Red RX7 Resurrection

[seaglen]

I agree , the pictures look better live than recorded. The edges of the chamber look clean, some badly corroded one's have obvious rust. Also rotor housing surface is consistent, problems in the spark area usually continues to the exhaust port in some way. Main issue may be galvanic erosion that won't show up in the chamber anyway. I think given the mileage on the engine it's worth running if possible.. I expect surface rust on the side housings will wear the oil seals and m make the engine smoky meaning a rebuild anyway. MAin purpose of camera was to make certain there was no obvious problem inside

[seaglen]

OK I finally got the turbo off the car and started cleaning it up. I Also removed the water pump and alternator that I quickly painted before when I put the engine in the car but are now quite shabby. The heat shields on the turbo were quire corroded. They have quite a dull phosphate coating or very thin galvanising, this has been corroded by either aluminium oxide or iron oxide form the other engine parts getting on them so just polishing them wasn't an option.
As these are going to get hot, but not red hot I chose a silver engine paint which will do for other untidy aluminium parts as well. Man is it shiny. I had hoped it would be closer to the original finish. I can always take it off and re-plate the panels if I don't like it. I'm going to use the electrolytic rust treatment with the washing soda and battery charger for the corroded bolts I take out so those can be reused later. In the meantime I have some heat shield bolts from a series 6 rx7 that are identical. Hint- always collect bolts and electrical parts and wiring, plugs and bolts are hard to get and expensive to buy. My Ford Laser/Mazda 323 donor wiring loom has many parts in common with early RX7.

OEM Finish complete with rust

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Bright and REALLY!!! shiny

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Ford Laser/ Mazda 323 donor loom, coloured wiring is expensive to buy

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[seaglen]

The turbo itself wasnt too bad, some powder corrosion on the cast iron and aluminium but not as bad as the front cover and airflow meter. I used oven cleaner on the aluminium with a wet cloth to remove the gunk. The waste-gate diaphragm housing had the same finish as the heatshield, so got the same treatment. The oil drain line cleaned up Ok just with some white spirit. I really just want to clean stuff up at this stage, Restoration can happen when the car is on the road, but this will get a bit more cleaning before it goes back on. Before and after photos. Also finally got the O2 sensor off. It was still tight from this position. Note to self, dont over tighten.

Before

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almost after

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front

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[seaglen]

Water pump was worst with powdered oxide emerging from the paint. Cleaning showed little paint left on the metal. This cleaned up nicely with plastic stripper wheel and wire wheel, also some hand scrubbing in the hard to reach areas. I used an epoxy single pack spraycan gloss black with anti corrosive additives. The photo shows the pump before cleaning.

I took apart the pump to see if the impeller had eroded. It was all in good condition. No sign of cavition marks in the pump housing.There are some small bubbles of metal missing from the impeller but nothing major. You'll notice the 'tide mark' which shows water level during storage. Most corrosion was in the airspace, so if you are storing an engine wet make sure its full. I did buy a new aluminium replacement shaft and impeller housing but I'll keep this as a spare as the new part doesnt have the low cavitation oem version which Mazda designed for high rpm use. New Aluminium part is QMB Japan 145-1180 ($NZ 32) ex EBAY

Water pump before with tide mark

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New part

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The paint requires mostly bare metal so I lightly polished the housing a bit more after this photo was taken. Notice all the rust under the paint. Note also the second sensor hole for the ECU water temperature sensor and the corroded return pipe from the warm up idle pellet on the throttle body. I cut the corroded end off the pipe, its still quite thick at the pump end and will hold the hose on OK. The other hole is for a Cosmo temperature sensor which I'm not using.

Result was obtained with one coat directly onto metal as the expoxy required no priming.

Before and after

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[seaglen]

I had painted the alternator black when I installed the engine. Its off my original series 1 as I found the 2 wire Cosmo alternator wasn't working, bonus was I didn't need to change the charging circuit. The paint is now looking seedy so is going to get a new coat. Also whenever you remove an air pump from a rotary using vbelts you must change to a 2 sheave alternator pully as the water pump no longer has sufficent drive from one belt due to the geometry which now tends to slip even if fully tensioned. I had bought an RX3 alternator off Trademe for $NZ60 for the pully as I knew my RX2 pully fitted OK on an RX7 alternator. Not in this case, the hole in the pully is elongated as it locks on a flange on the shaft. While I could shim it, life is too short.

alternator and 2 sheave RX3 pully

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Other issue was the Thermostat housing outlet . This was badly corroded when I got the engine. Most likely as a wiring loom earthing point attaches here. Its the GSL-SE type part number N236-15-170. It doesnt have the dogleg but is straight. I like this design as it must give better flow. While I do have an RX5/Cosmo 13B outlet (which has the sensor port) I'd like to stay with the straight outlet. As you can see the metal is now starting to fail, see the hole near the rim.

Time to failure???

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The Mazda part is no longer available, although they do come up now again at independent parts warehouses and on Ebay. Luckily I found a RX7 parts manufacture who makes them from aluminium billet and tube. Coincidentally they also make a 2 sheave pully. Only $US 18 versus the NZ$65 they go for here. Check out their online store as they also make some great brake and steering kits which i think I have seen other members mention. This includes big brakes for your series 1, a kit to make the front stub axle stronger or a full rack and pinion steering upgrade. http://www.re-speed.com/

Nice parts

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I'll leave the rusty item in place after a cleanup so I can start the engine and then replace it when the new one arrives which I have ordered. Other thing I'm doing is cleaning the water pump pully. Mundane I know but with the corrosion on the pully and the slipping I chewed through a new fan belt in about 40 minutes. I've also got my gravuty fed spray gun so will bee looking to do the inside of the guards and the repairs on the passenger side before the weather gets too cold heading toward Autumn (fall).

[seaglen]

Just noticed a few problems with respeed on this page viewtopic.php?f=14&t=950. That seems to be back in early 2013. Anyone know if things have improved. I will still order and see if things are any better. Will let you know.

[Hobbawobba]

Whoa that looks pretty gone aye. The bits you've painted look so much better. Great how small things can make a big difference! I believe its still best to stay away from Re-Speed unfortunately Which is a shame

[seaglen]

Had some bad weather over the past few weekends but finally go restarted today. I'm starting to clean the intake manifold and the front cover area. Theres a lot of iron and aluminium oxide as you can see in this before photo.

The oven cleaner I used on other parts darkened the aluminium but did remove the oxide lay. More suitable if you are painting it. Make sure to neutralise the oven cleaner before painting. I'll try phosphoric acid which is the other recommended item later, but for now a fine wire brush and some wax and grease removed seems to produce a good result. I also use a 3M plastic scouring pad this produces good results and reproduces the OEM matt finish quite well.

rusty as!

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Other couple of items of interest are my rear shocks and new clutch. You may recall when last started in 2007 the factory clutch was noisy, possibly due to corrosion on the friction and pressure plates or diaphragm or release bearing. Got an eclutchmaster kit off Ebay for $US 108 postage to NZ was $NZ73. still over $NZ150 less than the item sells for here. Supposedly it handles 227HP and 219ftlb, they call it stage 1. As its on a 1985 12a it uses the 1983-1991 Non-turbo clutch which is wider than the 1978-1983 12a ones . I chose this brand as it had more positive feedback than nearly all the cheap ebay clutches. It also features design I have found reliable in the past. I'll run it in properly (500 miles) and let you know how it goes.

rusty as!

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Also got pair of KYB gas adjust KG4644A rear shocks for $US19 and $US 23.75 each. Apparently these perform better than KYB GR2 shocks. I'll have to get GR2 shocks for the front though as there are few alternatives for a 1978.
I'll upload an after photo on the front cover and inlet manifold. I'm also wrapping the wiring on the engine which will be an opportunity to clean that that and taking off the top radiator support panel for painting. Other thing on todo is pressure testing the water jacket. I now have the pressure gauge and will fabricate a block-off plate from 4mm steel. I've also ordered some rubber plugs to block heater outlets etc. Cooling jacket will need to hold 12psi for 12 hours or its strip down time. Will post more next week when this is all done.

[KiwiDave]

FYI, GR2 and Excel G are the same animal, just a rebranding excercise from the former to the latter.

[seaglen]

OK finally back to work on the car after a 6 month break. Unfortunately the car sites in a puddle over winter. Not good I know but I have no other place to work. Besides weather is nicer in Auckland at this time of year.

I assembled the alternator and waterpump. These will go back on once the engine is pressure tested and cleaned up.

completed alternator

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water pump completed

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I also started some old school bumper repair on the front bumper. Then it will be primed and painted along with the inside of the front guards and any other small panels such as the headlight covers that need a touch-up

bumper repair

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