mack123

iTrader: (4)

hello all,

I have 3 questions about gasket sealer and Im sure there is a lot of experience out there on this one.. Im doing a rebuild within a week and any info would be helpful.

First, what are a few types, that seem to work BEST when assembling the rotary?

I counted about 8-10 different types of sealer at the auto store.. although most would work fine for a rebuild, there are sublte variances in all of them.. anyone who has seen all the types on store shelf knows what I mean.

Second, since there are different applications on any engine, those being air,water, oil, etc, this would also add to if there is ONE preferred type or do rotary builders prefer two or more types.

Third, since any sealed connection has 4 faces { example, intake manifold,the gasket that touches it, the other side of the gasket and the other metal face} I usually apply sealer to 2 {of the 4} faces. Just wondering how other builders on these engines do theirs ?

any info is appreciated, thanks all

alexdimen

iTrader: (13)

here's what i've gathered as the best way to go from the forums and talking to builders... i did alot of research:

manifold gaskets/faces: permatex high temp copper gasket spray on all mating faces
rotor housings to irons: coating of hylomar in seal groove and on seals (inner and outer) and a thin, even layer of high temp black rtv on the entire mating surface of the aluminum rotor housing...

mazda didn't use any sealants from what ive heard when assembling the housings... the rtv helps close up any corrosion from years of heat cycling and what not and the hylomar protects the seals and makes them easier to lay out. the problem with using only hylomar is that it washes away soon after the engine begins its new life.

anything else just use the appropriate sealant (oil pan, etc...)

mack123

iTrader: (4)

ok, this is good info. I havent ever heard of running a bead along the entire rotor housing circle, only rtv' ing the legs as it shows in the fsm.

How large of a bead do you run around the housing "circle" ?

RotaryEvolution

iTrader: (30)

i usually put the bead right on top of the inner and outer o-rings, helps prevent extra sealer from going into the conbustion chamber when it assembled. you do not need much sealer at all on the seals, maybe a 2-3mm bead.

mack123

iTrader: (4)

ok, I see how this could improve sealing.


Do you put the bead on top of the hylomar you have put on top of the seals, or do you skip the hylomar on top of the seals { coolant seals, inner and outer}and just put the bead on top ?

also do you put a little circle dab of rtv around the little dowel pin o-rings? or is the o-ring/hylomar combo sufficient ?

I realize people do different things, yet its helpful to know what techniques tend to work better in the long run.

RotaryEvolution

iTrader: (30)

i don't use hylomar on the face of the rotor housings, i only use it to keep the seals in their grooves. the hylomar dissipates into a black sooty crap which has no sealing properties after it dries up in the rotor housing areas due to the heat generated there. only think of hylomar as something to hold the o-rings in their place while you are assembling things.

slpin

iTrader: (9)

karack,

about the hylomar....
good idea to subsitute hylomar wiht the "black stuff"?

RotaryEvolution

iTrader: (30)

i wouldn't put the ultra black in the o-ring grooves, only on top of the seals, too much sealer is not a good thing.

RotaryResurrection

iTrader: (8)

Put the hylomar into the iron coolant seal grooves, lay the seals in. Take your rotorhousing, get some permatex ultra black rtv on your finger, and smudge it on around the rotorhousing-to-coolant seal mating surfaces (one large and one smaller oval). I personally lay on just enough so you can't see bare metal anymore...and about a finger's width. No problems with doing it this way, Ive built hundreds of engines this way. You can use the ultra black for the "legs" of the rotorhousings, too.

I use ultra black for most all engine applications, stuff works well and resists heat and almost everything else. For pesky sealing applications like oilpans, you can step up to hondabond which is one of the best sealers available, but is only available through honda car or cycle shops (to my knowledge).

mack123

iTrader: (4)

I really appreciate these gasket sealing tips,etc. It is valuable info for me at this time and I will apply it as described. thanks all.