Lewis_RX8
Member
- Messages
- 1,575
- Location
- Scotland
So to make a long story short i got a rebuilt Mazda 13B wankel engine from evil bay (first mistake) to swap out for the one in the rx8 at the moment. It held coolant pressure and oil pressure fine on the bench however when it was put into the car it was nearly impossible to start , misfired and had extremly low compression.
So the old one was put back in and now time for the teardown to find the fault in my " Rebuilt " engine.
First of all put onto the engine stand with a home made adaptor plate that can be seen painted grey.
Drained all fluids off to stop them coming out later at more inconvenient times.
Then time for another home made tool , to remove the flywheel from the taper.
After that was removed it was down to a bare block and a tiny engine for the power it produces.
The 18 bolts holding the block together where numbered and removed in the right order.
Then down to the first rotor and housing ( Think piston and cylinder)
And the fault with the compression of the engine became obvious instantly , The apex seals which seal the corner of the triangle rotor to the housing where put in back to front
You could easily see daylight through the seals when they where supposed to be holding 8-7 bar for combustion.
So the cowboy builder that built then shelled out for good condition parts brand new apex seals from mazda at £350 but then put them in the wrong way.
Here is a close up of the apex seal that "should" push agaisnt the housing wall and seal with the pressure from the spring behind it.
As the seals where in back to front the corner piece ( where that triangle gap at the bottom is) was not in properly and may aswell have had no seal there with a gap that big.
It was then fully stripped down to parts and glad to say i am quids in on this engine for how much it cost as it has alot of brand new or good condition parts , seals and gaskets.
This will be getting some other parts from a old engine where it needs it and then rebuilt.
So the moral of the story is.
If you want a job done right do it yourself.
So the old one was put back in and now time for the teardown to find the fault in my " Rebuilt " engine.
First of all put onto the engine stand with a home made adaptor plate that can be seen painted grey.
Drained all fluids off to stop them coming out later at more inconvenient times.
Then time for another home made tool , to remove the flywheel from the taper.
After that was removed it was down to a bare block and a tiny engine for the power it produces.
The 18 bolts holding the block together where numbered and removed in the right order.
Then down to the first rotor and housing ( Think piston and cylinder)
And the fault with the compression of the engine became obvious instantly , The apex seals which seal the corner of the triangle rotor to the housing where put in back to front
You could easily see daylight through the seals when they where supposed to be holding 8-7 bar for combustion.
So the cowboy builder that built then shelled out for good condition parts brand new apex seals from mazda at £350 but then put them in the wrong way.
Here is a close up of the apex seal that "should" push agaisnt the housing wall and seal with the pressure from the spring behind it.
As the seals where in back to front the corner piece ( where that triangle gap at the bottom is) was not in properly and may aswell have had no seal there with a gap that big.
It was then fully stripped down to parts and glad to say i am quids in on this engine for how much it cost as it has alot of brand new or good condition parts , seals and gaskets.
This will be getting some other parts from a old engine where it needs it and then rebuilt.
So the moral of the story is.
If you want a job done right do it yourself.