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I overheated the engine and the inner coolant seal broke, I had already taken the engine out and strip to the bare short block. It is my first time rebuilding the rotary, I have watched the video from Mazdatrix and read few forums, I am somewhat confident but I would like to start a thread and open to all suggestions, I heard we should go for Mazda oem 2mm apex seal and get the upgraded brown inner coolant seal, what do u guys think, the engine is ported with single turbo produces approx 430whp(precious owner built). I have not tear the engine apart yet, getting ready to take it apart this weekend.
I'm not an engine builder, but I'm educated on rotaries. In my opinion, if you're running OEM seals on a 400+ whp car...you're on borrowed time. Seal technology has come a long way in the last 25 years. Brands like Goopy have started producing MUCH stronger seals that can tolerate dramatically more abuse. I'd highly recommend looking into it.
Rebuilding a rotary is one of those things where it doesn't SEEM to be too hard, but there'a lot of finesse things that make the difference between a motor that's OK that won't last long and a motor that has great compression and will last a long time.
Hands down the trickiest part (and what I had LOTS of problems with on my first build) is getting the front cover "stack" right. All the needle bearings, spacers, bearing plates, etc. have to be installed EXACTLY right or you will have some crazy problems.
If you don't have an engine stand and engine stand adapter, get one. The 3-wheel engine stand from Harbor Freight does the job great and get the Pineapple Racing adapter to bolt to it. This will securely (and SAFELY) support the engine to work on it and allow you to rotate the engine - makes installing the front cover stack SO much easier, and also makes installing the oil pan much easier. You can bolt nearly everything on with it on the stand - turbo(s), intake manifolds, wiring, etc. and it's MUCH easier to do that with it on the stand than trying to do it with the engine in the car.
Another big thing here is TAKE YOUR TIME - don't rush it. If you see something wrong or "feels" wrong, step back and figure out why, get online and research the problem. If you see a gasket that's shot or something you missed, stop and order the right part.
As far as seal recommendations, I prefer using the Mazda OEM seals. Many of the aftermarket seals are not metric sized so they don't fit right - they are usually too small, and the manufacturer tells you to "stretch them out" before installing. I built a motor once with aftermarket seals and the seal jumped out of the groove and got pinched on assembly, motor immediately was puking water. Had to tear the whole thing down, re-clean everything, to fix the problem. The OEM seals do great if you keep the car running right - do yearly coolant changes, keep temps reasonable, and they'll last a very long time.
For apex seals, the Mazda seals are good but I wouldn't recommend them on a single turbo car. There's lots of other great options out there that can take a lot more abuse - Goopy, RX Parts, I-Rotary, etc. Do some reading and see what works for you.
Thank u guys for the valuable suggestions and opinions, I will definitely get the pineapple racing engine adapter, and look into the seals suitable for 400+ hp. Will post pics after disassemble and find out if housing and iron plates able to be reused.
At 400+ you should be upgrading the apex seals and thinking about engine studs. The stock seals can break with just a hint of detonation. The stock tension bolts stretch allowing the housings to walk against each other at higher than stock power and boost, leading to premature coolant seal failure. I recommend RX Parts apex seals and the Turblown ARP studs.
I had the same thought, they r only 35 mins from where I work. I will evaluate the situation after taking things apart, would be an option of having IRP to build for me.
I had the same thought, they r only 35 mins from where I work. I will evaluate the situation after taking things apart, would be an option of having IRP to build for me.
Whether you do it yourself or need help, don't hesitate to reach out to me if you have a question.
I had a very experienced former member here (fitzrx7) hold my hand on my rebuild some 12 years and 50k miles ago. It’s still going strong. Based on that experience I agree with DaleClark on everything...if it wasn’t high hp.
As for tips that come to mind....have a good space to do the work...clean and with good lighting. And if you’re re doing it at home do what you can to secure the area from any kids. My utility sink came in handy when de-carboning everything. I used Easy-off and plenty of WD-40 after scrubbing with a brass brush and rinsing. I used old hard seals to make sure the seal grooves were clean. Jon was pretty adamant on getting things really clean. I also remember spending time making sure the new journal bearings were sized right for my e-shaft and I had a trusted shop press those in.
I cleaned my whole garage for the rebuild and thinking about getting a parts washer as well, solvent ain’t cheap lol. The engine hoist adapter coming in next week, will keep u guys posted once taking the short block next week!
harborfreight has 20 gallon parts washer for $99 and i am gonna use 20% off coupon. Found 5 gallon CRC solvent for $106 from advanceauto, again, use 25% off coupon, lol.
i am thinking getting the dial indicator and precision V-block, these two will do the flatness of the iron plate and ecentric shaft. for the housing, do i have need to get the side housing measuring tool? cost $400 from pineapple racing, lol.
I personally don't know but I'm sure someone will chime in.
I vaguely remember CrispyRX7 having a good write up somewhere - either on here or on his web site.
I've had pretty good luck using diluted simple green as a degreaser for my rotary rebuilds. It's safer on the hands (still wear gloves, though) and can be poured down the sink (after you skim off the motor oil). A couple rounds of overnight soaks and a brass brush on a drill are usually good enough to clean irons and rotors. I get about 95% of the built up carbon off this way and it's not very labor intensive as I let the drill do the work and then back in the bath it goes.
Just don't soak the housings overnight as the Aluminum reacts with simple green. A quick dip, scrub and rinse is fine. Also don't use a brass or steel brush on them as it will scour the aluminum. I find the stiff plastic brushes work fine as the housings stay fairly clean.
Received the pineapple engine stand adapter, placed the engine on stand. The previous builder didn’t even use oil pan gasket, he used orange rtv instead, and three bolt stripped from the front cover, hence the oil pan has been slow leak. Tried using the two legs puller for the rear counterweight, no luck, i am gonna get the counterweight puller from racing beat.
The hex of the studs have cracks, is it normal?
r the counterweight hole pattern from 79-85 same as 93? Racingbeat puller specifies for 79-85 Rx7, just wonder if anyone used it on FDs, I’m gonna call racingbeat tmr to confirm.
Front cover should take a metal gasket. I don't know of anyone who HAS used the MAZDA oil pan gasket. I think it's safe to say that gasket is NOT recommended. Search in this section for acceptable gasket maker to use. I used HONDABOND but there are others. I also used a pan brace...it's still leak-free.
Without going nuts I might given it a couple of raps with a brass hammer and used an impact on that puller. Sometimes the quick application of force will break it free when a wrench won't.
The rear counterweight gets pressed onto the end of the eccentric shaft when the big nut is tightened on. Typically it just needs to be hit with a hammer, I usually use a dead blow hammer. You have to hit it to shock it loose, also it's worth putting the big nut back on a few threads to keep it from falling off.
The RB tool is probably the clean way to do it, but I've used a cheap Harbor Freight dead blow hammer for years.
The "cracks" on the bolts are normal, they are left over from the process used to make the bolts. Totally normal and nothing to worry about.
Heated up the counter weight while pulling by the puller, I used steel hammer to lite tap the counter weight, it popped!
Disassembled the engine, found that I may need to replace both housing so and resurface the iron plates, check out the pics below, what u guys think?
The iron plates air inlet port seem to be ported, do they look street port?
Also, r these studs seem to be standard? Look like few bolts r different from the color, most of the the them r black coded.
Thanks again for everyone’s inputs. Front plate Front housing Mid plate Rear housing Rear housing Rear plate
so the front and rear housings are different? according to atkinsrotary. Apart from jdm-planet, it seems front and rear r the same, not only that, it is about $2-300 less than atkinsrotary. i am confused.
most likely i will need two housing, front iron plate, need all other iron plates resurfaced, turblown engine studs, rx parts apex seals. already running up to $4k, with $4k i can get a jdm engine swap. or have a performance shop to do the rebuild? what you guys think?
09-26-19, 10:14 PM
