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Oct 11, 2017 13:58:25 GMT
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I'm going to replace every single bush, and wearable suspension component. So: - Bushes - Shocks - Springs - Bearings
Also going to get some rebuilt rear calipers (because after stripping mine down they're not worth fixing), I'll also be upgrading the curse word wiring and the useless alternator.
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Oct 12, 2017 18:47:27 GMT
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is anyone else not seeing the pictures ?
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Oct 16, 2017 19:30:27 GMT
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They're still showing for me. Anyway, some updates. The car had been having some problems with the fast idle when cold, namely that it didn't work and I had to blip the throttle like a two stroke to keep it running when cold. I imagined this would be a sticky mechanism, so I set about removing the throttle body and stripping + cleaning the mechanism. This fixed my stalling when cold problem, but at this point another problem manifested. Now the car was idling incredibly rich, popping and spluttering, it also wouldn't idle above 500 rpm. When driving it felt OK, but down on peak power, with a big flat spot near the redline. I had the intake on and off several times, checking all hoses, and anything that could cause a problem... Nothing. Now I had heard that the ACV on these can cause idle issues, so I decided just to get rid of it, its purely for emissions anyway, I dabbed up some ally blanking plates and installed. I also had to make a temporary solution to block off the pipe that injects air into the exhaust manifold as I didn't want hot exhaust gasses filling my engine bay. This made naff all difference to the idle, but it did make the exhaust back fire on every single gear shift, even while cruising at 30mph! A friend driving behind me said that literal flames were coming out the exhaust, very initial D, but not so good for the engine or fuel economy. A test of the plugs showed obvious problems with the front cylinder, with massive carbon build up compared to the other one. Unfortunately shortly after these photos, the engine refused to start. A compression test reveals what looks to be a broken or hopefully stuck apex seal. The forward cylinder had good even pulses of compression, the rear was very erratic. So I think I've blown up my first rotary. Damn. With an engine rebuild now on the cards there was no real to spend any more time on this car, so I've started cracking on with the good chassis to hopefully get it ready for next spring. Again, I'm surprised how overall rust free this chassis is. The plan is to strip what I can off and seal the underside / under the wings / bumpers etc with epoxy mastic. Underneath I've removed the fuel tank, brake and fuel lines, the last suspension bits, rear towing eyes, pretty much anything bolted on. I plan to underseal in stages, if I try and do it all in one go then it'll be a bit overwhelming, so first the rear, and then the front. The chassis rails looks like they've taken a couple of whacks, but the chassis looks straight still. I think I'll put MX5 frame rails on to stiffen it all up. In preparation for a Megasquirt stand alone ECU I've stripped out all the wires I will no longer be requiring from the standard engine harness. As you can see quite a lot went into the bin! And finally to sort out the awful electrical charging. (The alternator can't even keep up with the electrical loads from the lights driving at night! I picked up an RX8 alternator. The pulley was the wrong size so I got a double one off eBay, as I'm deleting the air pump this allows me to run two belts on the waterpump for added security. It doesn't quite fit yet, I need to make up a spacer to let the pulley fit. That's all I've got for the moment, quick question for anyone reading this, whens the best point in a build to go to the body shop for a respray? As soon as the chassis can roll, or as the last job after all else is finished?
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ian65
Part of things
Posts: 276
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Oct 16, 2017 20:15:31 GMT
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spray it as soon as you've got a rolling shell
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luckyseven
Posted a lot
Owning sneering dismissive pedantry since 1970
Posts: 3,839
Club RR Member Number: 45
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Oct 16, 2017 21:29:53 GMT
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Unfortunately shortly after these photos, the engine refused to start. A compression test reveals what looks to be a broken or hopefully stuck apex seal. The forward cylinder had good even pulses of compression, the rear was very erratic. How many "faces" have you lost compression on? And are you using a normal piston engine compression tester? They're notoriously inaccurate on rotaries; the three "strokes" per revolution confuse them horribly. Anyway, if you've broken an apex seal then you'll only have compression on one face out of three on that rotor as two chambers will no longer seal (either side of the tip). If it's only lost compression on one face then it's a stuck sideseal... they literally glue themselves into their groove but it's pretty unusual to break one. Scant comfort, you'll probably have to take it apart to fix it anyway but a sideseal gumming up is infinitely preferable tot he catastrophic damage an apex seal cutting loose will probably have caused. Good job it's not a turbo cos it'd have beastlified the hotwheel into the bargain
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Last Edit: Oct 16, 2017 21:30:36 GMT by luckyseven
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Oct 16, 2017 21:59:06 GMT
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I removed the schrader valve so that it wouldn't stop at the 'maximum' compression.
As you say its not easy to accurately read, but on the FWD chamber I get nice even pules. On the aft one I get a couple of lows then a high. I'm not exactly sure of the number of pules as its all happening quite quickly, I'm hoping its stuck due to carbon build up.
I've got a USB boroscope camera arriving from Amazon tomorrow (£10!) so I'll be putting that in the plug holes and rotating the engine to get a good look.
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Oct 17, 2017 12:59:39 GMT
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Video footage of rear cylinder: View My VideoApologies for the quality, I really needed 3 hands for this job. It 'appears' that all 3 Apex seals are there, plus tons of carbon. Thoughts?
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Oct 17, 2017 13:20:11 GMT
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Following with interest. Had one a year ago but i sold it as i didnt have the funds to do what i wanted.
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Oct 18, 2017 20:51:47 GMT
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Did one of the rear arches today. Absolutely no rust, not even a little bit. Time to keep it that way. That's one of about 6 lots I swept up, most of it landed in my hair, face etc. Took about 2 hours grinding with a knotted wire wheel to remove the underseal and paint. I did try to strip it with white spirit, but it had naff all effect. Note it doesn't matter that I didn't get every tiny bit of paint etc off, as long as its a good surface, with nothing loose. Next I mixed up my rustbuster epoxy mastic. This was actually pretty difficult, I should have heated it up before hand, the colour was easy enough, but the catalyst / hardner was gloopy. I thinned it down 10%. In hindsight I should have gone 15 for better flow and coverage. Still I got the job done, I'll have to do one more coat as it was still to thick and there are a few places where the brush dragged and the coverage wasn't as good. Of course spraying would have been better, but I don't have the equipment. After the final coat, I can't decide if I should cover it up with some wheel arch wax as well for extra chip protection, or leave it as is so I can see the condition of the metal.
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Oct 29, 2017 15:32:59 GMT
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End of week update. I've been getting on with stripping and undersealing underneath the rear, probably one of the most awful jobs I've done on a car. Dust, dirt, bit of underseal landing in my face, hair, clothes etc. Progress is very slow. Anyway, so I coated the other rear wheel well. Rear stripped down and ready. Time to crack on. Again, I don't have to take off all of the paint, just anything loose and to key it. Obviously the epoxy won't go over the rubberised under-seal so that has to be covered. I gave the rear bumper bar a couple of coats of black enamel after some rust removal and priming. The rear of the wheel well was coated with epoxy and then oversprayed with black enamel, the reason for this is that its actually slightly visible below the bottom of the bumper, so I needed something a little smarter. Also the epoxy doesn't like UV. Fine under the car, but not where the sun can touch it. Finally some pics of the undersealing, I'm as far forward as the prop tunnel, I'm having to do this area in sections as it takes a long time to get into all the nooks and crannies. In future I'd buy the equipment to spray as the finish would be far better. I'm not too sure if I'll leave it red, I may overspray with a paint chip coating to smarten things up a bit and to ensure coverage in the areas that were hard to get to. I'm undecided. I also picked up these: They are frame rail stiffeners for an MX5. I've seen an article on the RX7 forum that shows them being fitted to an FC. As my rails are pretty damaged, these should be a good addition.
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adam73bgt
Club Retro Rides Member
Posts: 4,865
Club RR Member Number: 58
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Oct 29, 2017 18:12:52 GMT
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Nice job, must be very satisfying to see all that metal underneath covered in nice fresh paint, I know mine would certainly need it if I could be bothered to get round to it haha Ah is that well at the back for the spare wheel on the coupe? they kept the well in place on the convertible also despite moving the spare wheel from there to behind the seats Interested to see how you get on with the frame rail stiffeners
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Oct 29, 2017 19:08:56 GMT
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Nice job, must be very satisfying to see all that metal underneath covered in nice fresh paint, I know mine would certainly need it if I could be bothered to get round to it haha Ah is that well at the back for the spare wheel on the coupe? they kept the well in place on the convertible also despite moving the spare wheel from there to behind the seats Interested to see how you get on with the frame rail stiffeners Well its quite viscous stuff, so its leaving brush strokes. Which in itself isn't a problem, I'm just hoping I'm getting enough coverage on everything. I may end up over coating with something else. If you're interested, this is someone else's frame rail installation. Might be a good shout on your vert. www.rx7club.com/2nd-generation-specific-1986-1992-17/how-reinforced-frame-rails-1088241/
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Interesting build! I always loved RX7, iam scared of a rotary tho...
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MX5 NA daily BMW E36 M52 Saloon driftcar
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Oct 31, 2017 11:18:10 GMT
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Yesterdays progress. Its been getting pretty cold, so I'm having to bring paints epoxies inside to sit in the sun by the window to make working with a bit easier. Epoxy is great stuff, but a real pain to mix up. The colour isn't so bad, but the catalyst is a bit too viscous to easily measure. Rear half of the car finally finished with the epoxy. Bumper bar reinstalled. I ditched the old (and perishing) neoprene seals and used butyl tape to seal the holes. This stuff lasts forever, and if it keeps saltwater out of my boat when the decks are awash then I'm sure it can cope with a few puddles. Today's plan was / is to carry on with the sanding underneath, but its raining so it will have to wait. I'm also thinking of investing in a compressor and LVLP spray gun to do the rest of the underside + epoxy prime the car. Watch this space.
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kitch
Part of things
Counting his chickens
Posts: 157
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Oct 31, 2017 13:52:52 GMT
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I love these cars, following with interest!
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Thanks for the comments, glad to know people are interested. Anyway, progress. Some parts arrived from the US of A, for a relatively modest price which was promptly doubled by customs and the scalpers at Parcelforce. Included is a clutch alignment tool, a pilot bearing tool and most importantly a fly wheel locking tool , but more on that later. Since I was feeling motivated I decided to crack on with some jobs that I'd been putting off. First to succumb was the sticky petrol cap release mechanism, cleaned and lubricated. Next in my sights was the steering wheel, which is in the way of the dashboard removal. Ostensibly an easy job, however it appeared to be unhappy with the idea of parting company from the column it had been part of for so long. A combination of a gear puller and a lot of hitting finally got it off. Fortunately I had the foresight to leave the nut on and stop it getting the last laugh by smacking me in the face. While I was in the groove I pulled out the instrument cluster, which was elementry once I realied I could push the speedo cable through from the engine bay and gain extra working room. Finally I coated both rear wells with an anti stone chip paint. (2 coats) In theory the epoxy doesn't need it, but I'm paranoid about Rust and its impossible too be careful when defending against the old adversary. I know I have some red bleeding through, the can ran out and I need buy another. Another post to follow.
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Now onto the good stuff. Since the engine I was planning to put into this Rex is no longer operating, I had no choice but to face the dark and expensive path of the rotary rebuild. However at £1500 quid for the absolute basic rebuilds this was definetely a job I'd have to do for myself. Now the engine was stripped down to just the block, however there's one thing standing between me and opening this Dorito sandwich... The flywheel nut! Previous attempts at moving this had proved futile, it laughed in the face of my ryobi torque wrench and eluded any attempt to lock it place so I could swing on a bar. The problem is that apart from being ridulously tight from the factory, they also use red loctite, which is unfortunately rather too good at what it does. Finally I decided to get the correct tools, enter the afformentioned flywheel locker. I also bought a gas torch to free up the loctite. With these weapons, nothing could stop me. Unfortunately my best attempts last night made no impact, despite heating with the torch, even with applying all the force I could on a 1m breaker bar it just wouldn't budge. After sleeping on it I got out of bed with just one goal. Get that curse word off. I borrowed a 3m fence aluminium scaffolding tube from my neighbour and after letting the nut cook for a while I gave it everything I had. Yep, it broke the breaker bar. Now my socket is actually for a 3/4" drive, and the breaker bar was 1/2" with an adaptor. Determined not to be beaten I headed down to machine mart and picked up a monster 900mm 3/4" breaker bar. Back in the garage, the next problem was that I was applying so much force it was not only tipping over the engine, it was lifting the large double decker rolling toolbox I'd put on top to stop it moving! Eventually I ended up having to put ANOTHER engine on top of the stand just to hold it down, and even that was starting to lift off. This finally did it, the nut came off with the noise of a gunshot! The socket fired off the bar and ricocheted into the wall, luckily avoiding anything expensive. Now I could start on the engine teardown properly. First came the sump. Then the oil pick up. Oil pump, counterweight, chain, torrington bearing, spacer and stationary gear. Flip the engine, and remove all the tension bolts. Time to open this bag of Doritos. I'm taking the time to label the seals incase I end up reusing any of them . If they are well within spec I see no reason not to. This is where I finished for the night, the other half will get disasmbled tomorrow.
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ian65
Part of things
Posts: 276
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good work... what condition are the housings in? Are you going to hand lap the plates?
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Cheers. The plates I think (at least for the half I've done) are OK. Despite there being visible wear marks, they can't be felt using a finger, completely imperceptible.
The first housing I'm not so sure about, there's definitely some wear I can feel in parts of the chamber. I'll have to do some research on what is and isn't acceptable.
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ian65
Part of things
Posts: 276
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main issue is usually chrome chipping from the edge of the housing... less than 3mm from the edge is ok. If you use new side seals then lapping the plates slightly will take the shine off them and help the seals to bed in... a bit like glaze busting a piston engine for new rings.
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Last Edit: Nov 1, 2017 20:28:42 GMT by ian65
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