Build thread

Regulator · Postby **Regulator** » Mon Apr 09, 2012 9:14

Reading this makes me wonder what the rotary engine could be if companies stepped up and built some quality parts. Its seems like the same story all across Mazda. Great start, bad follow through (aftermarket).

chickenwafer · Postby **chickenwafer** » Tue Apr 10, 2012 9:14

The rotary engine has had stunted oem development even, considering Mazda is the only mainstream auto manufacture to develop it. German manufacture NSU, Sachs, and Suzuki also made production rotary engines, but all but NSU only made motorcycle and other light duty engines.

Comparatively, the piston engine has obviously had hundreds of year of development and billions upon trillions dollars poured into it. It's really impressive that with such little development time and money, the rotary is even where it is.

The aftermarket support for the rotary is limited to mostly speciality shops, like most aftermarket Mazda part is seems. In the past couple years, however, we have seen an influx of new apex seals that work better than previous versions, and machining technics to save reviously unusable parts.

D Walker · Postby **D Walker** » Tue Apr 10, 2012 9:14

There is actually a lot of rotary engine development out there as powerplants for aircraft including UAV's etc. and it is this R&D that is driving the leaps and bounds we are seeing in rotary engine technology.Most of this research is based around longevity, fuel usage, and power to weight, which has remarkably few implications for high output street cars. However, what is applicable- Nikasil housings, apex seal material and design, rotor and bearing coatings, will all make huge leaps in modern rotary performance, and it is actually becoming more affordable. Goopy has its metallurgy done by literally rocket scientists and have gone through numerous revisions of their alloy to come up with what they have now, which in my experience breaks in faster than any other seal I have used, is kind to the housings, and I have yet to hear of one breaking, ever. ALS uses the same alloy as an early Goopy seal and it works OK, but is no longer cutting edge.

The piston engine on the other hand, has not seen a significant technological or design improvement in about 80 years, it is all just refined here and there. Anything that they come out with as "new" is stuff that was done more than likely a 100 years ago back when innovation and ingenuity were rewarded in this country.

speedjunkie · Postby **speedjunkie** » Wed Apr 11, 2012 9:14

Hey Don, depending on what I find when I tear the engine down tonight, I may get one of those rebuild kits from you. Although all I'll probably need is the oil rings, etc, not so much a whole kit. I may pick up a set of Goopy seals from you as well. What kinda price am I looking at? And is there a way you could overnight it? I'd like to be putting this back together by this weekend if possible. Thanks!

I got the engine ready to pull last night but figured I'd wait til tonight to pull it. I turned it over several times last night and nothing came out the exhaust ports.

D Walker · Postby **D Walker** » Wed Apr 11, 2012 9:14

Dude you are so lucky, as I am coming through CSprings pretty much every day this weekend as I travel back and forth to PPIR for the NASA event, and I can absolutely have a set of apex seals sent in to you no problem, just give me a call and answer a couple of questions for me and they are on their way. Will be glad to drop off a set of 0-rings etc. or take a look at anything you need me to.

speedjunkie · Postby **speedjunkie** » Wed Apr 11, 2012 9:14

We got the engine out right away tonight. Looked in the housings through the exhaust ports. Zico found a chip on the rear housing where it meets the center plate. As long as it doesn't spread I'm not too worried about it, but there's no guarantee it'll be ok. The oil pan was definitely only sealed with RTV. We also found some oil and assembly lube coming from both sides of the rear housing on the drivers side. That was disconcerting. I'm hoping the oil was just being sprayed out and the assembly lube attracted it. Not sure where oil would come from there anyway.

I tried removing the front bolt with an electric impact gun. No go. That's the most terrifying one for me. They're always such a pain to get out. Makes me not even want to tear the engine down. It doesn't look like too much of a problem in the housings from what we can tell, maybe some accelerated wear already from the apex seals.

What I might do is just fix the pan sealing problem for now, and in the mean time build another good engine for standby. But I'm so scared of home built engines now since I've been told they're so crappy. I mean, my first home built engine only lasted about 35-40 thousand miles, with heavy abuse. Whereas this professionally built race spec'd engine that cost me close to $4k lasted a whopping 1000 miles if that before having problems, so I definitely see his point. LOL

Thanks Don. I'll let you know. For the record, they're 2mm seals.

VRx8 · Postby **VRx8** » Thu Apr 12, 2012 9:14

Just pay another 4k and hope it doesn't burn oil. Lol I don't think that there is any tricks or secrets on putting a 13b together.

D Walker · Postby **D Walker** » Thu Apr 12, 2012 9:14

What did your plugs look like when pulled? Can you post pics of them?
Can you take pics of the other things like the chip in the housing your concerned about and post them?
That front bolt can be a serious PITA, if you need help with it just let me know.

There is no secret to building a 13B, but there is a lot of attention to detail that goes into building a good 13B. From the sound of it there is likely nothing major going on with your engine that couldnt be corrected with a few good parts and a couple hours fitting it together.

I will be passing through the Springs several times this weekend, so if you want I can drop by and take a look at what you have going on there.

chickenwafer · Postby **chickenwafer** » Thu Apr 12, 2012 9:14

So are you still unstacking the motor or just resealing the pan and dropping it back in?

I didn't use a gasket on my pan, just a thick bead of The Right Stuff RTV sealant, brand new OEM Mazda pan, and Banzai pan brace with studs. I heard this was the best solution as the OEM gasket is very stiff so it wont flex, meaning it will eventually crack and leak. But I know you said you previously used an OEM gasket with success, so I dont know.

speedjunkie · Postby **speedjunkie** » Thu Apr 12, 2012 9:14

VRx8 wrote:Just pay another 4k and hope it doesn't burn oil. Lol I don't think that there is any tricks or secrets on putting a 13b together.

Yeah I think I'll pass on that lol.

D Walker wrote:What did your plugs look like when pulled? Can you post pics of them?
Can you take pics of the other things like the chip in the housing your concerned about and post them?
That front bolt can be a serious PITA, if you need help with it just let me know.

There is no secret to building a 13B, but there is a lot of attention to detail that goes into building a good 13B. From the sound of it there is likely nothing major going on with your engine that couldnt be corrected with a few good parts and a couple hours fitting it together.

I will be passing through the Springs several times this weekend, so if you want I can drop by and take a look at what you have going on there.

My leading plugs were gunked up pretty thick, but it was baked on, really tough to get off. It was not gooey at all. I used a screwdriver to break through the majority of it, then used a wire brush to clean off the excess. I even took one of them over some fine grit sandpaper. The trailing plugs weren't near as bad. I have pics on my phone, but I don't have my laptop right now so I'll have to just see if I can post the pics from the phone. I might be able to get a pic of the chip inside, but I'm not sure the capabilities of my phone. I'll try tonight.

And to answer the rest of this and Dave's question all at once...

chickenwafer wrote:So are you still unstacking the motor or just resealing the pan and dropping it back in?

I didn't use a gasket on my pan, just a thick bead of The Right Stuff RTV sealant, brand new OEM Mazda pan, and Banzai pan brace with studs. I heard this was the best solution as the OEM gasket is very stiff so it wont flex, meaning it will eventually crack and leak. But I know you said you previously used an OEM gasket with success, so I dont know.

I think I'm just going to reseal the pan for now with a gasket and some light RTV on both sides. In the mean time I'm going to order new/low mileage/refurbished housings, new apex seals that aren't so hard, and a rebuild kit. If I put the engine in and don't lose oil anymore, I'll run this engine until next winter or sometime and rebuild the engine then with the new parts. If it does still lose oil, I'll skip DGRR, order the new parts and rebuild as soon as they get here, or as soon as I get back from leave.

I figure if I'm going to rebuild this thing, I want to go ahead and swap the housings as well, because of the chip and also because these seals look like they're doing a number on the housings already. There are a couple questionable scratches on the rear housing. I figure if I'm going to rebuild I'll just do it once I have all the parts, and I can't get all those parts fast enough to still make it to DGRR. We found A LOT of oil on the pan brace, and I also found that I was missing not just the one pan stud, but two studs, and they did in fact have a hole they could have threaded into, unlike what Rich said about "well, we wouldn't have just left them out of there, there probably isn't a hole there". Yeah right. So I guess I'll either find a couple more studs to put in there or I'll just put bolts in.

And I'm definitely using a gasket haha. I'm wondering if maybe I pressurized my oil pan enough to blow a hole in it to lose the oil.

Here are the facts (albeit quite a bit late lol)...

-It did not lose oil right away, only after several hundred miles.
-The day it started burning, I had given it some boost and I had a hose from the filler neck going through a check valve and to the UIM like stock. I did not have the other hose on the neck going to the intake pipe, also like stock.
-I'm still pretty sure at least the original turbo is bad and burning oil. I don't think I'm smoking as much as I was at MAC while getting tuned. I am still smoking at startup though and a few other times.
-I don't smell 2-cycle burning, and I should be. I'm injecting 2-cycle through the OMP and also premixing.
-I'm losing oil, but I'm not 100% sure if I'm burning it or losing it from the pan.
-When I removed the turbo and exhaust before, I ran the car and no smoke came out, indicating the problem was in the turbo.

I don't remember what else right now.

Website · Postby **Shadowden** » Thu Apr 12, 2012 9:14

That sucks....I would offer the mz3 for DGRR, but somehow, I don't think it would suffice.

Best of luck with the new oil pan seal doing the trick. I hope it works.

speedjunkie · Postby **speedjunkie** » Thu Apr 12, 2012 9:14

Thanks, I hope it works too but I can't say I'm counting on it lol.

D Walker · Postby **D Walker** » Fri Apr 13, 2012 9:14

if it doesnt I have two spare engines I would be glad to loan you, ready to drop in quickly.

speedjunkie · Postby **speedjunkie** » Sat Apr 14, 2012 9:14

Well I'm planning to drop the engine in tomorrow, but my IC and piping are being powder coated until tuesday lol. Luckily I have some extra piping I can cut up and use with my old IC in the mean time and test the car.

Thanks Don, I'll let you know.

I put the oil pan back on tonight, along with a few other things. I removed the LIM so I could look through the intake ports while turning over the engine. Looks like the outer metal ring that holds the outer oil control ring is halfway passing over the port as it goes by. It doesn't get as far as showing the space between the two rings, but still...

So I think I'm gonna go back to stock ports on the next engine.

I also noticed oil on the upper middle bolt while taking off the LIM. It's the hole on the side just under the primary injectors. There is absolutely no reason for oil to be there. So I'm really confused on that one lol.

Postby **RX-7 Chris** » Sat Apr 14, 2012 9:14

have you checked the coolant to see if there is oil in it?

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