Engine Rebuild - which route to take

[RETed]

Originally Posted by Caim

Oil controle rings unless you have the viton ones they last a while ha. Oil controle rings last a long time.

Unless we're talking about very low mileage on them, I change them out.
Oil control o-rings tend to "square out" and this causes more blow-by.
The oil control o-rings are the primary soft seal to minimize blow-by (and oil burning) from engine oil circulating in the engine.
The proper cross-sectional shape of the o-ring is ROUND, not square.
The green silicone ones from Mazda tend to hold their shape up until 50k miles - I replace them when they start heading towards 100k miles or more.
I don't use the aftermarket Viton ones cause they are not properly sized and cause their own headaches by not seating properly.
Really...the cost of these oil control o-rings are very minimal versus almost anything else in there.

As far as side seals i would buy about 3 or 4 of them so that way if you brake one or two of them when you are taking them out you have them. All side seals are good for about 300k miles. We measured the average wear on them and the minimal they could be and that is what we came up with.

Side seals should be fine to reuse on a motor that has no damage or abuse on it.
In fact, it's recommended due to the fact that they are all clearanced for each slot.
Newbies will find it difficult to clearance BRAND NEW side seals properly - you f*ck up the side seal and you blow $10+ for each seal you kill!
Too tight a clearance and the side seal seizes in the slot - increased blow-by.
Too much clearance and you get too much blow-by.
Screwing this up either way causes a motor to burn a lot of oil.
A motor that was overheated or drop of oil pressure will most likely kill all it's side seals - but a motor like this will most likely not be able to be reused in a rebuild.

New apex seals are needed and go with all new apex springs and side seal springs as well. As the side seal springs can be a pain and bend when you take them out. And yeah.

I've never had a side seal spring bend out of shape.
Even when the side seal spring is EMBEDDED in it's slot due to lots of carbon...
Of course, I don't FORCE the side seal spring out by twisting and torquing it if it's truly rusted into the side seal slot.
This is why I either soak the rotor down with WD-40 or equivalent or dunk them in a part wash soak.
If the side seal spring is rusted into the slot, the rotor is junk anyways - side seals should not be able to be removed in this case.


-Ted