just took apart my engine and to my susprise....
 

i pulled the lower intake off and found some very odd things.

1. there was an "o" ring in coolent passage closet to the firewall, what it was doing there I don't know, its really large and oval shapped

2. the coolent port in the front is clogged with some type of white grainy substance, looks like rice, but smaller bits.

3. I had porting done on my last rebuild. when he ported it, he only ported the engine side of the intake, the intake its self now has smaller ports than the engine. oh and on top of that he reused what looks like the very orginal gasket, it broken in many places and falling apart.

I have pictures of all this that I'll post when my friend uploads them. This is just more to add to my list of complants, but what really baffles me is the white stuff in my coolent passage. You guys don't think that he put that there on purpose to make my engine fail? Cause if so, it worked, it seized 7 months after I got it. I'm going down there tomorow to drop it off, I'll let you know what he has to say.

Chris

who ported your engine so I know to stay away from him?

I'm with you, stay the hell away from that man.

The stuff in your cooland passage is coolant that dried up.. This mean that it was probably not sealed well & was leaking..

-Zach

I heard that Water Wetter will leave a white substance behind in your engine. Were you using plain anti-freeze or something else?

Yeah, I found the same thing when I opened up my first t2 motor, had bad water seals. The o-ring that you noted near the firewall...where the stock lower intake bolts to the block, in the rear rotor housing, is SUPPOSED to be an o-ring for that coolant passage. IIRC this is the water feed for the turbo. The problem with my engine that time, apparently caused the whole thing to overheat(before I ever owned it) and then bad water seals due to overheating, was someone has installed that o-ring poorly and it did not seat, and thus leaked badly. All the coolant passages had shitloads of white stuff in there, like coral reef or some shit. Its just dried coolant. Ever open the radiator cap when hot and had some of it spew onto the surrounding stuff? It leaves a white residue...coolant.

Whats the word on your engine getting fixed then? I can do rebuild/ports for $1200 btw, and we've done business before so you know Im trustworthy. You can even watch me build it!

who else than rotar sports. i am the one driving us down there in my dads truck

Re: just took apart my engine and to my susprise....
 

Hmm, that sounds like couscous. I think that it's the Moroccan method of modifying a car, kinda like "ricing-out" a car in the US. :D

couscous is the shit, i love that stuff
garlic is the best, i need to get my mom and have her make some MUWAHAHAHAHA

well if jacob had spelled it right, yes, it is Rotor Sports. I'm taking my engine down there today to have in warranty work done. He damn well better not charge me! you guys have seen all the problems i've had.

1. What would cause the coolent to dry like that and block the whole passage?

2. As for that O ring, its way, way to big to be a seal between the lower intake and the engine. To tell you the truth it looks like the o ring that goes around the inside of the OMP.

3. As for the ports I'm not sure about there size, I don't have a micrometer, but you can look and see the difference with your eyes.

Kevin, I would surely let you rebuild my engine, but its under waranty right now so I want even touch it. All I do is add gas and change oil.

I'll get those pictures up soon.

ok dropped my engine off today. I asked him about the coolent clump thing and he kinda danced around the question. He says that you can plug those passages with out ill effect. if you do that it will stop the coolent from flowing though the intake. why does coolent flow though there anyway?

what all coolent lines can be removed from the TB. I remember reading some thing about a TB mod where you can remove the coolent that flows though there, where else can I block off unneeded coolent lines? I know there is one on the top of the engine. if seems to me that if you block those off you will get better flow though the engine and cooler air intake temps. please please correct me if i'm worng.

Chris

Chris,

IIRC the coolant flow through the lower intake manifold is the turbo water supply. You wouldnt wanna block that! THe TB mod most people speak of for t2s is removing the cold start thermowax and stuff, and capping off the coolant flow from the top of the block near the back, the small L elbow that is SO hard to attatch. From experience, I recommend against this. Instead, get some spare hose of the proper diamter, run it about 9" up off of the block nipple, behind the throttle body so it sticks up and is accessible. Run another similar line the same distance from the throttle body inlet, being sure the line isnt kinked at the bend. Old throttle body hoses from NAs, or the BAC area of t2s work well for this. Now, use a metal connector and good hose clamps to connect the 2. Saves you from having to reach underneath there and connnect it, search for leaks, etc. IF you ever wanna remove the UIM, just discnnect the lines at your joint and take them apart, so much easier.

Ive seen people strip a t2 motor down to nothing but a block, alternator, and TPS, and have them run ok, and it does give you a bit of throttle response that wasnt there before. But for every day driveability and idle quality, from my experience, I recmmend against removing stuff.

then why would he tell me to block it off? He also gave me the idea of tapping the oil fitting on the back of the engine on the drivers side with a banjo bolt with an right angle AN fitting, not replaceing the banjo, but drilling a hole in the top of it for the AN. then running a braided hose from there to the turbo to provide better oil flow.

basicly what i'm trying to do is preform all the mods that will provide either better cooling or better oil flow wile i have the engine stripped down to the short block before i stick it back in the car.

1.There should have been an O-ring at each of the passages.But if you look carefully at the lower manifold you will see that there is only one open passage(nearest the firewall).
2.The white stuff is probably phosphate deposits from the antifreeze.It precipitates out there because there is no coolant flow --it is a dead spot.It is not a cause for concern,every motor I have dismantled or seen dismantled had crap there. 3.According to the Mazda documentation I have,the main purpose of water cooling to the turbo is to prevent frying the oil in the turbo when you shut the motor down.According to Mazda,water cooling reduces the temperature of the turbo(and the oil in it)by about 300F on shut down compared to no water cooling.Note in both cases the temperature of the the turbo actually rises on shutdown.You can dispense with water cooling but the turbo may have a shorter life if you do not manage shutdowns carefully.Mine are still water cooled.

i want to keep the turbo water cooled, no way i'm not doing that. all i have is the hanyes manual and its not real clear on what everything is or does as far as coolent passages go. I now know that there is susposed to be o rings around those passages, but on the one closet to the firewall, the o ring was sucked in the hole.

What's included in the rebuild pricing?
 

You rebuild for $1200? Is that include parts and labor? Which pieces would you be replacing? How do you measure the housings for wear? Does that price include any machine work to bring things up to spec?

Dave

That seems awefully cheap, to cheap in fact for a real rebuild, it seems to me that alot of shops are just doing the rotary equivalent of a re-ring job on motors these days, how many shops actually have a polisher for the eccentric shaft, or a lapping table for the housings and end plates? Putting an engine together with all used parts is bad, putting engines together with half new and half old parts is even worse...Max

Yup. That includes parts and labor, if you bring me a bare block, and leave with a bare rebuilt block. Engine removal, accessory removal and reinstallation, and engine installation are extra.

This is using hurley 2pc steel seals, and the rest all mazda seals and gaskets. This price is for engines rebuilt with USED ROTOR HOUSINGS, thus the $1000 price difference from other rotary shops, who use new rotor housings. Obviously, I recommend using new housings, but this is the alternative for those of us who cannot afford new ones at the time. IF you can, then by all means get your engine built with all new housings, and the end plates surfaced and polished back out to spec while youre at it. The price we're discussing here is to take apart the engine, check parts to see if theyre reuseable(I also have other core engines for this purpose), install new seals and gaskets, and button her up. Porting is also available.

The shops that charge double what I do. Again, this is for those wanting an economy rebuild meant to last in the 3-5 year range. THat gives the poor college kid plenty of time to get a good job and save up to build a real racing spec engine with all new parts, and allows him to drive the car and have fun in the meantime.

True, I wont disagree there. BUt, tell that to Chris in Ashville NC, who just had a 87 t2 engine rebuilt adn ported by a "reputable" shop, costing probably around/over the $2k range, adn it lasted him less than 6 months or so I believe.

$3200 and it was 7 months. The engine is back at the shop. The engine failed due to lack of oil/low oil pressure. The only thing I can figure is that my oil pressure sender must be bad? According to my gauge it always ran at the normal levels. Because the engine failed due to lack of oil its not covered by the warranty, both rotor bearings seized, but they are going to fix in warranty for me. I cant begin to express how greatful I am for that. Before I put the engine back in the car I'm going to check the sender and make sure its good. I'm also probley going to get an oil temp and pressure gauge.

Damn dude that sucks.
at least they're fixing it.

The shop could still be liable. What if he didn't clean the passage well and some debris got into the oil passage. That could clog things up and cause low oil flow/pressure to some areas. I suspect even the pressure could be good to the pressure sensor but still not flow to the bearings.

Maybe the tolerances on the bearings were incorrect. Too much clearance or too little clearance on crankshaft bearings can cause major problems on piston engines, I figure the same for rotaries. I know on piston engines, that whenever you resurface the bearing journals on the cranshaft you have to get new size bearings to match, is it like this for rotaries?

I think it goes something like this: If the gap is too big, not enough oil pressure to maintain the required film of oil between shaft and bearing, if the gap is too small, not enough room for heat expansion.

Do rotary engines use solid bearings?

Dave

Yah there are some exceptions to the rules sometimes, for my job, I often rebuild expensive reciprocating gas compressors, like 6000 bucks for a crank expensive and 1100 for a rod type, corners get cut all the time, and in the long run it costs 3 to 4 times that it would have to do it all right the first time.. parts machined for new clearances with parts that are out of clearance or borderline never seem to get along that good, and end up taking out other parts,just my experience and .02 though.... Max

If the oil bypass valve in the eccentric shaft fails it can cause lack of oil pressure to the rotors/bearings. This is the one located behind the big nut on the front end of the e-shaft. Apparently, this type of failure does not show as low oil pressure during running - I would have yours tested or install the bypass (apparently its only there to aid in rapid warmup of the engine after starting to reduce emissions)

Henrik
87TII