I am currently awaiting a reman from Mazda, so I thought it is a good time to tackle cleaning/testing all the ancillaries. I have removed the SSV and VDI from the LIM, and plan on taking a soda blaster/blast cabinet to the outside of the LIM and maybe the SSV and VDI, but because my engine has 100k miles on it, all the inside passages/runners of the LIM are filled with carbon, and I am not sure how to get it out. I cannot fit a soda blaster (would be perfect) into the passages, nor can I fit my wire brush in more than an inch or two. I have searched, and not found anything on the topic; any ideas?

 

Some may disagree with my method, but I sprayed chemicals into the runners periodically every 10-15 minutes to soften the carbon up and flush out the loose bits, then I grabbed my electric pressure washer after every 4th soak and sprayed water down into the runner to flush out the cleaner and hopefully break free and clean the runners out. For the outside I simply used Chemical Guys wheel cleaner followed by the Chemical Guys Decon Pro Iron remover to clean the exterior of the LIM and scrubbed with a cheap toothbrush. I repeated that process until I was satisfied with the results, and made sure to sufficiently dry the entire manifold and applied a light spray of wd40 to protect the inside and outside surfaces and the appropriate lubricants on moving parts. Be sure to remove any and call electronic components that could get damaged and/or completely avoid the components should you choose the method I used.

 

Sounds interesting... I will try it...

sounds stupid, but I take it you removed the APV motor?

 

No I didn't, I just took extra care cleaning the APV runners and made sure to lightly re-grease the gears and actuators after finishing cleaning them. I made sure anything delicate I did not spray or wet directly.

The components "are delicate" technically, as they are sensitive and you need to take care not to damage them. However that said, a lot of it is exposed to elements on the exterior and the entire assembly does heat cycle with every use of the car. Cars have the block go from ambient to operating temperature several times a day for years and years. Just use common sense and caution when cleaning parts and you should be just fine.

 

Well if you’re going to soda blast it then you have ne choice but to full disassemble everything. Otherwise you’ll end up with fine grit in places where it shouldn’t be; like the APV actuating mechanisms.

 

Yea, that's true... I don't have to soda blast it, I just want to to make it look nice; if anyone has any seggustions for something that would make a old LIM look half decent, then let me know...

Maybe this is a bad idea, but I am tossing around the idea of painting it with a light coat of gunmetal engine paint, just to prevent the light surface pitting/corrosion in the future...

 

You can clean it with water and spray an acid wash on it and then spray it off. Napa sells it and it does an excellent job on aluminum. I clean all of my aluminum engine parts in it. You need to take care and ot let it sit too long before washing the acid off. You can always spray it again and wash it off. A rinse lather repeat process. Works very very well!!

I acid washed the intake manifold in my Porsche 944 a few years back and it turned out great. Much brighter than the aluminum cam tower next to it:

 

Have been away for the past week or so, just seeing this now...

I really like the acid wash idea, I think I will try that. The whole thing I was getting at with the soda blaster was to remove the pitting that has happened over the past 100k miles. It is not huge amounts of pitting, almost exactly like the cam tower in the picture. I basically just want it to look decent when I put it all back together.

 

Acid wash is going to provide that ugly dull gray industrial finish. Bead blasting or rotary wire brushing is going to provide the brighter look that most people are looking for. Brettus post a brushed LIM pic recently. Alternatively, painting, powder coating, or other coating processes are going to provide the best look when new. What it looks like later is going to depend on many variables, but there are aftermarket coating processes that will likely last longer than you own it if cared for properly.

.

 

https://www.rx8club.com/series-i-maj...4/#post4905338

 

Gee, that pic that Brettus posted looks really nice... not sure, might just end up going with the acid wash, as (I think) it would be less work.

 

I’m betting that it either won’t look any better or you’ll end up doing it the right way when you realize it still looks like poop.

 

I would paint it if that's what I do... I have some time because Mazda is out of stock of remans right now...

 

Well regular paint is tricky, but with enough care and prep it might not lift or flake off. The ceramic etc coatings likely makes the most sense for long term durability. Saw some pics of engine parts in cerakote with a darkish bronze/gold color over on RX7Club that looked pretty impressive.

https://www.cerakote.com/gallery/?htids=1393

 

I had my first one acid washed and it came out mint . Was a much better way to clean it up than what I just did .

 

Haha, well I convinced myself to send out the S2 LIM to be coated

 

I bought some high temp ceramic clear coat ..... then read the instructions lol . Seems it needs undercoat ....which isn't clear

 

I will probably just paint it... the car does have some rust, and with northern new england winters, and all the salt, even with the best of measures, it will probably only last 5 or 6 years at most, if I can get that out of it with it looking half-decent, then I would be thrilled

 

I had forgotten about this option, looks like a great way to restore metal parts like aluminum castings to a new, brite finish

https://walter-motorsports.com/vapor-honing

check out the photo gallery at the bottom of the page, those transmission after shots blew my mind ...

 

Wow, that is crazy... Those transmission shots are crazy.

I was doing a little bit of searching about cleaning the VDI and SSV, and a few people just soaked them in a bucket of carb cleaner, with great results. I think I am going to remove anything sensitive from the LIM and just get my hands on a lot of carb cleaner (ideally a big bucket), then soak the whole thing for a day or so... then I might sandblast the outside, and I forgot where I saw it, but I saw a can of Rustoleum crystal clear enamel. That might work alright to protect it.

 

Yeah, I use lacquer solvent for soaking the internal parts and they all came clean, but those are not the same kind of deposits and stains as externally and they’re also smooth precision castings not like the rough exterior. I wouldn’t expect too much doing it that way.

in the link above they told me a full set of trans casings takes about an hour. You should just disassemble the LIM and sent it to them imo.

 

Only an hour? I thought it would be much more expensive... I will definitely do them if that is the case.