mx5cartalk.com

Need other opinions on this.

Recently pulled off the head to check upon the overheated engine in my SE. This is what it looks like on top of my pistons and cylinder walls:


Cylinder 1 looks fine underneath:


Cylinder 2,3 and 4 however look a lil worse for wear:


If this is salvageable, is there a way to clean that gunk off without removing the pistons from the bore?

Thanks

if it was my $500 hyundai bush basher,i'd say clean it up in situ.(strong vacuum cleaner running continuously right next to where you are using a small scraper or dremel type wire brush)done it a few times over the years to a few holdens,datsuns,hyundais with results varying from no problems to waste of time.often steel top rings will have lost their temper when severely overheated.
If it was a nice red mx5 turbo i'd say do it properly,pull block out and at least,clean,hone and new rings.
while you are making up your mind,wipe some oil on bores to stop any further corrosion.
Mick

needs to come out and have the bore measured and the top surface checked for distorsion before anything can be decided upon.

Did you do a compression test before you pulled the head? If compression is good then all you'd need to do was check the top of the block for straightness. If it doesn't need a deck shave then just scrape the top of the block and piston crowns with a vacuum cleaner going. A bead of grease between the pistons and the cylinders also helps keep the rubbish out.

You know you really need to figure out why the mixture is up and down all over the place though, don't you?

manga_blue wrote:Did you do a compression test before you pulled the head? If compression is good then all you'd need to do was check the top of the block for straightness. If it doesn't need a deck shave then just scrape the top of the block and piston crowns with a vacuum cleaner going. A bead of grease between the pistons and the cylinders also helps keep the rubbish out.

You know you really need to figure out why the mixture is up and down all over the place though, don't you?

Compression done beforehand and yielded 0 on cylinders 2 and 3. Checked the head gasket and it was not in good shape so I assume it was the culprit?

That gunk would have been me trying to get the car off the freeway by filling up the radiator gain and cranking it over. Obviously with a blown head gasket it leaked into the cylinders..

Btw my experience with Royal Purple Purple Ice is not pleasant. Evidence is all over the head gasket..

My biggest concern is the walls and the rings. Could I fill up the cylinder with oil and do a visual check for leaks? Would that give me a better understanding of the condition of the rings?

Oh.

x2

project.r.racing wrote:needs to come out and have the bore measured and the top surface checked for distorsion before anything can be decided upon.

project.r.racing wrote:needs to come out and have the bore measured and the top surface checked for distorsion before anything can be decided upon.

+1 do it properly and save money/time....

G

project.r.racing wrote:needs to come out and have the bore measured and the top surface checked for distorsion before anything can be decided upon.

I would have to agree. If the compressions were more even, I would be more confident about just doing the head/ gasket etc.