Hello all,
So I pulled my engine apart because of the dread oil and coolant mixing. Anyway while I was inspecting the block I noticed a lot of wear on the cylinder walls. I decided to pull the pistons and inspect those as well. Well I pulled to pistons and they are shot. They are not going back in the engine, but I am curious to find out why this happened before I reassemble the engine with a new block and and pistons. The engine only had about 3-5K on it before oil and coolant came together. The car did go into a wall at the race track but I had driven after this for 3 months with the this engine. The engine has never been overheated. Any ideas are appreciated as well as questions. Just want to find out what I did wrong.
Thanks
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Maybe a piston to wall clearnece issue?
Insufficient piston to wall clearance.
If it were my motor I would have the bores honed about .002" larger, clean up the piston skirts, have the skirts coated with an abradable skirt coating, file fit a new set of rings, and put them back into service.
^^^^^^^
What they both said. It’s a bummer that you have to take the engine apart again.
thanks all for that information. I took it to a local machine shop and he said the same thing. So how would I go about reconditioning the pistons? Just use sand paper on it? I did take this to a proper shop to get the pistons and bore matched. I guess that didn't work out how I wanted it to. Really sucks that I spent all that money to just have to redo what I thought I had done right.
Okay so, not saying that the shop didnt do there job as they probably did, but depending on the material compound I know most aftermarket pistons are a 2618 for the M5x engine family. A little more detail here.
https://www.jepistons.com/blog/2618-...al-differences
If you get a machine shop that says well I *like to run my xxx clearence here* that's a load of bullshit follow the piston manufactures specifications. As a wise man once told me, everyone knows if your engine is too tight and nobody knows if its a hair loose.
A key component to having the right clearance is knowing what the power goals for the engine are. More power, more heat, more expansion = looser tolerances.
What pistons are those? JE's?
Was your engine guy familiar with boosted engines? Tolerances change dramatically. Probably find a new engine guy.
they were wisco pistons. Not sure about the exact clearances he use. He did know it was going to be turbo'd and tracked. Ill do better this next time around
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