Fixed Excessive Blow-by

[XFSE71]

I had been chasing excessive oil in the air tube and oil spitting all over under the hood on my newly aquired Aqua '93GL ATX. After several weeks of total denial and self flagellation, I finally gave in and yanked the pistons out of the block and tossed them up on the bench.

I found #1 to have been scorched by detonation/overheating which damaged the upper ring land causing the ring to stick. This caused excessive (rapid) wear in the cylinder causing the ring to hit the ridge creating an unhealthy clicking/knock.

Pistons #2 & #3 were badly chared from burning oil with an excess of carbon build up from burning oil and showed signs of having been scorched.
#4 had stuck rings from carbon and the same scoring as all the other syblings. So after thorough cleaning and careful inspection...

I have decided that all 4 pistons are still servicable and only a ring set is required. This includes the detonation damaged #1.

The cylinders honed out nicely and we shall see if the blow-by is truly fixed after reassembly sometime next week.
The rings are in the mail, arriving soon.
The sad news about all this is that I will be unable to attend the SW Festiva Meet in LV tomorrow.

[FestYboy]

those looked better than the ones i pulled out of Skippy... all the rings on ALL the pistons were siezed to the lands from gunk/carbon.

[XFSE71]

those looked better than the ones i pulled out of Skippy... all the rings on ALL the pistons were siezed to the lands from gunk/carbon.

Were you able to save your pistons? All of mine are scorched, but not to the point ofcondemnation. I filed #1 back into shape for what good that'll do. just cutting the ridge and reringing will do wonders for this poor little orphan step-child.

[blkfordsedan]

New pistons are less than $100 for a set. I got no issue re-using old pistons...just depends on how sloppy the ring lands are, how scored they are and how they measure out for wall clearance. I could have used the old pistons in my B6 rebuild, but new DNJ pistons were so cheap from Rock Auto, I just bought new ones. It was worth the $100 to not worry about piston clatter at start-up.

[FestYboy]

Were you able to save your pistons? All of mine are scorched, but not to the point ofcondemnation. I filed #1 back into shape for what good that'll do. just cutting the ridge and reringing will do wonders for this poor little orphan step-child.

all pistons and rings were reused.... once they were unsiezed and the lands cleaned, they looked good as new. so far so good now, and as of yet there is no piston clatter.

[XFSE71]

"all pistons and rings were reused"

I measured .020 ring gap, so I'll have to install new rings at the very least, bearings all look good. At least I got to see what the problems were inside the engine before it dumped. #1 had a lot of ridge wear, near the bore limit. Unfixed, high revs could have ended with a broken piston. It will all work out, I'm sure.

[FB71]

gents; I'm going to let a bit of the cat of the bag about XFSE71... he knows his stuff. I know this personally.

[blkfordsedan]

These B series seem to be predisposed to piston and ring issues....like broken pistons and
stuck rings. Are you guys related? You have the same last name..... "71"!

Any guy who used the Ford oval for his avitar is fine by me.

[XFSE71]

New pistons are less than $100 for a set. I got no issue re-using old pistons...just depends on how sloppy the ring lands are, how scored they are and how they measure out for wall clearance. I could have used the old pistons in my B6 rebuild, but new DNJ pistons were so cheap from Rock Auto, I just bought new ones. It was worth the $100 to not worry about piston clatter at start-up.

If this were a customer pay job, for sure all new pistons. Since this is all government warranty work, possibly a recheck, I'll just be happy I'm not trying to reuse my same old head gasket. And if I can hear #1 racking around in the morning, at least I'll know why it's so noisey. That in itself brings piece of mind.

[XFSE71]

Are you guys related? You have the same last name..... "71"


Yes, I'll admit it ... we both have that same blueblood flowing in our veins. Good catch!

[XFSE71]

I ended up pulling the engine out the bottom, glad I did. i found the rear main seal dried and cracked. next I'll toss valve seals on while the cylinder head is off, just because they came in the kit.

[sketchman]

These B series seem to be predisposed to piston and ring issues....like broken pistons and
stuck rings.

Look at how far down on the piston Mazda stuck the rings. I remember reading something from Smokey Yunick stating that OEMs were diehard believers that that was needed to keep from damaging things. He found out otherwise and in reality it was harmful because it left a big bunch of dead space. Tight dead space away from the spark. No bueno. One reason I wanted to use GLC pistons in my B6T rebuild.

Eventually I hope to ask Matt about a set of high ring land flat tops with standard or just barely raised compression for the B3. I expect good things.

[XFSE71]

I fired it up tonight. a new valve clatter noise means I'll re-pull the VC and look again at the valve train ... something is not right there. It runs.
To clarify, this is not a recheck, because it never left the shop ... no it's a yo-yo. One of those you can't quite get rid of, always there with you.

[Movin]

You put seals in but did nothing to change valve dimensions.
Partial lifter collapse can be caused by air getting into the oil at the suction side of the oil pump. Low oil pressure can also not pressure lifters properly.

It might be better if you find something simple under the VC LOL !

[XFSE71]

Look at how far down on the piston Mazda stuck the rings....

"Mazda stuck the rings ..." I was just happy they weren't steel pistons with an extra ring below the pin. You're right high perf pistons jamb the top ring on the edge of the crown. there are several advantages to building them that way, mainly a better burn. I think old world technology was dealing with preignition caused by an overtemp ring, moving them down on the piston away from the crown aleviated the overheat problem, only to cause a whole new series of problems. I love our Festivas because if you look at the technology from early to late models you will see how things did change, FBC to EFI. Even though it's not SEFI, it's better than TBI. I don't think they were into "hypereutectic piston metallurgy" although Ford was doing it. What we have is what I refer to as an "orphan step child". Yeah it's Mazda, but they don't claim us. KIA is gone to Hyundai and they just laugh at us. And yes that is a Ford logo and yes Ford does admit to fathering our cars, but they "Ain't Ford Tough". That means we really are not true Ford owners ergo step children. So the ring placement IMHO is a carry over from 50's technology, when they started dropping straight eights in favor of V types and hydraulics over adjustable rocker arms. The entire car was something that already exsisted and could accomplish the intended purpose, raise CAFE.