jayrerickson

The time has come for me to start building from bottom up.

This thread will show the process I take step by step for building the bottom end of the 13b. This is not just going to be a rebuild. I will be using parts and techniques that in theory will help the motor handle higher HP.

This is going in a 04 8 6spd. At the moment I am waiting on a host and stand which I should get next week. All that is needed to be done is taking the rest of the harness off the housings, exhaust and mounts.

I figure it would be nice to have a general discussion on the parts and process as I go and put it into action.

First it is time to order some parts. This is where I could use some help point me in the right direction. Where can I get it for the best price in which is good quality. I know I could find them, I would like to see what others have experienced and maybe knows where I can get a deal for it (vendors?).

The parts list.

Where to get 3mm apex seals with good springs?

Would like to use FD side seals and springs. Whats is the best brand to use?

Is there a kit or place where I can buy seal by seal. No point in buying things I don't need.

Where can I find thicker/better bolts for the housings?

I can find the parts, I don't want to spend the money and then a week later find a part that is 50-100 cheaper like I have done in the past. Or get a part that is a unreliable brand.

Its hard to see what is updated and what is not. Some threads I read are over 3 years old.

Will post pics later on what I have going on.

fallafalla

You are probably better off getting a full kit from Atkins or another reputable source as buying parts individually will cost a lot more, 2nd the RX8 has short 2mm apex seals and there really isn't a need for 3mm, I believe the shape of the FD side seals may be wrong for the RX8 rotors too but i haven't directly compared them, as for the larger bolts it is possible to fit a dowel kit, but its not really necessary for an N/A engine.

jayrerickson

That is the debate.

I figure why not as none of it has proof that it harms the motor. Will be doing some sort of porting.

This will have a power adder of some sort. Haven't decided yet.

So the Atkins kit has quality parts? I followed some builds and I swore he said the soft seals for the housing from Atkin were not that good.

fallafalla

3mm seals may increase housing wear and heat from what I've seen and are mostly used when seal grooves are worn, perhaps think about ceramic? and the Atkins kit appears to be OEM parts except for the Viton oil rings.

GK1707

iTrader: (10)

If I'm not mistaken, 3mm seals wont even fit our rotor grooves. You would have to get the rotors milled. Unless their already worn enough for 3mm seals to fit like fallafalla mentioned.

Carbon8

iTrader: (4)

Sub'd

On a side note, you do realize that a proper rebuild be it a DIY or from one of the reputable re-builders on here the price difference is marginal. Now I do understand that you want to DIY for the fact that you just do (I feel the same way). There's just a very large chance that it wont perform or last as long as the re-builds offered from RR, pettit, pineapple etc..

If the car needs to be rebuilt quickly, and is your DD than I would advise against it. My case my car is my project but I still went with Pettit on the account that even if I did do the rebuild to spec their is no way it would turn out as good as a shop who has done thousands of rotaries over the last 20 years. Thats why I have another blown engine laying around I will rebuild for fun.

jayrerickson

I did read that the 3mm will fit with out modifications. Read how this guy installed them for boost proposes, but he never came back on the thread to confirm the longevity. This could be a 3 year old thread too.

If it does fit with out modifications, I think its about the spring pressure that the seals has against the housing for wear and hot spots.

The real question is, is it 1mm taller or wider? I thought it is taller as no modifications are needed. If this is the case, all it would be is the spring is compressed 1mm more then stock. Like putting a 1mm spacer behind the spring. Giving the combustion camber a tighter seal for higher combustion's.

Wear would be minimal as it is the spring that is making the force for contact. It would still have give for more clearance. Probably a few inch pounds of more pressure against the housings.


This is not my DD, it is a project. I have built high HP piston motors before but never a rotary. There is no way I'm going to have someone else build it for me. I have to get my hands into this one. Its the best part of the project.

To me it really seems this motor will be easier then the piston motor.

diabolical1

you need to do more research.

1. no need to machine the rotors for 3 mm seals. it's pointless in the MSP.
2. side seals are in different locations to the older 13Bs. both contour and length will be off.
3. if you want to experiment with different apex seals, it's up to you. however, with the other seals and springs, just go OEM.
4. focus on lubrication, cooling and airflow.

Carbon8

iTrader: (4)

Rebuilding from spec is one thing, but all the proprietary mods that go into Pettit and pineapple motors are what set them apart. Specifically the oil and cooling channel machining they do. All the stuff you wont find in a rebuilding guide, thats what really makes the difference.

Either way goodluck

j9fd3s

Mazda has made several different sizes of seals, the 3mm vs 2mm refers to the WIDTH, and not the height, which does also change between 1968 and now. the 13B-MSP has 2mm wide seals that are SHORTER than the previous engine.

the main force that pushes the seal into contact with the housing is the gasses that get behind it, its the same as a piston engine in that respect. the spring is there for starting.

these engines are much easier than a piston engine, no valves, no cams, no head, no timing chain/belt... buy the engine rebuild manual (its separate) and have fun.

fallafalla

This is a good read for apex seals.

jayrerickson

These are the 2 kits i was looking at.

Atkins Rotary RX8 RX 8 renesis Engine Rotor Kit 2004 to 2011 | eBay

Mazda RX8 RX 8 2004 on Up New Install Gasket Kit | eBay

I think this is a good starting point. The basics of what I need. Have to crack her open to see what else. Bearings might be good.

Sorry 4 the crappy typing, keyboard went out and using the onscreen .

9krpmrx8

iTrader: (46)

Stay away from Atkins, my buddy got bunk apex seals from them recently and he ended having to rebuild his engine after 1500 miles. He had to buy new OEM apex seals and a housing before he rebuilt it again.

My friend was very understanding about it and contacted Atkins in an amicable manner to see if they would give him future credit, refund, etc. Dan basically told him there was no way they were warped because they would not have fit in his jig (whatever that means) if they were and to basically **** off.

The pictures pretty much spoke for themselves and my buddy is a stand up guy who spent a lot of money with Atkins and has no reason to try and get something for nothing.

But come to find out, problems with their seals is not unheard of. Use OEM seals, nothing else.

jayrerickson

Think I will be going with Aluminum-Filled Carbon Apex Seals. Can hold more pressure but has problems at idle. Stock seals will work but don't know it they will handle the end result.

Right now thinking 7-8 psi with 30-50 wet shot. Would like to have n2o with the setup. Many good factors running n2o that turbos cant do and will help the effectiveness of the turbo setup itself.

Is there anything else I can do about heat for the side seals? Other then exhaust wrap.

Read a sticky about how the side seal will give way and tare apart the apex seal. People then will misdiagnose the problem and blame the apex.

Worried that the porting will raise problems about heat being able to transfer faster with thinner walls. At the same time EGT's will be lower with more flow.

Right now what I need is it in front of my face.

I was thinking of dropping the "block" through the bottom, looks like it would fit. Don't want to wait for the hoist to get here.

Can any of you confirm this. Could I take the tranny out and then take the motor out through the bottom with out taking the cradle out with it?

9krpmrx8

iTrader: (46)

@ 8psi and N2O. Exhaust wrap would hurt the side seals more than help. Anything bouncing around in the combustion chamber will hurt the apex seals................

jayrerickson

Whats wrong with that?

Stock seals hold up to 12 psi on a good tune. Having 8psi and n2o with a good tune probably will give me better results then just 12psi. Plus the n2o will clean the IM, cleaner combustion, lower EGT's, lower spool time and you can hook up the purge to spray on the inner cooler.

I read that the side seals is one of the main causes for engine failure. Trying to figure out a solution.

diabolical1

again, more research needed.

don't use carbon seals with forced induction. also, where did you hear that nitrous "decreases" EGTs? if it's a typo or something, then disregard.

9krpmrx8

iTrader: (46)

Yeah there are so many people running 12psi with great results, Even lower psi setups are struggling to last 30k. So if you are cool with that, then ok. You just need to be realistic.

I used to run N2O, explain to me how it cleans the intake manifold or lowers EGT's? Spraying the intercooler is a good idea, that is about it. I was considering keeping my zex kit when I went turbo.

Side seal failure is a common cause of failure on these engines but I would not say it is the main failure mode. On a boosted application it is usually due to poor tuning and too much boost but side seal heat is an issue by design.

jayrerickson

Then stock seals its going to be. Figured try my hardest not to detonate but why take the chance.

As for EGT's.

If you had both power adders next to each other on different motors. Both produces 50hp more. The n2o will have lower EGT's.

One is a super cooled gas and the other is hot compressed air. One has a free flowing exhaust as the other has back pressure, heating up just from the system itself.

Adding them both together will dramatically increase the turbo's efficiency. Mainly cooling the intake charge by 90%. Cleaning the IM by spraying gas through it every time you spray. n2o will burn cleaner letting you get a better read on the plugs. Being able to have more control over the chemical balance between air/fuel and how it reacts in different conditions, raising or lowering psi/n2o. Having an end result of lower EGT's when both systems combined.

The question is, what is the weak point and how do we fix it? Side Seal, is there anything we can do to help this with out changing the design of the rotor.

9krpmrx8

iTrader: (46)

Test that theory yet? So are you going to make your nitrous activation boost dependent? That will get expensive quick. Also, I am interested to know how you plan to tune for the nitrous use?

jayrerickson

Where I'm at.

9krpmrx8

iTrader: (46)

Just remove the wiring harnesses already. No sense in risking damage.

jayrerickson

Yes, I will have a boost activation switch at a certain psi at a certain rpm. Just like you would for a meth kit.

I will have 2 maps. Haven't researched much into the tuning yet but seems COD is the way to go. One for full boost no n2o and one for both. The one for n2o, I will detune the effectiveness of the turbo tune to have both. Cant tell you exactly what it is because I haven't done it yet/research. But timing will be changed, probably colder plugs, adjust fuel maps as there will be a different fuel source, bla bla bla. We will get back to this once I get to this point.

Ether way it is one step at a time. Right now I need to figure out what I should do to the bottom end. I keep reading use OEM but OEM cant handle much.

9krpmrx8

iTrader: (46)

jayrerickson

All that's left is the harness going down the tranny. Still cant find were it goes. Was going to dropped the tranny then find it. Going to clean it up and probably paint it to look new anyway.

Now I have one of you saying to use Atkins and another saying not to.

Can I get some links to other kits...


Can I drop this motor from the bottom with out getting it stuck. Would like to see what I'm dealing with before I order a kit. If I need the master with everything or the basic kit (doesn't come with bearings).