Kill No Cone

iTrader: (6)

Ok, I have a good running four port 13B, but it seams to have a bad water seal inside. It tends to overheat, and it smokes white smoke when I start, but I don’t have the white foam in the oil. Compression seems to be good and it does not blow blue smoke.

Here is what I would like to do. Pull it apart, port it while it is in pieces, and change the water seals ONLY. Yes, I would check to make sure there is noting really worn, but I was planning on not touching the rotors at all.

I don’t have a ton of money to spend (doesn’t that sound familiar), and I just want to cure the current problem. I have done a couple rotary engines in the past, so it is not all new to me.

Will this work?

LongDuck

For the cost of a rebuild kit, you could do yourself a big favor by replacing all the seals and O-rings at once. I mean, if you already have the thing apart, you might as well take care of all of it at once. Much better likelihood that your engine will last a long longer.

Whenever you replace one thing with new parts, it creates weak 'links' in other systems that will soon crash. This happened to me when I replaced my stock brake lines with stainless braided teflon lines - within 2 months, the Master Cylinder seals went out from the overpressure. Something to think about...

Jeff20B

iTrader: (13)

The first rotary I ever rebuilt was a four port 13B.

Here is something to think about. When you get the engine apart, notice if any oil seals stick to the side plates (just due to the oil holding them against the flat surface). If so, you need new oil O rings. They are soft seals afterall, and ought to be replaced.

You honestly don't really need to clean the rotors. Just check for seal protrosion indicating the springs are good. Also check your apex seal springs.

The nice thing about your engine is that it's currently a runner, so you know things like end play are already correct etc.

rxtasy3

iTrader: (2)

get ya a set of micrometers so u can check things. that's how i found out i needed to replace more than expected.

mcnannay

im doing the same thing with my six port 13b, i ordered a set of seals from aviation rotary for like $157. Im broke too so that was really the only option, im about to dig into it here in a day or two...

peejay

If it still runs OK you don't need to change any of the rotor seals.

Just like how piston ring manufacturers recommend that, on engine teardown, if the rings are still in good shape, to *not* replace them or hone the cylinders.

rxtasy3

iTrader: (2)

then it should also be safe to say, when u put it back together, keep all metal seals in the same places, same rotors as they were when u tore it apart since everything has a specific wear to them.

this is especially true for lifters. i did head gaskets on a early 80's v6 many many yrs back and remembered too late what my dad said about cleaning lifters and putting them back where they came from, in no time, i had to replace the cam after those mixed up lifter locations wiped the lobes off the cam.

Wankelguy

Yes, it is okay to do just that if all the other seals are okay. I currently have a Jap-spec 4-port 13B that just needs oil control rings so I'm kind of in the same boat.
The bitchin' thing about the Jap-spec 4-port 13Bs is that they use the newer-style gas-nitrided side and center housings that don't wear as fast as the old cast-iron pieces used on the '74-'77 4-ports. They are also easier to port once you get through the hard gas-nitrided layer which is fairly thin as the underlying metal is actually softer.

Jeff20B

iTrader: (13)

You're probably talking about R5 plates, aren't you? I'm lucky enough to have two of them. I rebuilt them both without having to spend very much. Apex seals, oil O rings, gasket sets, adjustable oil pressure regulators etc. It helps that I was able to get some fo the parts for free or nearly free. I'd love to get several more R5s if I could.

10,000

my brother's '82 came withan R5 12a in it. Whats the story on the R5's? that thing was a runner, and all stock too.

peejay

Of course. I made some "seals trays" out of cheap styrofoam insulation. first i cut them to they fit into some convenient boxes that i had, next i cut appropriate sized/shaped grooves in them for the seals and springs, then i marked them as to where they were on the rotors.

Fuel524

This happened to me when I replaced my stock brake lines with stainless braided teflon lines - within 2 months, the Master Cylinder seals went out from the overpressure. Something to think about...
longduck have you heard of this happening b4 cuz i just ordered ss lines fromVB maybe i should get a new master cyl. is this common my 7 has 120k actuall miles.

Kill No Cone

iTrader: (6)

Ok, tell me what is an R5?
Does that mean the it has the very tall port in the center housings?

LongDuck

Fuel524 - not to jack the thread from these guys talking about engine rebuilds, but it's fairly common in different machines that if you build up one area, you just created a weak(er) spot in another - in other words, if you just strengthened the weakest link in your chain, something else has just become the weakest link.

With my brake issue, the rubber lines (stock) were helping to absorb some of the line pressure that worked just fine with the aging rubber seals in the Brake Master Cylinder (BMC). Once the SS lines were installed, they could hold much more pressure, and when I pressed on the brake pedal, this pressure was exerted on the rubber cups that form the pressure piston in the BMC. Soon enough, the piston was leaking and I needed a new BMC.

How this relates to engine rebuilds is that if you replace the Apex Seals, or Side Seals, only, then more than likely, your corner seals are now the weak link and will go out. When you have the entire engine pulled apart and all the seals in their 'boxes', you might as well change out all the 'soft' seals that you can. This ensures that once you get it all back together, your soft seals won't be the weak link that allows a coolant leak, an oil leak, etc. that will require pulling the engine and performing another teardown. HTH,

peejay

And if you do think about it, having a different kind of brake line won't change the pressure in the system. The pressure is dictated by how much force is applied on the master cylinder, the stainless steel lines simply don't "give" as much as the stock lines, so there is less pedal travel.

However, I bet you bled your brakes after you changed the lines. Bled them by pumping the brake pedal up and down. It's not uncommon for master cylinders to fail after having to bleed the brakes, what happens is normally the pistons and seals in the master only travel maybe 1/4"-1/2" tops. The parts of the bores that don't get swept by the seals get stalactites and stalagmites of crud on them, and when you go to bleed the brakes you're suddenly using all of the travel available, and you're forcing thr rubber seals over the junk in the bores, and it damages them a bit, and it redistributes the crud over to the "normally working" parts of the bore, and after a week or two the master is bypassing internally.