Fluidplay

...without removing engine. Has anyone done this and can share your thoughts/insights/recommendations.

Somewhere along the road of engine break in, something went horribly wrong. The rings have never seated, my compression numbers are below what i'd expect on a new motor (125-128) and leak down has gone from acceptable 5-7% to miserable 15-18%. It literally sounds like a jet taking off out of the oil filler tube.

This trully sucks...

lart951

I think it can be done, I have removed pistons from the top.

Chris White

Yes – its not a problem at all….but first you need to figure out why it failed. If the leak down numbers have gone down than its not a break in problem….refresh my memory – alusil or sleeved? What rings did you use? How many miles on it?

Willard Bridgham 3

Drop suspension/cross-bar from underneath and drop the oil pan, remove crank and pistons.

krazykarl

What sort of oil did you use and what was your break-in procedure? Were all the ring and cylinder tolerances in spec?

Fluidplay

Chris - I'm not exactly sure what the cause could be. I followed a conservative break in routine. I used non-syn 20/50, changed at 250/750/1500 from there went to VR1 20/50.

What else could cause this failure?

The bores are Alusil bored to 100.5. The pistons were new Mahle, with rings.

The motor has approx. 3,500 miles on it.

Back in the beginning...
The only thing I can think of is during my initial tuning it went extremely lean for a few moments before I shut it down. When I opened the hood the headers were glowing red hot. This all happened in the matter of seconds, it went very lean. I've always wondered about this. I might have cooked the top sealing ring just enough... At this point I'm really hoping this is my worst case scenario and the cylinders have escaped damage.

Weighting my options for the moment...

Chris White

Did the shop follow the correct alusil boring procedure?
Alusil usually is a lot less fussy than steel for break in.

Willard? Is that really you?....you don't usually miss stuff like that! Yes, you need to drop the oil pan and remove the pistons from the top - but dropping the crank takes a lot more - you would need to remove the entire front of the engine to get to the oil pump and remove that. You would also have to remove the bell housing to get the flywheel off....at that point you might as well just pull the engine!!

On the bright side - you can clean up the cylinders with the crank in place.

Fluidplay

All the machine work was done by a very respected shop here in So. Cal.

Willard Bridgham 3

I've done major engine work from both the top and bottom and prefer the top, but it's possible from the bottom.

Chris White

I am intrigued...how to you go about removing the crank from the block when its in the car?

Barry Johnson

You convince the crank its actually from a Mitsubishi and it'll walk itself out

Euro951

why woud you drop the crankshaft? C'mon

67King

Frikkin' score!

Was Mahle OEM? We had big time problems with aftermarket rings. Of course, I don't know of OEM ones are available 0.5mm over?

Willard Bridgham 3

I was wrong, we didn't remove the crank from the bottom, just the pan to get at the rods. Took off the head and took the pistons out through there.

Ski

They are if you get them from Mahle, pistons have ferroprint coating instead of ferrostan, but it is an iron based coating.