TL;DR Characteristic verbose Redline post. Spraying methanol appears to restore compression. Long version:
I was overdue for a compression test today. Last time I did one was immediately post-oil-overfill debacle, chronicled here: http://mazdaspeeds.org/index.php?threads/more-wot-smoke-w-100-methanol-after-oil-overfill.690/
Engine is at 70,xxx miles. Been on the BNR S3 since 42k. Been Freek'd at the numbers in my sig. since then, but have only been running 100% methanol on a CM10 (12.8GPH) for ~6 months (got for injector relief, cooler year-round BATs, intake valve cleaning, and additional safety layer of alky). I wanted to give the methanol time to clean out the remnants of the oil overfill. It did. And something else happened: I gained appreciable compression!
(all compression tests are dry with engine fully up-to-temp):
So here we go --the results for my 2010 CBM Mazdaspeed 3 @ 60,xxx miles:
Cylinder 1 - 180psi compression (was 182 8,xxx miles ago)
Cylinder 2 - 180psi compression (was 177 8,xxx miles ago)
Cylinder 3 - 180psi compression (was 179 8,xxx miles ago)
Cylinder 4 - 180psi compression (was 180 8,xxx miles ago)
Post oil overfill fiasco (http://mazdaspeeds.org/index.php?threads/more-wot-smoke-w-100-methanol-after-oil-overfill.690/), I did a compression test. Here's what I got (dry):
Cylinder 1 - 183psi
Cylinder 2 - 176psi
Cylinder 3 - 175psi
Cylinder 4 - 175psi
That's just a tad lower than I was used to seeing. I thought it may be because it was colder outside when it happened. I know that compression tests at higher altitude measure much lower, for instance. My methanol system had not been spraying for a long while - long story, here if you want to read: http://mazdaspeeds.org/index.php?threads/bnr-s3-methanol-awesomeness-i-hope.931/ This has since been fixed, and I've gone through several gallons of 100% methanol on my CM10 (12.8GPH). I figured this would've cleaned out the engine enough to do another compression test:
So here we go - the results for my 2010 CBM Mazdaspeed 3 @ 70,xxx miles:
Cylinder 1 - 190psi compression (was 183 after oil overfill, ~5,xxx miles ago)
Cylinder 2 - 184psi compression (was 176 after oil overfill, ~5,xxx miles ago)
Cylinder 3 - 189psi compression (was 175 after oil overfill, ~5,xxx miles ago)
Cylinder 4 - 180psi compression (was 175 after oil overfill, ~5,xxx miles ago)
These numbers are a good deal higher than I've ever seen (except cylinder 4)!!! I compression test religiously (that mid-turbo lyfe, tho), and without fail, I've always been 180 +/- 2-3 except for post oil overfill. Seems like the methanol cleaned everything out, and then some! Perhaps it unlocked rings that were crusted into place. I'm not exactly sure.
Out of curiosity, I shined a flashlight down into each cylinder to make sure there was no pool of oil on my pistons. None! I wanted to check this because the bottom of my spark plug threads had oil on them (likely a remnant from the oil overfill). I had taken off the VC to have it PC'd wrinkle black a while ago too, and had never retorqued the VC bolts after initial installation (complete with new VC gasket set), so I did that too, just in case oil was getting into the spark plug wells that way.
I cleaned up all the plugs, re-gapped them all back down to 0.026" (they were all between 0.028-0.029" and looked great - step colder NGK IXs FTW on my car), and reinstalled them.
But anyways, has anyone else had compression apparently restored by spraying methanol? There's science behind the steam-cleaning effect that running 50/50 or 80/20, for instance, has on cylinders. Shade-tree mechanics have been known to carefully pour water into the intake of engines to free seized rings by the steam-cleaning effect. I didn't think that 100% methanol would do this, though.
I'll be particularly interested to see my numbers next compression test. That'll help see if this was an aberration. Also, by the time all 4 cylinders were tested, my coolant temp was still 174. I do all tests hot and fast for consistent results.
I was overdue for a compression test today. Last time I did one was immediately post-oil-overfill debacle, chronicled here: http://mazdaspeeds.org/index.php?threads/more-wot-smoke-w-100-methanol-after-oil-overfill.690/
Engine is at 70,xxx miles. Been on the BNR S3 since 42k. Been Freek'd at the numbers in my sig. since then, but have only been running 100% methanol on a CM10 (12.8GPH) for ~6 months (got for injector relief, cooler year-round BATs, intake valve cleaning, and additional safety layer of alky). I wanted to give the methanol time to clean out the remnants of the oil overfill. It did. And something else happened: I gained appreciable compression!
(all compression tests are dry with engine fully up-to-temp):
So here we go --the results for my 2010 CBM Mazdaspeed 3 @ 60,xxx miles:
Cylinder 1 - 180psi compression (was 182 8,xxx miles ago)
Cylinder 2 - 180psi compression (was 177 8,xxx miles ago)
Cylinder 3 - 180psi compression (was 179 8,xxx miles ago)
Cylinder 4 - 180psi compression (was 180 8,xxx miles ago)
Post oil overfill fiasco (http://mazdaspeeds.org/index.php?threads/more-wot-smoke-w-100-methanol-after-oil-overfill.690/), I did a compression test. Here's what I got (dry):
Cylinder 1 - 183psi
Cylinder 2 - 176psi
Cylinder 3 - 175psi
Cylinder 4 - 175psi
That's just a tad lower than I was used to seeing. I thought it may be because it was colder outside when it happened. I know that compression tests at higher altitude measure much lower, for instance. My methanol system had not been spraying for a long while - long story, here if you want to read: http://mazdaspeeds.org/index.php?threads/bnr-s3-methanol-awesomeness-i-hope.931/ This has since been fixed, and I've gone through several gallons of 100% methanol on my CM10 (12.8GPH). I figured this would've cleaned out the engine enough to do another compression test:
So here we go - the results for my 2010 CBM Mazdaspeed 3 @ 70,xxx miles:
Cylinder 1 - 190psi compression (was 183 after oil overfill, ~5,xxx miles ago)
Cylinder 2 - 184psi compression (was 176 after oil overfill, ~5,xxx miles ago)
Cylinder 3 - 189psi compression (was 175 after oil overfill, ~5,xxx miles ago)
Cylinder 4 - 180psi compression (was 175 after oil overfill, ~5,xxx miles ago)
These numbers are a good deal higher than I've ever seen (except cylinder 4)!!! I compression test religiously (that mid-turbo lyfe, tho), and without fail, I've always been 180 +/- 2-3 except for post oil overfill. Seems like the methanol cleaned everything out, and then some! Perhaps it unlocked rings that were crusted into place. I'm not exactly sure.
Out of curiosity, I shined a flashlight down into each cylinder to make sure there was no pool of oil on my pistons. None! I wanted to check this because the bottom of my spark plug threads had oil on them (likely a remnant from the oil overfill). I had taken off the VC to have it PC'd wrinkle black a while ago too, and had never retorqued the VC bolts after initial installation (complete with new VC gasket set), so I did that too, just in case oil was getting into the spark plug wells that way.
I cleaned up all the plugs, re-gapped them all back down to 0.026" (they were all between 0.028-0.029" and looked great - step colder NGK IXs FTW on my car), and reinstalled them.
But anyways, has anyone else had compression apparently restored by spraying methanol? There's science behind the steam-cleaning effect that running 50/50 or 80/20, for instance, has on cylinders. Shade-tree mechanics have been known to carefully pour water into the intake of engines to free seized rings by the steam-cleaning effect. I didn't think that 100% methanol would do this, though.
I'll be particularly interested to see my numbers next compression test. That'll help see if this was an aberration. Also, by the time all 4 cylinders were tested, my coolant temp was still 174. I do all tests hot and fast for consistent results.
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I'm very scientific and consistent in how I do my frequent compression tests. Really, the only different variable is the spraying of a crapton of methanol. Promising, to say the least.