of each section were wrong. So I needed both sections while I searched for someone who can repair titanium
So.. engine, turbo, manifold, exhaust.
Anything else?
Well, yeah, actually. As I alluded to, J said he'd do the engine for free this time because he felt so bad for my situation, but we had to be able to guarantee this was never going to happen again. That meant further investigation into the cause of the blow-ups, and changing everything that was suspect. So I had to promise to commit to this, whatever it took. Fair enough, but I honestly wasn't sure if I could... or if I wanted too
So I sat back and sulked for a while. I listened to a lot of Rammstein, Killing Joke and Spacemen 3, which helped a bit. I made lists of all the bits on the car, and what I could expect to sell them for if I broke it for parts. I looked into selling it as a project. And a few things became apparent;
1) it was worth naff-all either as parts or shell in the current economic climate (this was early 2011), especially considering how much I'd spent on it.
2) I hate to lose.
3) I had such a fantastic group of mates in FDUK who couldn't have been more supportive, offering everything from a shoulder to cry on to parts from their own stashes and even off their own cars to help with a rebuild.
4) I really hate to lose
5) There was no other car that I could think of that offered the same thrill, amazing ride, fantastic performance, gorgeous looks, etc etc and there was no way I was going to while my life away growing old and grey in a soulless econo-box with the other doomed souls trudging around the congested tracks of our septic isle.
6) I really f
king hate losing, and the car deserved better.
That was the decision pretty much made then.
Go large, or go home. Again
Meanwhile...
It sorta goes without saying that this was another one of those low points. It was the piece de resistance when the guy who came to trailer the car up to Super 7 managed to crack the bumper winching it into his wagon with a badly-placed tow strap. It also goes without saying that the conversation was rather fraught when I finally got there. The way I saw it, there was clearly some underlying problem which was causing the car to keep breaking and it ought to have been sorted the first time, not allowed to continue blowing motors at random. The way J saw it was that he couldn't just keep throwing engines at me in the hope one held together. We settled our differences and came out the other side better for it, I think.
This time, the engine didn't even cost me the price of parts
However, I'm getting slightly ahead, lets have a look in the old one before we move onto the errrr.... fourth shall we?Errrm, yep. It was FUBAR.
The front rotor had blown again, which is slightly unusual. Generally the rear fails first, presumably due to the increased heat management problems back there. So at least it was consistent... Considering this time I'd driven it about five miles after it blew as opposed to the fifty the previous time, it was in a much worse state, it had let go big style
The rotor was scrap. It had dropped at least part of all three tips this time. To be fair, I've got quite a collection of these now, including one on the hearth in the front room. My wife's marvelous, she's very understanding
Pretty, innit!
Don't think I'm excessively weird, I'm just a true rotard lol. I deserve pity, not contempt ahaha. *ahem* Right, back to the autopsy. The three disappearing tips had obviously totally destroyed the rotor housing as well, it was ruined comprehensively. More depressingly, the turbine wheel of the turbo was now scrap as well (yep, that one I'd only had a year, barely boosted, and had paid about a grand on refurbishing, that one). A new wheel wouldn't have been a disaster, but in addition to that...
It had broken the turbine casing as well. This is a bit of a dodgy one, I can't prove anything one way or the other, so I won't go throwing blame around, but it appears the weld where the flange (ooooh, flange!
) had been fixed was no good. It's hard to see in these pics - ignore the black stuff, that's where petrol sloshed through the broken seals and washed the carbon out through the fracture. Makes it easier to see the break, I guessbut of course, the casing's cast iron, which is hard to weld at the best of times. As I understand it, it needs to be heated before welding to allow full penetration. Now the fault was clear, it was easy to see on close examination where the welded flange was simply stuck onto the surface without any real penetration. The local tame fabricator, a man of immense skills with a TiG torch, sucked his teeth and shook his head. He said it was more likely to shatter into a million pieces than stick back together if you tried a repair.
I've heard suggestions that the ceramic coating might have contributed to the demise of the metalwork by keeping too much of the heat in, forcing the metal to expand and contract too quickly. I don't know, I'm in no way qualified to hold an informed opinion on that. However, given the rate of failure, the dodgy colour of the coating, and the brief timescale since refurbishment, would I go back to the firm who did the work? Nope. Would I recommend anyone else did?
Nope
Oh, and the HKS manifold had cracked as well, in the web where the runners joined the turbo up-pipe.
So, to recap and precis... 50% of the engine was scrap; the turbo was scrap; the manifold was scrap. Oh, and I'd managed somehow to do the impossible...
Yep, I'd managed to break a titanium exhaust
God alone knows how, but one of the strengthening webs was missing and this crack in the weld for the mid-box was where the brace had been. I can only assume it took a clout from a speedhump or something, and the brace took the brunt of it, but cracked the weld in the process. Because the exhaust was designed as a system, a normal FD mid-pipe wouldn't fit with just the titanium back box because the lengths of each section were wrong. So I needed both sections while I searched for someone who can repair titaniumSo.. engine, turbo, manifold, exhaust.
Anything else?
Well, yeah, actually. As I alluded to, J said he'd do the engine for free this time because he felt so bad for my situation, but we had to be able to guarantee this was never going to happen again. That meant further investigation into the cause of the blow-ups, and changing everything that was suspect. So I had to promise to commit to this, whatever it took. Fair enough, but I honestly wasn't sure if I could... or if I wanted too
So I sat back and sulked for a while. I listened to a lot of Rammstein, Killing Joke and Spacemen 3, which helped a bit. I made lists of all the bits on the car, and what I could expect to sell them for if I broke it for parts. I looked into selling it as a project. And a few things became apparent;
1) it was worth naff-all either as parts or shell in the current economic climate (this was early 2011), especially considering how much I'd spent on it.
2) I hate to lose.
3) I had such a fantastic group of mates in FDUK who couldn't have been more supportive, offering everything from a shoulder to cry on to parts from their own stashes and even off their own cars to help with a rebuild.
4) I really hate to lose
5) There was no other car that I could think of that offered the same thrill, amazing ride, fantastic performance, gorgeous looks, etc etc and there was no way I was going to while my life away growing old and grey in a soulless econo-box with the other doomed souls trudging around the congested tracks of our septic isle.
6) I really f
king hate losing, and the car deserved better.That was the decision pretty much made then.
Go large, or go home. Again
So the great resurrection shuffle began again. The first thing we needed to eliminate from our enquiries was the wastegate. If you remember, it had come from a car that had blown up whilst mapping, and when we bolted it to mine we found a bit of apex seal still trapped in it. I'd had boost issues on the dyno to the point the mapper thought the boost controller had been plumbed wrongly. All this pointed to the wastegate perhaps not being all it could be. I was through taking risks on secondhand stuff, this was going to be done right this time.
A dude in FDUK imports bits from all over, mostly the Americas. He did me a mates rates deal on
a Tial v60 60mm wastegate It's a wee bit lovely, innit?
Right, moving on the next thing was I needed a manifold to replace the cracked cast one. Enter stage left...
A tubular stainless Trust/GReddy manifold. It was used,but that was OK cos we'd need to cut it about a bit anyway to fit with the rest of the gear. At least it was sound. The next major link in the chain was the wiring. About the time I was still having loads of problem with the rat's nest while on the twin turbo setup, the engine horse-shoe loom had been replaced (it runs round the engine bay in a big "U", hence "horseshoe"). It feeds sparks to all the engine ancillaries so it's rather important but the wires suffer from being cooked by turbo rotary heat and mine was 17 years old by then.
Of course, the replacement was designed for the twins and had loads of now obsolete wires and connectors hanging on it. Plus, it was getting as crusty and brittle as the last one. Since electrical issues could well have been to blame for the engine blowups, the loom had to be changed. And not for another manky used one, this time the only real way forward was making a one-off bespoke loom from scratch.
Which led on to the ECU. The Apexi had had its day as far as I was concerned. It was OK at running the car so long as everything was purring along, but it was just too numb and too slow to react to sudden mutant problems. More to the point, you had no way of interrogating it after the event to find out what had failed or why. It was time to move onwards and upwards, to be exact, a Link G4 rotary specific ECU. To my knowledge, the first on a UK street rotary.
They have a great rep amongst the Scooby boys,and are so much more advanced than the Apexi; packed with features, extra resolution, datalogging, ancilliary control (it'd even run the Oil Metering Pump that injects oil into the housings to lubricate the rotor tips). Yeah, it was twice the price of the Apexi, but hopefully it was twice as good.
Oh yeah, I almost forgot, I'll be needing one of these
Mmmm, nice, eh? Ed, the purveyor of fine wastegates to the stars also sorted me out with a cut-price Brazilian
Brazilian-made turbo, that is. It's an MPT64 with .70 on the front and .96 on the back on a P-trim. Or roughly a bit bigger than a T04R. Hmmm. Gonna need bigger engine porting.
An exhaust was flung together from a stainless Dragon mid-pipe with tiny silencer, and a very dirty and disreputable-looking Kakimoto Red Label. Which is supposed to be a competition-only exhaust. It's loud. Full circle, it's as loud as the first blue Rex was on the hilariously named "silent" Hi-Power
The parts were assembled (again), would it work?
Place your bets
A dude in FDUK imports bits from all over, mostly the Americas. He did me a mates rates deal on
a Tial v60 60mm wastegate
It's a wee bit lovely, innit?Right, moving on the next thing was I needed a manifold to replace the cracked cast one. Enter stage left...
A tubular stainless Trust/GReddy manifold. It was used,but that was OK cos we'd need to cut it about a bit anyway to fit with the rest of the gear. At least it was sound. The next major link in the chain was the wiring. About the time I was still having loads of problem with the rat's nest while on the twin turbo setup, the engine horse-shoe loom had been replaced (it runs round the engine bay in a big "U", hence "horseshoe"). It feeds sparks to all the engine ancillaries so it's rather important but the wires suffer from being cooked by turbo rotary heat and mine was 17 years old by then.
Of course, the replacement was designed for the twins and had loads of now obsolete wires and connectors hanging on it. Plus, it was getting as crusty and brittle as the last one. Since electrical issues could well have been to blame for the engine blowups, the loom had to be changed. And not for another manky used one, this time the only real way forward was making a one-off bespoke loom from scratch.
Which led on to the ECU. The Apexi had had its day as far as I was concerned. It was OK at running the car so long as everything was purring along, but it was just too numb and too slow to react to sudden mutant problems. More to the point, you had no way of interrogating it after the event to find out what had failed or why. It was time to move onwards and upwards, to be exact, a Link G4 rotary specific ECU. To my knowledge, the first on a UK street rotary.
They have a great rep amongst the Scooby boys,and are so much more advanced than the Apexi; packed with features, extra resolution, datalogging, ancilliary control (it'd even run the Oil Metering Pump that injects oil into the housings to lubricate the rotor tips). Yeah, it was twice the price of the Apexi, but hopefully it was twice as good.
Oh yeah, I almost forgot, I'll be needing one of these
Mmmm, nice, eh? Ed, the purveyor of fine wastegates to the stars also sorted me out with a cut-price Brazilian
Brazilian-made turbo, that is. It's an MPT64 with .70 on the front and .96 on the back on a P-trim. Or roughly a bit bigger than a T04R. Hmmm. Gonna need bigger engine porting.
An exhaust was flung together from a stainless Dragon mid-pipe with tiny silencer, and a very dirty and disreputable-looking Kakimoto Red Label. Which is supposed to be a competition-only exhaust. It's loud. Full circle, it's as loud as the first blue Rex was on the hilariously named "silent" Hi-Power
The parts were assembled (again), would it work?
Place your bets
Oooh boy Nik, im willing to bet you can put together a rotary engine blindfolded now cant you?
Kind of crazy how many parts can cause the engine to completely self-destruct, electrics, various valves, fobs, knobs and doo-dads...
Any hopefulls considering an RX for cheap thrills are gonna get linked to this thread and shall be sent home weeping.
Kind of crazy how many parts can cause the engine to completely self-destruct, electrics, various valves, fobs, knobs and doo-dads...
Any hopefulls considering an RX for cheap thrills are gonna get linked to this thread and shall be sent home weeping.
KarlMac said:
Currently have my Evo V up for sale with a view to repacking it with an RX7 for a weekend toy. I'd managed to mentally write off a lot of the horror stories as Internet over-dramatisation.
I'm now absolutely terrified of impending breakdowns and bills consisting of multiple zeros.
Thought of sending you the link to this, then forgot... I'm now absolutely terrified of impending breakdowns and bills consisting of multiple zeros.
Did think of you though - it's heresy but fancy getting a ls powered one so I can buy it off you in a year or two?
Sway said:
fancy getting a ls powered one so I can buy it off you in a year or two?
Or getting a normal rotor powered one, and swapping a sensible engine in once the rotor inevitably sts the bed?I seem to recall the vag 1.8T being a relatively easy swap, and a pretty tuneable engine.
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