fong

iTrader: (77)

I have heard in the forum that guys say about only $300 for an engine rebuild, etc... I am wondering how they did that. assuming a $160 mazdatrix engine overhaul gasket set is needed, then, plus the misc. they must reuse all the engine internal parts, like rotors, housings, irons, e-shaft, apex seals, side seals, corner seals, O rings..

so, how can we determine those seals are in good reusable condition? if we are looking for a minimal engine rebuilt here.

if a motor just blows the oil seal, or water seal, can we reuse all those apex seals, corner seal, side seals?

please don't call me "cheap ***". I just want to learn more about engine internal, other than simple, easy stuff about 7s.

WonkoTheSane

iTrader: (2)

First step would be to get the video How to Overhaul your Mazda 13b. by Bruce turrentine. It'll show you how to measure everything on the inside to figure out what you replace. I've heard to ALWAYS replace the apex seals. No matter what shape they're in. The soft seal kit you mentioned is a good place to start. Other than that, you're going to have to start checking clearances and tolerances to see what else needs replaced.

oh, btw: I got my kit+apex seals from Rotary Aviation. It wasn't too much for what I got..

But there's just not much you can do until you know what's dead...

RETed

Engine rebuilds are not for cheap asses.
If you get cheap, it IS going to bite you in the ***.
Why go through all that hassle just to save money?
Do it right the first time and pay for the right parts the first time.
Even working at McD's, you can save for two months of paychecks to pay for all the parts.

High mileage / original apex seals are most likely need to be replaced.
High mileage / original apex seal springs are most likely need to be replaced.
FD corner seal springs are highly recommended.
Corner seal rubber plugs need to be replaced.
Oil control o-rings need to be replaced.

Even if you go with an economical aftermarket apex seal, you're still looking at $500 worth of parts listed above.


-Ted

Atkins Dan

As Ted put it do it right the first time and you won't regret it .
I would buy the rebuild video on How to Overhaul your Mazda 13b first than that will at least show if you want to do the rebuild yourself.
just a thought anyway

Later
Dan

WAYNE88N/A

I noticed while rebuilding my 186,000 mile N/A engine that pretty much every seal and o-ring needed replacing except for the side seals- there was only 3 hundreths of a millimeter of wear (compared to the new ones) after all those miles-that amazed me. The stock apex seals had another .3 mil to go before they hit limits (which translates into at least another 20K miles). The rotor housings themselves actually seem to take the brunt of the wear on these things, and were the cause of the compression slowly falling, telling me it was time for a rebuild. The side housings showed almost negligible wear after 186,000- also amazing...

Mr. Gadget

Buy one of the videos and wath it like 20 times. Pay aprticular attention to the parts where your inspecting wear. I have about 40 rotor housings in my garage I choose not to reuse, yet, I am sure someone would and get 50K out of them - not my style - and since I do this for fun, its easier for me to be converative with the worn parts.

worn apex seals in a worn housing and worn springs are like one WOT away from making your engine FUBAR.

YearsOfDecay

Ummmmmmm Look man, you "CAN" re-use the old hard parts, but they have to pass inspection... the ONLY way i would ever re-use hard parts is if they had less than say 25K miles on them.

Its a real pain in the *** though, you have to put EVERY piece back in the EXACT place it came out of and check EVERY piece for tolerances and clearances. BUT, the Brucec T. video will show you how to do all that (so does the shop manual I scavengered up)

Rotors are usually re-useable, i've seen one that was bad, and that was from a 25lb boost spike that sent an apex seal on a rampage of destruction in the rear rotor housing.

If your engine has over 100K on it.. Replace EVERYTHING. That kit is about 900 bucks! versues about 500 for one that doesn't include corner seals, oil pump chain, side seals or the oil control hard rings.

I'm lucky enough to have the rotor bearing and stationary gear bearing removal/installation tools and a pilot bearing tool in my possession... if you don't have that, you could take your rotors and E-Shaft to a shop and have them replace the bearings.

After three rebuilds on diferent engines, i'd say the most important part is cleaning... if you don't have a parts washer.. you'd better think about getting one.. you have to remove EVERY bit of carbon and gunk from EVERYWHERE, especially the apex seal grooves and the o-ring channels. That is the most time intensive process.

ALSO,,, the engine rebuild kits do not come with the "installation" gaskets (manifoild, exhaust, ACV, EGR, oil pan.. all that happy crap) thats another 50 bucks for an N/A 140 for a TII!~!!

Mr. Gadget

Miles while a guideline are not the key, your micrometer is. If you dont have one your just guessing.

I agree on cleaning - here is a trick for rotors heavely covered in carbon. Go to a parts store and pick up a gallon of simple green degreaser, then pick up a 2.5 or 5.0 gallon bucket (smaller is better as long as the rotor fits) remove all rotor seals, and lay in bucket, pour the whole gallon of SG in and let it sit overnight.

The next day you should be able to clean the rotor in about 30 minutes to near new condition, the pic below is the front and blown rear from the same motor- BIG DIFFERENCE!

fong

iTrader: (77)

thanks, guys, that helps me a lot.

I got the video for my first engine rebuilt. I bought all the new internal parts for my first engine rebuilt. right now, I just torn down a s5 n/a engine recently, and the seals look good to me. that makes me wonder if I can reuse them.

using micrometer is good way to ensure the parts are good. but I wonder in the case of oil control ring broken, or water seals are broken(like white smoke, or black smoke), but the compression is good, then we can say to reuse those seals, right?

Mr. Gadget, that is good suggestion to clean the rotors.

Mr. Gadget

water seals must always be replaced -
broken anything - must be replaced -

fong

iTrader: (77)

yes, what about those hardware parts like corner, side, apex, spring?

RotaryWeaponSE7EN

iTrader: (6)

Get the Overhaul C kit from atkins, it comes w/ the seal kit and all the gaskets.

Mr. Gadget

clean, inspect and measure -



Great kit, great value, great company - just make sure you need all of it. Most only need B and many can go with A